                                Release Notes

   The release notes contain the significant changes in each PostgreSQL
   release, with major features and migration issues listed at the top.
   The release notes do not contain changes that affect only a few users
   or changes that are internal and therefore not user-visible. For
   example, the optimizer is improved in almost every release, but the
   improvements are usually observed by users as simply faster queries.

   A complete list of changes for each release can be obtained by viewing
   the Git logs for each release. The pgsql-committers email list records
   all source code changes as well. There is also a web interface that
   shows changes to specific files.

   The name appearing next to each item represents the major developer for
   that item. Of course all changes involve community discussion and patch
   review, so each item is truly a community effort.
     __________________________________________________________________

                                Release 9.3.2

     Release Date: 2013-12-05

   This release contains a variety of fixes from 9.3.1. For information
   about new features in the 9.3 major release, see the Section called
   Release 9.3.
     __________________________________________________________________

Migration to Version 9.3.2

   A dump/restore is not required for those running 9.3.X.

   However, this release corrects a number of potential data corruption
   issues. See the first three changelog entries below to find out whether
   your installation has been affected and what steps you can take if so.

   Also, if you are upgrading from a version earlier than 9.3.1, see the
   release notes for 9.3.1.
     __________________________________________________________________

Changes

     * Fix "VACUUM"'s tests to see whether it can update relfrozenxid
       (Andres Freund)
       In some cases "VACUUM" (either manual or autovacuum) could
       incorrectly advance a table's relfrozenxid value, allowing tuples
       to escape freezing, causing those rows to become invisible once
       2^31 transactions have elapsed. The probability of data loss is
       fairly low since multiple incorrect advancements would need to
       happen before actual loss occurs, but it's not zero. In 9.2.0 and
       later, the probability of loss is higher, and it's also possible to
       get "could not access status of transaction" errors as a
       consequence of this bug. Users upgrading from releases 9.0.4 or
       8.4.8 or earlier are not affected, but all later versions contain
       the bug.
       The issue can be ameliorated by, after upgrading, vacuuming all
       tables in all databases while having vacuum_freeze_table_age set to
       zero. This will fix any latent corruption but will not be able to
       fix all pre-existing data errors. However, an installation can be
       presumed safe after performing this vacuuming if it has executed
       fewer than 2^31 update transactions in its lifetime (check this
       with SELECT txid_current() < 2^31).
     * Fix multiple bugs in MultiXactId freezing (Andres Freund, Alvaro
       Herrera)
       These bugs could lead to "could not access status of transaction"
       errors, or to duplicate or vanishing rows. Users upgrading from
       releases prior to 9.3.0 are not affected.
       The issue can be ameliorated by, after upgrading, vacuuming all
       tables in all databases while having vacuum_freeze_table_age set to
       zero. This will fix latent corruption but will not be able to fix
       all pre-existing data errors.
       As a separate issue, these bugs can also cause standby servers to
       get out of sync with the primary, thus exhibiting data errors that
       are not in the primary. Therefore, it's recommended that 9.3.0 and
       9.3.1 standby servers be re-cloned from the primary (e.g., with a
       new base backup) after upgrading.
     * Fix initialization of "pg_clog" and "pg_subtrans" during hot
       standby startup (Andres Freund, Heikki Linnakangas)
       This bug can cause data loss on standby servers at the moment they
       start to accept hot-standby queries, by marking committed
       transactions as uncommitted. The likelihood of such corruption is
       small unless, at the time of standby startup, the primary server
       has executed many updating transactions since its last checkpoint.
       Symptoms include missing rows, rows that should have been deleted
       being still visible, and obsolete versions of updated rows being
       still visible alongside their newer versions.
       This bug was introduced in versions 9.3.0, 9.2.5, 9.1.10, and
       9.0.14. Standby servers that have only been running earlier
       releases are not at risk. It's recommended that standby servers
       that have ever run any of the buggy releases be re-cloned from the
       primary (e.g., with a new base backup) after upgrading.
     * Fix multiple bugs in update chain traversal (Andres Freund, Alvaro
       Herrera)
       These bugs could result in incorrect behavior, such as locking or
       even updating the wrong row, in the presence of concurrent updates.
       Spurious "unable to fetch updated version of tuple" errors were
       also possible.
     * Fix dangling-pointer problem in fast-path locking (Tom Lane)
       This could lead to corruption of the lock data structures in shared
       memory, causing "lock already held" and other odd errors.
     * Fix assorted race conditions in timeout management (Tom Lane)
       These errors could result in a server process becoming unresponsive
       because it had blocked SIGALRM and/or SIGINT.
     * Truncate "pg_multixact" contents during WAL replay (Andres Freund)
       This avoids ever-increasing disk space consumption in standby
       servers.
     * Ensure an anti-wraparound "VACUUM" counts a page as scanned when
       it's only verified that no tuples need freezing (Sergey Burladyan,
       Jeff Janes)
       This bug could result in failing to advance relfrozenxid, so that
       the table would still be thought to need another anti-wraparound
       vacuum. In the worst case the database might even shut down to
       prevent wraparound.
     * Fix full-table-vacuum request mechanism for MultiXactIds (Andres
       Freund)
       This bug could result in large amounts of useless autovacuum
       activity.
     * Fix race condition in GIN index posting tree page deletion (Heikki
       Linnakangas)
       This could lead to transient wrong answers or query failures.
     * Fix "unexpected spgdoinsert() failure" error during SP-GiST index
       creation (Teodor Sigaev)
     * Fix assorted bugs in materialized views (Kevin Grittner, Andres
       Freund)
     * Re-allow duplicate table aliases if they're within aliased JOINs
       (Tom Lane)
       Historically PostgreSQL has accepted queries like
SELECT ... FROM tab1 x CROSS JOIN (tab2 x CROSS JOIN tab3 y) z
       although a strict reading of the SQL standard would forbid the
       duplicate usage of table alias x. A misguided change in 9.3.0
       caused it to reject some such cases that were formerly accepted.
       Restore the previous behavior.
     * Avoid flattening a subquery whose SELECT list contains a volatile
       function wrapped inside a sub-SELECT (Tom Lane)
       This avoids unexpected results due to extra evaluations of the
       volatile function.
     * Fix planner's processing of non-simple-variable subquery outputs
       nested within outer joins (Tom Lane)
       This error could lead to incorrect plans for queries involving
       multiple levels of subqueries within JOIN syntax.
     * Fix incorrect planning in cases where the same non-strict
       expression appears in multiple WHERE and outer JOIN equality
       clauses (Tom Lane)
     * Fix planner crash with whole-row reference to a subquery (Tom Lane)
     * Fix incorrect generation of optimized MIN()/MAX() plans for
       inheritance trees (Tom Lane)
       The planner could fail in cases where the MIN()/MAX() argument was
       an expression rather than a simple variable.
     * Fix premature deletion of temporary files (Andres Freund)
     * Prevent intra-transaction memory leak when printing range values
       (Tom Lane)
       This fix actually cures transient memory leaks in any datatype
       output function, but range types are the only ones known to have
       had a significant problem.
     * Fix memory leaks when reloading configuration files (Heikki
       Linnakangas, Hari Babu)
     * Prevent incorrect display of dropped columns in NOT NULL and CHECK
       constraint violation messages (Michael Paquier and Tom Lane)
     * Allow default arguments and named-argument notation for window
       functions (Tom Lane)
       Previously, these cases were likely to crash.
     * Suppress trailing whitespace on each line when pretty-printing
       rules and views (Tom Lane)
       9.3.0 generated such whitespace in many more cases than previous
       versions did. To reduce unexpected behavioral changes, suppress
       unnecessary whitespace in all cases.
     * Fix possible read past end of memory in rule printing (Peter
       Eisentraut)
     * Fix array slicing of int2vector and oidvector values (Tom Lane)
       Expressions of this kind are now implicitly promoted to regular
       int2 or oid arrays.
     * Return a valid JSON value when converting an empty hstore value to
       json (Oskari Saarenmaa)
     * Fix incorrect behaviors when using a SQL-standard, simple GMT
       offset timezone (Tom Lane)
       In some cases, the system would use the simple GMT offset value
       when it should have used the regular timezone setting that had
       prevailed before the simple offset was selected. This change also
       causes the timeofday function to honor the simple GMT offset zone.
     * Prevent possible misbehavior when logging translations of Windows
       error codes (Tom Lane)
     * Properly quote generated command lines in pg_ctl (Naoya Anzai and
       Tom Lane)
       This fix applies only to Windows.
     * Fix pg_dumpall to work when a source database sets
       default_transaction_read_only via "ALTER DATABASE SET" (Kevin
       Grittner)
       Previously, the generated script would fail during restore.
     * Fix pg_isready to handle its "-d" option properly (Fabrizio de
       Royes Mello and Fujii Masao)
     * Fix parsing of WAL file names in pg_receivexlog (Heikki
       Linnakangas)
       This error made pg_receivexlog unable to restart streaming after
       stopping, once at least 4 GB of WAL had been written.
     * Report out-of-disk-space failures properly in pg_upgrade (Peter
       Eisentraut)
     * Make ecpg search for quoted cursor names case-sensitively (Zoltan
       Boszormenyi)
     * Fix ecpg's processing of lists of variables declared varchar
       (Zoltan Boszormenyi)
     * Make "contrib/lo" defend against incorrect trigger definitions
       (Marc Cousin)
     * Update time zone data files to tzdata release 2013h for DST law
       changes in Argentina, Brazil, Jordan, Libya, Liechtenstein,
       Morocco, and Palestine. Also, new timezone abbreviations WIB, WIT,
       WITA for Indonesia.
     __________________________________________________________________

                                Release 9.3.1

     Release Date: 2013-10-10

   This release contains a variety of fixes from 9.3.0. For information
   about new features in the 9.3 major release, see the Section called
   Release 9.3.
     __________________________________________________________________

Migration to Version 9.3.1

   A dump/restore is not required for those running 9.3.X.

   However, if you use the hstore extension, see the first changelog
   entry.
     __________________________________________________________________

Changes

     * Ensure new-in-9.3 JSON functionality is added to the hstore
       extension during an update (Andrew Dunstan)
       Users who upgraded a pre-9.3 database containing hstore should
       execute
ALTER EXTENSION hstore UPDATE;
       after installing 9.3.1, to add two new JSON functions and a cast.
       (If hstore is already up to date, this command does nothing.)
     * Fix memory leak when creating B-tree indexes on range columns
       (Heikki Linnakangas)
     * Fix memory leak caused by lo_open() failure (Heikki Linnakangas)
     * Serializable snapshot fixes (Kevin Grittner, Heikki Linnakangas)
     * Fix deadlock bug in libpq when using SSL (Stephen Frost)
     * Fix timeline handling bugs in pg_receivexlog (Heikki Linnakangas,
       Andrew Gierth)
     * Prevent "CREATE FUNCTION" from checking "SET" variables unless
       function body checking is enabled (Tom Lane)
     * Remove rare inaccurate warning during vacuum of index-less tables
       (Heikki Linnakangas)
     __________________________________________________________________

                                 Release 9.3

     Release Date: 2013-09-09
     __________________________________________________________________

Overview

   Major enhancements in PostgreSQL 9.3 include:

     * Add materialized views
     * Make simple views auto-updatable
     * Add many features for the JSON data type, including operators and
       functions to extract elements from JSON values
     * Implement SQL-standard LATERAL option for FROM-clause subqueries
       and function calls
     * Allow foreign data wrappers to support writes
       (inserts/updates/deletes) on foreign tables
     * Add a Postgres foreign data wrapper to allow access to other
       Postgres servers
     * Add support for event triggers
     * Add optional ability to checksum data pages and report corruption
     * Prevent non-key-field row updates from blocking foreign key checks
     * Greatly reduce System V shared memory requirements

   The above items are explained in more detail in the sections below.
     __________________________________________________________________

Migration to Version 9.3

   A dump/restore using pg_dumpall, or use of pg_upgrade, is required for
   those wishing to migrate data from any previous release.

   Version 9.3 contains a number of changes that may affect compatibility
   with previous releases. Observe the following incompatibilities:
     __________________________________________________________________

Server Settings

     * Rename replication_timeout to wal_sender_timeout (Amit Kapila)
       This setting controls the WAL sender timeout.
     * Require superuser privileges to set commit_delay because it can now
       potentially delay other sessions (Simon Riggs)
     * Allow in-memory sorts to use their full memory allocation (Jeff
       Janes)
       Users who have set work_mem based on the previous behavior may need
       to revisit that setting.
     __________________________________________________________________

Other

     * Throw an error if a tuple to be updated or deleted has already been
       updated or deleted by a BEFORE trigger (Kevin Grittner)
       Formerly, the originally-intended update was silently skipped,
       resulting in logical inconsistency since the trigger might have
       propagated data to other places based on the intended update. Now
       an error is thrown to prevent the inconsistent results from being
       committed. If this change affects your application, the best
       solution is usually to move the data-propagation actions to an
       AFTER trigger.
       This error will also be thrown if a query invokes a volatile
       function that modifies rows that are later modified by the query
       itself. Such cases likewise previously resulted in silently
       skipping updates.
     * Change multicolumn ON UPDATE SET NULL/SET DEFAULT foreign key
       actions to affect all columns of the constraint, not just those
       changed in the "UPDATE" (Tom Lane)
       Previously, we would set only those referencing columns that
       correspond to referenced columns that were changed by the "UPDATE".
       This was what was required by SQL-92, but more recent editions of
       the SQL standard specify the new behavior.
     * Force cached plans to be replanned if the search_path changes (Tom
       Lane)
       Previously, cached plans already generated in the current session
       were not redone if the query was re-executed with a new search_path
       setting, resulting in surprising behavior.
     * Fix to_number() to properly handle a period used as a thousands
       separator (Tom Lane)
       Previously, a period was considered to be a decimal point even when
       the locale says it isn't and the D format code is used to specify
       use of the locale-specific decimal point. This resulted in wrong
       answers if FM format was also used.
     * Fix STRICT non-set-returning functions that have set-returning
       functions in their arguments to properly return null rows (Tom
       Lane)
       A null value passed to the strict function should result in a null
       output, but instead, that output row was suppressed entirely.
     * Store WAL in a continuous stream, rather than skipping the last
       16MB segment every 4GB (Heikki Linnakangas)
       Previously, WAL files with names ending in FF were not used because
       of this skipping. If you have WAL backup or restore scripts that
       took this behavior into account, they will need to be adjusted.
     * In pg_constraint.confmatchtype, store the default foreign key match
       type (non-FULL, non-PARTIAL) as s for "simple" (Tom Lane)
       Previously this case was represented by u for "unspecified".
     __________________________________________________________________

Changes

   Below you will find a detailed account of the changes between
   PostgreSQL 9.3 and the previous major release.
     __________________________________________________________________

Server

Locking

     * Prevent non-key-field row updates from blocking foreign key checks
       (Alvaro Herrera, Noah Misch, Andres Freund, Alexander Shulgin,
       Marti Raudsepp, Alexander Shulgin)
       This change improves concurrency and reduces the probability of
       deadlocks when updating tables involved in a foreign-key
       constraint. "UPDATE"s that do not change any columns referenced in
       a foreign key now take the new NO KEY UPDATE lock mode on the row,
       while foreign key checks use the new KEY SHARE lock mode, which
       does not conflict with NO KEY UPDATE. So there is no blocking
       unless a foreign-key column is changed.
     * Add configuration variable lock_timeout to allow limiting how long
       a session will wait to acquire any one lock (Zoltan Boszormenyi)
     __________________________________________________________________

Indexes

     * Add SP-GiST support for range data types (Alexander Korotkov)
     * Allow GiST indexes to be unlogged (Jeevan Chalke)
     * Improve performance of GiST index insertion by randomizing the
       choice of which page to descend to when there are multiple equally
       good alternatives (Heikki Linnakangas)
     * Improve concurrency of hash index operations (Robert Haas)
     __________________________________________________________________

Optimizer

     * Collect and use histograms of upper and lower bounds, as well as
       range lengths, for range types (Alexander Korotkov)
     * Improve optimizer's cost estimation for index access (Tom Lane)
     * Improve optimizer's hash table size estimate for doing DISTINCT via
       hash aggregation (Tom Lane)
     * Suppress no-op Result and Limit plan nodes (Kyotaro Horiguchi, Amit
       Kapila, Tom Lane)
     * Reduce optimizer overhead by not keeping plans on the basis of
       cheap startup cost when the optimizer only cares about total cost
       overall (Tom Lane)
     __________________________________________________________________

General Performance

     * Add "COPY FREEZE" option to avoid the overhead of marking tuples as
       frozen later (Simon Riggs, Jeff Davis)
     * Improve performance of NUMERIC calculations (Kyotaro Horiguchi)
     * Improve synchronization of sessions waiting for commit_delay (Peter
       Geoghegan)
       This greatly improves the usefulness of commit_delay.
     * Improve performance of the "CREATE TEMPORARY TABLE ... ON COMMIT
       DELETE ROWS" option by not truncating such temporary tables in
       transactions that haven't touched any temporary tables (Heikki
       Linnakangas)
     * Make vacuum recheck visibility after it has removed expired tuples
       (Pavan Deolasee)
       This increases the chance of a page being marked as all-visible.
     * Add per-resource-owner lock caches (Jeff Janes)
       This speeds up lock bookkeeping at statement completion in
       multi-statement transactions that hold many locks; it is
       particularly useful for pg_dump.
     * Avoid scanning the entire relation cache at commit of a transaction
       that creates a new relation (Jeff Janes)
       This speeds up sessions that create many tables in successive small
       transactions, such as a pg_restore run.
     * Improve performance of transactions that drop many relations (Tomas
       Vondra)
     __________________________________________________________________

Monitoring

     * Add optional ability to checksum data pages and report corruption
       (Simon Riggs, Jeff Davis, Greg Smith, Ants Aasma)
       The checksum option can be set during initdb.
     * Split the statistics collector's data file into separate global and
       per-database files (Tomas Vondra)
       This reduces the I/O required for statistics tracking.
     * Fix the statistics collector to operate properly in cases where the
       system clock goes backwards (Tom Lane)
       Previously, statistics collection would stop until the time again
       reached the latest time previously recorded.
     * Emit an informative message to postmaster standard error when we
       are about to stop logging there (Tom Lane)
       This should help reduce user confusion about where to look for log
       output in common configurations that log to standard error only
       during postmaster startup.
     __________________________________________________________________

Authentication

     * When an authentication failure occurs, log the relevant
       "pg_hba.conf" line, to ease debugging of unintended failures
       (Magnus Hagander)
     * Improve LDAP error reporting and documentation (Peter Eisentraut)
     * Add support for specifying LDAP authentication parameters in URL
       format, per RFC 4516 (Peter Eisentraut)
     * Change the ssl_ciphers parameter to start with DEFAULT, rather than
       ALL, then remove insecure ciphers (Magnus Hagander)
       This should yield a more appropriate SSL cipher set.
     * Parse and load "pg_ident.conf" once, not during each connection
       (Amit Kapila)
       This is similar to how "pg_hba.conf" is processed.
     __________________________________________________________________

Server Settings

     * Greatly reduce System V shared memory requirements (Robert Haas)
       On Unix-like systems, mmap() is now used for most of PostgreSQL's
       shared memory. For most users, this will eliminate any need to
       adjust kernel parameters for shared memory.
     * Allow the postmaster to listen on multiple Unix-domain sockets
       (Honza Horak)
       The configuration parameter unix_socket_directory is replaced by
       unix_socket_directories, which accepts a list of directories.
     * Allow a directory of configuration files to be processed (Magnus
       Hagander, Greg Smith, Selena Deckelmann)
       Such a directory is specified with include_dir in the server
       configuration file.
     * Increase the maximum initdb-configured value for shared_buffers to
       128MB (Robert Haas)
       This is the maximum value that initdb will attempt to set in
       "postgresql.conf"; the previous maximum was 32MB.
     * Remove the external PID file, if any, on postmaster exit (Peter
       Eisentraut)
     __________________________________________________________________

Replication and Recovery

     * Allow a streaming replication standby to follow a timeline switch
       (Heikki Linnakangas)
       This allows streaming standby servers to receive WAL data from a
       slave newly promoted to master status. Previously, other standbys
       would require a resync to begin following the new master.
     * Add SQL functions pg_is_in_backup() and pg_backup_start_time()
       (Gilles Darold)
       These functions report the status of base backups.
     * Improve performance of streaming log shipping with
       synchronous_commit disabled (Andres Freund)
     * Allow much faster promotion of a streaming standby to primary
       (Simon Riggs, Kyotaro Horiguchi)
     * Add the last checkpoint's redo location to pg_controldata's output
       (Fujii Masao)
       This information is useful for determining which WAL files are
       needed for restore.
     * Allow tools like pg_receivexlog to run on computers with different
       architectures (Heikki Linnakangas)
       WAL files can still only be replayed on servers with the same
       architecture as the primary; but they can now be transmitted to and
       stored on machines of any architecture, since the streaming
       replication protocol is now machine-independent.
     * Make pg_basebackup "--write-recovery-conf" output a minimal
       "recovery.conf" file (Zoltan Boszormenyi, Magnus Hagander)
       This simplifies setting up a standby server.
     * Allow pg_receivexlog and pg_basebackup "--xlog-method" to handle
       streaming timeline switches (Heikki Linnakangas)
     * Add wal_receiver_timeout parameter to control the WAL receiver's
       timeout (Amit Kapila)
       This allows more rapid detection of connection failure.
     * Change the WAL record format to allow splitting the record header
       across pages (Heikki Linnakangas)
       The new format is slightly more compact, and is more efficient to
       write.
     __________________________________________________________________

Queries

     * Implement SQL-standard LATERAL option for FROM-clause subqueries
       and function calls (Tom Lane)
       This feature allows subqueries and functions in FROM to reference
       columns from other tables in the FROM clause. The LATERAL keyword
       is optional for functions.
     * Add support for piping "COPY" and psql "\copy" data to/from an
       external program (Etsuro Fujita)
     * Allow a multirow VALUES clause in a rule to reference OLD/NEW (Tom
       Lane)
     __________________________________________________________________

Object Manipulation

     * Add support for event triggers (Dimitri Fontaine, Robert Haas,
       Alvaro Herrera)
       This allows server-side functions written in event-enabled
       languages to be called when DDL commands are run.
     * Allow foreign data wrappers to support writes
       (inserts/updates/deletes) on foreign tables (KaiGai Kohei)
     * Add "CREATE SCHEMA ... IF NOT EXISTS" clause (Fabrizio de Royes
       Mello)
     * Make "REASSIGN OWNED" also change ownership of shared objects
       (Alvaro Herrera)
     * Make "CREATE AGGREGATE" complain if the given initial value string
       is not valid input for the transition datatype (Tom Lane)
     * Suppress "CREATE TABLE"'s messages about implicit index and
       sequence creation (Robert Haas)
       These messages now appear at DEBUG1 verbosity, so that they will
       not be shown by default.
     * Allow "DROP TABLE IF EXISTS" to succeed when a non-existent schema
       is specified in the table name (Bruce Momjian)
       Previously, it threw an error if the schema did not exist.
     * Provide clients with constraint violation details as separate
       fields (Pavel Stehule)
       This allows clients to retrieve table, column, data type, or
       constraint name error details. Previously such information had to
       be extracted from error strings. Client library support is required
       to access these fields.
     __________________________________________________________________

ALTER

     * Support IF NOT EXISTS option in "ALTER TYPE ... ADD VALUE" (Andrew
       Dunstan)
       This is useful for conditionally adding values to enumerated types.
     * Add "ALTER ROLE ALL SET" to establish settings for all users (Peter
       Eisentraut)
       This allows settings to apply to all users in all databases. "ALTER
       DATABASE SET" already allowed addition of settings for all users in
       a single database. "postgresql.conf" has a similar effect.
     * Add support for "ALTER RULE ... RENAME" (Ali Dar)
     __________________________________________________________________

VIEWs

     * Add materialized views (Kevin Grittner)
       Unlike ordinary views, where the base tables are read on every
       access, materialized views create physical tables at creation or
       refresh time. Access to the materialized view then reads from its
       physical table. There is not yet any facility for incrementally
       refreshing materialized views or auto-accessing them via base table
       access.
     * Make simple views auto-updatable (Dean Rasheed)
       Simple views that reference some or all columns from a single base
       table are now updatable by default. More complex views can be made
       updatable using INSTEAD OF triggers or INSTEAD rules.
     * Add "CREATE RECURSIVE VIEW" syntax (Peter Eisentraut)
       Internally this is translated into "CREATE VIEW ... WITH RECURSIVE
       ...".
     * Improve view/rule printing code to handle cases where referenced
       tables are renamed, or columns are renamed, added, or dropped (Tom
       Lane)
       Table and column renamings can produce cases where, if we merely
       substitute the new name into the original text of a rule or view,
       the result is ambiguous. This change fixes the rule-dumping code to
       insert manufactured table and column aliases when needed to
       preserve the original semantics.
     __________________________________________________________________

Data Types

     * Increase the maximum size of large objects from 2GB to 4TB (Nozomi
       Anzai, Yugo Nagata)
       This change includes adding 64-bit-capable large object access
       functions, both in the server and in libpq.
     * Allow text timezone designations, e.g. "America/Chicago", in the
       "T" field of ISO-format timestamptz input (Bruce Momjian)
     __________________________________________________________________

JSON

     * Add operators and functions to extract elements from JSON values
       (Andrew Dunstan)
     * Allow JSON values to be converted into records (Andrew Dunstan)
     * Add functions to convert scalars, records, and hstore values to
       JSON (Andrew Dunstan)
     __________________________________________________________________

Functions

     * Add array_remove() and array_replace() functions (Marco Nenciarini,
       Gabriele Bartolini)
     * Allow concat() and format() to properly expand VARIADIC-labeled
       arguments (Pavel Stehule)
     * Improve format() to provide field width and left/right alignment
       options (Pavel Stehule)
     * Make to_char(), to_date(), and to_timestamp() handle negative (BC)
       century values properly (Bruce Momjian)
       Previously the behavior was either wrong or inconsistent with
       positive/AD handling, e.g. with the format mask "IYYY-IW-DY".
     * Make to_date() and to_timestamp() return proper results when mixing
       ISO and Gregorian week/day designations (Bruce Momjian)
     * Cause pg_get_viewdef() to start a new line by default after each
       SELECT target list entry and FROM entry (Marko Tiikkaja)
       This reduces line length in view printing, for instance in pg_dump
       output.
     * Fix map_sql_value_to_xml_value() to print values of domain types
       the same way their base type would be printed (Pavel Stehule)
       There are special formatting rules for certain built-in types such
       as boolean; these rules now also apply to domains over these types.
     __________________________________________________________________

Server-Side Languages

PL/pgSQL Server-Side Language

     * Allow PL/pgSQL to use RETURN with a composite-type expression (Asif
       Rehman)
       Previously, in a function returning a composite type, RETURN could
       only reference a variable of that type.
     * Allow PL/pgSQL to access constraint violation details as separate
       fields (Pavel Stehule)
     * Allow PL/pgSQL to access the number of rows processed by "COPY"
       (Pavel Stehule)
       A "COPY" executed in a PL/pgSQL function now updates the value
       retrieved by "GET DIAGNOSTICS x = ROW_COUNT".
     * Allow unreserved keywords to be used as identifiers everywhere in
       PL/pgSQL (Tom Lane)
       In certain places in the PL/pgSQL grammar, keywords had to be
       quoted to be used as identifiers, even if they were nominally
       unreserved.
     __________________________________________________________________

PL/Python Server-Side Language

     * Add PL/Python result object string handler (Peter Eisentraut)
       This allows plpy.debug(rv) to output something reasonable.
     * Make PL/Python convert OID values to a proper Python numeric type
       (Peter Eisentraut)
     * Handle SPI errors raised explicitly (with PL/Python's RAISE) the
       same as internal SPI errors (Oskari Saarenmaa and Jan Urbanski)
     __________________________________________________________________

Server Programming Interface (SPI)

     * Prevent leakage of SPI tuple tables during subtransaction abort
       (Tom Lane)
       At the end of any failed subtransaction, the core SPI code now
       releases any SPI tuple tables that were created during that
       subtransaction. This avoids the need for SPI-using code to keep
       track of such tuple tables and release them manually in
       error-recovery code. Failure to do so caused a number of
       transaction-lifespan memory leakage issues in PL/pgSQL and perhaps
       other SPI clients. SPI_freetuptable() now protects itself against
       multiple freeing requests, so any existing code that did take care
       to clean up shouldn't be broken by this change.
     * Allow SPI functions to access the number of rows processed by
       "COPY" (Pavel Stehule)
     __________________________________________________________________

Client Applications

     * Add command-line utility pg_isready to check if the server is ready
       to accept connections (Phil Sorber)
     * Support multiple "--table" arguments for pg_restore, clusterdb,
       reindexdb, and vacuumdb (Josh Kupershmidt)
       This is similar to the way pg_dump's "--table" option works.
     * Add "--dbname" option to pg_dumpall, pg_basebackup, and
       pg_receivexlog to allow specifying a connection string (Amit
       Kapila)
     * Add libpq function PQconninfo() to return connection information
       (Zoltan Boszormenyi, Magnus Hagander)
     __________________________________________________________________

psql

     * Adjust function cost settings so psql tab completion and pattern
       searching are more efficient (Tom Lane)
     * Improve psql's tab completion coverage (Jeff Janes, Dean Rasheed,
       Peter Eisentraut, Magnus Hagander)
     * Allow the psql "--single-transaction" mode to work when reading
       from standard input (Fabien Coelho, Robert Haas)
       Previously this option only worked when reading from a file.
     * Remove psql warning when connecting to an older server (Peter
       Eisentraut)
       A warning is still issued when connecting to a server of a newer
       major version than psql's.
     __________________________________________________________________

Backslash Commands

     * Add psql command "\watch" to repeatedly execute a SQL command (Will
       Leinweber)
     * Add psql command "\gset" to store query results in psql variables
       (Pavel Stehule)
     * Add SSL information to psql's "\conninfo" command (Alastair Turner)
     * Add "Security" column to psql's "\df+" output (Jon Erdman)
     * Allow psql command "\l" to accept a database name pattern (Peter
       Eisentraut)
     * In psql, do not allow "\connect" to use defaults if there is no
       active connection (Bruce Momjian)
       This might be the case if the server had crashed.
     * Properly reset state after failure of a SQL command executed with
       psql's \g "file" (Tom Lane)
       Previously, the output from subsequent SQL commands would
       unexpectedly continue to go to the same file.
     __________________________________________________________________

Output

     * Add a latex-longtable output format to psql (Bruce Momjian)
       This format allows tables to span multiple pages.
     * Add a border=3 output mode to the psql latex format (Bruce Momjian)
     * In psql's tuples-only and expanded output modes, no longer emit
       "(No rows)" for zero rows (Peter Eisentraut)
     * In psql's unaligned, expanded output mode, no longer print an empty
       line for zero rows (Peter Eisentraut)
     __________________________________________________________________

pg_dump

     * Add pg_dump "--jobs" option to dump tables in parallel (Joachim
       Wieland)
     * Make pg_dump output functions in a more predictable order (Joel
       Jacobson)
     * Fix tar files emitted by pg_dump to be POSIX conformant (Brian
       Weaver, Tom Lane)
     * Add "--dbname" option to pg_dump, for consistency with other client
       commands (Heikki Linnakangas)
       The database name could already be supplied last without a flag.
     __________________________________________________________________

initdb

     * Make initdb fsync the newly created data directory (Jeff Davis)
       This insures data integrity in event of a system crash shortly
       after initdb. This can be disabled by using "--nosync".
     * Add initdb "--sync-only" option to sync the data directory to
       durable storage (Bruce Momjian)
       This is used by pg_upgrade.
     * Make initdb issue a warning about placing the data directory at the
       top of a file system mount point (Bruce Momjian)
     __________________________________________________________________

Source Code

     * Add infrastructure to allow plug-in background worker processes
       (Alvaro Herrera)
     * Create a centralized timeout API (Zoltan Boszormenyi)
     * Create libpgcommon and move pg_malloc() and other functions there
       (Alvaro Herrera, Andres Freund)
       This allows libpgport to be used solely for portability-related
       code.
     * Add support for list links embedded in larger structs (Andres
       Freund)
     * Use SA_RESTART for all signals, including SIGALRM (Tom Lane)
     * Ensure that the correct text domain is used when translating
       errcontext() messages (Heikki Linnakangas)
     * Standardize naming of client-side memory allocation functions (Tom
       Lane)
     * Provide support for "static assertions" that will fail at compile
       time if some compile-time-constant condition is not met (Andres
       Freund, Tom Lane)
     * Support Assert() in client-side code (Andrew Dunstan)
     * Add decoration to inform the C compiler that some ereport() and
       elog() calls do not return (Peter Eisentraut, Andres Freund, Tom
       Lane, Heikki Linnakangas)
     * Allow options to be passed to the regression test output comparison
       utility via PG_REGRESS_DIFF_OPTS (Peter Eisentraut)
     * Add isolation tests for "CREATE INDEX CONCURRENTLY" (Abhijit
       Menon-Sen)
     * Remove typedefs for int2/int4 as they are better represented as
       int16/int32 (Peter Eisentraut)
     * Fix install-strip on Mac OS X (Peter Eisentraut)
     * Remove configure flag "--disable-shared", as it is no longer
       supported (Bruce Momjian)
     * Rewrite pgindent in Perl (Andrew Dunstan)
     * Provide Emacs macro to set Perl formatting to match PostgreSQL's
       perltidy settings (Peter Eisentraut)
     * Run tool to check the keyword list whenever the backend grammar is
       changed (Tom Lane)
     * Change the way UESCAPE is lexed, to significantly reduce the size
       of the lexer tables (Heikki Linnakangas)
     * Centralize flex and bison make rules (Peter Eisentraut)
       This is useful for pgxs authors.
     * Change many internal backend functions to return object OIDs rather
       than void (Dimitri Fontaine)
       This is useful for event triggers.
     * Invent pre-commit/pre-prepare/pre-subcommit events for transaction
       callbacks (Tom Lane)
       Loadable modules that use transaction callbacks might need
       modification to handle these new event types.
     * Add function pg_identify_object() to produce a machine-readable
       description of a database object (Alvaro Herrera)
     * Add post-"ALTER"-object server hooks (KaiGai Kohei)
     * Implement a generic binary heap and use it for Merge-Append
       operations (Abhijit Menon-Sen)
     * Provide a tool to help detect timezone abbreviation changes when
       updating the "src/timezone/data" files (Tom Lane)
     * Add pkg-config support for libpq and ecpg libraries (Peter
       Eisentraut)
     * Remove "src/tool/backend", now that the content is on the
       PostgreSQL wiki (Bruce Momjian)
     * Split out WAL reading as an independent facility (Heikki
       Linnakangas, Andres Freund)
     * Use a 64-bit integer to represent WAL positions (XLogRecPtr)
       instead of two 32-bit integers (Heikki Linnakangas)
       Generally, tools that need to read the WAL format will need to be
       adjusted.
     * Allow PL/Python to support platform-specific include directories
       (Peter Eisentraut)
     * Allow PL/Python on OS X to build against custom versions of Python
       (Peter Eisentraut)
     __________________________________________________________________

Additional Modules

     * Add a Postgres foreign data wrapper contrib module to allow access
       to other Postgres servers (Shigeru Hanada)
       This foreign data wrapper supports writes.
     * Add pg_xlogdump contrib program (Andres Freund)
     * Add support for indexing of regular-expression searches in pg_trgm
       (Alexander Korotkov)
     * Improve pg_trgm's handling of multibyte characters (Tom Lane)
       On a platform that does not have the wcstombs() or towlower()
       library functions, this could result in an incompatible change in
       the contents of pg_trgm indexes for non-ASCII data. In such cases,
       "REINDEX" those indexes to ensure correct search results.
     * Add a pgstattuple function to report the size of the
       pending-insertions list of a GIN index (Fujii Masao)
     * Make oid2name, pgbench, and vacuumlo set fallback_application_name
       (Amit Kapila)
     * Improve output of pg_test_timing (Bruce Momjian)
     * Improve output of pg_test_fsync (Peter Geoghegan)
     * Create a dedicated foreign data wrapper, with its own option
       validator function, for dblink (Shigeru Hanada)
       When using this FDW to define the target of a dblink connection,
       instead of using a hard-wired list of connection options, the
       underlying libpq library is consulted to see what connection
       options it supports.
     __________________________________________________________________

pg_upgrade

     * Allow pg_upgrade to do dumps and restores in parallel (Bruce
       Momjian, Andrew Dunstan)
       This allows parallel schema dump/restore of databases, as well as
       parallel copy/link of data files per tablespace. Use the "--jobs"
       option to specify the level of parallelism.
     * Make pg_upgrade create Unix-domain sockets in the current directory
       (Bruce Momjian, Tom Lane)
       This reduces the possibility that someone will accidentally connect
       during the upgrade.
     * Make pg_upgrade "--check" mode properly detect the location of
       non-default socket directories (Bruce Momjian, Tom Lane)
     * Improve performance of pg_upgrade for databases with many tables
       (Bruce Momjian)
     * Improve pg_upgrade's logs by showing executed commands (Alvaro
       Herrera)
     * Improve pg_upgrade's status display during copy/link (Bruce
       Momjian)
     __________________________________________________________________

pgbench

     * Add "--foreign-keys" option to pgbench (Jeff Janes)
       This adds foreign key constraints to the standard tables created by
       pgbench, for use in foreign key performance testing.
     * Allow pgbench to aggregate performance statistics and produce
       output every "--aggregate-interval" seconds (Tomas Vondra)
     * Add pgbench "--sampling-rate" option to control the percentage of
       transactions logged (Tomas Vondra)
     * Reduce and improve the status message output of pgbench's
       initialization mode (Robert Haas, Peter Eisentraut)
     * Add pgbench "-q" mode to print one output line every five seconds
       (Tomas Vondra)
     * Output pgbench elapsed and estimated remaining time during
       initialization (Tomas Vondra)
     * Allow pgbench to use much larger scale factors, by changing
       relevant columns from integer to bigint when the requested scale
       factor exceeds 20000 (Greg Smith)
     __________________________________________________________________

Documentation

     * Allow EPUB-format documentation to be created (Peter Eisentraut)
     * Update FreeBSD kernel configuration documentation (Brad Davis)
     * Improve WINDOW function documentation (Bruce Momjian, Florian
       Pflug)
     * Add instructions for setting up the documentation tool chain on Mac
       OS X (Peter Eisentraut)
     * Improve commit_delay documentation (Peter Geoghegan)
     __________________________________________________________________

                                Release 9.2.6

     Release Date: 2013-12-05

   This release contains a variety of fixes from 9.2.5. For information
   about new features in the 9.2 major release, see the Section called
   Release 9.2.
     __________________________________________________________________

Migration to Version 9.2.6

   A dump/restore is not required for those running 9.2.X.

   However, this release corrects a number of potential data corruption
   issues. See the first two changelog entries below to find out whether
   your installation has been affected and what steps you can take if so.

   Also, if you are upgrading from a version earlier than 9.2.4, see the
   release notes for 9.2.4.
     __________________________________________________________________

Changes

     * Fix "VACUUM"'s tests to see whether it can update relfrozenxid
       (Andres Freund)
       In some cases "VACUUM" (either manual or autovacuum) could
       incorrectly advance a table's relfrozenxid value, allowing tuples
       to escape freezing, causing those rows to become invisible once
       2^31 transactions have elapsed. The probability of data loss is
       fairly low since multiple incorrect advancements would need to
       happen before actual loss occurs, but it's not zero. In 9.2.0 and
       later, the probability of loss is higher, and it's also possible to
       get "could not access status of transaction" errors as a
       consequence of this bug. Users upgrading from releases 9.0.4 or
       8.4.8 or earlier are not affected, but all later versions contain
       the bug.
       The issue can be ameliorated by, after upgrading, vacuuming all
       tables in all databases while having vacuum_freeze_table_age set to
       zero. This will fix any latent corruption but will not be able to
       fix all pre-existing data errors. However, an installation can be
       presumed safe after performing this vacuuming if it has executed
       fewer than 2^31 update transactions in its lifetime (check this
       with SELECT txid_current() < 2^31).
     * Fix initialization of "pg_clog" and "pg_subtrans" during hot
       standby startup (Andres Freund, Heikki Linnakangas)
       This bug can cause data loss on standby servers at the moment they
       start to accept hot-standby queries, by marking committed
       transactions as uncommitted. The likelihood of such corruption is
       small unless, at the time of standby startup, the primary server
       has executed many updating transactions since its last checkpoint.
       Symptoms include missing rows, rows that should have been deleted
       being still visible, and obsolete versions of updated rows being
       still visible alongside their newer versions.
       This bug was introduced in versions 9.3.0, 9.2.5, 9.1.10, and
       9.0.14. Standby servers that have only been running earlier
       releases are not at risk. It's recommended that standby servers
       that have ever run any of the buggy releases be re-cloned from the
       primary (e.g., with a new base backup) after upgrading.
     * Fix dangling-pointer problem in fast-path locking (Tom Lane)
       This could lead to corruption of the lock data structures in shared
       memory, causing "lock already held" and other odd errors.
     * Truncate "pg_multixact" contents during WAL replay (Andres Freund)
       This avoids ever-increasing disk space consumption in standby
       servers.
     * Ensure an anti-wraparound "VACUUM" counts a page as scanned when
       it's only verified that no tuples need freezing (Sergey Burladyan,
       Jeff Janes)
       This bug could result in failing to advance relfrozenxid, so that
       the table would still be thought to need another anti-wraparound
       vacuum. In the worst case the database might even shut down to
       prevent wraparound.
     * Fix race condition in GIN index posting tree page deletion (Heikki
       Linnakangas)
       This could lead to transient wrong answers or query failures.
     * Fix "unexpected spgdoinsert() failure" error during SP-GiST index
       creation (Teodor Sigaev)
     * Avoid flattening a subquery whose SELECT list contains a volatile
       function wrapped inside a sub-SELECT (Tom Lane)
       This avoids unexpected results due to extra evaluations of the
       volatile function.
     * Fix planner's processing of non-simple-variable subquery outputs
       nested within outer joins (Tom Lane)
       This error could lead to incorrect plans for queries involving
       multiple levels of subqueries within JOIN syntax.
     * Fix incorrect planning in cases where the same non-strict
       expression appears in multiple WHERE and outer JOIN equality
       clauses (Tom Lane)
     * Fix planner crash with whole-row reference to a subquery (Tom Lane)
     * Fix incorrect generation of optimized MIN()/MAX() plans for
       inheritance trees (Tom Lane)
       The planner could fail in cases where the MIN()/MAX() argument was
       an expression rather than a simple variable.
     * Fix premature deletion of temporary files (Andres Freund)
     * Prevent intra-transaction memory leak when printing range values
       (Tom Lane)
       This fix actually cures transient memory leaks in any datatype
       output function, but range types are the only ones known to have
       had a significant problem.
     * Prevent incorrect display of dropped columns in NOT NULL and CHECK
       constraint violation messages (Michael Paquier and Tom Lane)
     * Allow default arguments and named-argument notation for window
       functions (Tom Lane)
       Previously, these cases were likely to crash.
     * Fix possible read past end of memory in rule printing (Peter
       Eisentraut)
     * Fix array slicing of int2vector and oidvector values (Tom Lane)
       Expressions of this kind are now implicitly promoted to regular
       int2 or oid arrays.
     * Fix incorrect behaviors when using a SQL-standard, simple GMT
       offset timezone (Tom Lane)
       In some cases, the system would use the simple GMT offset value
       when it should have used the regular timezone setting that had
       prevailed before the simple offset was selected. This change also
       causes the timeofday function to honor the simple GMT offset zone.
     * Prevent possible misbehavior when logging translations of Windows
       error codes (Tom Lane)
     * Properly quote generated command lines in pg_ctl (Naoya Anzai and
       Tom Lane)
       This fix applies only to Windows.
     * Fix pg_dumpall to work when a source database sets
       default_transaction_read_only via "ALTER DATABASE SET" (Kevin
       Grittner)
       Previously, the generated script would fail during restore.
     * Make ecpg search for quoted cursor names case-sensitively (Zoltan
       Boszormenyi)
     * Fix ecpg's processing of lists of variables declared varchar
       (Zoltan Boszormenyi)
     * Make "contrib/lo" defend against incorrect trigger definitions
       (Marc Cousin)
     * Update time zone data files to tzdata release 2013h for DST law
       changes in Argentina, Brazil, Jordan, Libya, Liechtenstein,
       Morocco, and Palestine. Also, new timezone abbreviations WIB, WIT,
       WITA for Indonesia.
     __________________________________________________________________

                                Release 9.2.5

     Release Date: 2013-10-10

   This release contains a variety of fixes from 9.2.4. For information
   about new features in the 9.2 major release, see the Section called
   Release 9.2.
     __________________________________________________________________

Migration to Version 9.2.5

   A dump/restore is not required for those running 9.2.X.

   However, if you are upgrading from a version earlier than 9.2.4, see
   the release notes for 9.2.4.
     __________________________________________________________________

Changes

     * Prevent corruption of multi-byte characters when attempting to
       case-fold identifiers (Andrew Dunstan)
       PostgreSQL case-folds non-ASCII characters only when using a
       single-byte server encoding.
     * Fix memory leak when creating B-tree indexes on range columns
       (Heikki Linnakangas)
     * Fix checkpoint memory leak in background writer when wal_level =
       hot_standby (Naoya Anzai)
     * Fix memory leak caused by lo_open() failure (Heikki Linnakangas)
     * Fix memory overcommit bug when work_mem is using more than 24GB of
       memory (Stephen Frost)
     * Serializable snapshot fixes (Kevin Grittner, Heikki Linnakangas)
     * Fix deadlock bug in libpq when using SSL (Stephen Frost)
     * Fix possible SSL state corruption in threaded libpq applications
       (Nick Phillips, Stephen Frost)
     * Improve estimate of planner cost when choosing between generic and
       custom plans (Tom Lane)
       This change will favor generic plans when planning cost is high.
     * Properly compute row estimates for boolean columns containing many
       NULL values (Andrew Gierth)
       Previously tests like col IS NOT TRUE and col IS NOT FALSE did not
       properly factor in NULL values when estimating plan costs.
     * Fix accounting for qualifier evaluation costs in UNION ALL and
       inheritance queries (Tom Lane)
       This fixes cases where suboptimal query plans could be chosen if
       some WHERE clauses are expensive to calculate.
     * Prevent pushing down WHERE clauses into unsafe UNION/INTERSECT
       subqueries (Tom Lane)
       Subqueries of a UNION or INTERSECT that contain set-returning
       functions or volatile functions in their SELECT lists could be
       improperly optimized, leading to run-time errors or incorrect query
       results.
     * Fix rare case of "failed to locate grouping columns" planner
       failure (Tom Lane)
     * Fix pg_dump of foreign tables with dropped columns (Andrew Dunstan)
       Previously such cases could cause a pg_upgrade error.
     * Reorder pg_dump processing of extension-related rules and event
       triggers (Joe Conway)
     * Force dumping of extension tables if specified by "pg_dump -t" or
       -n (Joe Conway)
     * Improve view dumping code's handling of dropped columns in
       referenced tables (Tom Lane)
     * Fix "pg_restore -l" with the directory archive to display the
       correct format name (Fujii Masao)
     * Properly record index comments created using UNIQUE and PRIMARY KEY
       syntax (Andres Freund)
       This fixes a parallel pg_restore failure.
     * Cause "pg_basebackup -x" with an empty xlog directory to throw an
       error rather than crashing (Magnus Hagander, Haruka Takatsuka)
     * Properly guarantee transmission of WAL files before clean
       switchover (Fujii Masao)
       Previously, the streaming replication connection might close before
       all WAL files had been replayed on the standby.
     * Fix WAL segment timeline handling during recovery (Mitsumasa Kondo,
       Heikki Linnakangas)
       WAL file recycling during standby recovery could lead to premature
       recovery completion, resulting in data loss.
     * Fix "REINDEX TABLE" and "REINDEX DATABASE" to properly revalidate
       constraints and mark invalidated indexes as valid (Noah Misch)
       "REINDEX INDEX" has always worked properly.
     * Avoid deadlocks during insertion into SP-GiST indexes (Teodor
       Sigaev)
     * Fix possible deadlock during concurrent "CREATE INDEX CONCURRENTLY"
       operations (Tom Lane)
     * Fix GiST index lookup crash (Tom Lane)
     * Fix regexp_matches() handling of zero-length matches (Jeevan
       Chalke)
       Previously, zero-length matches like '^' could return too many
       matches.
     * Fix crash for overly-complex regular expressions (Heikki
       Linnakangas)
     * Fix regular expression match failures for back references combined
       with non-greedy quantifiers (Jeevan Chalke)
     * Prevent "CREATE FUNCTION" from checking "SET" variables unless
       function body checking is enabled (Tom Lane)
     * Allow "ALTER DEFAULT PRIVILEGES" to operate on schemas without
       requiring CREATE permission (Tom Lane)
     * Loosen restriction on keywords used in queries (Tom Lane)
       Specifically, lessen keyword restrictions for role names, language
       names, "EXPLAIN" and "COPY" options, and "SET" values. This allows
       COPY ... (FORMAT BINARY) to work as expected; previously BINARY
       needed to be quoted.
     * Print proper line number during "COPY" failure (Heikki Linnakangas)
     * Fix pgp_pub_decrypt() so it works for secret keys with passwords
       (Marko Kreen)
     * Make pg_upgrade use pg_dump --quote-all-identifiers to avoid
       problems with keyword changes between releases (Tom Lane)
     * Remove rare inaccurate warning during vacuum of index-less tables
       (Heikki Linnakangas)
     * Ensure that "VACUUM ANALYZE" still runs the ANALYZE phase if its
       attempt to truncate the file is cancelled due to lock conflicts
       (Kevin Grittner)
     * Avoid possible failure when performing transaction control commands
       (e.g "ROLLBACK") in prepared queries (Tom Lane)
     * Ensure that floating-point data input accepts standard spellings of
       "infinity" on all platforms (Tom Lane)
       The C99 standard says that allowable spellings are inf, +inf, -inf,
       infinity, +infinity, and -infinity. Make sure we recognize these
       even if the platform's strtod function doesn't.
     * Avoid unnecessary reporting when track_activities is off (Tom Lane)
     * Expand ability to compare rows to records and arrays (Rafal
       Rzepecki, Tom Lane)
     * Prevent crash when psql's PSQLRC variable contains a tilde (Bruce
       Momjian)
     * Add spinlock support for ARM64 (Mark Salter)
     * Update time zone data files to tzdata release 2013d for DST law
       changes in Israel, Morocco, Palestine, and Paraguay. Also,
       historical zone data corrections for Macquarie Island.
     __________________________________________________________________

                                Release 9.2.4

     Release Date: 2013-04-04

   This release contains a variety of fixes from 9.2.3. For information
   about new features in the 9.2 major release, see the Section called
   Release 9.2.
     __________________________________________________________________

Migration to Version 9.2.4

   A dump/restore is not required for those running 9.2.X.

   However, this release corrects several errors in management of GiST
   indexes. After installing this update, it is advisable to "REINDEX" any
   GiST indexes that meet one or more of the conditions described below.

   Also, if you are upgrading from a version earlier than 9.2.2, see the
   release notes for 9.2.2.
     __________________________________________________________________

Changes

     * Fix insecure parsing of server command-line switches (Mitsumasa
       Kondo, Kyotaro Horiguchi)
       A connection request containing a database name that begins with
       "-" could be crafted to damage or destroy files within the server's
       data directory, even if the request is eventually rejected.
       (CVE-2013-1899)
     * Reset OpenSSL randomness state in each postmaster child process
       (Marko Kreen)
       This avoids a scenario wherein random numbers generated by
       "contrib/pgcrypto" functions might be relatively easy for another
       database user to guess. The risk is only significant when the
       postmaster is configured with ssl = on but most connections don't
       use SSL encryption. (CVE-2013-1900)
     * Make REPLICATION privilege checks test current user not
       authenticated user (Noah Misch)
       An unprivileged database user could exploit this mistake to call
       pg_start_backup() or pg_stop_backup(), thus possibly interfering
       with creation of routine backups. (CVE-2013-1901)
     * Fix GiST indexes to not use "fuzzy" geometric comparisons when it's
       not appropriate to do so (Alexander Korotkov)
       The core geometric types perform comparisons using "fuzzy"
       equality, but gist_box_same must do exact comparisons, else GiST
       indexes using it might become inconsistent. After installing this
       update, users should "REINDEX" any GiST indexes on box, polygon,
       circle, or point columns, since all of these use gist_box_same.
     * Fix erroneous range-union and penalty logic in GiST indexes that
       use "contrib/btree_gist" for variable-width data types, that is
       text, bytea, bit, and numeric columns (Tom Lane)
       These errors could result in inconsistent indexes in which some
       keys that are present would not be found by searches, and also in
       useless index bloat. Users are advised to "REINDEX" such indexes
       after installing this update.
     * Fix bugs in GiST page splitting code for multi-column indexes (Tom
       Lane)
       These errors could result in inconsistent indexes in which some
       keys that are present would not be found by searches, and also in
       indexes that are unnecessarily inefficient to search. Users are
       advised to "REINDEX" multi-column GiST indexes after installing
       this update.
     * Fix gist_point_consistent to handle fuzziness consistently
       (Alexander Korotkov)
       Index scans on GiST indexes on point columns would sometimes yield
       results different from a sequential scan, because
       gist_point_consistent disagreed with the underlying operator code
       about whether to do comparisons exactly or fuzzily.
     * Fix buffer leak in WAL replay (Heikki Linnakangas)
       This bug could result in "incorrect local pin count" errors during
       replay, making recovery impossible.
     * Ensure we do crash recovery before entering archive recovery, if
       the database was not stopped cleanly and a "recovery.conf" file is
       present (Heikki Linnakangas, Kyotaro Horiguchi, Mitsumasa Kondo)
       This is needed to ensure that the database is consistent in certain
       scenarios, such as initializing a standby server with a filesystem
       snapshot from a running server.
     * Avoid deleting not-yet-archived WAL files during crash recovery
       (Heikki Linnakangas, Fujii Masao)
     * Fix race condition in "DELETE RETURNING" (Tom Lane)
       Under the right circumstances, "DELETE RETURNING" could attempt to
       fetch data from a shared buffer that the current process no longer
       has any pin on. If some other process changed the buffer meanwhile,
       this would lead to garbage RETURNING output, or even a crash.
     * Fix infinite-loop risk in regular expression compilation (Tom Lane,
       Don Porter)
     * Fix potential null-pointer dereference in regular expression
       compilation (Tom Lane)
     * Fix to_char() to use ASCII-only case-folding rules where
       appropriate (Tom Lane)
       This fixes misbehavior of some template patterns that should be
       locale-independent, but mishandled "I" and "i" in Turkish locales.
     * Fix unwanted rejection of timestamp 1999-12-31 24:00:00 (Tom Lane)
     * Fix SQL-language functions to be safely usable as support functions
       for range types (Tom Lane)
     * Fix logic error when a single transaction does "UNLISTEN" then
       "LISTEN" (Tom Lane)
       The session wound up not listening for notify events at all, though
       it surely should listen in this case.
     * Fix possible planner crash after columns have been added to a view
       that's depended on by another view (Tom Lane)
     * Fix performance issue in EXPLAIN (ANALYZE, TIMING OFF) (Pavel
       Stehule)
     * Remove useless "picksplit doesn't support secondary split" log
       messages (Josh Hansen, Tom Lane)
       This message seems to have been added in expectation of code that
       was never written, and probably never will be, since GiST's default
       handling of secondary splits is actually pretty good. So stop
       nagging end users about it.
     * Remove vestigial secondary-split support in gist_box_picksplit()
       (Tom Lane)
       Not only was this implementation of secondary-split not better than
       the default implementation, it's actually worse. So remove it and
       let the default code path handle the case.
     * Fix possible failure to send a session's last few transaction
       commit/abort counts to the statistics collector (Tom Lane)
     * Eliminate memory leaks in PL/Perl's spi_prepare() function (Alex
       Hunsaker, Tom Lane)
     * Fix pg_dumpall to handle database names containing "=" correctly
       (Heikki Linnakangas)
     * Avoid crash in pg_dump when an incorrect connection string is given
       (Heikki Linnakangas)
     * Ignore invalid indexes in pg_dump and pg_upgrade (Michael Paquier,
       Bruce Momjian)
       Dumping invalid indexes can cause problems at restore time, for
       example if the reason the index creation failed was because it
       tried to enforce a uniqueness condition not satisfied by the
       table's data. Also, if the index creation is in fact still in
       progress, it seems reasonable to consider it to be an uncommitted
       DDL change, which pg_dump wouldn't be expected to dump anyway.
       pg_upgrade now also skips invalid indexes rather than failing.
     * In pg_basebackup, include only the current server version's
       subdirectory when backing up a tablespace (Heikki Linnakangas)
     * Add a server version check in pg_basebackup and pg_receivexlog, so
       they fail cleanly with version combinations that won't work (Heikki
       Linnakangas)
     * Fix "contrib/dblink" to handle inconsistent settings of DateStyle
       or IntervalStyle safely (Daniel Farina, Tom Lane)
       Previously, if the remote server had different settings of these
       parameters, ambiguous dates might be read incorrectly. This fix
       ensures that datetime and interval columns fetched by a "dblink"
       query will be interpreted correctly. Note however that inconsistent
       settings are still risky, since literal values appearing in SQL
       commands sent to the remote server might be interpreted differently
       than they would be locally.
     * Fix "contrib/pg_trgm"'s similarity() function to return zero for
       trigram-less strings (Tom Lane)
       Previously it returned NaN due to internal division by zero.
     * Enable building PostgreSQL with Microsoft Visual Studio 2012 (Brar
       Piening, Noah Misch)
     * Update time zone data files to tzdata release 2013b for DST law
       changes in Chile, Haiti, Morocco, Paraguay, and some Russian areas.
       Also, historical zone data corrections for numerous places.
       Also, update the time zone abbreviation files for recent changes in
       Russia and elsewhere: CHOT, GET, IRKT, KGT, KRAT, MAGT, MAWT, MSK,
       NOVT, OMST, TKT, VLAT, WST, YAKT, YEKT now follow their current
       meanings, and VOLT (Europe/Volgograd) and MIST
       (Antarctica/Macquarie) are added to the default abbreviations list.
     __________________________________________________________________

                                Release 9.2.3

     Release Date: 2013-02-07

   This release contains a variety of fixes from 9.2.2. For information
   about new features in the 9.2 major release, see the Section called
   Release 9.2.
     __________________________________________________________________

Migration to Version 9.2.3

   A dump/restore is not required for those running 9.2.X.

   However, if you are upgrading from a version earlier than 9.2.2, see
   the release notes for 9.2.2.
     __________________________________________________________________

Changes

     * Prevent execution of enum_recv from SQL (Tom Lane)
       The function was misdeclared, allowing a simple SQL command to
       crash the server. In principle an attacker might be able to use it
       to examine the contents of server memory. Our thanks to Sumit Soni
       (via Secunia SVCRP) for reporting this issue. (CVE-2013-0255)
     * Fix multiple problems in detection of when a consistent database
       state has been reached during WAL replay (Fujii Masao, Heikki
       Linnakangas, Simon Riggs, Andres Freund)
     * Fix detection of end-of-backup point when no actual redo work is
       required (Heikki Linnakangas)
       This mistake could result in incorrect "WAL ends before end of
       online backup" errors.
     * Update minimum recovery point when truncating a relation file
       (Heikki Linnakangas)
       Once data has been discarded, it's no longer safe to stop recovery
       at an earlier point in the timeline.
     * Fix recycling of WAL segments after changing recovery target
       timeline (Heikki Linnakangas)
     * Properly restore timeline history files from archive on cascading
       standby servers (Heikki Linnakangas)
     * Fix lock conflict detection on hot-standby servers (Andres Freund,
       Robert Haas)
     * Fix missing cancellations in hot standby mode (Noah Misch, Simon
       Riggs)
       The need to cancel conflicting hot-standby queries would sometimes
       be missed, allowing those queries to see inconsistent data.
     * Prevent recovery pause feature from pausing before users can
       connect (Tom Lane)
     * Fix SQL grammar to allow subscripting or field selection from a
       sub-SELECT result (Tom Lane)
     * Fix performance problems with autovacuum truncation in busy
       workloads (Jan Wieck)
       Truncation of empty pages at the end of a table requires exclusive
       lock, but autovacuum was coded to fail (and release the table lock)
       when there are conflicting lock requests. Under load, it is easily
       possible that truncation would never occur, resulting in table
       bloat. Fix by performing a partial truncation, releasing the lock,
       then attempting to re-acquire the lock and continue. This fix also
       greatly reduces the average time before autovacuum releases the
       lock after a conflicting request arrives.
     * Improve performance of SPI_execute and related functions, thereby
       improving PL/pgSQL's EXECUTE (Heikki Linnakangas, Tom Lane)
       Remove some data-copying overhead that was added in 9.2 as a
       consequence of revisions in the plan caching mechanism. This
       eliminates a performance regression compared to 9.1, and also saves
       memory, especially when the query string to be executed contains
       many SQL statements.
       A side benefit is that multi-statement query strings are now
       processed fully serially, that is we complete execution of earlier
       statements before running parse analysis and planning on the
       following ones. This eliminates a long-standing issue, in that DDL
       that should affect the behavior of a later statement will now
       behave as expected.
     * Restore pre-9.2 cost estimates for index usage (Tom Lane)
       An ill-considered change of a fudge factor led to undesirably high
       cost estimates for use of very large indexes.
     * Fix intermittent crash in DROP INDEX CONCURRENTLY (Tom Lane)
     * Fix potential corruption of shared-memory lock table during
       "CREATE/DROP INDEX CONCURRENTLY" (Tom Lane)
     * Fix "COPY"'s multiple-tuple-insertion code for the case of a tuple
       larger than page size minus fillfactor (Heikki Linnakangas)
       The previous coding could get into an infinite loop.
     * Protect against race conditions when scanning pg_tablespace
       (Stephen Frost, Tom Lane)
       "CREATE DATABASE" and "DROP DATABASE" could misbehave if there were
       concurrent updates of pg_tablespace entries.
     * Prevent "DROP OWNED" from trying to drop whole databases or
       tablespaces (Alvaro Herrera)
       For safety, ownership of these objects must be reassigned, not
       dropped.
     * Fix error in vacuum_freeze_table_age implementation (Andres Freund)
       In installations that have existed for more than
       vacuum_freeze_min_age transactions, this mistake prevented
       autovacuum from using partial-table scans, so that a full-table
       scan would always happen instead.
     * Prevent misbehavior when a RowExpr or XmlExpr is parse-analyzed
       twice (Andres Freund, Tom Lane)
       This mistake could be user-visible in contexts such as CREATE TABLE
       LIKE INCLUDING INDEXES.
     * Improve defenses against integer overflow in hashtable sizing
       calculations (Jeff Davis)
     * Fix some bugs associated with privileges on datatypes (Tom Lane)
       There were some issues with default privileges for types, and
       pg_dump failed to dump such privileges at all.
     * Fix failure to ignore leftover temporary tables after a server
       crash (Tom Lane)
     * Fix failure to rotate postmaster log files for size reasons on
       Windows (Jeff Janes, Heikki Linnakangas)
     * Reject out-of-range dates in to_date() (Hitoshi Harada)
     * Fix pg_extension_config_dump() to handle extension-update cases
       properly (Tom Lane)
       This function will now replace any existing entry for the target
       table, making it usable in extension update scripts.
     * Fix PL/pgSQL's reporting of plan-time errors in possibly-simple
       expressions (Tom Lane)
       The previous coding resulted in sometimes omitting the first line
       in the CONTEXT traceback for the error.
     * Fix PL/Python's handling of functions used as triggers on multiple
       tables (Andres Freund)
     * Ensure that non-ASCII prompt strings are translated to the correct
       code page on Windows (Alexander Law, Noah Misch)
       This bug affected psql and some other client programs.
     * Fix possible crash in psql's "\?" command when not connected to a
       database (Meng Qingzhong)
     * Fix possible error if a relation file is removed while
       pg_basebackup is running (Heikki Linnakangas)
     * Tolerate timeline switches while pg_basebackup -X fetch is backing
       up a standby server (Heikki Linnakangas)
     * Make pg_dump exclude data of unlogged tables when running on a
       hot-standby server (Magnus Hagander)
       This would fail anyway because the data is not available on the
       standby server, so it seems most convenient to assume
       "--no-unlogged-table-data" automatically.
     * Fix pg_upgrade to deal with invalid indexes safely (Bruce Momjian)
     * Fix pg_upgrade's -O/-o options (Marti Raudsepp)
     * Fix one-byte buffer overrun in libpq's PQprintTuples (Xi Wang)
       This ancient function is not used anywhere by PostgreSQL itself,
       but it might still be used by some client code.
     * Make ecpglib use translated messages properly (Chen Huajun)
     * Properly install ecpg_compat and pgtypes libraries on MSVC (Jiang
       Guiqing)
     * Include our version of isinf() in libecpg if it's not provided by
       the system (Jiang Guiqing)
     * Rearrange configure's tests for supplied functions so it is not
       fooled by bogus exports from libedit/libreadline (Christoph Berg)
     * Ensure Windows build number increases over time (Magnus Hagander)
     * Make pgxs build executables with the right .exe suffix when
       cross-compiling for Windows (Zoltan Boszormenyi)
     * Add new timezone abbreviation FET (Tom Lane)
       This is now used in some eastern-European time zones.
     __________________________________________________________________

                                Release 9.2.2

     Release Date: 2012-12-06

   This release contains a variety of fixes from 9.2.1. For information
   about new features in the 9.2 major release, see the Section called
   Release 9.2.
     __________________________________________________________________

Migration to Version 9.2.2

   A dump/restore is not required for those running 9.2.X.

   However, you may need to perform "REINDEX" operations to correct
   problems in concurrently-built indexes, as described in the first
   changelog item below.

   Also, if you are upgrading from version 9.2.0, see the release notes
   for 9.2.1.
     __________________________________________________________________

Changes

     * Fix multiple bugs associated with "CREATE/DROP INDEX CONCURRENTLY"
       (Andres Freund, Tom Lane, Simon Riggs, Pavan Deolasee)
       An error introduced while adding "DROP INDEX CONCURRENTLY" allowed
       incorrect indexing decisions to be made during the initial phase of
       "CREATE INDEX CONCURRENTLY"; so that indexes built by that command
       could be corrupt. It is recommended that indexes built in 9.2.X
       with "CREATE INDEX CONCURRENTLY" be rebuilt after applying this
       update.
       In addition, fix "CREATE/DROP INDEX CONCURRENTLY" to use in-place
       updates when changing the state of an index's pg_index row. This
       prevents race conditions that could cause concurrent sessions to
       miss updating the target index, thus again resulting in corrupt
       concurrently-created indexes.
       Also, fix various other operations to ensure that they ignore
       invalid indexes resulting from a failed "CREATE INDEX CONCURRENTLY"
       command. The most important of these is "VACUUM", because an
       auto-vacuum could easily be launched on the table before corrective
       action can be taken to fix or remove the invalid index.
       Also fix "DROP INDEX CONCURRENTLY" to not disable insertions into
       the target index until all queries using it are done.
       Also fix misbehavior if "DROP INDEX CONCURRENTLY" is canceled: the
       previous coding could leave an un-droppable index behind.
     * Correct predicate locking for "DROP INDEX CONCURRENTLY" (Kevin
       Grittner)
       Previously, SSI predicate locks were processed at the wrong time,
       possibly leading to incorrect behavior of serializable transactions
       executing in parallel with the "DROP".
     * Fix buffer locking during WAL replay (Tom Lane)
       The WAL replay code was insufficiently careful about locking
       buffers when replaying WAL records that affect more than one page.
       This could result in hot standby queries transiently seeing
       inconsistent states, resulting in wrong answers or unexpected
       failures.
     * Fix an error in WAL generation logic for GIN indexes (Tom Lane)
       This could result in index corruption, if a torn-page failure
       occurred.
     * Fix an error in WAL replay logic for SP-GiST indexes (Tom Lane)
       This could result in index corruption after a crash, or on a
       standby server.
     * Fix incorrect detection of end-of-base-backup location during WAL
       recovery (Heikki Linnakangas)
       This mistake allowed hot standby mode to start up before the
       database reaches a consistent state.
     * Properly remove startup process's virtual XID lock when promoting a
       hot standby server to normal running (Simon Riggs)
       This oversight could prevent subsequent execution of certain
       operations such as "CREATE INDEX CONCURRENTLY".
     * Avoid bogus "out-of-sequence timeline ID" errors in standby mode
       (Heikki Linnakangas)
     * Prevent the postmaster from launching new child processes after
       it's received a shutdown signal (Tom Lane)
       This mistake could result in shutdown taking longer than it should,
       or even never completing at all without additional user action.
     * Fix the syslogger process to not fail when log_rotation_age exceeds
       2^31 milliseconds (about 25 days) (Tom Lane)
     * Fix WaitLatch() to return promptly when the requested timeout
       expires (Jeff Janes, Tom Lane)
       With the previous coding, a steady stream of non-wait-terminating
       interrupts could delay return from WaitLatch() indefinitely. This
       has been shown to be a problem for the autovacuum launcher process,
       and might cause trouble elsewhere as well.
     * Avoid corruption of internal hash tables when out of memory
       (Hitoshi Harada)
     * Prevent file descriptors for dropped tables from being held open
       past transaction end (Tom Lane)
       This should reduce problems with long-since-dropped tables
       continuing to occupy disk space.
     * Prevent database-wide crash and restart when a new child process is
       unable to create a pipe for its latch (Tom Lane)
       Although the new process must fail, there is no good reason to
       force a database-wide restart, so avoid that. This improves
       robustness when the kernel is nearly out of file descriptors.
     * Avoid planner crash with joins to unflattened subqueries (Tom Lane)
     * Fix planning of non-strict equivalence clauses above outer joins
       (Tom Lane)
       The planner could derive incorrect constraints from a clause
       equating a non-strict construct to something else, for example
       WHERE COALESCE(foo, 0) = 0 when foo is coming from the nullable
       side of an outer join. 9.2 showed this type of error in more cases
       than previous releases, but the basic bug has been there for a long
       time.
     * Fix "SELECT DISTINCT" with index-optimized MIN/MAX on an
       inheritance tree (Tom Lane)
       The planner would fail with "failed to re-find MinMaxAggInfo
       record" given this combination of factors.
     * Make sure the planner sees implicit and explicit casts as
       equivalent for all purposes, except in the minority of cases where
       there's actually a semantic difference (Tom Lane)
     * Include join clauses when considering whether partial indexes can
       be used for a query (Tom Lane)
       A strict join clause can be sufficient to establish an "x" IS NOT
       NULL predicate, for example. This fixes a planner regression in
       9.2, since previous versions could make comparable deductions.
     * Limit growth of planning time when there are many indexable join
       clauses for the same index (Tom Lane)
     * Improve planner's ability to prove exclusion constraints from
       equivalence classes (Tom Lane)
     * Fix partial-row matching in hashed subplans to handle cross-type
       cases correctly (Tom Lane)
       This affects multicolumn NOT IN subplans, such as WHERE (a, b) NOT
       IN (SELECT x, y FROM ...) when for instance b and y are int4 and
       int8 respectively. This mistake led to wrong answers or crashes
       depending on the specific datatypes involved.
     * Fix btree mark/restore functions to handle array keys (Tom Lane)
       This oversight could result in wrong answers from merge joins whose
       inner side is an index scan using an indexed_column = ANY(array)
       condition.
     * Revert patch for taking fewer snapshots (Tom Lane)
       The 9.2 change to reduce the number of snapshots taken during query
       execution led to some anomalous behaviors not seen in previous
       releases, because execution would proceed with a snapshot acquired
       before locking the tables used by the query. Thus, for example, a
       query would not be guaranteed to see updates committed by a
       preceding transaction even if that transaction had exclusive lock.
       We'll probably revisit this in future releases, but meanwhile put
       it back the way it was before 9.2.
     * Acquire buffer lock when re-fetching the old tuple for an AFTER ROW
       UPDATE/DELETE trigger (Andres Freund)
       In very unusual circumstances, this oversight could result in
       passing incorrect data to a trigger WHEN condition, or to the
       precheck logic for a foreign-key enforcement trigger. That could
       result in a crash, or in an incorrect decision about whether to
       fire the trigger.
     * Fix "ALTER COLUMN TYPE" to handle inherited check constraints
       properly (Pavan Deolasee)
       This worked correctly in pre-8.4 releases, and now works correctly
       in 8.4 and later.
     * Fix "ALTER EXTENSION SET SCHEMA"'s failure to move some subsidiary
       objects into the new schema (Alvaro Herrera, Dimitri Fontaine)
     * Handle "CREATE TABLE AS EXECUTE" correctly in extended query
       protocol (Tom Lane)
     * Don't modify the input parse tree in "DROP RULE IF NOT EXISTS" and
       "DROP TRIGGER IF NOT EXISTS" (Tom Lane)
       This mistake would cause errors if a cached statement of one of
       these types was re-executed.
     * Fix "REASSIGN OWNED" to handle grants on tablespaces (Alvaro
       Herrera)
     * Ignore incorrect pg_attribute entries for system columns for views
       (Tom Lane)
       Views do not have any system columns. However, we forgot to remove
       such entries when converting a table to a view. That's fixed
       properly for 9.3 and later, but in previous branches we need to
       defend against existing mis-converted views.
     * Fix rule printing to dump INSERT INTO table DEFAULT VALUES
       correctly (Tom Lane)
     * Guard against stack overflow when there are too many
       UNION/INTERSECT/EXCEPT clauses in a query (Tom Lane)
     * Prevent platform-dependent failures when dividing the minimum
       possible integer value by -1 (Xi Wang, Tom Lane)
     * Fix possible access past end of string in date parsing (Hitoshi
       Harada)
     * Fix failure to advance XID epoch if XID wraparound happens during a
       checkpoint and wal_level is hot_standby (Tom Lane, Andres Freund)
       While this mistake had no particular impact on PostgreSQL itself,
       it was bad for applications that rely on txid_current() and related
       functions: the TXID value would appear to go backwards.
     * Fix pg_terminate_backend() and pg_cancel_backend() to not throw
       error for a non-existent target process (Josh Kupershmidt)
       This case already worked as intended when called by a superuser,
       but not so much when called by ordinary users.
     * Fix display of pg_stat_replication.sync_state at a page boundary
       (Kyotaro Horiguchi)
     * Produce an understandable error message if the length of the path
       name for a Unix-domain socket exceeds the platform-specific limit
       (Tom Lane, Andrew Dunstan)
       Formerly, this would result in something quite unhelpful, such as
       "Non-recoverable failure in name resolution".
     * Fix memory leaks when sending composite column values to the client
       (Tom Lane)
     * Save some cycles by not searching for subtransaction locks at
       commit (Simon Riggs)
       In a transaction holding many exclusive locks, this useless
       activity could be quite costly.
     * Make pg_ctl more robust about reading the "postmaster.pid" file
       (Heikki Linnakangas)
       This fixes race conditions and possible file descriptor leakage.
     * Fix possible crash in psql if incorrectly-encoded data is presented
       and the client_encoding setting is a client-only encoding, such as
       SJIS (Jiang Guiqing)
     * Make pg_dump dump SEQUENCE SET items in the data not pre-data
       section of the archive (Tom Lane)
       This fixes an undesirable inconsistency between the meanings of
       "--data-only" and "--section=data", and also fixes dumping of
       sequences that are marked as extension configuration tables.
     * Fix pg_dump's handling of "DROP DATABASE" commands in "--clean"
       mode (Guillaume Lelarge)
       Beginning in 9.2.0, pg_dump --clean would issue a "DROP DATABASE"
       command, which was either useless or dangerous depending on the
       usage scenario. It no longer does that. This change also fixes the
       combination of "--clean" and "--create" to work sensibly, i.e.,
       emit "DROP DATABASE" then "CREATE DATABASE" before reconnecting to
       the target database.
     * Fix pg_dump for views with circular dependencies and no relation
       options (Tom Lane)
       The previous fix to dump relation options when a view is involved
       in a circular dependency didn't work right for the case that the
       view has no options; it emitted ALTER VIEW foo SET () which is
       invalid syntax.
     * Fix bugs in the "restore.sql" script emitted by pg_dump in tar
       output format (Tom Lane)
       The script would fail outright on tables whose names include
       upper-case characters. Also, make the script capable of restoring
       data in "--inserts" mode as well as the regular COPY mode.
     * Fix pg_restore to accept POSIX-conformant tar files (Brian Weaver,
       Tom Lane)
       The original coding of pg_dump's tar output mode produced files
       that are not fully conformant with the POSIX standard. This has
       been corrected for version 9.3. This patch updates previous
       branches so that they will accept both the incorrect and the
       corrected formats, in hopes of avoiding compatibility problems when
       9.3 comes out.
     * Fix tar files emitted by pg_basebackup to be POSIX conformant
       (Brian Weaver, Tom Lane)
     * Fix pg_resetxlog to locate "postmaster.pid" correctly when given a
       relative path to the data directory (Tom Lane)
       This mistake could lead to pg_resetxlog not noticing that there is
       an active postmaster using the data directory.
     * Fix libpq's lo_import() and lo_export() functions to report file
       I/O errors properly (Tom Lane)
     * Fix ecpg's processing of nested structure pointer variables
       (Muhammad Usama)
     * Fix ecpg's ecpg_get_data function to handle arrays properly
       (Michael Meskes)
     * Prevent pg_upgrade from trying to process TOAST tables for system
       catalogs (Bruce Momjian)
       This fixes an error seen when the information_schema has been
       dropped and recreated. Other failures were also possible.
     * Improve pg_upgrade performance by setting synchronous_commit to off
       in the new cluster (Bruce Momjian)
     * Make "contrib/pageinspect"'s btree page inspection functions take
       buffer locks while examining pages (Tom Lane)
     * Work around unportable behavior of malloc(0) and realloc(NULL, 0)
       (Tom Lane)
       On platforms where these calls return NULL, some code mistakenly
       thought that meant out-of-memory. This is known to have broken
       pg_dump for databases containing no user-defined aggregates. There
       might be other cases as well.
     * Ensure that make install for an extension creates the "extension"
       installation directory (Cedric Villemain)
       Previously, this step was missed if MODULEDIR was set in the
       extension's Makefile.
     * Fix pgxs support for building loadable modules on AIX (Tom Lane)
       Building modules outside the original source tree didn't work on
       AIX.
     * Update time zone data files to tzdata release 2012j for DST law
       changes in Cuba, Israel, Jordan, Libya, Palestine, Western Samoa,
       and portions of Brazil.
     __________________________________________________________________

                                Release 9.2.1

     Release Date: 2012-09-24

   This release contains a variety of fixes from 9.2.0. For information
   about new features in the 9.2 major release, see the Section called
   Release 9.2.
     __________________________________________________________________

Migration to Version 9.2.1

   A dump/restore is not required for those running 9.2.X.

   However, you may need to perform "REINDEX" and/or "VACUUM" operations
   to recover from the effects of the data corruption bug described in the
   first changelog item below.
     __________________________________________________________________

Changes

     * Fix persistence marking of shared buffers during WAL replay (Jeff
       Davis)
       This mistake can result in buffers not being written out during
       checkpoints, resulting in data corruption if the server later
       crashes without ever having written those buffers. Corruption can
       occur on any server following crash recovery, but it is
       significantly more likely to occur on standby slave servers since
       those perform much more WAL replay. There is a low probability of
       corruption of btree and GIN indexes. There is a much higher
       probability of corruption of table "visibility maps", which might
       lead to wrong answers from index-only scans. Table data proper
       cannot be corrupted by this bug.
       While no index corruption due to this bug is known to have occurred
       in the field, as a precautionary measure it is recommended that
       production installations "REINDEX" all btree and GIN indexes at a
       convenient time after upgrading to 9.2.1.
       Also, it is recommended to perform a "VACUUM" of all tables while
       having vacuum_freeze_table_age set to zero. This will fix any
       incorrect visibility map data. vacuum_cost_delay can be adjusted to
       reduce the performance impact of vacuuming, while causing it to
       take longer to finish.
     * Fix possible incorrect sorting of output from queries involving
       WHERE indexed_column IN (list_of_values) (Tom Lane)
     * Fix planner failure for queries involving GROUP BY expressions
       along with window functions and aggregates (Tom Lane)
     * Fix planner's assignment of executor parameters (Tom Lane)
       This error could result in wrong answers from queries that scan the
       same WITH subquery multiple times.
     * Improve planner's handling of join conditions in index scans (Tom
       Lane)
     * Improve selectivity estimation for text search queries involving
       prefixes, i.e. "word":* patterns (Tom Lane)
     * Fix delayed recognition of permissions changes (Tom Lane)
       A command that needed no locks other than ones its transaction
       already had might fail to notice a concurrent "GRANT" or "REVOKE"
       that committed since the start of its transaction.
     * Fix "ANALYZE" to not fail when a column is a domain over an array
       type (Tom Lane)
     * Prevent PL/Perl from crashing if a recursive PL/Perl function is
       redefined while being executed (Tom Lane)
     * Work around possible misoptimization in PL/Perl (Tom Lane)
       Some Linux distributions contain an incorrect version of
       "pthread.h" that results in incorrect compiled code in PL/Perl,
       leading to crashes if a PL/Perl function calls another one that
       throws an error.
     * Remove unnecessary dependency on pg_config from pg_upgrade (Peter
       Eisentraut)
     * Update time zone data files to tzdata release 2012f for DST law
       changes in Fiji
     __________________________________________________________________

                                 Release 9.2

     Release Date: 2012-09-10
     __________________________________________________________________

Overview

   This release has been largely focused on performance improvements,
   though new SQL features are not lacking. Work also continues in the
   area of replication support. Major enhancements include:

     * Allow queries to retrieve data only from indexes, avoiding heap
       access (index-only scans)
     * Allow the planner to generate custom plans for specific parameter
       values even when using prepared statements
     * Improve the planner's ability to use nested loops with inner index
       scans
     * Allow streaming replication slaves to forward data to other slaves
       (cascading replication)
     * Allow pg_basebackup to make base backups from standby servers
     * Add a pg_receivexlog tool to archive WAL file changes as they are
       written
     * Add the SP-GiST (Space-Partitioned GiST) index access method
     * Add support for range data types
     * Add a JSON data type
     * Add a security_barrier option for views
     * Allow libpq connection strings to have the format of a URI
     * Add a single-row processing mode to libpq for better handling of
       large result sets

   The above items are explained in more detail in the sections below.
     __________________________________________________________________

Migration to Version 9.2

   A dump/restore using pg_dump, or use of pg_upgrade, is required for
   those wishing to migrate data from any previous release.

   Version 9.2 contains a number of changes that may affect compatibility
   with previous releases. Observe the following incompatibilities:
     __________________________________________________________________

System Catalogs

     * Remove the spclocation field from pg_tablespace (Magnus Hagander)
       This field was duplicative of the symbolic links that actually
       define tablespace locations, and thus risked errors of omission
       when moving a tablespace. This change allows tablespace directories
       to be moved while the server is down, by manually adjusting the
       symbolic links. To replace this field, we have added
       pg_tablespace_location() to allow querying of the symbolic links.
     * Move tsvector most-common-element statistics to new pg_stats
       columns (Alexander Korotkov)
       Consult most_common_elems and most_common_elem_freqs for the data
       formerly available in most_common_vals and most_common_freqs for a
       tsvector column.
     __________________________________________________________________

Functions

     * Remove hstore's => operator (Robert Haas)
       Users should now use hstore(text, text). Since PostgreSQL 9.0, a
       warning message has been emitted when an operator named => is
       created because the SQL standard reserves that token for another
       use.
     * Ensure that xpath() escapes special characters in string values
       (Florian Pflug)
       Without this it is possible for the result not to be valid XML.
     * Make pg_relation_size() and friends return NULL if the object does
       not exist (Phil Sorber)
       This prevents queries that call these functions from returning
       errors immediately after a concurrent "DROP".
     * Make EXTRACT(EPOCH FROM timestamp without time zone) measure the
       epoch from local midnight, not UTC midnight (Tom Lane)
       This change reverts an ill-considered change made in release 7.3.
       Measuring from UTC midnight was inconsistent because it made the
       result dependent on the timezone setting, which computations for
       timestamp without time zone should not be. The previous behavior
       remains available by casting the input value to timestamp with time
       zone.
     * Properly parse time strings with trailing yesterday, today, and
       tomorrow (Dean Rasheed)
       Previously, SELECT '04:00:00 yesterday'::timestamp returned
       yesterday's date at midnight.
     * Fix to_date() and to_timestamp() to wrap incomplete dates toward
       2020 (Bruce Momjian)
       Previously, supplied years and year masks of less than four digits
       wrapped inconsistently.
     __________________________________________________________________

Object Modification

     * Prevent "ALTER DOMAIN" from working on non-domain types (Peter
       Eisentraut)
       Owner and schema changes were previously possible on non-domain
       types.
     * No longer forcibly lowercase procedural language names in "CREATE
       FUNCTION" (Robert Haas)
       While unquoted language identifiers are still lowercased, strings
       and quoted identifiers are no longer forcibly down-cased. Thus for
       example CREATE FUNCTION ... LANGUAGE 'C' will no longer work; it
       must be spelled 'c', or better omit the quotes.
     * Change system-generated names of foreign key enforcement triggers
       (Tom Lane)
       This change ensures that the triggers fire in the correct order in
       some corner cases involving self-referential foreign key
       constraints.
     __________________________________________________________________

Command-Line Tools

     * Provide consistent backquote, variable expansion, and quoted
       substring behavior in psql meta-command arguments (Tom Lane)
       Previously, such references were treated oddly when not separated
       by whitespace from adjacent text. For example 'FOO'BAR was output
       as FOO BAR (unexpected insertion of a space) and FOO'BAR'BAZ was
       output unchanged (not removing the quotes as most would expect).
     * No longer treat clusterdb table names as double-quoted; no longer
       treat reindexdb table and index names as double-quoted (Bruce
       Momjian)
       Users must now include double-quotes in the command arguments if
       quoting is wanted.
     * createuser no longer prompts for option settings by default (Peter
       Eisentraut)
       Use "--interactive" to obtain the old behavior.
     * Disable prompting for the user name in dropuser unless
       "--interactive" is specified (Peter Eisentraut)
     __________________________________________________________________

Server Settings

     * Add server parameters for specifying the locations of server-side
       SSL files (Peter Eisentraut)
       This allows changing the names and locations of the files that were
       previously hard-coded as "server.crt", "server.key", "root.crt",
       and "root.crl" in the data directory. *The server will no longer
       examine root.crt or root.crl by default*; to load these files, the
       associated parameters must be set to non-default values.
     * Remove the silent_mode parameter (Heikki Linnakangas)
       Similar behavior can be obtained with "pg_ctl start -l
       postmaster.log".
     * Remove the wal_sender_delay parameter, as it is no longer needed
       (Tom Lane)
     * Remove the custom_variable_classes parameter (Tom Lane)
       The checking provided by this setting was dubious. Now any setting
       can be prefixed by any class name.
     __________________________________________________________________

Monitoring

     * Rename pg_stat_activity.procpid to pid, to match other system
       tables (Magnus Hagander)
     * Create a separate pg_stat_activity column to report process state
       (Scott Mead, Magnus Hagander)
       The previous query and query_start values now remain available for
       an idle session, allowing enhanced analysis.
     * Rename pg_stat_activity.current_query to query because it is not
       cleared when the query completes (Magnus Hagander)
     * Change all SQL-level statistics timing values to be float8 columns
       measured in milliseconds (Tom Lane)
       This change eliminates the designed-in assumption that the values
       are accurate to microseconds and no more (since the float8 values
       can be fractional). The columns affected are
       pg_stat_user_functions.total_time,
       pg_stat_user_functions.self_time,
       pg_stat_xact_user_functions.total_time, and
       pg_stat_xact_user_functions.self_time. The statistics functions
       underlying these columns now also return float8 milliseconds,
       rather than bigint microseconds. "contrib/pg_stat_statements"'
       total_time column is now also measured in milliseconds.
     __________________________________________________________________

Changes

   Below you will find a detailed account of the changes between
   PostgreSQL 9.2 and the previous major release.
     __________________________________________________________________

Server

Performance

     * Allow queries to retrieve data only from indexes, avoiding heap
       access (Robert Haas, Ibrar Ahmed, Heikki Linnakangas, Tom Lane)
       This feature is often called index-only scans. Heap access can be
       skipped for heap pages containing only tuples that are visible to
       all sessions, as reported by the visibility map; so the benefit
       applies mainly to mostly-static data. The visibility map was made
       crash-safe as a necessary part of implementing this feature.
     * Add the SP-GiST (Space-Partitioned GiST) index access method
       (Teodor Sigaev, Oleg Bartunov, Tom Lane)
       SP-GiST is comparable to GiST in flexibility, but supports
       unbalanced partitioned search structures rather than balanced
       trees. For suitable problems, SP-GiST can be faster than GiST in
       both index build time and search time.
     * Allow group commit to work effectively under heavy load (Peter
       Geoghegan, Simon Riggs, Heikki Linnakangas)
       Previously, batching of commits became ineffective as the write
       workload increased, because of internal lock contention.
     * Allow uncontended locks to be managed using a new fast-path lock
       mechanism (Robert Haas)
     * Reduce overhead of creating virtual transaction ID locks (Robert
       Haas)
     * Reduce the overhead of serializable isolation level locks (Dan
       Ports)
     * Improve PowerPC and Itanium spinlock performance (Manabu Ori,
       Robert Haas, Tom Lane)
     * Reduce overhead for shared invalidation cache messages (Robert
       Haas)
     * Move the frequently accessed members of the PGPROC shared memory
       array to a separate array (Pavan Deolasee, Heikki Linnakangas,
       Robert Haas)
     * Improve "COPY" performance by adding tuples to the heap in batches
       (Heikki Linnakangas)
     * Improve GiST index performance for geometric data types by
       producing better trees with less memory allocation overhead
       (Alexander Korotkov)
     * Improve GiST index build times (Alexander Korotkov, Heikki
       Linnakangas)
     * Allow hint bits to be set sooner for temporary and unlogged tables
       (Robert Haas)
     * Allow sorting to be performed by inlined, non-SQL-callable
       comparison functions (Peter Geoghegan, Robert Haas, Tom Lane)
     * Make the number of CLOG buffers scale based on shared_buffers
       (Robert Haas, Simon Riggs, Tom Lane)
     * Improve performance of buffer pool scans that occur when tables or
       databases are dropped (Jeff Janes, Simon Riggs)
     * Improve performance of checkpointer's fsync-request queue when many
       tables are being dropped or truncated (Tom Lane)
     * Pass the safe number of file descriptors to child processes on
       Windows (Heikki Linnakangas)
       This allows Windows sessions to use more open file descriptors than
       before.
     __________________________________________________________________

Process Management

     * Create a dedicated background process to perform checkpoints (Simon
       Riggs)
       Formerly the background writer did both dirty-page writing and
       checkpointing. Separating this into two processes allows each goal
       to be accomplished more predictably.
     * Improve asynchronous commit behavior by waking the walwriter sooner
       (Simon Riggs)
       Previously, only wal_writer_delay triggered WAL flushing to disk;
       now filling a WAL buffer also triggers WAL writes.
     * Allow the bgwriter, walwriter, checkpointer, statistics collector,
       log collector, and archiver background processes to sleep more
       efficiently during periods of inactivity (Peter Geoghegan, Tom
       Lane)
       This series of changes reduces the frequency of process wake-ups
       when there is nothing to do, dramatically reducing power
       consumption on idle servers.
     __________________________________________________________________

Optimizer

     * Allow the planner to generate custom plans for specific parameter
       values even when using prepared statements (Tom Lane)
       In the past, a prepared statement always had a single "generic"
       plan that was used for all parameter values, which was frequently
       much inferior to the plans used for non-prepared statements
       containing explicit constant values. Now, the planner attempts to
       generate custom plans for specific parameter values. A generic plan
       will only be used after custom plans have repeatedly proven to
       provide no benefit. This change should eliminate the performance
       penalties formerly seen from use of prepared statements (including
       non-dynamic statements in PL/pgSQL).
     * Improve the planner's ability to use nested loops with inner index
       scans (Tom Lane)
       The new "parameterized path" mechanism allows inner index scans to
       use values from relations that are more than one join level up from
       the scan. This can greatly improve performance in situations where
       semantic restrictions (such as outer joins) limit the allowed join
       orderings.
     * Improve the planning API for foreign data wrappers (Etsuro Fujita,
       Shigeru Hanada, Tom Lane)
       Wrappers can now provide multiple access "paths" for their tables,
       allowing more flexibility in join planning.
     * Recognize self-contradictory restriction clauses for non-table
       relations (Tom Lane)
       This check is only performed when constraint_exclusion is on.
     * Allow indexed_col op ANY(ARRAY[...]) conditions to be used in plain
       index scans and index-only scans (Tom Lane)
       Formerly such conditions could only be used in bitmap index scans.
     * Support MIN/MAX index optimizations on boolean columns (Marti
       Raudsepp)
     * Account for set-returning functions in "SELECT" target lists when
       setting row count estimates (Tom Lane)
     * Fix planner to handle indexes with duplicated columns more reliably
       (Tom Lane)
     * Collect and use element-frequency statistics for arrays (Alexander
       Korotkov, Tom Lane)
       This change improves selectivity estimation for the array <@, &&,
       and @> operators (array containment and overlaps).
     * Allow statistics to be collected for foreign tables (Etsuro Fujita)
     * Improve cost estimates for use of partial indexes (Tom Lane)
     * Improve the planner's ability to use statistics for columns
       referenced in subqueries (Tom Lane)
     * Improve statistical estimates for subqueries using DISTINCT (Tom
       Lane)
     __________________________________________________________________

Authentication

     * Do not treat role names and samerole specified in "pg_hba.conf" as
       automatically including superusers (Andrew Dunstan)
       This makes it easier to use reject lines with group roles.
     * Adjust "pg_hba.conf" processing to handle token parsing more
       consistently (Brendan Jurd, Alvaro Herrera)
     * Disallow empty "pg_hba.conf" files (Tom Lane)
       This was done to more quickly detect misconfiguration.
     * Make superuser privilege imply replication privilege (Noah Misch)
       This avoids the need to explicitly assign such privileges.
     __________________________________________________________________

Monitoring

     * Attempt to log the current query string during a backend crash
       (Marti Raudsepp)
     * Make logging of autovacuum I/O activity more verbose (Greg Smith,
       Noah Misch)
       This logging is triggered by log_autovacuum_min_duration.
     * Make WAL replay report failures sooner (Fujii Masao)
       There were some cases where failures were only reported once the
       server went into master mode.
     * Add pg_xlog_location_diff() to simplify WAL location comparisons
       (Euler Taveira de Oliveira)
       This is useful for computing replication lag.
     * Support configurable event log application names on Windows
       (MauMau, Magnus Hagander)
       This allows different instances to use the event log with different
       identifiers, by setting the event_source server parameter, which is
       similar to how syslog_ident works.
     * Change "unexpected EOF" messages to DEBUG1 level, except when there
       is an open transaction (Magnus Hagander)
       This change reduces log chatter caused by applications that close
       database connections ungracefully.
     __________________________________________________________________

Statistical Views

     * Track temporary file sizes and file counts in the pg_stat_database
       system view (Tomas Vondra)
     * Add a deadlock counter to the pg_stat_database system view (Magnus
       Hagander)
     * Add a server parameter track_io_timing to track I/O timings (Ants
       Aasma, Robert Haas)
     * Report checkpoint timing information in pg_stat_bgwriter (Greg
       Smith, Peter Geoghegan)
     __________________________________________________________________

Server Settings

     * Silently ignore nonexistent schemas specified in search_path (Tom
       Lane)
       This makes it more convenient to use generic path settings, which
       might include some schemas that don't exist in all databases.
     * Allow superusers to set deadlock_timeout per-session, not just
       per-cluster (Noah Misch)
       This allows deadlock_timeout to be reduced for transactions that
       are likely to be involved in a deadlock, thus detecting the failure
       more quickly. Alternatively, increasing the value can be used to
       reduce the chances of a session being chosen for cancellation due
       to a deadlock.
     * Add a server parameter temp_file_limit to constrain temporary file
       space usage per session (Mark Kirkwood)
     * Allow a superuser to "SET" an extension's superuser-only custom
       variable before loading the associated extension (Tom Lane)
       The system now remembers whether a "SET" was performed by a
       superuser, so that proper privilege checking can be done when the
       extension is loaded.
     * Add postmaster "-C" option to query configuration parameters (Bruce
       Momjian)
       This allows pg_ctl to better handle cases where PGDATA or "-D"
       points to a configuration-only directory.
     * Replace an empty locale name with the implied value in "CREATE
       DATABASE" (Tom Lane)
       This prevents cases where pg_database.datcollate or datctype could
       be interpreted differently after a server restart.
     __________________________________________________________________

postgresql.conf

     * Allow multiple errors in "postgresql.conf" to be reported, rather
       than just the first one (Alexey Klyukin, Tom Lane)
     * Allow a reload of "postgresql.conf" to be processed by all
       sessions, even if there are some settings that are invalid for
       particular sessions (Alexey Klyukin)
       Previously, such not-valid-within-session values would cause all
       setting changes to be ignored by that session.
     * Add an include_if_exists facility for configuration files (Greg
       Smith)
       This works the same as include, except that an error is not thrown
       if the file is missing.
     * Identify the server time zone during initdb, and set
       "postgresql.conf" entries timezone and log_timezone accordingly
       (Tom Lane)
       This avoids expensive time zone probes during server start.
     * Fix pg_settings to report "postgresql.conf" line numbers on Windows
       (Tom Lane)
     __________________________________________________________________

Replication and Recovery

     * Allow streaming replication slaves to forward data to other slaves
       (cascading replication) (Fujii Masao)
       Previously, only the master server could supply streaming
       replication log files to standby servers.
     * Add new synchronous_commit mode remote_write (Fujii Masao, Simon
       Riggs)
       This mode waits for the standby server to write transaction data to
       its own operating system, but does not wait for the data to be
       flushed to the standby's disk.
     * Add a pg_receivexlog tool to archive WAL file changes as they are
       written, rather than waiting for completed WAL files (Magnus
       Hagander)
     * Allow pg_basebackup to make base backups from standby servers (Jun
       Ishizuka, Fujii Masao)
       This feature lets the work of making new base backups be off-loaded
       from the primary server.
     * Allow streaming of WAL files while pg_basebackup is performing a
       backup (Magnus Hagander)
       This allows passing of WAL files to the standby before they are
       discarded on the primary.
     __________________________________________________________________

Queries

     * Cancel the running query if the client gets disconnected (Florian
       Pflug)
       If the backend detects loss of client connection during a query, it
       will now cancel the query rather than attempting to finish it.
     * Retain column names at run time for row expressions (Andrew
       Dunstan, Tom Lane)
       This change allows better results when a row value is converted to
       hstore or json type: the fields of the resulting value will now
       have the expected names.
     * Improve column labels used for sub-"SELECT" results (Marti
       Raudsepp)
       Previously, the generic label ?column? was used.
     * Improve heuristics for determining the types of unknown values (Tom
       Lane)
       The longstanding rule that an unknown constant might have the same
       type as the value on the other side of the operator using it is now
       applied when considering polymorphic operators, not only for simple
       operator matches.
     * Warn about creating casts to or from domain types (Robert Haas)
       Such casts have no effect.
     * When a row fails a CHECK or NOT NULL constraint, show the row's
       contents as error detail (Jan Kundrat)
       This should make it easier to identify which row is problematic
       when an insert or update is processing many rows.
     __________________________________________________________________

Object Manipulation

     * Provide more reliable operation during concurrent DDL (Robert Haas,
       Noah Misch)
       This change adds locking that should eliminate "cache lookup
       failed" errors in many scenarios. Also, it is no longer possible to
       add relations to a schema that is being concurrently dropped, a
       scenario that formerly led to inconsistent system catalog contents.
     * Add CONCURRENTLY option to "DROP INDEX" (Simon Riggs)
       This allows index removal without blocking other sessions.
     * Allow foreign data wrappers to have per-column options (Shigeru
       Hanada)
     * Improve pretty-printing of view definitions (Andrew Dunstan)
     __________________________________________________________________

Constraints

     * Allow CHECK constraints to be declared NOT VALID (Alvaro Herrera)
       Adding a NOT VALID constraint does not cause the table to be
       scanned to verify that existing rows meet the constraint.
       Subsequently, newly added or updated rows are checked. Such
       constraints are ignored by the planner when considering
       constraint_exclusion, since it is not certain that all rows meet
       the constraint.
       The new "ALTER TABLE VALIDATE" command allows NOT VALID constraints
       to be checked for existing rows, after which they are converted
       into ordinary constraints.
     * Allow CHECK constraints to be declared NO INHERIT (Nikhil Sontakke,
       Alex Hunsaker, Alvaro Herrera)
       This makes them enforceable only on the parent table, not on child
       tables.
     * Add the ability to rename constraints (Peter Eisentraut)
     __________________________________________________________________

ALTER

     * Reduce need to rebuild tables and indexes for certain "ALTER TABLE"
       ... ALTER COLUMN TYPE operations (Noah Misch)
       Increasing the length limit for a varchar or varbit column, or
       removing the limit altogether, no longer requires a table rewrite.
       Similarly, increasing the allowable precision of a numeric column,
       or changing a column from constrained numeric to unconstrained
       numeric, no longer requires a table rewrite. Table rewrites are
       also avoided in similar cases involving the interval, timestamp,
       and timestamptz types.
     * Avoid having "ALTER TABLE" revalidate foreign key constraints in
       some cases where it is not necessary (Noah Misch)
     * Add IF EXISTS options to some "ALTER" commands (Pavel Stehule)
       For example, "ALTER FOREIGN TABLE IF EXISTS foo RENAME TO bar".
     * Add "ALTER FOREIGN DATA WRAPPER" ... RENAME and "ALTER SERVER" ...
       RENAME (Peter Eisentraut)
     * Add "ALTER DOMAIN" ... RENAME (Peter Eisentraut)
       You could already rename domains using "ALTER TYPE".
     * Throw an error for "ALTER DOMAIN" ... DROP CONSTRAINT on a
       nonexistent constraint (Peter Eisentraut)
       An IF EXISTS option has been added to provide the previous
       behavior.
     __________________________________________________________________

CREATE TABLE

     * Allow "CREATE TABLE (LIKE ...)" from foreign tables, views, and
       composite types (Peter Eisentraut)
       For example, this allows a table to be created whose schema matches
       a view.
     * Fix "CREATE TABLE (LIKE ...)" to avoid index name conflicts when
       copying index comments (Tom Lane)
     * Fix "CREATE TABLE" ... AS EXECUTE to handle WITH NO DATA and column
       name specifications (Tom Lane)
     __________________________________________________________________

Object Permissions

     * Add a security_barrier option for views (KaiGai Kohei, Robert Haas)
       This option prevents optimizations that might allow view-protected
       data to be exposed to users, for example pushing a clause involving
       an insecure function into the WHERE clause of the view. Such views
       can be expected to perform more poorly than ordinary views.
     * Add a new LEAKPROOF function attribute to mark functions that can
       safely be pushed down into security_barrier views (KaiGai Kohei)
     * Add support for privileges on data types (Peter Eisentraut)
       This adds support for the SQL-conforming USAGE privilege on types
       and domains. The intent is to be able to restrict which users can
       create dependencies on types, since such dependencies limit the
       owner's ability to alter the type.
     * Check for "INSERT" privileges in "SELECT INTO" / "CREATE TABLE AS"
       (KaiGai Kohei)
       Because the object is being created by "SELECT INTO" or "CREATE
       TABLE AS", the creator would ordinarily have insert permissions;
       but there are corner cases where this is not true, such as when
       ALTER DEFAULT PRIVILEGES has removed such permissions.
     __________________________________________________________________

Utility Operations

     * Allow "VACUUM" to more easily skip pages that cannot be locked
       (Simon Riggs, Robert Haas)
       This change should greatly reduce the incidence of "VACUUM" getting
       "stuck" waiting for other sessions.
     * Make "EXPLAIN" (BUFFERS) count blocks dirtied and written (Robert
       Haas)
     * Make "EXPLAIN ANALYZE" report the number of rows rejected by filter
       steps (Marko Tiikkaja)
     * Allow "EXPLAIN ANALYZE" to avoid timing overhead when time values
       are not wanted (Tomas Vondra)
       This is accomplished by setting the new TIMING option to FALSE.
     __________________________________________________________________

Data Types

     * Add support for range data types (Jeff Davis, Tom Lane, Alexander
       Korotkov)
       A range data type stores a lower and upper bound belonging to its
       base data type. It supports operations like contains, overlaps, and
       intersection.
     * Add a JSON data type (Robert Haas)
       This type stores JSON (JavaScript Object Notation) data with proper
       validation.
     * Add array_to_json() and row_to_json() (Andrew Dunstan)
     * Add a SMALLSERIAL data type (Mike Pultz)
       This is like SERIAL, except it stores the sequence in a two-byte
       integer column (int2).
     * Allow domains to be declared NOT VALID (Alvaro Herrera)
       This option can be set at domain creation time, or via "ALTER
       DOMAIN" ... ADD CONSTRAINT ... NOT VALID. "ALTER DOMAIN" ...
       VALIDATE CONSTRAINT fully validates the constraint.
     * Support more locale-specific formatting options for the money data
       type (Tom Lane)
       Specifically, honor all the POSIX options for ordering of the
       value, sign, and currency symbol in monetary output. Also, make
       sure that the thousands separator is only inserted to the left of
       the decimal point, as required by POSIX.
     * Add bitwise "and", "or", and "not" operators for the macaddr data
       type (Brendan Jurd)
     * Allow xpath() to return a single-element XML array when supplied a
       scalar value (Florian Pflug)
       Previously, it returned an empty array. This change will also cause
       xpath_exists() to return true, not false, for such expressions.
     * Improve XML error handling to be more robust (Florian Pflug)
     __________________________________________________________________

Functions

     * Allow non-superusers to use pg_cancel_backend() and
       pg_terminate_backend() on other sessions belonging to the same user
       (Magnus Hagander, Josh Kupershmidt, Dan Farina)
       Previously only superusers were allowed to use these functions.
     * Allow importing and exporting of transaction snapshots (Joachim
       Wieland, Tom Lane)
       This allows multiple transactions to share identical views of the
       database state. Snapshots are exported via pg_export_snapshot() and
       imported via "SET TRANSACTION SNAPSHOT". Only snapshots from
       currently-running transactions can be imported.
     * Support COLLATION FOR on expressions (Peter Eisentraut)
       This returns a string representing the collation of the expression.
     * Add pg_opfamily_is_visible() (Josh Kupershmidt)
     * Add a numeric variant of pg_size_pretty() for use with
       pg_xlog_location_diff() (Fujii Masao)
     * Add a pg_trigger_depth() function (Kevin Grittner)
       This reports the current trigger call depth.
     * Allow string_agg() to process bytea values (Pavel Stehule)
     * Fix regular expressions in which a back-reference occurs within a
       larger quantified subexpression (Tom Lane)
       For example, ^(\w+)( \1)+$. Previous releases did not check that
       the back-reference actually matched the first occurrence.
     __________________________________________________________________

Information Schema

     * Add information schema views role_udt_grants, udt_privileges, and
       user_defined_types (Peter Eisentraut)
     * Add composite-type attributes to the information schema
       element_types view (Peter Eisentraut)
     * Implement interval_type columns in the information schema (Peter
       Eisentraut)
       Formerly these columns read as nulls.
     * Implement collation-related columns in the information schema
       attributes, columns, domains, and element_types views (Peter
       Eisentraut)
     * Implement the with_hierarchy column in the information schema
       table_privileges view (Peter Eisentraut)
     * Add display of sequence USAGE privileges to information schema
       (Peter Eisentraut)
     * Make the information schema show default privileges (Peter
       Eisentraut)
       Previously, non-empty default permissions were not represented in
       the views.
     __________________________________________________________________

Server-Side Languages

PL/pgSQL Server-Side Language

     * Allow the PL/pgSQL "OPEN" cursor command to supply parameters by
       name (Yeb Havinga)
     * Add a "GET STACKED DIAGNOSTICS" PL/pgSQL command to retrieve
       exception info (Pavel Stehule)
     * Speed up PL/pgSQL array assignment by caching type information
       (Pavel Stehule)
     * Improve performance and memory consumption for long chains of ELSIF
       clauses (Tom Lane)
     * Output the function signature, not just the name, in PL/pgSQL error
       messages (Pavel Stehule)
     __________________________________________________________________

PL/Python Server-Side Language

     * Add PL/Python SPI cursor support (Jan Urbanski)
       This allows PL/Python to read partial result sets.
     * Add result metadata functions to PL/Python (Peter Eisentraut)
       Specifically, this adds result object functions .colnames,
       .coltypes, and .coltypmods.
     * Remove support for Python 2.2 (Peter Eisentraut)
     __________________________________________________________________

SQL Server-Side Language

     * Allow SQL-language functions to reference parameters by name
       (Matthew Draper)
       To use this, simply name the function arguments and then reference
       the argument names in the SQL function body.
     __________________________________________________________________

Client Applications

     * Add initdb options "--auth-local" and "--auth-host" (Peter
       Eisentraut)
       This allows separate control of local and host "pg_hba.conf"
       authentication settings. "--auth" still controls both.
     * Add "--replication"/"--no-replication" flags to createuser to
       control replication permission (Fujii Masao)
     * Add the "--if-exists" option to dropdb and dropuser (Josh
       Kupershmidt)
     * Give command-line tools the ability to specify the name of the
       database to connect to, and fall back to template1 if a postgres
       database connection fails (Robert Haas)
     __________________________________________________________________

psql

     * Add a display mode to auto-expand output based on the display width
       (Peter Eisentraut)
       This adds the auto option to the "\x" command, which switches to
       the expanded mode when the normal output would be wider than the
       screen.
     * Allow inclusion of a script file that is named relative to the
       directory of the file from which it was invoked (Gurjeet Singh)
       This is done with a new command "\ir".
     * Add support for non-ASCII characters in psql variable names (Tom
       Lane)
     * Add support for major-version-specific ".psqlrc" files (Bruce
       Momjian)
       psql already supported minor-version-specific ".psqlrc" files.
     * Provide environment variable overrides for psql history and startup
       file locations (Andrew Dunstan)
       PSQL_HISTORY and PSQLRC now determine these file names if set.
     * Add a "\setenv" command to modify the environment variables passed
       to child processes (Andrew Dunstan)
     * Name psql's temporary editor files with a ".sql" extension (Peter
       Eisentraut)
       This allows extension-sensitive editors to select the right mode.
     * Allow psql to use zero-byte field and record separators (Peter
       Eisentraut)
       Various shell tools use zero-byte (NUL) separators, e.g. find.
     * Make the "\timing" option report times for failed queries (Magnus
       Hagander)
       Previously times were reported only for successful queries.
     * Unify and tighten psql's treatment of "\copy" and SQL "COPY" (Noah
       Misch)
       This fix makes failure behavior more predictable and honors "\set
       ON_ERROR_ROLLBACK".
     __________________________________________________________________

Informational Commands

     * Make "\d" on a sequence show the table/column name owning it
       (Magnus Hagander)
     * Show statistics target for columns in "\d+" (Magnus Hagander)
     * Show role password expiration dates in "\du" (Fabrizio de Royes
       Mello)
     * Display comments for casts, conversions, domains, and languages
       (Josh Kupershmidt)
       These are included in the output of "\dC+", "\dc+", "\dD+", and
       "\dL" respectively.
     * Display comments for SQL/MED objects (Josh Kupershmidt)
       These are included in the output of "\des+", "\det+", and "\dew+"
       for foreign servers, foreign tables, and foreign data wrappers
       respectively.
     * Change "\dd" to display comments only for object types without
       their own backslash command (Josh Kupershmidt)
     __________________________________________________________________

Tab Completion

     * In psql tab completion, complete SQL keywords in either upper or
       lower case according to the new COMP_KEYWORD_CASE setting (Peter
       Eisentraut)
     * Add tab completion support for "EXECUTE" (Andreas Karlsson)
     * Allow tab completion of role references in "GRANT"/"REVOKE" (Peter
       Eisentraut)
     * Allow tab completion of file names to supply quotes, when necessary
       (Noah Misch)
     * Change tab completion support for "TABLE" to also include views
       (Magnus Hagander)
     __________________________________________________________________

pg_dump

     * Add an "--exclude-table-data" option to pg_dump (Andrew Dunstan)
       This allows dumping of a table's definition but not its data, on a
       per-table basis.
     * Add a "--section" option to pg_dump and pg_restore (Andrew Dunstan)
       Valid values are pre-data, data, and post-data. The option can be
       given more than once to select two or more sections.
     * Make pg_dumpall dump all roles first, then all configuration
       settings on roles (Phil Sorber)
       This allows a role's configuration settings to mention other roles
       without generating an error.
     * Allow pg_dumpall to avoid errors if the postgres database is
       missing in the new cluster (Robert Haas)
     * Dump foreign server user mappings in user name order (Peter
       Eisentraut)
       This helps produce deterministic dump files.
     * Dump operators in a predictable order (Peter Eisentraut)
     * Tighten rules for when extension configuration tables are dumped by
       pg_dump (Tom Lane)
     * Make pg_dump emit more useful dependency information (Tom Lane)
       The dependency links included in archive-format dumps were formerly
       of very limited use, because they frequently referenced objects
       that appeared nowhere in the dump. Now they represent actual
       dependencies (possibly indirect) among the dumped objects.
     * Improve pg_dump's performance when dumping many database objects
       (Tom Lane)
     __________________________________________________________________

libpq

     * Allow libpq connection strings to have the format of a URI
       (Alexander Shulgin)
       The syntax begins with postgres://. This can allow applications to
       avoid implementing their own parser for URIs representing database
       connections.
     * Add a connection option to disable SSL compression (Laurenz Albe)
       This can be used to remove the overhead of SSL compression on fast
       networks.
     * Add a single-row processing mode for better handling of large
       result sets (Kyotaro Horiguchi, Marko Kreen)
       Previously, libpq always collected the entire query result in
       memory before passing it back to the application.
     * Add const qualifiers to the declarations of the functions
       PQconnectdbParams, PQconnectStartParams, and PQpingParams (Lionel
       Elie Mamane)
     * Allow the ".pgpass" file to include escaped characters in the
       password field (Robert Haas)
     * Make library functions use abort() instead of exit() when it is
       necessary to terminate the process (Peter Eisentraut)
       This choice does not interfere with the normal exit codes used by
       the program, and generates a signal that can be caught by the
       caller.
     __________________________________________________________________

Source Code

     * Remove dead ports (Peter Eisentraut)
       The following platforms are no longer supported: dgux, nextstep,
       sunos4, svr4, ultrix4, univel, bsdi.
     * Add support for building with MS Visual Studio 2010 (Brar Piening)
     * Enable compiling with the MinGW-w64 32-bit compiler (Lars Kanis)
     * Install "plpgsql.h" into "include/server" during installation
       (Heikki Linnakangas)
     * Improve the latch facility to include detection of postmaster death
       (Peter Geoghegan, Heikki Linnakangas, Tom Lane)
       This eliminates one of the main reasons that background processes
       formerly had to wake up to poll for events.
     * Use C flexible array members, where supported (Peter Eisentraut)
     * Improve the concurrent transaction regression tests
       (isolationtester) (Noah Misch)
     * Modify thread_test to create its test files in the current
       directory, rather than "/tmp" (Bruce Momjian)
     * Improve flex and bison warning and error reporting (Tom Lane)
     * Add memory barrier support (Robert Haas)
       This is currently unused.
     * Modify pgindent to use a typedef file (Bruce Momjian)
     * Add a hook for processing messages due to be sent to the server log
       (Martin Pihlak)
     * Add object access hooks for "DROP" commands (KaiGai Kohei)
     * Centralize "DROP" handling for some object types (KaiGai Kohei)
     * Add a pg_upgrade test suite (Peter Eisentraut)
     * Sync regular expression code with TCL 8.5.11 and improve internal
       processing (Tom Lane)
     * Move CRC tables to libpgport, and provide them in a separate
       include file (Daniel Farina)
     * Add options to git_changelog for use in major release note creation
       (Bruce Momjian)
     * Support Linux's "/proc/self/oom_score_adj" API (Tom Lane)
     __________________________________________________________________

Additional Modules

     * Improve efficiency of dblink by using libpq's new single-row
       processing mode (Kyotaro Horiguchi, Marko Kreen)
       This improvement does not apply to
       dblink_send_query()/dblink_get_result().
     * Support force_not_null option in file_fdw (Shigeru Hanada)
     * Implement dry-run mode for pg_archivecleanup (Gabriele Bartolini)
       This only outputs the names of files to be deleted.
     * Add new pgbench switches "--unlogged-tables", "--tablespace", and
       "--index-tablespace" (Robert Haas)
     * Change pg_test_fsync to test for a fixed amount of time, rather
       than a fixed number of cycles (Bruce Momjian)
       The "-o"/cycles option was removed, and "-s"/seconds added.
     * Add a pg_test_timing utility to measure clock monotonicity and
       timing overhead (Ants Aasma, Greg Smith)
     * Add a tcn (triggered change notification) module to generate
       "NOTIFY" events on table changes (Kevin Grittner)
     __________________________________________________________________

pg_upgrade

     * Adjust pg_upgrade environment variables (Bruce Momjian)
       Rename data, bin, and port environment variables to begin with PG,
       and support PGPORTOLD/PGPORTNEW, to replace PGPORT.
     * Overhaul pg_upgrade logging and failure reporting (Bruce Momjian)
       Create four append-only log files, and delete them on success. Add
       "-r"/"--retain" option to unconditionally retain these files. Also
       remove pg_upgrade options "-g"/"-G"/"-l" options as unnecessary,
       and tighten log file permissions.
     * Make pg_upgrade create a script to incrementally generate more
       accurate optimizer statistics (Bruce Momjian)
       This reduces the time needed to generate minimal cluster statistics
       after an upgrade.
     * Allow pg_upgrade to upgrade an old cluster that does not have a
       postgres database (Bruce Momjian)
     * Allow pg_upgrade to handle cases where some old or new databases
       are missing, as long as they are empty (Bruce Momjian)
     * Allow pg_upgrade to handle configuration-only directory
       installations (Bruce Momjian)
     * In pg_upgrade, add "-o"/"-O" options to pass parameters to the
       servers (Bruce Momjian)
       This is useful for configuration-only directory installs.
     * Change pg_upgrade to use port 50432 by default (Bruce Momjian)
       This helps avoid unintended client connections during the upgrade.
     * Reduce cluster locking in pg_upgrade (Bruce Momjian)
       Specifically, only lock the old cluster if link mode is used, and
       do it right after the schema is restored.
     __________________________________________________________________

pg_stat_statements

     * Allow pg_stat_statements to aggregate similar queries via SQL text
       normalization (Peter Geoghegan, Tom Lane)
       Users with applications that use non-parameterized SQL will now be
       able to monitor query performance without detailed log analysis.
     * Add dirtied and written block counts and read/write times to
       pg_stat_statements (Robert Haas, Ants Aasma)
     * Prevent pg_stat_statements from double-counting "PREPARE" and
       "EXECUTE" commands (Tom Lane)
     __________________________________________________________________

sepgsql

     * Support SECURITY LABEL on global objects (KaiGai Kohei, Robert
       Haas)
       Specifically, add security labels to databases, tablespaces, and
       roles.
     * Allow sepgsql to honor database labels (KaiGai Kohei)
     * Perform sepgsql permission checks during the creation of various
       objects (KaiGai Kohei)
     * Add sepgsql_setcon() and related functions to control the sepgsql
       security domain (KaiGai Kohei)
     * Add a user space access cache to sepgsql to improve performance
       (KaiGai Kohei)
     __________________________________________________________________

Documentation

     * Add a rule to optionally build HTML documentation using the
       stylesheet from the website (Magnus Hagander)
       Use "gmake STYLE=website draft".
     * Improve "EXPLAIN" documentation (Tom Lane)
     * Document that user/database names are preserved with double-quoting
       by command-line tools like vacuumdb (Bruce Momjian)
     * Document the actual string returned by the client for MD5
       authentication (Cyan Ogilvie)
     * Deprecate use of GLOBAL and LOCAL in "CREATE TEMP TABLE" (Noah
       Misch)
       PostgreSQL has long treated these keyword as no-ops, and continues
       to do so; but in future they might mean what the SQL standard says
       they mean, so applications should avoid using them.
     __________________________________________________________________

                               Release 9.1.11

     Release Date: 2013-12-05

   This release contains a variety of fixes from 9.1.10. For information
   about new features in the 9.1 major release, see the Section called
   Release 9.1.
     __________________________________________________________________

Migration to Version 9.1.11

   A dump/restore is not required for those running 9.1.X.

   However, this release corrects a number of potential data corruption
   issues. See the first two changelog entries below to find out whether
   your installation has been affected and what steps you can take if so.

   Also, if you are upgrading from a version earlier than 9.1.9, see the
   release notes for 9.1.9.
     __________________________________________________________________

Changes

     * Fix "VACUUM"'s tests to see whether it can update relfrozenxid
       (Andres Freund)
       In some cases "VACUUM" (either manual or autovacuum) could
       incorrectly advance a table's relfrozenxid value, allowing tuples
       to escape freezing, causing those rows to become invisible once
       2^31 transactions have elapsed. The probability of data loss is
       fairly low since multiple incorrect advancements would need to
       happen before actual loss occurs, but it's not zero. Users
       upgrading from releases 9.0.4 or 8.4.8 or earlier are not affected,
       but all later versions contain the bug.
       The issue can be ameliorated by, after upgrading, vacuuming all
       tables in all databases while having vacuum_freeze_table_age set to
       zero. This will fix any latent corruption but will not be able to
       fix all pre-existing data errors. However, an installation can be
       presumed safe after performing this vacuuming if it has executed
       fewer than 2^31 update transactions in its lifetime (check this
       with SELECT txid_current() < 2^31).
     * Fix initialization of "pg_clog" and "pg_subtrans" during hot
       standby startup (Andres Freund, Heikki Linnakangas)
       This bug can cause data loss on standby servers at the moment they
       start to accept hot-standby queries, by marking committed
       transactions as uncommitted. The likelihood of such corruption is
       small unless, at the time of standby startup, the primary server
       has executed many updating transactions since its last checkpoint.
       Symptoms include missing rows, rows that should have been deleted
       being still visible, and obsolete versions of updated rows being
       still visible alongside their newer versions.
       This bug was introduced in versions 9.3.0, 9.2.5, 9.1.10, and
       9.0.14. Standby servers that have only been running earlier
       releases are not at risk. It's recommended that standby servers
       that have ever run any of the buggy releases be re-cloned from the
       primary (e.g., with a new base backup) after upgrading.
     * Truncate "pg_multixact" contents during WAL replay (Andres Freund)
       This avoids ever-increasing disk space consumption in standby
       servers.
     * Fix race condition in GIN index posting tree page deletion (Heikki
       Linnakangas)
       This could lead to transient wrong answers or query failures.
     * Avoid flattening a subquery whose SELECT list contains a volatile
       function wrapped inside a sub-SELECT (Tom Lane)
       This avoids unexpected results due to extra evaluations of the
       volatile function.
     * Fix planner's processing of non-simple-variable subquery outputs
       nested within outer joins (Tom Lane)
       This error could lead to incorrect plans for queries involving
       multiple levels of subqueries within JOIN syntax.
     * Fix incorrect generation of optimized MIN()/MAX() plans for
       inheritance trees (Tom Lane)
       The planner could fail in cases where the MIN()/MAX() argument was
       an expression rather than a simple variable.
     * Fix premature deletion of temporary files (Andres Freund)
     * Fix possible read past end of memory in rule printing (Peter
       Eisentraut)
     * Fix array slicing of int2vector and oidvector values (Tom Lane)
       Expressions of this kind are now implicitly promoted to regular
       int2 or oid arrays.
     * Fix incorrect behaviors when using a SQL-standard, simple GMT
       offset timezone (Tom Lane)
       In some cases, the system would use the simple GMT offset value
       when it should have used the regular timezone setting that had
       prevailed before the simple offset was selected. This change also
       causes the timeofday function to honor the simple GMT offset zone.
     * Prevent possible misbehavior when logging translations of Windows
       error codes (Tom Lane)
     * Properly quote generated command lines in pg_ctl (Naoya Anzai and
       Tom Lane)
       This fix applies only to Windows.
     * Fix pg_dumpall to work when a source database sets
       default_transaction_read_only via "ALTER DATABASE SET" (Kevin
       Grittner)
       Previously, the generated script would fail during restore.
     * Make ecpg search for quoted cursor names case-sensitively (Zoltan
       Boszormenyi)
     * Fix ecpg's processing of lists of variables declared varchar
       (Zoltan Boszormenyi)
     * Make "contrib/lo" defend against incorrect trigger definitions
       (Marc Cousin)
     * Update time zone data files to tzdata release 2013h for DST law
       changes in Argentina, Brazil, Jordan, Libya, Liechtenstein,
       Morocco, and Palestine. Also, new timezone abbreviations WIB, WIT,
       WITA for Indonesia.
     __________________________________________________________________

                               Release 9.1.10

     Release Date: 2013-10-10

   This release contains a variety of fixes from 9.1.9. For information
   about new features in the 9.1 major release, see the Section called
   Release 9.1.
     __________________________________________________________________

Migration to Version 9.1.10

   A dump/restore is not required for those running 9.1.X.

   However, if you are upgrading from a version earlier than 9.1.9, see
   the release notes for 9.1.9.
     __________________________________________________________________

Changes

     * Prevent corruption of multi-byte characters when attempting to
       case-fold identifiers (Andrew Dunstan)
       PostgreSQL case-folds non-ASCII characters only when using a
       single-byte server encoding.
     * Fix checkpoint memory leak in background writer when wal_level =
       hot_standby (Naoya Anzai)
     * Fix memory leak caused by lo_open() failure (Heikki Linnakangas)
     * Fix memory overcommit bug when work_mem is using more than 24GB of
       memory (Stephen Frost)
     * Serializable snapshot fixes (Kevin Grittner, Heikki Linnakangas)
     * Fix deadlock bug in libpq when using SSL (Stephen Frost)
     * Fix possible SSL state corruption in threaded libpq applications
       (Nick Phillips, Stephen Frost)
     * Properly compute row estimates for boolean columns containing many
       NULL values (Andrew Gierth)
       Previously tests like col IS NOT TRUE and col IS NOT FALSE did not
       properly factor in NULL values when estimating plan costs.
     * Prevent pushing down WHERE clauses into unsafe UNION/INTERSECT
       subqueries (Tom Lane)
       Subqueries of a UNION or INTERSECT that contain set-returning
       functions or volatile functions in their SELECT lists could be
       improperly optimized, leading to run-time errors or incorrect query
       results.
     * Fix rare case of "failed to locate grouping columns" planner
       failure (Tom Lane)
     * Fix pg_dump of foreign tables with dropped columns (Andrew Dunstan)
       Previously such cases could cause a pg_upgrade error.
     * Reorder pg_dump processing of extension-related rules and event
       triggers (Joe Conway)
     * Force dumping of extension tables if specified by "pg_dump -t" or
       -n (Joe Conway)
     * Improve view dumping code's handling of dropped columns in
       referenced tables (Tom Lane)
     * Fix "pg_restore -l" with the directory archive to display the
       correct format name (Fujii Masao)
     * Properly record index comments created using UNIQUE and PRIMARY KEY
       syntax (Andres Freund)
       This fixes a parallel pg_restore failure.
     * Properly guarantee transmission of WAL files before clean
       switchover (Fujii Masao)
       Previously, the streaming replication connection might close before
       all WAL files had been replayed on the standby.
     * Fix WAL segment timeline handling during recovery (Mitsumasa Kondo,
       Heikki Linnakangas)
       WAL file recycling during standby recovery could lead to premature
       recovery completion, resulting in data loss.
     * Fix "REINDEX TABLE" and "REINDEX DATABASE" to properly revalidate
       constraints and mark invalidated indexes as valid (Noah Misch)
       "REINDEX INDEX" has always worked properly.
     * Fix possible deadlock during concurrent "CREATE INDEX CONCURRENTLY"
       operations (Tom Lane)
     * Fix regexp_matches() handling of zero-length matches (Jeevan
       Chalke)
       Previously, zero-length matches like '^' could return too many
       matches.
     * Fix crash for overly-complex regular expressions (Heikki
       Linnakangas)
     * Fix regular expression match failures for back references combined
       with non-greedy quantifiers (Jeevan Chalke)
     * Prevent "CREATE FUNCTION" from checking "SET" variables unless
       function body checking is enabled (Tom Lane)
     * Allow "ALTER DEFAULT PRIVILEGES" to operate on schemas without
       requiring CREATE permission (Tom Lane)
     * Loosen restriction on keywords used in queries (Tom Lane)
       Specifically, lessen keyword restrictions for role names, language
       names, "EXPLAIN" and "COPY" options, and "SET" values. This allows
       COPY ... (FORMAT BINARY) to work as expected; previously BINARY
       needed to be quoted.
     * Fix pgp_pub_decrypt() so it works for secret keys with passwords
       (Marko Kreen)
     * Make pg_upgrade use pg_dump --quote-all-identifiers to avoid
       problems with keyword changes between releases (Tom Lane)
     * Remove rare inaccurate warning during vacuum of index-less tables
       (Heikki Linnakangas)
     * Ensure that "VACUUM ANALYZE" still runs the ANALYZE phase if its
       attempt to truncate the file is cancelled due to lock conflicts
       (Kevin Grittner)
     * Avoid possible failure when performing transaction control commands
       (e.g "ROLLBACK") in prepared queries (Tom Lane)
     * Ensure that floating-point data input accepts standard spellings of
       "infinity" on all platforms (Tom Lane)
       The C99 standard says that allowable spellings are inf, +inf, -inf,
       infinity, +infinity, and -infinity. Make sure we recognize these
       even if the platform's strtod function doesn't.
     * Expand ability to compare rows to records and arrays (Rafal
       Rzepecki, Tom Lane)
     * Update time zone data files to tzdata release 2013d for DST law
       changes in Israel, Morocco, Palestine, and Paraguay. Also,
       historical zone data corrections for Macquarie Island.
     __________________________________________________________________

                                Release 9.1.9

     Release Date: 2013-04-04

   This release contains a variety of fixes from 9.1.8. For information
   about new features in the 9.1 major release, see the Section called
   Release 9.1.
     __________________________________________________________________

Migration to Version 9.1.9

   A dump/restore is not required for those running 9.1.X.

   However, this release corrects several errors in management of GiST
   indexes. After installing this update, it is advisable to "REINDEX" any
   GiST indexes that meet one or more of the conditions described below.

   Also, if you are upgrading from a version earlier than 9.1.6, see the
   release notes for 9.1.6.
     __________________________________________________________________

Changes

     * Fix insecure parsing of server command-line switches (Mitsumasa
       Kondo, Kyotaro Horiguchi)
       A connection request containing a database name that begins with
       "-" could be crafted to damage or destroy files within the server's
       data directory, even if the request is eventually rejected.
       (CVE-2013-1899)
     * Reset OpenSSL randomness state in each postmaster child process
       (Marko Kreen)
       This avoids a scenario wherein random numbers generated by
       "contrib/pgcrypto" functions might be relatively easy for another
       database user to guess. The risk is only significant when the
       postmaster is configured with ssl = on but most connections don't
       use SSL encryption. (CVE-2013-1900)
     * Make REPLICATION privilege checks test current user not
       authenticated user (Noah Misch)
       An unprivileged database user could exploit this mistake to call
       pg_start_backup() or pg_stop_backup(), thus possibly interfering
       with creation of routine backups. (CVE-2013-1901)
     * Fix GiST indexes to not use "fuzzy" geometric comparisons when it's
       not appropriate to do so (Alexander Korotkov)
       The core geometric types perform comparisons using "fuzzy"
       equality, but gist_box_same must do exact comparisons, else GiST
       indexes using it might become inconsistent. After installing this
       update, users should "REINDEX" any GiST indexes on box, polygon,
       circle, or point columns, since all of these use gist_box_same.
     * Fix erroneous range-union and penalty logic in GiST indexes that
       use "contrib/btree_gist" for variable-width data types, that is
       text, bytea, bit, and numeric columns (Tom Lane)
       These errors could result in inconsistent indexes in which some
       keys that are present would not be found by searches, and also in
       useless index bloat. Users are advised to "REINDEX" such indexes
       after installing this update.
     * Fix bugs in GiST page splitting code for multi-column indexes (Tom
       Lane)
       These errors could result in inconsistent indexes in which some
       keys that are present would not be found by searches, and also in
       indexes that are unnecessarily inefficient to search. Users are
       advised to "REINDEX" multi-column GiST indexes after installing
       this update.
     * Fix gist_point_consistent to handle fuzziness consistently
       (Alexander Korotkov)
       Index scans on GiST indexes on point columns would sometimes yield
       results different from a sequential scan, because
       gist_point_consistent disagreed with the underlying operator code
       about whether to do comparisons exactly or fuzzily.
     * Fix buffer leak in WAL replay (Heikki Linnakangas)
       This bug could result in "incorrect local pin count" errors during
       replay, making recovery impossible.
     * Fix race condition in "DELETE RETURNING" (Tom Lane)
       Under the right circumstances, "DELETE RETURNING" could attempt to
       fetch data from a shared buffer that the current process no longer
       has any pin on. If some other process changed the buffer meanwhile,
       this would lead to garbage RETURNING output, or even a crash.
     * Fix infinite-loop risk in regular expression compilation (Tom Lane,
       Don Porter)
     * Fix potential null-pointer dereference in regular expression
       compilation (Tom Lane)
     * Fix to_char() to use ASCII-only case-folding rules where
       appropriate (Tom Lane)
       This fixes misbehavior of some template patterns that should be
       locale-independent, but mishandled "I" and "i" in Turkish locales.
     * Fix unwanted rejection of timestamp 1999-12-31 24:00:00 (Tom Lane)
     * Fix logic error when a single transaction does "UNLISTEN" then
       "LISTEN" (Tom Lane)
       The session wound up not listening for notify events at all, though
       it surely should listen in this case.
     * Fix possible planner crash after columns have been added to a view
       that's depended on by another view (Tom Lane)
     * Remove useless "picksplit doesn't support secondary split" log
       messages (Josh Hansen, Tom Lane)
       This message seems to have been added in expectation of code that
       was never written, and probably never will be, since GiST's default
       handling of secondary splits is actually pretty good. So stop
       nagging end users about it.
     * Fix possible failure to send a session's last few transaction
       commit/abort counts to the statistics collector (Tom Lane)
     * Eliminate memory leaks in PL/Perl's spi_prepare() function (Alex
       Hunsaker, Tom Lane)
     * Fix pg_dumpall to handle database names containing "=" correctly
       (Heikki Linnakangas)
     * Avoid crash in pg_dump when an incorrect connection string is given
       (Heikki Linnakangas)
     * Ignore invalid indexes in pg_dump and pg_upgrade (Michael Paquier,
       Bruce Momjian)
       Dumping invalid indexes can cause problems at restore time, for
       example if the reason the index creation failed was because it
       tried to enforce a uniqueness condition not satisfied by the
       table's data. Also, if the index creation is in fact still in
       progress, it seems reasonable to consider it to be an uncommitted
       DDL change, which pg_dump wouldn't be expected to dump anyway.
       pg_upgrade now also skips invalid indexes rather than failing.
     * In pg_basebackup, include only the current server version's
       subdirectory when backing up a tablespace (Heikki Linnakangas)
     * Add a server version check in pg_basebackup and pg_receivexlog, so
       they fail cleanly with version combinations that won't work (Heikki
       Linnakangas)
     * Fix "contrib/pg_trgm"'s similarity() function to return zero for
       trigram-less strings (Tom Lane)
       Previously it returned NaN due to internal division by zero.
     * Update time zone data files to tzdata release 2013b for DST law
       changes in Chile, Haiti, Morocco, Paraguay, and some Russian areas.
       Also, historical zone data corrections for numerous places.
       Also, update the time zone abbreviation files for recent changes in
       Russia and elsewhere: CHOT, GET, IRKT, KGT, KRAT, MAGT, MAWT, MSK,
       NOVT, OMST, TKT, VLAT, WST, YAKT, YEKT now follow their current
       meanings, and VOLT (Europe/Volgograd) and MIST
       (Antarctica/Macquarie) are added to the default abbreviations list.
     __________________________________________________________________

                                Release 9.1.8

     Release Date: 2013-02-07

   This release contains a variety of fixes from 9.1.7. For information
   about new features in the 9.1 major release, see the Section called
   Release 9.1.
     __________________________________________________________________

Migration to Version 9.1.8

   A dump/restore is not required for those running 9.1.X.

   However, if you are upgrading from a version earlier than 9.1.6, see
   the release notes for 9.1.6.
     __________________________________________________________________

Changes

     * Prevent execution of enum_recv from SQL (Tom Lane)
       The function was misdeclared, allowing a simple SQL command to
       crash the server. In principle an attacker might be able to use it
       to examine the contents of server memory. Our thanks to Sumit Soni
       (via Secunia SVCRP) for reporting this issue. (CVE-2013-0255)
     * Fix multiple problems in detection of when a consistent database
       state has been reached during WAL replay (Fujii Masao, Heikki
       Linnakangas, Simon Riggs, Andres Freund)
     * Update minimum recovery point when truncating a relation file
       (Heikki Linnakangas)
       Once data has been discarded, it's no longer safe to stop recovery
       at an earlier point in the timeline.
     * Fix recycling of WAL segments after changing recovery target
       timeline (Heikki Linnakangas)
     * Fix missing cancellations in hot standby mode (Noah Misch, Simon
       Riggs)
       The need to cancel conflicting hot-standby queries would sometimes
       be missed, allowing those queries to see inconsistent data.
     * Prevent recovery pause feature from pausing before users can
       connect (Tom Lane)
     * Fix SQL grammar to allow subscripting or field selection from a
       sub-SELECT result (Tom Lane)
     * Fix performance problems with autovacuum truncation in busy
       workloads (Jan Wieck)
       Truncation of empty pages at the end of a table requires exclusive
       lock, but autovacuum was coded to fail (and release the table lock)
       when there are conflicting lock requests. Under load, it is easily
       possible that truncation would never occur, resulting in table
       bloat. Fix by performing a partial truncation, releasing the lock,
       then attempting to re-acquire the lock and continue. This fix also
       greatly reduces the average time before autovacuum releases the
       lock after a conflicting request arrives.
     * Protect against race conditions when scanning pg_tablespace
       (Stephen Frost, Tom Lane)
       "CREATE DATABASE" and "DROP DATABASE" could misbehave if there were
       concurrent updates of pg_tablespace entries.
     * Prevent "DROP OWNED" from trying to drop whole databases or
       tablespaces (Alvaro Herrera)
       For safety, ownership of these objects must be reassigned, not
       dropped.
     * Fix error in vacuum_freeze_table_age implementation (Andres Freund)
       In installations that have existed for more than
       vacuum_freeze_min_age transactions, this mistake prevented
       autovacuum from using partial-table scans, so that a full-table
       scan would always happen instead.
     * Prevent misbehavior when a RowExpr or XmlExpr is parse-analyzed
       twice (Andres Freund, Tom Lane)
       This mistake could be user-visible in contexts such as CREATE TABLE
       LIKE INCLUDING INDEXES.
     * Improve defenses against integer overflow in hashtable sizing
       calculations (Jeff Davis)
     * Fix failure to ignore leftover temporary tables after a server
       crash (Tom Lane)
     * Reject out-of-range dates in to_date() (Hitoshi Harada)
     * Fix pg_extension_config_dump() to handle extension-update cases
       properly (Tom Lane)
       This function will now replace any existing entry for the target
       table, making it usable in extension update scripts.
     * Fix PL/Python's handling of functions used as triggers on multiple
       tables (Andres Freund)
     * Ensure that non-ASCII prompt strings are translated to the correct
       code page on Windows (Alexander Law, Noah Misch)
       This bug affected psql and some other client programs.
     * Fix possible crash in psql's "\?" command when not connected to a
       database (Meng Qingzhong)
     * Fix possible error if a relation file is removed while
       pg_basebackup is running (Heikki Linnakangas)
     * Make pg_dump exclude data of unlogged tables when running on a
       hot-standby server (Magnus Hagander)
       This would fail anyway because the data is not available on the
       standby server, so it seems most convenient to assume
       "--no-unlogged-table-data" automatically.
     * Fix pg_upgrade to deal with invalid indexes safely (Bruce Momjian)
     * Fix one-byte buffer overrun in libpq's PQprintTuples (Xi Wang)
       This ancient function is not used anywhere by PostgreSQL itself,
       but it might still be used by some client code.
     * Make ecpglib use translated messages properly (Chen Huajun)
     * Properly install ecpg_compat and pgtypes libraries on MSVC (Jiang
       Guiqing)
     * Include our version of isinf() in libecpg if it's not provided by
       the system (Jiang Guiqing)
     * Rearrange configure's tests for supplied functions so it is not
       fooled by bogus exports from libedit/libreadline (Christoph Berg)
     * Ensure Windows build number increases over time (Magnus Hagander)
     * Make pgxs build executables with the right .exe suffix when
       cross-compiling for Windows (Zoltan Boszormenyi)
     * Add new timezone abbreviation FET (Tom Lane)
       This is now used in some eastern-European time zones.
     __________________________________________________________________

                                Release 9.1.7

     Release Date: 2012-12-06

   This release contains a variety of fixes from 9.1.6. For information
   about new features in the 9.1 major release, see the Section called
   Release 9.1.
     __________________________________________________________________

Migration to Version 9.1.7

   A dump/restore is not required for those running 9.1.X.

   However, if you are upgrading from a version earlier than 9.1.6, see
   the release notes for 9.1.6.
     __________________________________________________________________

Changes

     * Fix multiple bugs associated with "CREATE INDEX CONCURRENTLY"
       (Andres Freund, Tom Lane)
       Fix "CREATE INDEX CONCURRENTLY" to use in-place updates when
       changing the state of an index's pg_index row. This prevents race
       conditions that could cause concurrent sessions to miss updating
       the target index, thus resulting in corrupt concurrently-created
       indexes.
       Also, fix various other operations to ensure that they ignore
       invalid indexes resulting from a failed "CREATE INDEX CONCURRENTLY"
       command. The most important of these is "VACUUM", because an
       auto-vacuum could easily be launched on the table before corrective
       action can be taken to fix or remove the invalid index.
     * Fix buffer locking during WAL replay (Tom Lane)
       The WAL replay code was insufficiently careful about locking
       buffers when replaying WAL records that affect more than one page.
       This could result in hot standby queries transiently seeing
       inconsistent states, resulting in wrong answers or unexpected
       failures.
     * Fix an error in WAL generation logic for GIN indexes (Tom Lane)
       This could result in index corruption, if a torn-page failure
       occurred.
     * Properly remove startup process's virtual XID lock when promoting a
       hot standby server to normal running (Simon Riggs)
       This oversight could prevent subsequent execution of certain
       operations such as "CREATE INDEX CONCURRENTLY".
     * Avoid bogus "out-of-sequence timeline ID" errors in standby mode
       (Heikki Linnakangas)
     * Prevent the postmaster from launching new child processes after
       it's received a shutdown signal (Tom Lane)
       This mistake could result in shutdown taking longer than it should,
       or even never completing at all without additional user action.
     * Avoid corruption of internal hash tables when out of memory
       (Hitoshi Harada)
     * Prevent file descriptors for dropped tables from being held open
       past transaction end (Tom Lane)
       This should reduce problems with long-since-dropped tables
       continuing to occupy disk space.
     * Prevent database-wide crash and restart when a new child process is
       unable to create a pipe for its latch (Tom Lane)
       Although the new process must fail, there is no good reason to
       force a database-wide restart, so avoid that. This improves
       robustness when the kernel is nearly out of file descriptors.
     * Fix planning of non-strict equivalence clauses above outer joins
       (Tom Lane)
       The planner could derive incorrect constraints from a clause
       equating a non-strict construct to something else, for example
       WHERE COALESCE(foo, 0) = 0 when foo is coming from the nullable
       side of an outer join.
     * Fix "SELECT DISTINCT" with index-optimized MIN/MAX on an
       inheritance tree (Tom Lane)
       The planner would fail with "failed to re-find MinMaxAggInfo
       record" given this combination of factors.
     * Improve planner's ability to prove exclusion constraints from
       equivalence classes (Tom Lane)
     * Fix partial-row matching in hashed subplans to handle cross-type
       cases correctly (Tom Lane)
       This affects multicolumn NOT IN subplans, such as WHERE (a, b) NOT
       IN (SELECT x, y FROM ...) when for instance b and y are int4 and
       int8 respectively. This mistake led to wrong answers or crashes
       depending on the specific datatypes involved.
     * Acquire buffer lock when re-fetching the old tuple for an AFTER ROW
       UPDATE/DELETE trigger (Andres Freund)
       In very unusual circumstances, this oversight could result in
       passing incorrect data to a trigger WHEN condition, or to the
       precheck logic for a foreign-key enforcement trigger. That could
       result in a crash, or in an incorrect decision about whether to
       fire the trigger.
     * Fix "ALTER COLUMN TYPE" to handle inherited check constraints
       properly (Pavan Deolasee)
       This worked correctly in pre-8.4 releases, and now works correctly
       in 8.4 and later.
     * Fix "ALTER EXTENSION SET SCHEMA"'s failure to move some subsidiary
       objects into the new schema (Alvaro Herrera, Dimitri Fontaine)
     * Fix "REASSIGN OWNED" to handle grants on tablespaces (Alvaro
       Herrera)
     * Ignore incorrect pg_attribute entries for system columns for views
       (Tom Lane)
       Views do not have any system columns. However, we forgot to remove
       such entries when converting a table to a view. That's fixed
       properly for 9.3 and later, but in previous branches we need to
       defend against existing mis-converted views.
     * Fix rule printing to dump INSERT INTO table DEFAULT VALUES
       correctly (Tom Lane)
     * Guard against stack overflow when there are too many
       UNION/INTERSECT/EXCEPT clauses in a query (Tom Lane)
     * Prevent platform-dependent failures when dividing the minimum
       possible integer value by -1 (Xi Wang, Tom Lane)
     * Fix possible access past end of string in date parsing (Hitoshi
       Harada)
     * Fix failure to advance XID epoch if XID wraparound happens during a
       checkpoint and wal_level is hot_standby (Tom Lane, Andres Freund)
       While this mistake had no particular impact on PostgreSQL itself,
       it was bad for applications that rely on txid_current() and related
       functions: the TXID value would appear to go backwards.
     * Fix display of pg_stat_replication.sync_state at a page boundary
       (Kyotaro Horiguchi)
     * Produce an understandable error message if the length of the path
       name for a Unix-domain socket exceeds the platform-specific limit
       (Tom Lane, Andrew Dunstan)
       Formerly, this would result in something quite unhelpful, such as
       "Non-recoverable failure in name resolution".
     * Fix memory leaks when sending composite column values to the client
       (Tom Lane)
     * Make pg_ctl more robust about reading the "postmaster.pid" file
       (Heikki Linnakangas)
       Fix race conditions and possible file descriptor leakage.
     * Fix possible crash in psql if incorrectly-encoded data is presented
       and the client_encoding setting is a client-only encoding, such as
       SJIS (Jiang Guiqing)
     * Make pg_dump dump SEQUENCE SET items in the data not pre-data
       section of the archive (Tom Lane)
       This change fixes dumping of sequences that are marked as extension
       configuration tables.
     * Fix bugs in the "restore.sql" script emitted by pg_dump in tar
       output format (Tom Lane)
       The script would fail outright on tables whose names include
       upper-case characters. Also, make the script capable of restoring
       data in "--inserts" mode as well as the regular COPY mode.
     * Fix pg_restore to accept POSIX-conformant tar files (Brian Weaver,
       Tom Lane)
       The original coding of pg_dump's tar output mode produced files
       that are not fully conformant with the POSIX standard. This has
       been corrected for version 9.3. This patch updates previous
       branches so that they will accept both the incorrect and the
       corrected formats, in hopes of avoiding compatibility problems when
       9.3 comes out.
     * Fix tar files emitted by pg_basebackup to be POSIX conformant
       (Brian Weaver, Tom Lane)
     * Fix pg_resetxlog to locate "postmaster.pid" correctly when given a
       relative path to the data directory (Tom Lane)
       This mistake could lead to pg_resetxlog not noticing that there is
       an active postmaster using the data directory.
     * Fix libpq's lo_import() and lo_export() functions to report file
       I/O errors properly (Tom Lane)
     * Fix ecpg's processing of nested structure pointer variables
       (Muhammad Usama)
     * Fix ecpg's ecpg_get_data function to handle arrays properly
       (Michael Meskes)
     * Make "contrib/pageinspect"'s btree page inspection functions take
       buffer locks while examining pages (Tom Lane)
     * Ensure that make install for an extension creates the "extension"
       installation directory (Cedric Villemain)
       Previously, this step was missed if MODULEDIR was set in the
       extension's Makefile.
     * Fix pgxs support for building loadable modules on AIX (Tom Lane)
       Building modules outside the original source tree didn't work on
       AIX.
     * Update time zone data files to tzdata release 2012j for DST law
       changes in Cuba, Israel, Jordan, Libya, Palestine, Western Samoa,
       and portions of Brazil.
     __________________________________________________________________

                                Release 9.1.6

     Release Date: 2012-09-24

   This release contains a variety of fixes from 9.1.5. For information
   about new features in the 9.1 major release, see the Section called
   Release 9.1.
     __________________________________________________________________

Migration to Version 9.1.6

   A dump/restore is not required for those running 9.1.X.

   However, you may need to perform "REINDEX" operations to recover from
   the effects of the data corruption bug described in the first changelog
   item below.

   Also, if you are upgrading from a version earlier than 9.1.4, see the
   release notes for 9.1.4.
     __________________________________________________________________

Changes

     * Fix persistence marking of shared buffers during WAL replay (Jeff
       Davis)
       This mistake can result in buffers not being written out during
       checkpoints, resulting in data corruption if the server later
       crashes without ever having written those buffers. Corruption can
       occur on any server following crash recovery, but it is
       significantly more likely to occur on standby slave servers since
       those perform much more WAL replay. There is a low probability of
       corruption of btree and GIN indexes. There is a much higher
       probability of corruption of table "visibility maps". Fortunately,
       visibility maps are non-critical data in 9.1, so the worst
       consequence of such corruption in 9.1 installations is transient
       inefficiency of vacuuming. Table data proper cannot be corrupted by
       this bug.
       While no index corruption due to this bug is known to have occurred
       in the field, as a precautionary measure it is recommended that
       production installations "REINDEX" all btree and GIN indexes at a
       convenient time after upgrading to 9.1.6.
       Also, if you intend to do an in-place upgrade to 9.2.X, before
       doing so it is recommended to perform a "VACUUM" of all tables
       while having vacuum_freeze_table_age set to zero. This will ensure
       that any lingering wrong data in the visibility maps is corrected
       before 9.2.X can depend on it. vacuum_cost_delay can be adjusted to
       reduce the performance impact of vacuuming, while causing it to
       take longer to finish.
     * Fix planner's assignment of executor parameters, and fix executor's
       rescan logic for CTE plan nodes (Tom Lane)
       These errors could result in wrong answers from queries that scan
       the same WITH subquery multiple times.
     * Fix misbehavior when default_transaction_isolation is set to
       serializable (Kevin Grittner, Tom Lane, Heikki Linnakangas)
       Symptoms include crashes at process start on Windows, and crashes
       in hot standby operation.
     * Improve selectivity estimation for text search queries involving
       prefixes, i.e. "word":* patterns (Tom Lane)
     * Improve page-splitting decisions in GiST indexes (Alexander
       Korotkov, Robert Haas, Tom Lane)
       Multi-column GiST indexes might suffer unexpected bloat due to this
       error.
     * Fix cascading privilege revoke to stop if privileges are still held
       (Tom Lane)
       If we revoke a grant option from some role "X", but "X" still holds
       that option via a grant from someone else, we should not
       recursively revoke the corresponding privilege from role(s) "Y"
       that "X" had granted it to.
     * Disallow extensions from containing the schema they are assigned to
       (Thom Brown)
       This situation creates circular dependencies that confuse pg_dump
       and probably other things. It's confusing for humans too, so
       disallow it.
     * Improve error messages for Hot Standby misconfiguration errors
       (Gurjeet Singh)
     * Make configure probe for mbstowcs_l (Tom Lane)
       This fixes build failures on some versions of AIX.
     * Fix handling of SIGFPE when PL/Perl is in use (Andres Freund)
       Perl resets the process's SIGFPE handler to SIG_IGN, which could
       result in crashes later on. Restore the normal Postgres signal
       handler after initializing PL/Perl.
     * Prevent PL/Perl from crashing if a recursive PL/Perl function is
       redefined while being executed (Tom Lane)
     * Work around possible misoptimization in PL/Perl (Tom Lane)
       Some Linux distributions contain an incorrect version of
       "pthread.h" that results in incorrect compiled code in PL/Perl,
       leading to crashes if a PL/Perl function calls another one that
       throws an error.
     * Fix bugs in "contrib/pg_trgm"'s LIKE pattern analysis code (Fujii
       Masao)
       LIKE queries using a trigram index could produce wrong results if
       the pattern contained LIKE escape characters.
     * Fix pg_upgrade's handling of line endings on Windows (Andrew
       Dunstan)
       Previously, pg_upgrade might add or remove carriage returns in
       places such as function bodies.
     * On Windows, make pg_upgrade use backslash path separators in the
       scripts it emits (Andrew Dunstan)
     * Remove unnecessary dependency on pg_config from pg_upgrade (Peter
       Eisentraut)
     * Update time zone data files to tzdata release 2012f for DST law
       changes in Fiji
     __________________________________________________________________

                                Release 9.1.5

     Release Date: 2012-08-17

   This release contains a variety of fixes from 9.1.4. For information
   about new features in the 9.1 major release, see the Section called
   Release 9.1.
     __________________________________________________________________

Migration to Version 9.1.5

   A dump/restore is not required for those running 9.1.X.

   However, if you are upgrading from a version earlier than 9.1.4, see
   the release notes for 9.1.4.
     __________________________________________________________________

Changes

     * Prevent access to external files/URLs via XML entity references
       (Noah Misch, Tom Lane)
       xml_parse() would attempt to fetch external files or URLs as needed
       to resolve DTD and entity references in an XML value, thus allowing
       unprivileged database users to attempt to fetch data with the
       privileges of the database server. While the external data wouldn't
       get returned directly to the user, portions of it could be exposed
       in error messages if the data didn't parse as valid XML; and in any
       case the mere ability to check existence of a file might be useful
       to an attacker. (CVE-2012-3489)
     * Prevent access to external files/URLs via "contrib/xml2"'s
       xslt_process() (Peter Eisentraut)
       libxslt offers the ability to read and write both files and URLs
       through stylesheet commands, thus allowing unprivileged database
       users to both read and write data with the privileges of the
       database server. Disable that through proper use of libxslt's
       security options. (CVE-2012-3488)
       Also, remove xslt_process()'s ability to fetch documents and
       stylesheets from external files/URLs. While this was a documented
       "feature", it was long regarded as a bad idea. The fix for
       CVE-2012-3489 broke that capability, and rather than expend effort
       on trying to fix it, we're just going to summarily remove it.
     * Prevent too-early recycling of btree index pages (Noah Misch)
       When we allowed read-only transactions to skip assigning XIDs, we
       introduced the possibility that a deleted btree page could be
       recycled while a read-only transaction was still in flight to it.
       This would result in incorrect index search results. The
       probability of such an error occurring in the field seems very low
       because of the timing requirements, but nonetheless it should be
       fixed.
     * Fix crash-safety bug with newly-created-or-reset sequences (Tom
       Lane)
       If "ALTER SEQUENCE" was executed on a freshly created or reset
       sequence, and then precisely one nextval() call was made on it, and
       then the server crashed, WAL replay would restore the sequence to a
       state in which it appeared that no nextval() had been done, thus
       allowing the first sequence value to be returned again by the next
       nextval() call. In particular this could manifest for serial
       columns, since creation of a serial column's sequence includes an
       "ALTER SEQUENCE OWNED BY" step.
     * Fix race condition in enum-type value comparisons (Robert Haas, Tom
       Lane)
       Comparisons could fail when encountering an enum value added since
       the current query started.
     * Fix txid_current() to report the correct epoch when not in hot
       standby (Heikki Linnakangas)
       This fixes a regression introduced in the previous minor release.
     * Prevent selection of unsuitable replication connections as the
       synchronous standby (Fujii Masao)
       The master might improperly choose pseudo-servers such as
       pg_receivexlog or pg_basebackup as the synchronous standby, and
       then wait indefinitely for them.
     * Fix bug in startup of Hot Standby when a master transaction has
       many subtransactions (Andres Freund)
       This mistake led to failures reported as "out-of-order XID
       insertion in KnownAssignedXids".
     * Ensure the "backup_label" file is fsync'd after pg_start_backup()
       (Dave Kerr)
     * Fix timeout handling in walsender processes (Tom Lane)
       WAL sender background processes neglected to establish a SIGALRM
       handler, meaning they would wait forever in some corner cases where
       a timeout ought to happen.
     * Wake walsenders after each background flush by walwriter (Andres
       Freund, Simon Riggs)
       This greatly reduces replication delay when the workload contains
       only asynchronously-committed transactions.
     * Fix LISTEN/NOTIFY to cope better with I/O problems, such as out of
       disk space (Tom Lane)
       After a write failure, all subsequent attempts to send more NOTIFY
       messages would fail with messages like "Could not read from file
       "pg_notify/nnnn" at offset nnnnn: Success".
     * Only allow autovacuum to be auto-canceled by a directly blocked
       process (Tom Lane)
       The original coding could allow inconsistent behavior in some
       cases; in particular, an autovacuum could get canceled after less
       than deadlock_timeout grace period.
     * Improve logging of autovacuum cancels (Robert Haas)
     * Fix log collector so that log_truncate_on_rotation works during the
       very first log rotation after server start (Tom Lane)
     * Fix WITH attached to a nested set operation
       (UNION/INTERSECT/EXCEPT) (Tom Lane)
     * Ensure that a whole-row reference to a subquery doesn't include any
       extra GROUP BY or ORDER BY columns (Tom Lane)
     * Fix dependencies generated during ALTER TABLE ... ADD CONSTRAINT
       USING INDEX (Tom Lane)
       This command left behind a redundant pg_depend entry for the index,
       which could confuse later operations, notably ALTER TABLE ... ALTER
       COLUMN TYPE on one of the indexed columns.
     * Fix "REASSIGN OWNED" to work on extensions (Alvaro Herrera)
     * Disallow copying whole-row references in CHECK constraints and
       index definitions during "CREATE TABLE" (Tom Lane)
       This situation can arise in "CREATE TABLE" with LIKE or INHERITS.
       The copied whole-row variable was incorrectly labeled with the row
       type of the original table not the new one. Rejecting the case
       seems reasonable for LIKE, since the row types might well diverge
       later. For INHERITS we should ideally allow it, with an implicit
       coercion to the parent table's row type; but that will require more
       work than seems safe to back-patch.
     * Fix memory leak in ARRAY(SELECT ...) subqueries (Heikki
       Linnakangas, Tom Lane)
     * Fix planner to pass correct collation to operator selectivity
       estimators (Tom Lane)
       This was not previously required by any core selectivity estimation
       function, but third-party code might need it.
     * Fix extraction of common prefixes from regular expressions (Tom
       Lane)
       The code could get confused by quantified parenthesized
       subexpressions, such as ^(foo)?bar. This would lead to incorrect
       index optimization of searches for such patterns.
     * Fix bugs with parsing signed "hh":"mm" and "hh":"mm":"ss" fields in
       interval constants (Amit Kapila, Tom Lane)
     * Fix pg_dump to better handle views containing partial GROUP BY
       lists (Tom Lane)
       A view that lists only a primary key column in GROUP BY, but uses
       other table columns as if they were grouped, gets marked as
       depending on the primary key. Improper handling of such primary key
       dependencies in pg_dump resulted in poorly-ordered dumps, which at
       best would be inefficient to restore and at worst could result in
       outright failure of a parallel pg_restore run.
     * In PL/Perl, avoid setting UTF8 flag when in SQL_ASCII encoding
       (Alex Hunsaker, Kyotaro Horiguchi, Alvaro Herrera)
     * Use Postgres' encoding conversion functions, not Python's, when
       converting a Python Unicode string to the server encoding in
       PL/Python (Jan Urbanski)
       This avoids some corner-case problems, notably that Python doesn't
       support all the encodings Postgres does. A notable functional
       change is that if the server encoding is SQL_ASCII, you will get
       the UTF-8 representation of the string; formerly, any non-ASCII
       characters in the string would result in an error.
     * Fix mapping of PostgreSQL encodings to Python encodings in
       PL/Python (Jan Urbanski)
     * Report errors properly in "contrib/xml2"'s xslt_process() (Tom
       Lane)
     * Update time zone data files to tzdata release 2012e for DST law
       changes in Morocco and Tokelau
     __________________________________________________________________

                                Release 9.1.4

     Release Date: 2012-06-04

   This release contains a variety of fixes from 9.1.3. For information
   about new features in the 9.1 major release, see the Section called
   Release 9.1.
     __________________________________________________________________

Migration to Version 9.1.4

   A dump/restore is not required for those running 9.1.X.

   However, if you use the citext data type, and you upgraded from a
   previous major release by running pg_upgrade, you should run CREATE
   EXTENSION citext FROM unpackaged to avoid collation-related failures in
   citext operations. The same is necessary if you restore a dump from a
   pre-9.1 database that contains an instance of the citext data type. If
   you've already run the "CREATE EXTENSION" command before upgrading to
   9.1.4, you will instead need to do manual catalog updates as explained
   in the third changelog item below.

   Also, if you are upgrading from a version earlier than 9.1.2, see the
   release notes for 9.1.2.
     __________________________________________________________________

Changes

     * Fix incorrect password transformation in "contrib/pgcrypto"'s DES
       crypt() function (Solar Designer)
       If a password string contained the byte value 0x80, the remainder
       of the password was ignored, causing the password to be much weaker
       than it appeared. With this fix, the rest of the string is properly
       included in the DES hash. Any stored password values that are
       affected by this bug will thus no longer match, so the stored
       values may need to be updated. (CVE-2012-2143)
     * Ignore SECURITY DEFINER and SET attributes for a procedural
       language's call handler (Tom Lane)
       Applying such attributes to a call handler could crash the server.
       (CVE-2012-2655)
     * Make "contrib/citext"'s upgrade script fix collations of citext
       arrays and domains over citext (Tom Lane)
       Release 9.1.2 provided a fix for collations of citext columns and
       indexes in databases upgraded or reloaded from pre-9.1
       installations, but that fix was incomplete: it neglected to handle
       arrays and domains over citext. This release extends the module's
       upgrade script to handle these cases. As before, if you have
       already run the upgrade script, you'll need to run the collation
       update commands by hand instead. See the 9.1.2 release notes for
       more information about doing this.
     * Allow numeric timezone offsets in timestamp input to be up to 16
       hours away from UTC (Tom Lane)
       Some historical time zones have offsets larger than 15 hours, the
       previous limit. This could result in dumped data values being
       rejected during reload.
     * Fix timestamp conversion to cope when the given time is exactly the
       last DST transition time for the current timezone (Tom Lane)
       This oversight has been there a long time, but was not noticed
       previously because most DST-using zones are presumed to have an
       indefinite sequence of future DST transitions.
     * Fix text to name and char to name casts to perform string
       truncation correctly in multibyte encodings (Karl Schnaitter)
     * Fix memory copying bug in to_tsquery() (Heikki Linnakangas)
     * Ensure txid_current() reports the correct epoch when executed in
       hot standby (Simon Riggs)
     * Fix planner's handling of outer PlaceHolderVars within subqueries
       (Tom Lane)
       This bug concerns sub-SELECTs that reference variables coming from
       the nullable side of an outer join of the surrounding query. In
       9.1, queries affected by this bug would fail with "ERROR:
       Upper-level PlaceHolderVar found where not expected". But in 9.0
       and 8.4, you'd silently get possibly-wrong answers, since the value
       transmitted into the subquery wouldn't go to null when it should.
     * Fix planning of UNION ALL subqueries with output columns that are
       not simple variables (Tom Lane)
       Planning of such cases got noticeably worse in 9.1 as a result of a
       misguided fix for "MergeAppend child's targetlist doesn't match
       MergeAppend" errors. Revert that fix and do it another way.
     * Fix slow session startup when pg_attribute is very large (Tom Lane)
       If pg_attribute exceeds one-fourth of shared_buffers, cache
       rebuilding code that is sometimes needed during session start would
       trigger the synchronized-scan logic, causing it to take many times
       longer than normal. The problem was particularly acute if many new
       sessions were starting at once.
     * Ensure sequential scans check for query cancel reasonably often
       (Merlin Moncure)
       A scan encountering many consecutive pages that contain no live
       tuples would not respond to interrupts meanwhile.
     * Ensure the Windows implementation of PGSemaphoreLock() clears
       ImmediateInterruptOK before returning (Tom Lane)
       This oversight meant that a query-cancel interrupt received later
       in the same query could be accepted at an unsafe time, with
       unpredictable but not good consequences.
     * Show whole-row variables safely when printing views or rules (Abbas
       Butt, Tom Lane)
       Corner cases involving ambiguous names (that is, the name could be
       either a table or column name of the query) were printed in an
       ambiguous way, risking that the view or rule would be interpreted
       differently after dump and reload. Avoid the ambiguous case by
       attaching a no-op cast.
     * Fix "COPY FROM" to properly handle null marker strings that
       correspond to invalid encoding (Tom Lane)
       A null marker string such as E'\\0' should work, and did work in
       the past, but the case got broken in 8.4.
     * Fix "EXPLAIN VERBOSE" for writable CTEs containing RETURNING
       clauses (Tom Lane)
     * Fix "PREPARE TRANSACTION" to work correctly in the presence of
       advisory locks (Tom Lane)
       Historically, "PREPARE TRANSACTION" has simply ignored any
       session-level advisory locks the session holds, but this case was
       accidentally broken in 9.1.
     * Fix truncation of unlogged tables (Robert Haas)
     * Ignore missing schemas during non-interactive assignments of
       search_path (Tom Lane)
       This re-aligns 9.1's behavior with that of older branches.
       Previously 9.1 would throw an error for nonexistent schemas
       mentioned in search_path settings obtained from places such as
       "ALTER DATABASE SET".
     * Fix bugs with temporary or transient tables used in extension
       scripts (Tom Lane)
       This includes cases such as a rewriting "ALTER TABLE" within an
       extension update script, since that uses a transient table behind
       the scenes.
     * Ensure autovacuum worker processes perform stack depth checking
       properly (Heikki Linnakangas)
       Previously, infinite recursion in a function invoked by
       auto-"ANALYZE" could crash worker processes.
     * Fix logging collector to not lose log coherency under high load
       (Andrew Dunstan)
       The collector previously could fail to reassemble large messages if
       it got too busy.
     * Fix logging collector to ensure it will restart file rotation after
       receiving SIGHUP (Tom Lane)
     * Fix "too many LWLocks taken" failure in GiST indexes (Heikki
       Linnakangas)
     * Fix WAL replay logic for GIN indexes to not fail if the index was
       subsequently dropped (Tom Lane)
     * Correctly detect SSI conflicts of prepared transactions after a
       crash (Dan Ports)
     * Avoid synchronous replication delay when committing a transaction
       that only modified temporary tables (Heikki Linnakangas)
       In such a case the transaction's commit record need not be flushed
       to standby servers, but some of the code didn't know that and
       waited for it to happen anyway.
     * Fix error handling in pg_basebackup (Thomas Ogrisegg, Fujii Masao)
     * Fix walsender to not go into a busy loop if connection is
       terminated (Fujii Masao)
     * Fix memory leak in PL/pgSQL's "RETURN NEXT" command (Joe Conway)
     * Fix PL/pgSQL's "GET DIAGNOSTICS" command when the target is the
       function's first variable (Tom Lane)
     * Ensure that PL/Perl package-qualifies the _TD variable (Alex
       Hunsaker)
       This bug caused trigger invocations to fail when they are nested
       within a function invocation that changes the current package.
     * Fix PL/Python functions returning composite types to accept a
       string for their result value (Jan Urbanski)
       This case was accidentally broken by the 9.1 additions to allow a
       composite result value to be supplied in other formats, such as
       dictionaries.
     * Fix potential access off the end of memory in psql's expanded
       display ("\x") mode (Peter Eisentraut)
     * Fix several performance problems in pg_dump when the database
       contains many objects (Jeff Janes, Tom Lane)
       pg_dump could get very slow if the database contained many schemas,
       or if many objects are in dependency loops, or if there are many
       owned sequences.
     * Fix memory and file descriptor leaks in pg_restore when reading a
       directory-format archive (Peter Eisentraut)
     * Fix pg_upgrade for the case that a database stored in a non-default
       tablespace contains a table in the cluster's default tablespace
       (Bruce Momjian)
     * In ecpg, fix rare memory leaks and possible overwrite of one byte
       after the sqlca_t structure (Peter Eisentraut)
     * Fix "contrib/dblink"'s dblink_exec() to not leak temporary database
       connections upon error (Tom Lane)
     * Fix "contrib/dblink" to report the correct connection name in error
       messages (Kyotaro Horiguchi)
     * Fix "contrib/vacuumlo" to use multiple transactions when dropping
       many large objects (Tim Lewis, Robert Haas, Tom Lane)
       This change avoids exceeding max_locks_per_transaction when many
       objects need to be dropped. The behavior can be adjusted with the
       new -l (limit) option.
     * Update time zone data files to tzdata release 2012c for DST law
       changes in Antarctica, Armenia, Chile, Cuba, Falkland Islands,
       Gaza, Haiti, Hebron, Morocco, Syria, and Tokelau Islands; also
       historical corrections for Canada.
     __________________________________________________________________

                                Release 9.1.3

     Release Date: 2012-02-27

   This release contains a variety of fixes from 9.1.2. For information
   about new features in the 9.1 major release, see the Section called
   Release 9.1.
     __________________________________________________________________

Migration to Version 9.1.3

   A dump/restore is not required for those running 9.1.X.

   However, if you are upgrading from a version earlier than 9.1.2, see
   the release notes for 9.1.2.
     __________________________________________________________________

Changes

     * Require execute permission on the trigger function for "CREATE
       TRIGGER" (Robert Haas)
       This missing check could allow another user to execute a trigger
       function with forged input data, by installing it on a table he
       owns. This is only of significance for trigger functions marked
       SECURITY DEFINER, since otherwise trigger functions run as the
       table owner anyway. (CVE-2012-0866)
     * Remove arbitrary limitation on length of common name in SSL
       certificates (Heikki Linnakangas)
       Both libpq and the server truncated the common name extracted from
       an SSL certificate at 32 bytes. Normally this would cause nothing
       worse than an unexpected verification failure, but there are some
       rather-implausible scenarios in which it might allow one
       certificate holder to impersonate another. The victim would have to
       have a common name exactly 32 bytes long, and the attacker would
       have to persuade a trusted CA to issue a certificate in which the
       common name has that string as a prefix. Impersonating a server
       would also require some additional exploit to redirect client
       connections. (CVE-2012-0867)
     * Convert newlines to spaces in names written in pg_dump comments
       (Robert Haas)
       pg_dump was incautious about sanitizing object names that are
       emitted within SQL comments in its output script. A name containing
       a newline would at least render the script syntactically incorrect.
       Maliciously crafted object names could present a SQL injection risk
       when the script is reloaded. (CVE-2012-0868)
     * Fix btree index corruption from insertions concurrent with
       vacuuming (Tom Lane)
       An index page split caused by an insertion could sometimes cause a
       concurrently-running "VACUUM" to miss removing index entries that
       it should remove. After the corresponding table rows are removed,
       the dangling index entries would cause errors (such as "could not
       read block N in file ...") or worse, silently wrong query results
       after unrelated rows are re-inserted at the now-free table
       locations. This bug has been present since release 8.2, but occurs
       so infrequently that it was not diagnosed until now. If you have
       reason to suspect that it has happened in your database, reindexing
       the affected index will fix things.
     * Fix transient zeroing of shared buffers during WAL replay (Tom
       Lane)
       The replay logic would sometimes zero and refill a shared buffer,
       so that the contents were transiently invalid. In hot standby mode
       this can result in a query that's executing in parallel seeing
       garbage data. Various symptoms could result from that, but the most
       common one seems to be "invalid memory alloc request size".
     * Fix handling of data-modifying WITH subplans in READ COMMITTED
       rechecking (Tom Lane)
       A WITH clause containing "INSERT"/"UPDATE"/"DELETE" would crash if
       the parent "UPDATE" or "DELETE" command needed to be re-evaluated
       at one or more rows due to concurrent updates in READ COMMITTED
       mode.
     * Fix corner case in SSI transaction cleanup (Dan Ports)
       When finishing up a read-write serializable transaction, a crash
       could occur if all remaining active serializable transactions are
       read-only.
     * Fix postmaster to attempt restart after a hot-standby crash (Tom
       Lane)
       A logic error caused the postmaster to terminate, rather than
       attempt to restart the cluster, if any backend process crashed
       while operating in hot standby mode.
     * Fix "CLUSTER"/"VACUUM FULL" handling of toast values owned by
       recently-updated rows (Tom Lane)
       This oversight could lead to "duplicate key value violates unique
       constraint" errors being reported against the toast table's index
       during one of these commands.
     * Update per-column permissions, not only per-table permissions, when
       changing table owner (Tom Lane)
       Failure to do this meant that any previously granted column
       permissions were still shown as having been granted by the old
       owner. This meant that neither the new owner nor a superuser could
       revoke the now-untraceable-to-table-owner permissions.
     * Support foreign data wrappers and foreign servers in "REASSIGN
       OWNED" (Alvaro Herrera)
       This command failed with "unexpected classid" errors if it needed
       to change the ownership of any such objects.
     * Allow non-existent values for some settings in "ALTER USER/DATABASE
       SET" (Heikki Linnakangas)
       Allow default_text_search_config, default_tablespace, and
       temp_tablespaces to be set to names that are not known. This is
       because they might be known in another database where the setting
       is intended to be used, or for the tablespace cases because the
       tablespace might not be created yet. The same issue was previously
       recognized for search_path, and these settings now act like that
       one.
     * Fix "unsupported node type" error caused by COLLATE in an "INSERT"
       expression (Tom Lane)
     * Avoid crashing when we have problems deleting table files
       post-commit (Tom Lane)
       Dropping a table should lead to deleting the underlying disk files
       only after the transaction commits. In event of failure then (for
       instance, because of wrong file permissions) the code is supposed
       to just emit a warning message and go on, since it's too late to
       abort the transaction. This logic got broken as of release 8.4,
       causing such situations to result in a PANIC and an unrestartable
       database.
     * Recover from errors occurring during WAL replay of "DROP
       TABLESPACE" (Tom Lane)
       Replay will attempt to remove the tablespace's directories, but
       there are various reasons why this might fail (for example,
       incorrect ownership or permissions on those directories). Formerly
       the replay code would panic, rendering the database unrestartable
       without manual intervention. It seems better to log the problem and
       continue, since the only consequence of failure to remove the
       directories is some wasted disk space.
     * Fix race condition in logging AccessExclusiveLocks for hot standby
       (Simon Riggs)
       Sometimes a lock would be logged as being held by "transaction
       zero". This is at least known to produce assertion failures on
       slave servers, and might be the cause of more serious problems.
     * Track the OID counter correctly during WAL replay, even when it
       wraps around (Tom Lane)
       Previously the OID counter would remain stuck at a high value until
       the system exited replay mode. The practical consequences of that
       are usually nil, but there are scenarios wherein a standby server
       that's been promoted to master might take a long time to advance
       the OID counter to a reasonable value once values are needed.
     * Prevent emitting misleading "consistent recovery state reached" log
       message at the beginning of crash recovery (Heikki Linnakangas)
     * Fix initial value of pg_stat_replication.replay_location (Fujii
       Masao)
       Previously, the value shown would be wrong until at least one WAL
       record had been replayed.
     * Fix regular expression back-references with * attached (Tom Lane)
       Rather than enforcing an exact string match, the code would
       effectively accept any string that satisfies the pattern
       sub-expression referenced by the back-reference symbol.
       A similar problem still afflicts back-references that are embedded
       in a larger quantified expression, rather than being the immediate
       subject of the quantifier. This will be addressed in a future
       PostgreSQL release.
     * Fix recently-introduced memory leak in processing of inet/cidr
       values (Heikki Linnakangas)
       A patch in the December 2011 releases of PostgreSQL caused memory
       leakage in these operations, which could be significant in
       scenarios such as building a btree index on such a column.
     * Fix planner's ability to push down index-expression restrictions
       through UNION ALL (Tom Lane)
       This type of optimization was inadvertently disabled by a fix for
       another problem in 9.1.2.
     * Fix planning of WITH clauses referenced in "UPDATE"/"DELETE" on an
       inherited table (Tom Lane)
       This bug led to "could not find plan for CTE" failures.
     * Fix GIN cost estimation to handle column IN (...) index conditions
       (Marti Raudsepp)
       This oversight would usually lead to crashes if such a condition
       could be used with a GIN index.
     * Prevent assertion failure when exiting a session with an open,
       failed transaction (Tom Lane)
       This bug has no impact on normal builds with asserts not enabled.
     * Fix dangling pointer after "CREATE TABLE AS"/"SELECT INTO" in a
       SQL-language function (Tom Lane)
       In most cases this only led to an assertion failure in
       assert-enabled builds, but worse consequences seem possible.
     * Avoid double close of file handle in syslogger on Windows (MauMau)
       Ordinarily this error was invisible, but it would cause an
       exception when running on a debug version of Windows.
     * Fix I/O-conversion-related memory leaks in plpgsql (Andres Freund,
       Jan Urbanski, Tom Lane)
       Certain operations would leak memory until the end of the current
       function.
     * Work around bug in perl's SvPVutf8() function (Andrew Dunstan)
       This function crashes when handed a typeglob or certain read-only
       objects such as $^V. Make plperl avoid passing those to it.
     * In pg_dump, don't dump contents of an extension's configuration
       tables if the extension itself is not being dumped (Tom Lane)
     * Improve pg_dump's handling of inherited table columns (Tom Lane)
       pg_dump mishandled situations where a child column has a different
       default expression than its parent column. If the default is
       textually identical to the parent's default, but not actually the
       same (for instance, because of schema search path differences) it
       would not be recognized as different, so that after dump and
       restore the child would be allowed to inherit the parent's default.
       Child columns that are NOT NULL where their parent is not could
       also be restored subtly incorrectly.
     * Fix pg_restore's direct-to-database mode for INSERT-style table
       data (Tom Lane)
       Direct-to-database restores from archive files made with
       "--inserts" or "--column-inserts" options fail when using
       pg_restore from a release dated September or December 2011, as a
       result of an oversight in a fix for another problem. The archive
       file itself is not at fault, and text-mode output is okay.
     * Teach pg_upgrade to handle renaming of plpython's shared library
       (Bruce Momjian)
       Upgrading a pre-9.1 database that included plpython would fail
       because of this oversight.
     * Allow pg_upgrade to process tables containing regclass columns
       (Bruce Momjian)
       Since pg_upgrade now takes care to preserve pg_class OIDs, there
       was no longer any reason for this restriction.
     * Make libpq ignore ENOTDIR errors when looking for an SSL client
       certificate file (Magnus Hagander)
       This allows SSL connections to be established, though without a
       certificate, even when the user's home directory is set to
       something like /dev/null.
     * Fix some more field alignment issues in ecpg's SQLDA area (Zoltan
       Boszormenyi)
     * Allow AT option in ecpg DEALLOCATE statements (Michael Meskes)
       The infrastructure to support this has been there for awhile, but
       through an oversight there was still an error check rejecting the
       case.
     * Do not use the variable name when defining a varchar structure in
       ecpg (Michael Meskes)
     * Fix "contrib/auto_explain"'s JSON output mode to produce valid JSON
       (Andrew Dunstan)
       The output used brackets at the top level, when it should have used
       braces.
     * Fix error in "contrib/intarray"'s int[] & int[] operator (Guillaume
       Lelarge)
       If the smallest integer the two input arrays have in common is 1,
       and there are smaller values in either array, then 1 would be
       incorrectly omitted from the result.
     * Fix error detection in "contrib/pgcrypto"'s encrypt_iv() and
       decrypt_iv() (Marko Kreen)
       These functions failed to report certain types of invalid-input
       errors, and would instead return random garbage values for
       incorrect input.
     * Fix one-byte buffer overrun in "contrib/test_parser" (Paul Guyot)
       The code would try to read one more byte than it should, which
       would crash in corner cases. Since "contrib/test_parser" is only
       example code, this is not a security issue in itself, but bad
       example code is still bad.
     * Use __sync_lock_test_and_set() for spinlocks on ARM, if available
       (Martin Pitt)
       This function replaces our previous use of the SWPB instruction,
       which is deprecated and not available on ARMv6 and later. Reports
       suggest that the old code doesn't fail in an obvious way on recent
       ARM boards, but simply doesn't interlock concurrent accesses,
       leading to bizarre failures in multiprocess operation.
     * Use "-fexcess-precision=standard" option when building with gcc
       versions that accept it (Andrew Dunstan)
       This prevents assorted scenarios wherein recent versions of gcc
       will produce creative results.
     * Allow use of threaded Python on FreeBSD (Chris Rees)
       Our configure script previously believed that this combination
       wouldn't work; but FreeBSD fixed the problem, so remove that error
       check.
     * Allow MinGW builds to use standardly-named OpenSSL libraries
       (Tomasz Ostrowski)
     __________________________________________________________________

                                Release 9.1.2

     Release Date: 2011-12-05

   This release contains a variety of fixes from 9.1.1. For information
   about new features in the 9.1 major release, see the Section called
   Release 9.1.
     __________________________________________________________________

Migration to Version 9.1.2

   A dump/restore is not required for those running 9.1.X.

   However, a longstanding error was discovered in the definition of the
   information_schema.referential_constraints view. If you rely on correct
   results from that view, you should replace its definition as explained
   in the first changelog item below.

   Also, if you use the citext data type, and you upgraded from a previous
   major release by running pg_upgrade, you should run CREATE EXTENSION
   citext FROM unpackaged to avoid collation-related failures in citext
   operations. The same is necessary if you restore a dump from a pre-9.1
   database that contains an instance of the citext data type. If you've
   already run the "CREATE EXTENSION" command before upgrading to 9.1.2,
   you will instead need to do manual catalog updates as explained in the
   second changelog item.
     __________________________________________________________________

Changes

     * Fix bugs in information_schema.referential_constraints view (Tom
       Lane)
       This view was being insufficiently careful about matching the
       foreign-key constraint to the depended-on primary or unique key
       constraint. That could result in failure to show a foreign key
       constraint at all, or showing it multiple times, or claiming that
       it depends on a different constraint than the one it really does.
       Since the view definition is installed by initdb, merely upgrading
       will not fix the problem. If you need to fix this in an existing
       installation, you can (as a superuser) drop the information_schema
       schema then re-create it by sourcing
       "SHAREDIR/information_schema.sql". (Run pg_config --sharedir if
       you're uncertain where "SHAREDIR" is.) This must be repeated in
       each database to be fixed.
     * Make "contrib/citext"'s upgrade script fix collations of citext
       columns and indexes (Tom Lane)
       Existing citext columns and indexes aren't correctly marked as
       being of a collatable data type during pg_upgrade from a pre-9.1
       server, or when a pre-9.1 dump containing the citext type is loaded
       into a 9.1 server. That leads to operations on these columns
       failing with errors such as "could not determine which collation to
       use for string comparison". This change allows them to be fixed by
       the same script that upgrades the citext module into a proper 9.1
       extension during CREATE EXTENSION citext FROM unpackaged.
       If you have a previously-upgraded database that is suffering from
       this problem, and you already ran the "CREATE EXTENSION" command,
       you can manually run (as superuser) the "UPDATE" commands found at
       the end of "SHAREDIR/extension/citext--unpackaged--1.0.sql". (Run
       pg_config --sharedir if you're uncertain where "SHAREDIR" is.)
       There is no harm in doing this again if unsure.
     * Fix possible crash during "UPDATE" or "DELETE" that joins to the
       output of a scalar-returning function (Tom Lane)
       A crash could only occur if the target row had been concurrently
       updated, so this problem surfaced only intermittently.
     * Fix incorrect replay of WAL records for GIN index updates (Tom
       Lane)
       This could result in transiently failing to find index entries
       after a crash, or on a hot-standby server. The problem would be
       repaired by the next "VACUUM" of the index, however.
     * Fix TOAST-related data corruption during CREATE TABLE dest AS
       SELECT * FROM src or INSERT INTO dest SELECT * FROM src (Tom Lane)
       If a table has been modified by "ALTER TABLE ADD COLUMN", attempts
       to copy its data verbatim to another table could produce corrupt
       results in certain corner cases. The problem can only manifest in
       this precise form in 8.4 and later, but we patched earlier versions
       as well in case there are other code paths that could trigger the
       same bug.
     * Fix possible failures during hot standby startup (Simon Riggs)
     * Start hot standby faster when initial snapshot is incomplete (Simon
       Riggs)
     * Fix race condition during toast table access from stale syscache
       entries (Tom Lane)
       The typical symptom was transient errors like "missing chunk number
       0 for toast value NNNNN in pg_toast_2619", where the cited toast
       table would always belong to a system catalog.
     * Track dependencies of functions on items used in parameter default
       expressions (Tom Lane)
       Previously, a referenced object could be dropped without having
       dropped or modified the function, leading to misbehavior when the
       function was used. Note that merely installing this update will not
       fix the missing dependency entries; to do that, you'd need to
       "CREATE OR REPLACE" each such function afterwards. If you have
       functions whose defaults depend on non-built-in objects, doing so
       is recommended.
     * Fix incorrect management of placeholder variables in nestloop joins
       (Tom Lane)
       This bug is known to lead to "variable not found in subplan target
       list" planner errors, and could possibly result in wrong query
       output when outer joins are involved.
     * Fix window functions that sort by expressions involving aggregates
       (Tom Lane)
       Previously these could fail with "could not find pathkey item to
       sort" planner errors.
     * Fix "MergeAppend child's targetlist doesn't match MergeAppend"
       planner errors (Tom Lane)
     * Fix index matching for operators with both collatable and
       noncollatable inputs (Tom Lane)
       In 9.1.0, an indexable operator that has a non-collatable left-hand
       input type and a collatable right-hand input type would not be
       recognized as matching the left-hand column's index. An example is
       the hstore ? text operator.
     * Allow inlining of set-returning SQL functions with multiple OUT
       parameters (Tom Lane)
     * Don't trust deferred-unique indexes for join removal (Tom Lane and
       Marti Raudsepp)
       A deferred uniqueness constraint might not hold intra-transaction,
       so assuming that it does could give incorrect query results.
     * Make DatumGetInetP() unpack inet datums that have a 1-byte header,
       and add a new macro, DatumGetInetPP(), that does not (Heikki
       Linnakangas)
       This change affects no core code, but might prevent crashes in
       add-on code that expects DatumGetInetP() to produce an unpacked
       datum as per usual convention.
     * Improve locale support in money type's input and output (Tom Lane)
       Aside from not supporting all standard lc_monetary formatting
       options, the input and output functions were inconsistent, meaning
       there were locales in which dumped money values could not be
       re-read.
     * Don't let transform_null_equals affect CASE foo WHEN NULL ...
       constructs (Heikki Linnakangas)
       transform_null_equals is only supposed to affect foo = NULL
       expressions written directly by the user, not equality checks
       generated internally by this form of CASE.
     * Change foreign-key trigger creation order to better support
       self-referential foreign keys (Tom Lane)
       For a cascading foreign key that references its own table, a row
       update will fire both the ON UPDATE trigger and the CHECK trigger
       as one event. The ON UPDATE trigger must execute first, else the
       CHECK will check a non-final state of the row and possibly throw an
       inappropriate error. However, the firing order of these triggers is
       determined by their names, which generally sort in creation order
       since the triggers have auto-generated names following the
       convention "RI_ConstraintTrigger_NNNN". A proper fix would require
       modifying that convention, which we will do in 9.2, but it seems
       risky to change it in existing releases. So this patch just changes
       the creation order of the triggers. Users encountering this type of
       error should drop and re-create the foreign key constraint to get
       its triggers into the right order.
     * Fix IF EXISTS to work correctly in "DROP OPERATOR FAMILY" (Robert
       Haas)
     * Disallow dropping of an extension from within its own script (Tom
       Lane)
       This prevents odd behavior in case of incorrect management of
       extension dependencies.
     * Don't mark auto-generated types as extension members (Robert Haas)
       Relation rowtypes and automatically-generated array types do not
       need to have their own extension membership entries in pg_depend,
       and creating such entries complicates matters for extension
       upgrades.
     * Cope with invalid pre-existing search_path settings during "CREATE
       EXTENSION" (Tom Lane)
     * Avoid floating-point underflow while tracking buffer allocation
       rate (Greg Matthews)
       While harmless in itself, on certain platforms this would result in
       annoying kernel log messages.
     * Prevent autovacuum transactions from running in serializable mode
       (Tom Lane)
       Autovacuum formerly used the cluster-wide default transaction
       isolation level, but there is no need for it to use anything higher
       than READ COMMITTED, and using SERIALIZABLE could result in
       unnecessary delays for other processes.
     * Ensure walsender processes respond promptly to SIGTERM (Magnus
       Hagander)
     * Exclude "postmaster.opts" from base backups (Magnus Hagander)
     * Preserve configuration file name and line number values when
       starting child processes under Windows (Tom Lane)
       Formerly, these would not be displayed correctly in the pg_settings
       view.
     * Fix incorrect field alignment in ecpg's SQLDA area (Zoltan
       Boszormenyi)
     * Preserve blank lines within commands in psql's command history
       (Robert Haas)
       The former behavior could cause problems if an empty line was
       removed from within a string literal, for example.
     * Avoid platform-specific infinite loop in pg_dump (Steve Singer)
     * Fix compression of plain-text output format in pg_dump (Adrian
       Klaver and Tom Lane)
       pg_dump has historically understood -Z with no -F switch to mean
       that it should emit a gzip-compressed version of its plain text
       output. Restore that behavior.
     * Fix pg_dump to dump user-defined casts between auto-generated
       types, such as table rowtypes (Tom Lane)
     * Fix missed quoting of foreign server names in pg_dump (Tom Lane)
     * Assorted fixes for pg_upgrade (Bruce Momjian)
       Handle exclusion constraints correctly, avoid failures on Windows,
       don't complain about mismatched toast table names in 8.4 databases.
     * In PL/pgSQL, allow foreign tables to define row types (Alexander
       Soudakov)
     * Fix up conversions of PL/Perl functions' results (Alex Hunsaker and
       Tom Lane)
       Restore the pre-9.1 behavior that PL/Perl functions returning void
       ignore the result value of their last Perl statement; 9.1.0 would
       throw an error if that statement returned a reference. Also, make
       sure it works to return a string value for a composite type, so
       long as the string meets the type's input format. In addition,
       throw errors for attempts to return Perl arrays or hashes when the
       function's declared result type is not an array or composite type,
       respectively. (Pre-9.1 versions rather uselessly returned strings
       like ARRAY(0x221a9a0) or HASH(0x221aa90) in such cases.)
     * Ensure PL/Perl strings are always correctly UTF8-encoded (Amit
       Khandekar and Alex Hunsaker)
     * Use the preferred version of xsubpp to build PL/Perl, not
       necessarily the operating system's main copy (David Wheeler and
       Alex Hunsaker)
     * Correctly propagate SQLSTATE in PL/Python exceptions (Mika Eloranta
       and Jan Urbanski)
     * Do not install PL/Python extension files for Python major versions
       other than the one built against (Peter Eisentraut)
     * Change all the "contrib" extension script files to report a useful
       error message if they are fed to psql (Andrew Dunstan and Tom Lane)
       This should help teach people about the new method of using "CREATE
       EXTENSION" to load these files. In most cases, sourcing the scripts
       directly would fail anyway, but with harder-to-interpret messages.
     * Fix incorrect coding in "contrib/dict_int" and "contrib/dict_xsyn"
       (Tom Lane)
       Some functions incorrectly assumed that memory returned by palloc()
       is guaranteed zeroed.
     * Remove "contrib/sepgsql" tests from the regular regression test
       mechanism (Tom Lane)
       Since these tests require root privileges for setup, they're
       impractical to run automatically. Switch over to a manual approach
       instead, and provide a testing script to help with that.
     * Fix assorted errors in "contrib/unaccent"'s configuration file
       parsing (Tom Lane)
     * Honor query cancel interrupts promptly in pgstatindex() (Robert
       Haas)
     * Fix incorrect quoting of log file name in Mac OS X start script
       (Sidar Lopez)
     * Revert unintentional enabling of WAL_DEBUG (Robert Haas)
       Fortunately, as debugging tools go, this one is pretty cheap; but
       it's not intended to be enabled by default, so revert.
     * Ensure VPATH builds properly install all server header files (Peter
       Eisentraut)
     * Shorten file names reported in verbose error messages (Peter
       Eisentraut)
       Regular builds have always reported just the name of the C file
       containing the error message call, but VPATH builds formerly
       reported an absolute path name.
     * Fix interpretation of Windows timezone names for Central America
       (Tom Lane)
       Map "Central America Standard Time" to CST6, not CST6CDT, because
       DST is generally not observed anywhere in Central America.
     * Update time zone data files to tzdata release 2011n for DST law
       changes in Brazil, Cuba, Fiji, Palestine, Russia, and Samoa; also
       historical corrections for Alaska and British East Africa.
     __________________________________________________________________

                                Release 9.1.1

     Release Date: 2011-09-26

   This release contains a small number of fixes from 9.1.0. For
   information about new features in the 9.1 major release, see the
   Section called Release 9.1.
     __________________________________________________________________

Migration to Version 9.1.1

   A dump/restore is not required for those running 9.1.X.
     __________________________________________________________________

Changes

     * Make pg_options_to_table return NULL for an option with no value
       (Tom Lane)
       Previously such cases would result in a server crash.
     * Fix memory leak at end of a GiST index scan (Tom Lane)
       Commands that perform many separate GiST index scans, such as
       verification of a new GiST-based exclusion constraint on a table
       already containing many rows, could transiently require large
       amounts of memory due to this leak.
     * Fix explicit reference to pg_temp schema in "CREATE TEMPORARY
       TABLE" (Robert Haas)
       This used to be allowed, but failed in 9.1.0.
     __________________________________________________________________

                                 Release 9.1

     Release Date: 2011-09-12
     __________________________________________________________________

Overview

   This release shows PostgreSQL moving beyond the traditional
   relational-database feature set with new, ground-breaking functionality
   that is unique to PostgreSQL. The streaming replication feature
   introduced in release 9.0 is significantly enhanced by adding a
   synchronous-replication option, streaming backups, and monitoring
   improvements. Major enhancements include:

     * Allow synchronous replication
     * Add support for foreign tables
     * Add per-column collation support
     * Add extensions which simplify packaging of additions to PostgreSQL
     * Add a true serializable isolation level
     * Support unlogged tables using the UNLOGGED option in "CREATE TABLE"
     * Allow data-modification commands ("INSERT"/"UPDATE"/"DELETE") in
       WITH clauses
     * Add nearest-neighbor (order-by-operator) searching to GiST indexes
     * Add a "SECURITY LABEL" command and support for SELinux permissions
       control
     * Update the PL/Python server-side language

   The above items are explained in more detail in the sections below.
     __________________________________________________________________

Migration to Version 9.1

   A dump/restore using pg_dump, or use of pg_upgrade, is required for
   those wishing to migrate data from any previous release.

   Version 9.1 contains a number of changes that may affect compatibility
   with previous releases. Observe the following incompatibilities:
     __________________________________________________________________

Strings

     * Change the default value of standard_conforming_strings to on
       (Robert Haas)
       By default, backslashes are now ordinary characters in string
       literals, not escape characters. This change removes a
       long-standing incompatibility with the SQL standard.
       escape_string_warning has produced warnings about this usage for
       years. E'' strings are the proper way to embed backslash escapes in
       strings and are unaffected by this change.

                                       Warning
       This change can break applications that are not expecting it and do
       their own string escaping according to the old rules. The consequences
       could be as severe as introducing SQL-injection security holes. Be sure
       to test applications that are exposed to untrusted input, to ensure
       that they correctly handle single quotes and backslashes in text
       strings.
     __________________________________________________________________

Casting

     * Disallow function-style and attribute-style data type casts for
       composite types (Tom Lane)
       For example, disallow composite_value.text and
       text(composite_value). Unintentional uses of this syntax have
       frequently resulted in bug reports; although it was not a bug, it
       seems better to go back to rejecting such expressions. The CAST and
       :: syntaxes are still available for use when a cast of an entire
       composite value is actually intended.
     * Tighten casting checks for domains based on arrays (Tom Lane)
       When a domain is based on an array type, it is allowed to "look
       through" the domain type to access the array elements, including
       subscripting the domain value to fetch or assign an element.
       Assignment to an element of such a domain value, for instance via
       UPDATE ... SET domaincol[5] = ..., will now result in rechecking
       the domain type's constraints, whereas before the checks were
       skipped.
     __________________________________________________________________

Arrays

     * Change string_to_array() to return an empty array for a zero-length
       string (Pavel Stehule)
       Previously this returned a null value.
     * Change string_to_array() so a NULL separator splits the string into
       characters (Pavel Stehule)
       Previously this returned a null value.
     __________________________________________________________________

Object Modification

     * Fix improper checks for before/after triggers (Tom Lane)
       Triggers can now be fired in three cases: BEFORE, AFTER, or INSTEAD
       OF some action. Trigger function authors should verify that their
       logic behaves sanely in all three cases.
     * Require superuser or CREATEROLE permissions in order to set
       comments on roles (Tom Lane)
     __________________________________________________________________

Server Settings

     * Change pg_last_xlog_receive_location() so it never moves backwards
       (Fujii Masao)
       Previously, the value of pg_last_xlog_receive_location() could move
       backward when streaming replication is restarted.
     * Have logging of replication connections honor log_connections
       (Magnus Hagander)
       Previously, replication connections were always logged.
     __________________________________________________________________

PL/pgSQL Server-Side Language

     * Change PL/pgSQL's RAISE command without parameters to be catchable
       by the attached exception block (Piyush Newe)
       Previously RAISE in a code block was always scoped to an attached
       exception block, so it was uncatchable at the same scope.
     * Adjust PL/pgSQL's error line numbering code to be consistent with
       other PLs (Pavel Stehule)
       Previously, PL/pgSQL would ignore (not count) an empty line at the
       start of the function body. Since this was inconsistent with all
       other languages, the special case was removed.
     * Make PL/pgSQL complain about conflicting IN and OUT parameter names
       (Tom Lane)
       Formerly, the collision was not detected, and the name would just
       silently refer to only the OUT parameter.
     * Type modifiers of PL/pgSQL variables are now visible to the SQL
       parser (Tom Lane)
       A type modifier (such as a varchar length limit) attached to a
       PL/pgSQL variable was formerly enforced during assignments, but was
       ignored for all other purposes. Such variables will now behave more
       like table columns declared with the same modifier. This is not
       expected to make any visible difference in most cases, but it could
       result in subtle changes for some SQL commands issued by PL/pgSQL
       functions.
     __________________________________________________________________

Contrib

     * All contrib modules are now installed with "CREATE EXTENSION"
       rather than by manually invoking their SQL scripts (Dimitri
       Fontaine, Tom Lane)
       To update an existing database containing the 9.0 version of a
       contrib module, use CREATE EXTENSION ... FROM unpackaged to wrap
       the existing contrib module's objects into an extension. When
       updating from a pre-9.0 version, drop the contrib module's objects
       using its old uninstall script, then use CREATE EXTENSION.
     __________________________________________________________________

Other Incompatibilities

     * Make pg_stat_reset() reset all database-level statistics (Tomas
       Vondra)
       Some pg_stat_database counters were not being reset.
     * Fix some information_schema.triggers column names to match the new
       SQL-standard names (Dean Rasheed)
     * Treat ECPG cursor names as case-insensitive (Zoltan Boszormenyi)
     __________________________________________________________________

Changes

   Below you will find a detailed account of the changes between
   PostgreSQL 9.1 and the previous major release.
     __________________________________________________________________

Server

Performance

     * Support unlogged tables using the UNLOGGED option in "CREATE TABLE"
       (Robert Haas)
       Such tables provide better update performance than regular tables,
       but are not crash-safe: their contents are automatically cleared in
       case of a server crash. Their contents do not propagate to
       replication slaves, either.
     * Allow FULL OUTER JOIN to be implemented as a hash join, and allow
       either side of a LEFT OUTER JOIN or RIGHT OUTER JOIN to be hashed
       (Tom Lane)
       Previously FULL OUTER JOIN could only be implemented as a merge
       join, and LEFT OUTER JOIN and RIGHT OUTER JOIN could hash only the
       nullable side of the join. These changes provide additional query
       optimization possibilities.
     * Merge duplicate fsync requests (Robert Haas, Greg Smith)
       This greatly improves performance under heavy write loads.
     * Improve performance of commit_siblings (Greg Smith)
       This allows the use of commit_siblings with less overhead.
     * Reduce the memory requirement for large ispell dictionaries (Pavel
       Stehule, Tom Lane)
     * Avoid leaving data files open after "blind writes" (Alvaro Herrera)
       This fixes scenarios in which backends might hold files open long
       after they were deleted, preventing the kernel from reclaiming disk
       space.
     __________________________________________________________________

Optimizer

     * Allow inheritance table scans to return meaningfully-sorted results
       (Greg Stark, Hans-Jurgen Schonig, Robert Haas, Tom Lane)
       This allows better optimization of queries that use ORDER BY,
       LIMIT, or MIN/MAX with inherited tables.
     * Improve GIN index scan cost estimation (Teodor Sigaev)
     * Improve cost estimation for aggregates and window functions (Tom
       Lane)
     __________________________________________________________________

Authentication

     * Support host names and host suffixes (e.g. .example.com) in
       "pg_hba.conf" (Peter Eisentraut)
       Previously only host IP addresses and CIDR values were supported.
     * Support the key word all in the host column of "pg_hba.conf" (Peter
       Eisentraut)
       Previously people used 0.0.0.0/0 or ::/0 for this.
     * Reject local lines in "pg_hba.conf" on platforms that don't support
       Unix-socket connections (Magnus Hagander)
       Formerly, such lines were silently ignored, which could be
       surprising. This makes the behavior more like other unsupported
       cases.
     * Allow GSSAPI to be used to authenticate to servers via SSPI
       (Christian Ullrich)
       Specifically this allows Unix-based GSSAPI clients to do SSPI
       authentication with Windows servers.
     * ident authentication over local sockets is now known as peer
       (Magnus Hagander)
       The old term is still accepted for backward compatibility, but
       since the two methods are fundamentally different, it seemed better
       to adopt different names for them.
     * Rewrite peer authentication to avoid use of credential control
       messages (Tom Lane)
       This change makes the peer authentication code simpler and
       better-performing. However, it requires the platform to provide the
       getpeereid function or an equivalent socket operation. So far as is
       known, the only platform for which peer authentication worked
       before and now will not is pre-5.0 NetBSD.
     __________________________________________________________________

Monitoring

     * Add details to the logging of restartpoints and checkpoints, which
       is controlled by log_checkpoints (Fujii Masao, Greg Smith)
       New details include WAL file and sync activity.
     * Add log_file_mode which controls the permissions on log files
       created by the logging collector (Martin Pihlak)
     * Reduce the default maximum line length for syslog logging to 900
       bytes plus prefixes (Noah Misch)
       This avoids truncation of long log lines on syslog implementations
       that have a 1KB length limit, rather than the more common 2KB.
     __________________________________________________________________

Statistical Views

     * Add client_hostname column to pg_stat_activity (Peter Eisentraut)
       Previously only the client address was reported.
     * Add pg_stat_xact_* statistics functions and views (Joel Jacobson)
       These are like the database-wide statistics counter views, but
       reflect counts for only the current transaction.
     * Add time of last reset in database-level and background writer
       statistics views (Tomas Vondra)
     * Add columns showing the number of vacuum and analyze operations in
       pg_stat_*_tables views (Magnus Hagander)
     * Add buffers_backend_fsync column to pg_stat_bgwriter (Greg Smith)
       This new column counts the number of times a backend fsyncs a
       buffer.
     __________________________________________________________________

Server Settings

     * Provide auto-tuning of wal_buffers (Greg Smith)
       By default, the value of wal_buffers is now chosen automatically
       based on the value of shared_buffers.
     * Increase the maximum values for deadlock_timeout,
       log_min_duration_statement, and log_autovacuum_min_duration (Peter
       Eisentraut)
       The maximum value for each of these parameters was previously only
       about 35 minutes. Much larger values are now allowed.
     __________________________________________________________________

Replication and Recovery

Streaming Replication and Continuous Archiving

     * Allow synchronous replication (Simon Riggs, Fujii Masao)
       This allows the primary server to wait for a standby to write a
       transaction's information to disk before acknowledging the commit.
       One standby at a time can take the role of the synchronous standby,
       as controlled by the synchronous_standby_names setting. Synchronous
       replication can be enabled or disabled on a per-transaction basis
       using the synchronous_commit setting.
     * Add protocol support for sending file system backups to standby
       servers using the streaming replication network connection (Magnus
       Hagander, Heikki Linnakangas)
       This avoids the requirement of manually transferring a file system
       backup when setting up a standby server.
     * Add replication_timeout setting (Fujii Masao, Heikki Linnakangas)
       Replication connections that are idle for more than the
       replication_timeout interval will be terminated automatically.
       Formerly, a failed connection was typically not detected until the
       TCP timeout elapsed, which is inconveniently long in many
       situations.
     * Add command-line tool pg_basebackup for creating a new standby
       server or database backup (Magnus Hagander)
     * Add a replication permission for roles (Magnus Hagander)
       This is a read-only permission used for streaming replication. It
       allows a non-superuser role to be used for replication connections.
       Previously only superusers could initiate replication connections;
       superusers still have this permission by default.
     __________________________________________________________________

Replication Monitoring

     * Add system view pg_stat_replication which displays activity of WAL
       sender processes (Itagaki Takahiro, Simon Riggs)
       This reports the status of all connected standby servers.
     * Add monitoring function pg_last_xact_replay_timestamp() (Fujii
       Masao)
       This returns the time at which the primary generated the most
       recent commit or abort record applied on the standby.
     __________________________________________________________________

Hot Standby

     * Add configuration parameter hot_standby_feedback to enable standbys
       to postpone cleanup of old row versions on the primary (Simon
       Riggs)
       This helps avoid canceling long-running queries on the standby.
     * Add the pg_stat_database_conflicts system view to show queries that
       have been canceled and the reason (Magnus Hagander)
       Cancellations can occur because of dropped tablespaces, lock
       timeouts, old snapshots, pinned buffers, and deadlocks.
     * Add a conflicts count to pg_stat_database (Magnus Hagander)
       This is the number of conflicts that occurred in the database.
     * Increase the maximum values for max_standby_archive_delay and
       max_standby_streaming_delay
       The maximum value for each of these parameters was previously only
       about 35 minutes. Much larger values are now allowed.
     * Add ERRCODE_T_R_DATABASE_DROPPED error code to report recovery
       conflicts due to dropped databases (Tatsuo Ishii)
       This is useful for connection pooling software.
     __________________________________________________________________

Recovery Control

     * Add functions to control streaming replication replay (Simon Riggs)
       The new functions are pg_xlog_replay_pause(),
       pg_xlog_replay_resume(), and the status function
       pg_is_xlog_replay_paused().
     * Add "recovery.conf" setting pause_at_recovery_target to pause
       recovery at target (Simon Riggs)
       This allows a recovery server to be queried to check whether the
       recovery point is the one desired.
     * Add the ability to create named restore points using
       pg_create_restore_point() (Jaime Casanova)
       These named restore points can be specified as recovery targets
       using the new "recovery.conf" setting recovery_target_name.
     * Allow standby recovery to switch to a new timeline automatically
       (Heikki Linnakangas)
       Now standby servers scan the archive directory for new timelines
       periodically.
     * Add restart_after_crash setting which disables automatic server
       restart after a backend crash (Robert Haas)
       This allows external cluster management software to control whether
       the database server restarts or not.
     * Allow "recovery.conf" to use the same quoting behavior as
       "postgresql.conf" (Dimitri Fontaine)
       Previously all values had to be quoted.
     __________________________________________________________________

Queries

     * Add a true serializable isolation level (Kevin Grittner, Dan Ports)
       Previously, asking for serializable isolation guaranteed only that
       a single MVCC snapshot would be used for the entire transaction,
       which allowed certain documented anomalies. The old snapshot
       isolation behavior is still available by requesting the REPEATABLE
       READ isolation level.
     * Allow data-modification commands ("INSERT"/"UPDATE"/"DELETE") in
       WITH clauses (Marko Tiikkaja, Hitoshi Harada)
       These commands can use RETURNING to pass data up to the containing
       query.
     * Allow WITH clauses to be attached to "INSERT", "UPDATE", "DELETE"
       statements (Marko Tiikkaja, Hitoshi Harada)
     * Allow non-GROUP BY columns in the query target list when the
       primary key is specified in the GROUP BY clause (Peter Eisentraut)
       The SQL standard allows this behavior, and because of the primary
       key, the result is unambiguous.
     * Allow use of the key word DISTINCT in UNION/INTERSECT/EXCEPT
       clauses (Tom Lane)
       DISTINCT is the default behavior so use of this key word is
       redundant, but the SQL standard allows it.
     * Fix ordinary queries with rules to use the same snapshot behavior
       as "EXPLAIN ANALYZE" (Marko Tiikkaja)
       Previously "EXPLAIN ANALYZE" used slightly different snapshot
       timing for queries involving rules. The "EXPLAIN ANALYZE" behavior
       was judged to be more logical.
     __________________________________________________________________

Strings

     * Add per-column collation support (Peter Eisentraut, Tom Lane)
       Previously collation (the sort ordering of text strings) could only
       be chosen at database creation. Collation can now be set per
       column, domain, index, or expression, via the SQL-standard COLLATE
       clause.
     __________________________________________________________________

Object Manipulation

     * Add extensions which simplify packaging of additions to PostgreSQL
       (Dimitri Fontaine, Tom Lane)
       Extensions are controlled by the new "CREATE"/"ALTER"/"DROP
       EXTENSION" commands. This replaces ad-hoc methods of grouping
       objects that are added to a PostgreSQL installation.
     * Add support for foreign tables (Shigeru Hanada, Robert Haas, Jan
       Urbanski, Heikki Linnakangas)
       This allows data stored outside the database to be used like native
       PostgreSQL-stored data. Foreign tables are currently read-only,
       however.
     * Allow new values to be added to an existing enum type via "ALTER
       TYPE" (Andrew Dunstan)
     * Add "ALTER TYPE ... ADD/DROP/ALTER/RENAME ATTRIBUTE" (Peter
       Eisentraut)
       This allows modification of composite types.
     __________________________________________________________________

ALTER Object

     * Add RESTRICT/CASCADE to "ALTER TYPE" operations on typed tables
       (Peter Eisentraut)
       This controls ADD/DROP/ALTER/RENAME ATTRIBUTE cascading behavior.
     * Support ALTER TABLE name {OF | NOT OF} type (Noah Misch)
       This syntax allows a standalone table to be made into a typed
       table, or a typed table to be made standalone.
     * Add support for more object types in "ALTER ... SET SCHEMA"
       commands (Dimitri Fontaine)
       This command is now supported for conversions, operators, operator
       classes, operator families, text search configurations, text search
       dictionaries, text search parsers, and text search templates.
     __________________________________________________________________

CREATE/ALTER TABLE

     * Add "ALTER TABLE ... ADD UNIQUE/PRIMARY KEY USING INDEX" (Gurjeet
       Singh)
       This allows a primary key or unique constraint to be defined using
       an existing unique index, including a concurrently created unique
       index.
     * Allow "ALTER TABLE" to add foreign keys without validation (Simon
       Riggs)
       The new option is called NOT VALID. The constraint's state can
       later be modified to VALIDATED and validation checks performed.
       Together these allow you to add a foreign key with minimal impact
       on read and write operations.
     * Allow "ALTER TABLE ... SET DATA TYPE" to avoid table rewrites in
       appropriate cases (Noah Misch, Robert Haas)
       For example, converting a varchar column to text no longer requires
       a rewrite of the table. However, increasing the length constraint
       on a varchar column still requires a table rewrite.
     * Add "CREATE TABLE IF NOT EXISTS" syntax (Robert Haas)
       This allows table creation without causing an error if the table
       already exists.
     * Fix possible "tuple concurrently updated" error when two backends
       attempt to add an inheritance child to the same table at the same
       time (Robert Haas)
       "ALTER TABLE" now takes a stronger lock on the parent table, so
       that the sessions cannot try to update it simultaneously.
     __________________________________________________________________

Object Permissions

     * Add a "SECURITY LABEL" command (KaiGai Kohei)
       This allows security labels to be assigned to objects.
     __________________________________________________________________

Utility Operations

     * Add transaction-level advisory locks (Marko Tiikkaja)
       These are similar to the existing session-level advisory locks, but
       such locks are automatically released at transaction end.
     * Make "TRUNCATE ... RESTART IDENTITY" restart sequences
       transactionally (Steve Singer)
       Previously the counter could have been left out of sync if a
       backend crashed between the on-commit truncation activity and
       commit completion.
     __________________________________________________________________

COPY

     * Add ENCODING option to "COPY TO/FROM" (Hitoshi Harada, Itagaki
       Takahiro)
       This allows the encoding of the "COPY" file to be specified
       separately from client encoding.
     * Add bidirectional "COPY" protocol support (Fujii Masao)
       This is currently only used by streaming replication.
     __________________________________________________________________

EXPLAIN

     * Make "EXPLAIN VERBOSE" show the function call expression in a
       FunctionScan node (Tom Lane)
     __________________________________________________________________

VACUUM

     * Add additional details to the output of "VACUUM FULL VERBOSE" and
       "CLUSTER VERBOSE" (Itagaki Takahiro)
       New information includes the live and dead tuple count and whether
       "CLUSTER" is using an index to rebuild.
     * Prevent autovacuum from waiting if it cannot acquire a table lock
       (Robert Haas)
       It will try to vacuum that table later.
     __________________________________________________________________

CLUSTER

     * Allow "CLUSTER" to sort the table rather than scanning the index
       when it seems likely to be cheaper (Leonardo Francalanci)
     __________________________________________________________________

Indexes

     * Add nearest-neighbor (order-by-operator) searching to GiST indexes
       (Teodor Sigaev, Tom Lane)
       This allows GiST indexes to quickly return the "N" closest values
       in a query with LIMIT. For example
SELECT * FROM places ORDER BY location <-> point '(101,456)' LIMIT 10;
       finds the ten places closest to a given target point.
     * Allow GIN indexes to index null and empty values (Tom Lane)
       This allows full GIN index scans, and fixes various corner cases in
       which GIN scans would fail.
     * Allow GIN indexes to better recognize duplicate search entries (Tom
       Lane)
       This reduces the cost of index scans, especially in cases where it
       avoids unnecessary full index scans.
     * Fix GiST indexes to be fully crash-safe (Heikki Linnakangas)
       Previously there were rare cases where a "REINDEX" would be
       required (you would be informed).
     __________________________________________________________________

Data Types

     * Allow numeric to use a more compact, two-byte header in common
       cases (Robert Haas)
       Previously all numeric values had four-byte headers; this change
       saves on disk storage.
     * Add support for dividing money by money (Andy Balholm)
     * Allow binary I/O on type void (Radoslaw Smogura)
     * Improve hypotenuse calculations for geometric operators (Paul
       Matthews)
       This avoids unnecessary overflows, and may also be more accurate.
     * Support hashing array values (Tom Lane)
       This provides additional query optimization possibilities.
     * Don't treat a composite type as sortable unless all its column
       types are sortable (Tom Lane)
       This avoids possible "could not identify a comparison function"
       failures at runtime, if it is possible to implement the query
       without sorting. Also, "ANALYZE" won't try to use inappropriate
       statistics-gathering methods for columns of such composite types.
     __________________________________________________________________

Casting

     * Add support for casting between money and numeric (Andy Balholm)
     * Add support for casting from int4 and int8 to money (Joey Adams)
     * Allow casting a table's row type to the table's supertype if it's a
       typed table (Peter Eisentraut)
       This is analogous to the existing facility that allows casting a
       row type to a supertable's row type.
     __________________________________________________________________

XML

     * Add XML function XMLEXISTS and xpath_exists() functions (Mike
       Fowler)
       These are used for XPath matching.
     * Add XML functions xml_is_well_formed(),
       xml_is_well_formed_document(), xml_is_well_formed_content() (Mike
       Fowler)
       These check whether the input is properly-formed XML. They provide
       functionality that was previously available only in the deprecated
       "contrib/xml2" module.
     __________________________________________________________________

Functions

     * Add SQL function format(text, ...), which behaves analogously to
       C's printf() (Pavel Stehule, Robert Haas)
       It currently supports formats for strings, SQL literals, and SQL
       identifiers.
     * Add string functions concat(), concat_ws(), left(), right(), and
       reverse() (Pavel Stehule)
       These improve compatibility with other database products.
     * Add function pg_read_binary_file() to read binary files (Dimitri
       Fontaine, Itagaki Takahiro)
     * Add a single-parameter version of function pg_read_file() to read
       an entire file (Dimitri Fontaine, Itagaki Takahiro)
     * Add three-parameter forms of array_to_string() and
       string_to_array() for null value processing control (Pavel Stehule)
     __________________________________________________________________

Object Information Functions

     * Add the pg_describe_object() function (Alvaro Herrera)
       This function is used to obtain a human-readable string describing
       an object, based on the pg_class OID, object OID, and sub-object
       ID. It can be used to help interpret the contents of pg_depend.
     * Update comments for built-in operators and their underlying
       functions (Tom Lane)
       Functions that are meant to be used via an associated operator are
       now commented as such.
     * Add variable quote_all_identifiers to force the quoting of all
       identifiers in "EXPLAIN" and in system catalog functions like
       pg_get_viewdef() (Robert Haas)
       This makes exporting schemas to tools and other databases with
       different quoting rules easier.
     * Add columns to the information_schema.sequences system view (Peter
       Eisentraut)
       Previously, though the view existed, the columns about the sequence
       parameters were unimplemented.
     * Allow public as a pseudo-role name in has_table_privilege() and
       related functions (Alvaro Herrera)
       This allows checking for public permissions.
     __________________________________________________________________

Function and Trigger Creation

     * Support INSTEAD OF triggers on views (Dean Rasheed)
       This feature can be used to implement fully updatable views.
     __________________________________________________________________

Server-Side Languages

PL/pgSQL Server-Side Language

     * Add "FOREACH IN ARRAY" to PL/pgSQL (Pavel Stehule)
       This is more efficient and readable than previous methods of
       iterating through the elements of an array value.
     * Allow "RAISE" without parameters to be caught in the same places
       that could catch a "RAISE ERROR" from the same location (Piyush
       Newe)
       The previous coding threw the error from the block containing the
       active exception handler. The new behavior is more consistent with
       other DBMS products.
     __________________________________________________________________

PL/Perl Server-Side Language

     * Allow generic record arguments to PL/Perl functions (Andrew
       Dunstan)
       PL/Perl functions can now be declared to accept type record. The
       behavior is the same as for any named composite type.
     * Convert PL/Perl array arguments to Perl arrays (Alexey Klyukin,
       Alex Hunsaker)
       String representations are still available.
     * Convert PL/Perl composite-type arguments to Perl hashes (Alexey
       Klyukin, Alex Hunsaker)
       String representations are still available.
     __________________________________________________________________

PL/Python Server-Side Language

     * Add table function support for PL/Python (Jan Urbanski)
       PL/Python can now return multiple OUT parameters and record sets.
     * Add a validator to PL/Python (Jan Urbanski)
       This allows PL/Python functions to be syntax-checked at function
       creation time.
     * Allow exceptions for SQL queries in PL/Python (Jan Urbanski)
       This allows access to SQL-generated exception error codes from
       PL/Python exception blocks.
     * Add explicit subtransactions to PL/Python (Jan Urbanski)
     * Add PL/Python functions for quoting strings (Jan Urbanski)
       These functions are plpy.quote_ident, plpy.quote_literal, and
       plpy.quote_nullable.
     * Add traceback information to PL/Python errors (Jan Urbanski)
     * Report PL/Python errors from iterators with PLy_elog (Jan Urbanski)
     * Fix exception handling with Python 3 (Jan Urbanski)
       Exception classes were previously not available in plpy under
       Python 3.
     __________________________________________________________________

Client Applications

     * Mark createlang and droplang as deprecated now that they just
       invoke extension commands (Tom Lane)
     __________________________________________________________________

psql

     * Add psql command \conninfo to show current connection information
       (David Christensen)
     * Add psql command \sf to show a function's definition (Pavel
       Stehule)
     * Add psql command \dL to list languages (Fernando Ike)
     * Add the "S" ("system") option to psql's \dn (list schemas) command
       (Tom Lane)
       \dn without S now suppresses system schemas.
     * Allow psql's \e and \ef commands to accept a line number to be used
       to position the cursor in the editor (Pavel Stehule)
       This is passed to the editor according to the
       PSQL_EDITOR_LINENUMBER_ARG environment variable.
     * Have psql set the client encoding from the operating system locale
       by default (Heikki Linnakangas)
       This only happens if the PGCLIENTENCODING environment variable is
       not set.
     * Make \d distinguish between unique indexes and unique constraints
       (Josh Kupershmidt)
     * Make \dt+ report pg_table_size instead of pg_relation_size when
       talking to 9.0 or later servers (Bernd Helmle)
       This is a more useful measure of table size, but note that it is
       not identical to what was previously reported in the same display.
     * Additional tab completion support (Itagaki Takahiro, Pavel Stehule,
       Andrey Popp, Christoph Berg, David Fetter, Josh Kupershmidt)
     __________________________________________________________________

pg_dump

     * Add pg_dump and pg_dumpall option "--quote-all-identifiers" to
       force quoting of all identifiers (Robert Haas)
     * Add directory format to pg_dump (Joachim Wieland, Heikki
       Linnakangas)
       This is internally similar to the tar pg_dump format.
     __________________________________________________________________

pg_ctl

     * Fix pg_ctl so it no longer incorrectly reports that the server is
       not running (Bruce Momjian)
       Previously this could happen if the server was running but pg_ctl
       could not authenticate.
     * Improve pg_ctl start's "wait" ("-w") option (Bruce Momjian, Tom
       Lane)
       The wait mode is now significantly more robust. It will not get
       confused by non-default postmaster port numbers, non-default
       Unix-domain socket locations, permission problems, or stale
       postmaster lock files.
     * Add promote option to pg_ctl to switch a standby server to primary
       (Fujii Masao)
     __________________________________________________________________

Development Tools

libpq

     * Add a libpq connection option client_encoding which behaves like
       the PGCLIENTENCODING environment variable (Heikki Linnakangas)
       The value auto sets the client encoding based on the operating
       system locale.
     * Add PQlibVersion() function which returns the libpq library version
       (Magnus Hagander)
       libpq already had PQserverVersion() which returns the server
       version.
     * Allow libpq-using clients to check the user name of the server
       process when connecting via Unix-domain sockets, with the new
       requirepeer connection option (Peter Eisentraut)
       PostgreSQL already allowed servers to check the client user name
       when connecting via Unix-domain sockets.
     * Add PQping() and PQpingParams() to libpq (Bruce Momjian, Tom Lane)
       These functions allow detection of the server's status without
       trying to open a new session.
     __________________________________________________________________

ECPG

     * Allow ECPG to accept dynamic cursor names even in WHERE CURRENT OF
       clauses (Zoltan Boszormenyi)
     * Make ecpglib write double values with a precision of 15 digits, not
       14 as formerly (Akira Kurosawa)
     __________________________________________________________________

Build Options

     * Use +Olibmerrno compile flag with HP-UX C compilers that accept it
       (Ibrar Ahmed)
       This avoids possible misbehavior of math library calls on recent HP
       platforms.
     __________________________________________________________________

Makefiles

     * Improved parallel make support (Peter Eisentraut)
       This allows for faster compiles. Also, make -k now works more
       consistently.
     * Require GNU make 3.80 or newer (Peter Eisentraut)
       This is necessary because of the parallel-make improvements.
     * Add make maintainer-check target (Peter Eisentraut)
       This target performs various source code checks that are not
       appropriate for either the build or the regression tests.
       Currently: duplicate_oids, SGML syntax and tabs check, NLS syntax
       check.
     * Support make check in "contrib" (Peter Eisentraut)
       Formerly only make installcheck worked, but now there is support
       for testing in a temporary installation. The top-level make
       check-world target now includes testing "contrib" this way.
     __________________________________________________________________

Windows

     * On Windows, allow pg_ctl to register the service as auto-start or
       start-on-demand (Quan Zongliang)
     * Add support for collecting crash dumps on Windows (Craig Ringer,
       Magnus Hagander)
       minidumps can now be generated by non-debug Windows binaries and
       analyzed by standard debugging tools.
     * Enable building with the MinGW64 compiler (Andrew Dunstan)
       This allows building 64-bit Windows binaries even on non-Windows
       platforms via cross-compiling.
     __________________________________________________________________

Source Code

     * Revise the API for GUC variable assign hooks (Tom Lane)
       The previous functions of assign hooks are now split between check
       hooks and assign hooks, where the former can fail but the latter
       shouldn't. This change will impact add-on modules that define
       custom GUC parameters.
     * Add latches to the source code to support waiting for events
       (Heikki Linnakangas)
     * Centralize data modification permissions-checking logic (KaiGai
       Kohei)
     * Add missing get_object_oid() functions, for consistency (Robert
       Haas)
     * Improve ability to use C++ compilers for compiling add-on modules
       by removing conflicting key words (Tom Lane)
     * Add support for DragonFly BSD (Rumko)
     * Expose quote_literal_cstr() for backend use (Robert Haas)
     * Run regression tests in the default encoding (Peter Eisentraut)
       Regression tests were previously always run with SQL_ASCII
       encoding.
     * Add src/tools/git_changelog to replace cvs2cl and pgcvslog (Robert
       Haas, Tom Lane)
     * Add git-external-diff script to "src/tools" (Bruce Momjian)
       This is used to generate context diffs from git.
     * Improve support for building with Clang (Peter Eisentraut)
     __________________________________________________________________

Server Hooks

     * Add source code hooks to check permissions (Robert Haas, Stephen
       Frost)
     * Add post-object-creation function hooks for use by security
       frameworks (KaiGai Kohei)
     * Add a client authentication hook (KaiGai Kohei)
     __________________________________________________________________

Contrib

     * Modify "contrib" modules and procedural languages to install via
       the new extension mechanism (Tom Lane, Dimitri Fontaine)
     * Add "contrib/file_fdw" foreign-data wrapper (Shigeru Hanada)
       Foreign tables using this foreign data wrapper can read flat files
       in a manner very similar to "COPY".
     * Add nearest-neighbor search support to "contrib/pg_trgm" and
       "contrib/btree_gist" (Teodor Sigaev)
     * Add "contrib/btree_gist" support for searching on not-equals (Jeff
       Davis)
     * Fix "contrib/fuzzystrmatch"'s levenshtein() function to handle
       multibyte characters (Alexander Korotkov)
     * Add ssl_cipher() and ssl_version() functions to "contrib/sslinfo"
       (Robert Haas)
     * Fix "contrib/intarray" and "contrib/hstore" to give consistent
       results with indexed empty arrays (Tom Lane)
       Previously an empty-array query that used an index might return
       different results from one that used a sequential scan.
     * Allow "contrib/intarray" to work properly on multidimensional
       arrays (Tom Lane)
     * In "contrib/intarray", avoid errors complaining about the presence
       of nulls in cases where no nulls are actually present (Tom Lane)
     * In "contrib/intarray", fix behavior of containment operators with
       respect to empty arrays (Tom Lane)
       Empty arrays are now correctly considered to be contained in any
       other array.
     * Remove "contrib/xml2"'s arbitrary limit on the number of
       "parameter"="value" pairs that can be handled by xslt_process()
       (Pavel Stehule)
       The previous limit was 10.
     * In "contrib/pageinspect", fix heap_page_item to return infomasks as
       32-bit values (Alvaro Herrera)
       This avoids returning negative values, which was confusing. The
       underlying value is a 16-bit unsigned integer.
     __________________________________________________________________

Security

     * Add "contrib/sepgsql" to interface permission checks with SELinux
       (KaiGai Kohei)
       This uses the new "SECURITY LABEL" facility.
     * Add contrib module "auth_delay" (KaiGai Kohei)
       This causes the server to pause before returning authentication
       failure; it is designed to make brute force password attacks more
       difficult.
     * Add "dummy_seclabel" contrib module (KaiGai Kohei)
       This is used for permission regression testing.
     __________________________________________________________________

Performance

     * Add support for LIKE and ILIKE index searches to "contrib/pg_trgm"
       (Alexander Korotkov)
     * Add levenshtein_less_equal() function to "contrib/fuzzystrmatch",
       which is optimized for small distances (Alexander Korotkov)
     * Improve performance of index lookups on "contrib/seg" columns
       (Alexander Korotkov)
     * Improve performance of pg_upgrade for databases with many relations
       (Bruce Momjian)
     * Add flag to "contrib/pgbench" to report per-statement latencies
       (Florian Pflug)
     __________________________________________________________________

Fsync Testing

     * Move "src/tools/test_fsync" to "contrib/pg_test_fsync" (Bruce
       Momjian, Tom Lane)
     * Add O_DIRECT support to "contrib/pg_test_fsync" (Bruce Momjian)
       This matches the use of O_DIRECT by wal_sync_method.
     * Add new tests to "contrib/pg_test_fsync" (Bruce Momjian)
     __________________________________________________________________

Documentation

     * Extensive ECPG documentation improvements (Satoshi Nagayasu)
     * Extensive proofreading and documentation improvements (Thom Brown,
       Josh Kupershmidt, Susanne Ebrecht)
     * Add documentation for exit_on_error (Robert Haas)
       This parameter causes sessions to exit on any error.
     * Add documentation for pg_options_to_table() (Josh Berkus)
       This function shows table storage options in a readable form.
     * Document that it is possible to access all composite type fields
       using (compositeval).* syntax (Peter Eisentraut)
     * Document that translate() removes characters in from that don't
       have a corresponding to character (Josh Kupershmidt)
     * Merge documentation for "CREATE CONSTRAINT TRIGGER" and "CREATE
       TRIGGER" (Alvaro Herrera)
     * Centralize permission and upgrade documentation (Bruce Momjian)
     * Add kernel tuning documentation for Solaris 10 (Josh Berkus)
       Previously only Solaris 9 kernel tuning was documented.
     * Handle non-ASCII characters consistently in "HISTORY" file (Peter
       Eisentraut)
       While the "HISTORY" file is in English, we do have to deal with
       non-ASCII letters in contributor names. These are now
       transliterated so that they are reasonably legible without
       assumptions about character set.
     __________________________________________________________________

                               Release 9.0.15

     Release Date: 2013-12-05

   This release contains a variety of fixes from 9.0.14. For information
   about new features in the 9.0 major release, see the Section called
   Release 9.0.
     __________________________________________________________________

Migration to Version 9.0.15

   A dump/restore is not required for those running 9.0.X.

   However, this release corrects a number of potential data corruption
   issues. See the first two changelog entries below to find out whether
   your installation has been affected and what steps you can take if so.

   Also, if you are upgrading from a version earlier than 9.0.13, see the
   release notes for 9.0.13.
     __________________________________________________________________

Changes

     * Fix "VACUUM"'s tests to see whether it can update relfrozenxid
       (Andres Freund)
       In some cases "VACUUM" (either manual or autovacuum) could
       incorrectly advance a table's relfrozenxid value, allowing tuples
       to escape freezing, causing those rows to become invisible once
       2^31 transactions have elapsed. The probability of data loss is
       fairly low since multiple incorrect advancements would need to
       happen before actual loss occurs, but it's not zero. Users
       upgrading from releases 9.0.4 or 8.4.8 or earlier are not affected,
       but all later versions contain the bug.
       The issue can be ameliorated by, after upgrading, vacuuming all
       tables in all databases while having vacuum_freeze_table_age set to
       zero. This will fix any latent corruption but will not be able to
       fix all pre-existing data errors. However, an installation can be
       presumed safe after performing this vacuuming if it has executed
       fewer than 2^31 update transactions in its lifetime (check this
       with SELECT txid_current() < 2^31).
     * Fix initialization of "pg_clog" and "pg_subtrans" during hot
       standby startup (Andres Freund, Heikki Linnakangas)
       This bug can cause data loss on standby servers at the moment they
       start to accept hot-standby queries, by marking committed
       transactions as uncommitted. The likelihood of such corruption is
       small unless, at the time of standby startup, the primary server
       has executed many updating transactions since its last checkpoint.
       Symptoms include missing rows, rows that should have been deleted
       being still visible, and obsolete versions of updated rows being
       still visible alongside their newer versions.
       This bug was introduced in versions 9.3.0, 9.2.5, 9.1.10, and
       9.0.14. Standby servers that have only been running earlier
       releases are not at risk. It's recommended that standby servers
       that have ever run any of the buggy releases be re-cloned from the
       primary (e.g., with a new base backup) after upgrading.
     * Truncate "pg_multixact" contents during WAL replay (Andres Freund)
       This avoids ever-increasing disk space consumption in standby
       servers.
     * Fix race condition in GIN index posting tree page deletion (Heikki
       Linnakangas)
       This could lead to transient wrong answers or query failures.
     * Avoid flattening a subquery whose SELECT list contains a volatile
       function wrapped inside a sub-SELECT (Tom Lane)
       This avoids unexpected results due to extra evaluations of the
       volatile function.
     * Fix planner's processing of non-simple-variable subquery outputs
       nested within outer joins (Tom Lane)
       This error could lead to incorrect plans for queries involving
       multiple levels of subqueries within JOIN syntax.
     * Fix premature deletion of temporary files (Andres Freund)
     * Fix possible read past end of memory in rule printing (Peter
       Eisentraut)
     * Fix array slicing of int2vector and oidvector values (Tom Lane)
       Expressions of this kind are now implicitly promoted to regular
       int2 or oid arrays.
     * Fix incorrect behaviors when using a SQL-standard, simple GMT
       offset timezone (Tom Lane)
       In some cases, the system would use the simple GMT offset value
       when it should have used the regular timezone setting that had
       prevailed before the simple offset was selected. This change also
       causes the timeofday function to honor the simple GMT offset zone.
     * Prevent possible misbehavior when logging translations of Windows
       error codes (Tom Lane)
     * Properly quote generated command lines in pg_ctl (Naoya Anzai and
       Tom Lane)
       This fix applies only to Windows.
     * Fix pg_dumpall to work when a source database sets
       default_transaction_read_only via "ALTER DATABASE SET" (Kevin
       Grittner)
       Previously, the generated script would fail during restore.
     * Fix ecpg's processing of lists of variables declared varchar
       (Zoltan Boszormenyi)
     * Make "contrib/lo" defend against incorrect trigger definitions
       (Marc Cousin)
     * Update time zone data files to tzdata release 2013h for DST law
       changes in Argentina, Brazil, Jordan, Libya, Liechtenstein,
       Morocco, and Palestine. Also, new timezone abbreviations WIB, WIT,
       WITA for Indonesia.
     __________________________________________________________________

                               Release 9.0.14

     Release Date: 2013-10-10

   This release contains a variety of fixes from 9.0.13. For information
   about new features in the 9.0 major release, see the Section called
   Release 9.0.
     __________________________________________________________________

Migration to Version 9.0.14

   A dump/restore is not required for those running 9.0.X.

   However, if you are upgrading from a version earlier than 9.0.13, see
   the release notes for 9.0.13.
     __________________________________________________________________

Changes

     * Prevent corruption of multi-byte characters when attempting to
       case-fold identifiers (Andrew Dunstan)
       PostgreSQL case-folds non-ASCII characters only when using a
       single-byte server encoding.
     * Fix checkpoint memory leak in background writer when wal_level =
       hot_standby (Naoya Anzai)
     * Fix memory leak caused by lo_open() failure (Heikki Linnakangas)
     * Fix memory overcommit bug when work_mem is using more than 24GB of
       memory (Stephen Frost)
     * Fix deadlock bug in libpq when using SSL (Stephen Frost)
     * Fix possible SSL state corruption in threaded libpq applications
       (Nick Phillips, Stephen Frost)
     * Properly compute row estimates for boolean columns containing many
       NULL values (Andrew Gierth)
       Previously tests like col IS NOT TRUE and col IS NOT FALSE did not
       properly factor in NULL values when estimating plan costs.
     * Prevent pushing down WHERE clauses into unsafe UNION/INTERSECT
       subqueries (Tom Lane)
       Subqueries of a UNION or INTERSECT that contain set-returning
       functions or volatile functions in their SELECT lists could be
       improperly optimized, leading to run-time errors or incorrect query
       results.
     * Fix rare case of "failed to locate grouping columns" planner
       failure (Tom Lane)
     * Improve view dumping code's handling of dropped columns in
       referenced tables (Tom Lane)
     * Properly record index comments created using UNIQUE and PRIMARY KEY
       syntax (Andres Freund)
       This fixes a parallel pg_restore failure.
     * Fix "REINDEX TABLE" and "REINDEX DATABASE" to properly revalidate
       constraints and mark invalidated indexes as valid (Noah Misch)
       "REINDEX INDEX" has always worked properly.
     * Fix possible deadlock during concurrent "CREATE INDEX CONCURRENTLY"
       operations (Tom Lane)
     * Fix regexp_matches() handling of zero-length matches (Jeevan
       Chalke)
       Previously, zero-length matches like '^' could return too many
       matches.
     * Fix crash for overly-complex regular expressions (Heikki
       Linnakangas)
     * Fix regular expression match failures for back references combined
       with non-greedy quantifiers (Jeevan Chalke)
     * Prevent "CREATE FUNCTION" from checking "SET" variables unless
       function body checking is enabled (Tom Lane)
     * Allow "ALTER DEFAULT PRIVILEGES" to operate on schemas without
       requiring CREATE permission (Tom Lane)
     * Loosen restriction on keywords used in queries (Tom Lane)
       Specifically, lessen keyword restrictions for role names, language
       names, "EXPLAIN" and "COPY" options, and "SET" values. This allows
       COPY ... (FORMAT BINARY) to work as expected; previously BINARY
       needed to be quoted.
     * Fix pgp_pub_decrypt() so it works for secret keys with passwords
       (Marko Kreen)
     * Remove rare inaccurate warning during vacuum of index-less tables
       (Heikki Linnakangas)
     * Ensure that "VACUUM ANALYZE" still runs the ANALYZE phase if its
       attempt to truncate the file is cancelled due to lock conflicts
       (Kevin Grittner)
     * Avoid possible failure when performing transaction control commands
       (e.g ROLLBACK) in prepared queries (Tom Lane)
     * Ensure that floating-point data input accepts standard spellings of
       "infinity" on all platforms (Tom Lane)
       The C99 standard says that allowable spellings are inf, +inf, -inf,
       infinity, +infinity, and -infinity. Make sure we recognize these
       even if the platform's strtod function doesn't.
     * Expand ability to compare rows to records and arrays (Rafal
       Rzepecki, Tom Lane)
     * Update time zone data files to tzdata release 2013d for DST law
       changes in Israel, Morocco, Palestine, and Paraguay. Also,
       historical zone data corrections for Macquarie Island.
     __________________________________________________________________

                               Release 9.0.13

     Release Date: 2013-04-04

   This release contains a variety of fixes from 9.0.12. For information
   about new features in the 9.0 major release, see the Section called
   Release 9.0.
     __________________________________________________________________

Migration to Version 9.0.13

   A dump/restore is not required for those running 9.0.X.

   However, this release corrects several errors in management of GiST
   indexes. After installing this update, it is advisable to "REINDEX" any
   GiST indexes that meet one or more of the conditions described below.

   Also, if you are upgrading from a version earlier than 9.0.6, see the
   release notes for 9.0.6.
     __________________________________________________________________

Changes

     * Fix insecure parsing of server command-line switches (Mitsumasa
       Kondo, Kyotaro Horiguchi)
       A connection request containing a database name that begins with
       "-" could be crafted to damage or destroy files within the server's
       data directory, even if the request is eventually rejected.
       (CVE-2013-1899)
     * Reset OpenSSL randomness state in each postmaster child process
       (Marko Kreen)
       This avoids a scenario wherein random numbers generated by
       "contrib/pgcrypto" functions might be relatively easy for another
       database user to guess. The risk is only significant when the
       postmaster is configured with ssl = on but most connections don't
       use SSL encryption. (CVE-2013-1900)
     * Fix GiST indexes to not use "fuzzy" geometric comparisons when it's
       not appropriate to do so (Alexander Korotkov)
       The core geometric types perform comparisons using "fuzzy"
       equality, but gist_box_same must do exact comparisons, else GiST
       indexes using it might become inconsistent. After installing this
       update, users should "REINDEX" any GiST indexes on box, polygon,
       circle, or point columns, since all of these use gist_box_same.
     * Fix erroneous range-union and penalty logic in GiST indexes that
       use "contrib/btree_gist" for variable-width data types, that is
       text, bytea, bit, and numeric columns (Tom Lane)
       These errors could result in inconsistent indexes in which some
       keys that are present would not be found by searches, and also in
       useless index bloat. Users are advised to "REINDEX" such indexes
       after installing this update.
     * Fix bugs in GiST page splitting code for multi-column indexes (Tom
       Lane)
       These errors could result in inconsistent indexes in which some
       keys that are present would not be found by searches, and also in
       indexes that are unnecessarily inefficient to search. Users are
       advised to "REINDEX" multi-column GiST indexes after installing
       this update.
     * Fix gist_point_consistent to handle fuzziness consistently
       (Alexander Korotkov)
       Index scans on GiST indexes on point columns would sometimes yield
       results different from a sequential scan, because
       gist_point_consistent disagreed with the underlying operator code
       about whether to do comparisons exactly or fuzzily.
     * Fix buffer leak in WAL replay (Heikki Linnakangas)
       This bug could result in "incorrect local pin count" errors during
       replay, making recovery impossible.
     * Fix race condition in "DELETE RETURNING" (Tom Lane)
       Under the right circumstances, "DELETE RETURNING" could attempt to
       fetch data from a shared buffer that the current process no longer
       has any pin on. If some other process changed the buffer meanwhile,
       this would lead to garbage RETURNING output, or even a crash.
     * Fix infinite-loop risk in regular expression compilation (Tom Lane,
       Don Porter)
     * Fix potential null-pointer dereference in regular expression
       compilation (Tom Lane)
     * Fix to_char() to use ASCII-only case-folding rules where
       appropriate (Tom Lane)
       This fixes misbehavior of some template patterns that should be
       locale-independent, but mishandled "I" and "i" in Turkish locales.
     * Fix unwanted rejection of timestamp 1999-12-31 24:00:00 (Tom Lane)
     * Fix logic error when a single transaction does "UNLISTEN" then
       "LISTEN" (Tom Lane)
       The session wound up not listening for notify events at all, though
       it surely should listen in this case.
     * Remove useless "picksplit doesn't support secondary split" log
       messages (Josh Hansen, Tom Lane)
       This message seems to have been added in expectation of code that
       was never written, and probably never will be, since GiST's default
       handling of secondary splits is actually pretty good. So stop
       nagging end users about it.
     * Fix possible failure to send a session's last few transaction
       commit/abort counts to the statistics collector (Tom Lane)
     * Eliminate memory leaks in PL/Perl's spi_prepare() function (Alex
       Hunsaker, Tom Lane)
     * Fix pg_dumpall to handle database names containing "=" correctly
       (Heikki Linnakangas)
     * Avoid crash in pg_dump when an incorrect connection string is given
       (Heikki Linnakangas)
     * Ignore invalid indexes in pg_dump and pg_upgrade (Michael Paquier,
       Bruce Momjian)
       Dumping invalid indexes can cause problems at restore time, for
       example if the reason the index creation failed was because it
       tried to enforce a uniqueness condition not satisfied by the
       table's data. Also, if the index creation is in fact still in
       progress, it seems reasonable to consider it to be an uncommitted
       DDL change, which pg_dump wouldn't be expected to dump anyway.
       pg_upgrade now also skips invalid indexes rather than failing.
     * Fix "contrib/pg_trgm"'s similarity() function to return zero for
       trigram-less strings (Tom Lane)
       Previously it returned NaN due to internal division by zero.
     * Update time zone data files to tzdata release 2013b for DST law
       changes in Chile, Haiti, Morocco, Paraguay, and some Russian areas.
       Also, historical zone data corrections for numerous places.
       Also, update the time zone abbreviation files for recent changes in
       Russia and elsewhere: CHOT, GET, IRKT, KGT, KRAT, MAGT, MAWT, MSK,
       NOVT, OMST, TKT, VLAT, WST, YAKT, YEKT now follow their current
       meanings, and VOLT (Europe/Volgograd) and MIST
       (Antarctica/Macquarie) are added to the default abbreviations list.
     __________________________________________________________________

                               Release 9.0.12

     Release Date: 2013-02-07

   This release contains a variety of fixes from 9.0.11. For information
   about new features in the 9.0 major release, see the Section called
   Release 9.0.
     __________________________________________________________________

Migration to Version 9.0.12

   A dump/restore is not required for those running 9.0.X.

   However, if you are upgrading from a version earlier than 9.0.6, see
   the release notes for 9.0.6.
     __________________________________________________________________

Changes

     * Prevent execution of enum_recv from SQL (Tom Lane)
       The function was misdeclared, allowing a simple SQL command to
       crash the server. In principle an attacker might be able to use it
       to examine the contents of server memory. Our thanks to Sumit Soni
       (via Secunia SVCRP) for reporting this issue. (CVE-2013-0255)
     * Fix multiple problems in detection of when a consistent database
       state has been reached during WAL replay (Fujii Masao, Heikki
       Linnakangas, Simon Riggs, Andres Freund)
     * Update minimum recovery point when truncating a relation file
       (Heikki Linnakangas)
       Once data has been discarded, it's no longer safe to stop recovery
       at an earlier point in the timeline.
     * Fix missing cancellations in hot standby mode (Noah Misch, Simon
       Riggs)
       The need to cancel conflicting hot-standby queries would sometimes
       be missed, allowing those queries to see inconsistent data.
     * Fix SQL grammar to allow subscripting or field selection from a
       sub-SELECT result (Tom Lane)
     * Fix performance problems with autovacuum truncation in busy
       workloads (Jan Wieck)
       Truncation of empty pages at the end of a table requires exclusive
       lock, but autovacuum was coded to fail (and release the table lock)
       when there are conflicting lock requests. Under load, it is easily
       possible that truncation would never occur, resulting in table
       bloat. Fix by performing a partial truncation, releasing the lock,
       then attempting to re-acquire the lock and continue. This fix also
       greatly reduces the average time before autovacuum releases the
       lock after a conflicting request arrives.
     * Protect against race conditions when scanning pg_tablespace
       (Stephen Frost, Tom Lane)
       "CREATE DATABASE" and "DROP DATABASE" could misbehave if there were
       concurrent updates of pg_tablespace entries.
     * Prevent "DROP OWNED" from trying to drop whole databases or
       tablespaces (Alvaro Herrera)
       For safety, ownership of these objects must be reassigned, not
       dropped.
     * Fix error in vacuum_freeze_table_age implementation (Andres Freund)
       In installations that have existed for more than
       vacuum_freeze_min_age transactions, this mistake prevented
       autovacuum from using partial-table scans, so that a full-table
       scan would always happen instead.
     * Prevent misbehavior when a RowExpr or XmlExpr is parse-analyzed
       twice (Andres Freund, Tom Lane)
       This mistake could be user-visible in contexts such as CREATE TABLE
       LIKE INCLUDING INDEXES.
     * Improve defenses against integer overflow in hashtable sizing
       calculations (Jeff Davis)
     * Reject out-of-range dates in to_date() (Hitoshi Harada)
     * Ensure that non-ASCII prompt strings are translated to the correct
       code page on Windows (Alexander Law, Noah Misch)
       This bug affected psql and some other client programs.
     * Fix possible crash in psql's "\?" command when not connected to a
       database (Meng Qingzhong)
     * Fix pg_upgrade to deal with invalid indexes safely (Bruce Momjian)
     * Fix one-byte buffer overrun in libpq's PQprintTuples (Xi Wang)
       This ancient function is not used anywhere by PostgreSQL itself,
       but it might still be used by some client code.
     * Make ecpglib use translated messages properly (Chen Huajun)
     * Properly install ecpg_compat and pgtypes libraries on MSVC (Jiang
       Guiqing)
     * Include our version of isinf() in libecpg if it's not provided by
       the system (Jiang Guiqing)
     * Rearrange configure's tests for supplied functions so it is not
       fooled by bogus exports from libedit/libreadline (Christoph Berg)
     * Ensure Windows build number increases over time (Magnus Hagander)
     * Make pgxs build executables with the right .exe suffix when
       cross-compiling for Windows (Zoltan Boszormenyi)
     * Add new timezone abbreviation FET (Tom Lane)
       This is now used in some eastern-European time zones.
     __________________________________________________________________

                               Release 9.0.11

     Release Date: 2012-12-06

   This release contains a variety of fixes from 9.0.10. For information
   about new features in the 9.0 major release, see the Section called
   Release 9.0.
     __________________________________________________________________

Migration to Version 9.0.11

   A dump/restore is not required for those running 9.0.X.

   However, if you are upgrading from a version earlier than 9.0.6, see
   the release notes for 9.0.6.
     __________________________________________________________________

Changes

     * Fix multiple bugs associated with "CREATE INDEX CONCURRENTLY"
       (Andres Freund, Tom Lane)
       Fix "CREATE INDEX CONCURRENTLY" to use in-place updates when
       changing the state of an index's pg_index row. This prevents race
       conditions that could cause concurrent sessions to miss updating
       the target index, thus resulting in corrupt concurrently-created
       indexes.
       Also, fix various other operations to ensure that they ignore
       invalid indexes resulting from a failed "CREATE INDEX CONCURRENTLY"
       command. The most important of these is "VACUUM", because an
       auto-vacuum could easily be launched on the table before corrective
       action can be taken to fix or remove the invalid index.
     * Fix buffer locking during WAL replay (Tom Lane)
       The WAL replay code was insufficiently careful about locking
       buffers when replaying WAL records that affect more than one page.
       This could result in hot standby queries transiently seeing
       inconsistent states, resulting in wrong answers or unexpected
       failures.
     * Fix an error in WAL generation logic for GIN indexes (Tom Lane)
       This could result in index corruption, if a torn-page failure
       occurred.
     * Properly remove startup process's virtual XID lock when promoting a
       hot standby server to normal running (Simon Riggs)
       This oversight could prevent subsequent execution of certain
       operations such as "CREATE INDEX CONCURRENTLY".
     * Avoid bogus "out-of-sequence timeline ID" errors in standby mode
       (Heikki Linnakangas)
     * Prevent the postmaster from launching new child processes after
       it's received a shutdown signal (Tom Lane)
       This mistake could result in shutdown taking longer than it should,
       or even never completing at all without additional user action.
     * Avoid corruption of internal hash tables when out of memory
       (Hitoshi Harada)
     * Fix planning of non-strict equivalence clauses above outer joins
       (Tom Lane)
       The planner could derive incorrect constraints from a clause
       equating a non-strict construct to something else, for example
       WHERE COALESCE(foo, 0) = 0 when foo is coming from the nullable
       side of an outer join.
     * Improve planner's ability to prove exclusion constraints from
       equivalence classes (Tom Lane)
     * Fix partial-row matching in hashed subplans to handle cross-type
       cases correctly (Tom Lane)
       This affects multicolumn NOT IN subplans, such as WHERE (a, b) NOT
       IN (SELECT x, y FROM ...) when for instance b and y are int4 and
       int8 respectively. This mistake led to wrong answers or crashes
       depending on the specific datatypes involved.
     * Acquire buffer lock when re-fetching the old tuple for an AFTER ROW
       UPDATE/DELETE trigger (Andres Freund)
       In very unusual circumstances, this oversight could result in
       passing incorrect data to the precheck logic for a foreign-key
       enforcement trigger. That could result in a crash, or in an
       incorrect decision about whether to fire the trigger.
     * Fix "ALTER COLUMN TYPE" to handle inherited check constraints
       properly (Pavan Deolasee)
       This worked correctly in pre-8.4 releases, and now works correctly
       in 8.4 and later.
     * Fix "REASSIGN OWNED" to handle grants on tablespaces (Alvaro
       Herrera)
     * Ignore incorrect pg_attribute entries for system columns for views
       (Tom Lane)
       Views do not have any system columns. However, we forgot to remove
       such entries when converting a table to a view. That's fixed
       properly for 9.3 and later, but in previous branches we need to
       defend against existing mis-converted views.
     * Fix rule printing to dump INSERT INTO table DEFAULT VALUES
       correctly (Tom Lane)
     * Guard against stack overflow when there are too many
       UNION/INTERSECT/EXCEPT clauses in a query (Tom Lane)
     * Prevent platform-dependent failures when dividing the minimum
       possible integer value by -1 (Xi Wang, Tom Lane)
     * Fix possible access past end of string in date parsing (Hitoshi
       Harada)
     * Fix failure to advance XID epoch if XID wraparound happens during a
       checkpoint and wal_level is hot_standby (Tom Lane, Andres Freund)
       While this mistake had no particular impact on PostgreSQL itself,
       it was bad for applications that rely on txid_current() and related
       functions: the TXID value would appear to go backwards.
     * Produce an understandable error message if the length of the path
       name for a Unix-domain socket exceeds the platform-specific limit
       (Tom Lane, Andrew Dunstan)
       Formerly, this would result in something quite unhelpful, such as
       "Non-recoverable failure in name resolution".
     * Fix memory leaks when sending composite column values to the client
       (Tom Lane)
     * Make pg_ctl more robust about reading the "postmaster.pid" file
       (Heikki Linnakangas)
       Fix race conditions and possible file descriptor leakage.
     * Fix possible crash in psql if incorrectly-encoded data is presented
       and the client_encoding setting is a client-only encoding, such as
       SJIS (Jiang Guiqing)
     * Fix bugs in the "restore.sql" script emitted by pg_dump in tar
       output format (Tom Lane)
       The script would fail outright on tables whose names include
       upper-case characters. Also, make the script capable of restoring
       data in "--inserts" mode as well as the regular COPY mode.
     * Fix pg_restore to accept POSIX-conformant tar files (Brian Weaver,
       Tom Lane)
       The original coding of pg_dump's tar output mode produced files
       that are not fully conformant with the POSIX standard. This has
       been corrected for version 9.3. This patch updates previous
       branches so that they will accept both the incorrect and the
       corrected formats, in hopes of avoiding compatibility problems when
       9.3 comes out.
     * Fix pg_resetxlog to locate "postmaster.pid" correctly when given a
       relative path to the data directory (Tom Lane)
       This mistake could lead to pg_resetxlog not noticing that there is
       an active postmaster using the data directory.
     * Fix libpq's lo_import() and lo_export() functions to report file
       I/O errors properly (Tom Lane)
     * Fix ecpg's processing of nested structure pointer variables
       (Muhammad Usama)
     * Fix ecpg's ecpg_get_data function to handle arrays properly
       (Michael Meskes)
     * Make "contrib/pageinspect"'s btree page inspection functions take
       buffer locks while examining pages (Tom Lane)
     * Fix pgxs support for building loadable modules on AIX (Tom Lane)
       Building modules outside the original source tree didn't work on
       AIX.
     * Update time zone data files to tzdata release 2012j for DST law
       changes in Cuba, Israel, Jordan, Libya, Palestine, Western Samoa,
       and portions of Brazil.
     __________________________________________________________________

                               Release 9.0.10

     Release Date: 2012-09-24

   This release contains a variety of fixes from 9.0.9. For information
   about new features in the 9.0 major release, see the Section called
   Release 9.0.
     __________________________________________________________________

Migration to Version 9.0.10

   A dump/restore is not required for those running 9.0.X.

   However, if you are upgrading from a version earlier than 9.0.6, see
   the release notes for 9.0.6.
     __________________________________________________________________

Changes

     * Fix planner's assignment of executor parameters, and fix executor's
       rescan logic for CTE plan nodes (Tom Lane)
       These errors could result in wrong answers from queries that scan
       the same WITH subquery multiple times.
     * Improve page-splitting decisions in GiST indexes (Alexander
       Korotkov, Robert Haas, Tom Lane)
       Multi-column GiST indexes might suffer unexpected bloat due to this
       error.
     * Fix cascading privilege revoke to stop if privileges are still held
       (Tom Lane)
       If we revoke a grant option from some role "X", but "X" still holds
       that option via a grant from someone else, we should not
       recursively revoke the corresponding privilege from role(s) "Y"
       that "X" had granted it to.
     * Improve error messages for Hot Standby misconfiguration errors
       (Gurjeet Singh)
     * Fix handling of SIGFPE when PL/Perl is in use (Andres Freund)
       Perl resets the process's SIGFPE handler to SIG_IGN, which could
       result in crashes later on. Restore the normal Postgres signal
       handler after initializing PL/Perl.
     * Prevent PL/Perl from crashing if a recursive PL/Perl function is
       redefined while being executed (Tom Lane)
     * Work around possible misoptimization in PL/Perl (Tom Lane)
       Some Linux distributions contain an incorrect version of
       "pthread.h" that results in incorrect compiled code in PL/Perl,
       leading to crashes if a PL/Perl function calls another one that
       throws an error.
     * Fix pg_upgrade's handling of line endings on Windows (Andrew
       Dunstan)
       Previously, pg_upgrade might add or remove carriage returns in
       places such as function bodies.
     * On Windows, make pg_upgrade use backslash path separators in the
       scripts it emits (Andrew Dunstan)
     * Update time zone data files to tzdata release 2012f for DST law
       changes in Fiji
     __________________________________________________________________

                                Release 9.0.9

     Release Date: 2012-08-17

   This release contains a variety of fixes from 9.0.8. For information
   about new features in the 9.0 major release, see the Section called
   Release 9.0.
     __________________________________________________________________

Migration to Version 9.0.9

   A dump/restore is not required for those running 9.0.X.

   However, if you are upgrading from a version earlier than 9.0.6, see
   the release notes for 9.0.6.
     __________________________________________________________________

Changes

     * Prevent access to external files/URLs via XML entity references
       (Noah Misch, Tom Lane)
       xml_parse() would attempt to fetch external files or URLs as needed
       to resolve DTD and entity references in an XML value, thus allowing
       unprivileged database users to attempt to fetch data with the
       privileges of the database server. While the external data wouldn't
       get returned directly to the user, portions of it could be exposed
       in error messages if the data didn't parse as valid XML; and in any
       case the mere ability to check existence of a file might be useful
       to an attacker. (CVE-2012-3489)
     * Prevent access to external files/URLs via "contrib/xml2"'s
       xslt_process() (Peter Eisentraut)
       libxslt offers the ability to read and write both files and URLs
       through stylesheet commands, thus allowing unprivileged database
       users to both read and write data with the privileges of the
       database server. Disable that through proper use of libxslt's
       security options. (CVE-2012-3488)
       Also, remove xslt_process()'s ability to fetch documents and
       stylesheets from external files/URLs. While this was a documented
       "feature", it was long regarded as a bad idea. The fix for
       CVE-2012-3489 broke that capability, and rather than expend effort
       on trying to fix it, we're just going to summarily remove it.
     * Prevent too-early recycling of btree index pages (Noah Misch)
       When we allowed read-only transactions to skip assigning XIDs, we
       introduced the possibility that a deleted btree page could be
       recycled while a read-only transaction was still in flight to it.
       This would result in incorrect index search results. The
       probability of such an error occurring in the field seems very low
       because of the timing requirements, but nonetheless it should be
       fixed.
     * Fix crash-safety bug with newly-created-or-reset sequences (Tom
       Lane)
       If "ALTER SEQUENCE" was executed on a freshly created or reset
       sequence, and then precisely one nextval() call was made on it, and
       then the server crashed, WAL replay would restore the sequence to a
       state in which it appeared that no nextval() had been done, thus
       allowing the first sequence value to be returned again by the next
       nextval() call. In particular this could manifest for serial
       columns, since creation of a serial column's sequence includes an
       "ALTER SEQUENCE OWNED BY" step.
     * Fix txid_current() to report the correct epoch when not in hot
       standby (Heikki Linnakangas)
       This fixes a regression introduced in the previous minor release.
     * Fix bug in startup of Hot Standby when a master transaction has
       many subtransactions (Andres Freund)
       This mistake led to failures reported as "out-of-order XID
       insertion in KnownAssignedXids".
     * Ensure the "backup_label" file is fsync'd after pg_start_backup()
       (Dave Kerr)
     * Fix timeout handling in walsender processes (Tom Lane)
       WAL sender background processes neglected to establish a SIGALRM
       handler, meaning they would wait forever in some corner cases where
       a timeout ought to happen.
     * Back-patch 9.1 improvement to compress the fsync request queue
       (Robert Haas)
       This improves performance during checkpoints. The 9.1 change has
       now seen enough field testing to seem safe to back-patch.
     * Fix LISTEN/NOTIFY to cope better with I/O problems, such as out of
       disk space (Tom Lane)
       After a write failure, all subsequent attempts to send more NOTIFY
       messages would fail with messages like "Could not read from file
       "pg_notify/nnnn" at offset nnnnn: Success".
     * Only allow autovacuum to be auto-canceled by a directly blocked
       process (Tom Lane)
       The original coding could allow inconsistent behavior in some
       cases; in particular, an autovacuum could get canceled after less
       than deadlock_timeout grace period.
     * Improve logging of autovacuum cancels (Robert Haas)
     * Fix log collector so that log_truncate_on_rotation works during the
       very first log rotation after server start (Tom Lane)
     * Fix WITH attached to a nested set operation
       (UNION/INTERSECT/EXCEPT) (Tom Lane)
     * Ensure that a whole-row reference to a subquery doesn't include any
       extra GROUP BY or ORDER BY columns (Tom Lane)
     * Disallow copying whole-row references in CHECK constraints and
       index definitions during "CREATE TABLE" (Tom Lane)
       This situation can arise in "CREATE TABLE" with LIKE or INHERITS.
       The copied whole-row variable was incorrectly labeled with the row
       type of the original table not the new one. Rejecting the case
       seems reasonable for LIKE, since the row types might well diverge
       later. For INHERITS we should ideally allow it, with an implicit
       coercion to the parent table's row type; but that will require more
       work than seems safe to back-patch.
     * Fix memory leak in ARRAY(SELECT ...) subqueries (Heikki
       Linnakangas, Tom Lane)
     * Fix extraction of common prefixes from regular expressions (Tom
       Lane)
       The code could get confused by quantified parenthesized
       subexpressions, such as ^(foo)?bar. This would lead to incorrect
       index optimization of searches for such patterns.
     * Fix bugs with parsing signed "hh":"mm" and "hh":"mm":"ss" fields in
       interval constants (Amit Kapila, Tom Lane)
     * Use Postgres' encoding conversion functions, not Python's, when
       converting a Python Unicode string to the server encoding in
       PL/Python (Jan Urbanski)
       This avoids some corner-case problems, notably that Python doesn't
       support all the encodings Postgres does. A notable functional
       change is that if the server encoding is SQL_ASCII, you will get
       the UTF-8 representation of the string; formerly, any non-ASCII
       characters in the string would result in an error.
     * Fix mapping of PostgreSQL encodings to Python encodings in
       PL/Python (Jan Urbanski)
     * Report errors properly in "contrib/xml2"'s xslt_process() (Tom
       Lane)
     * Update time zone data files to tzdata release 2012e for DST law
       changes in Morocco and Tokelau
     __________________________________________________________________

                                Release 9.0.8

     Release Date: 2012-06-04

   This release contains a variety of fixes from 9.0.7. For information
   about new features in the 9.0 major release, see the Section called
   Release 9.0.
     __________________________________________________________________

Migration to Version 9.0.8

   A dump/restore is not required for those running 9.0.X.

   However, if you are upgrading from a version earlier than 9.0.6, see
   the release notes for 9.0.6.
     __________________________________________________________________

Changes

     * Fix incorrect password transformation in "contrib/pgcrypto"'s DES
       crypt() function (Solar Designer)
       If a password string contained the byte value 0x80, the remainder
       of the password was ignored, causing the password to be much weaker
       than it appeared. With this fix, the rest of the string is properly
       included in the DES hash. Any stored password values that are
       affected by this bug will thus no longer match, so the stored
       values may need to be updated. (CVE-2012-2143)
     * Ignore SECURITY DEFINER and SET attributes for a procedural
       language's call handler (Tom Lane)
       Applying such attributes to a call handler could crash the server.
       (CVE-2012-2655)
     * Allow numeric timezone offsets in timestamp input to be up to 16
       hours away from UTC (Tom Lane)
       Some historical time zones have offsets larger than 15 hours, the
       previous limit. This could result in dumped data values being
       rejected during reload.
     * Fix timestamp conversion to cope when the given time is exactly the
       last DST transition time for the current timezone (Tom Lane)
       This oversight has been there a long time, but was not noticed
       previously because most DST-using zones are presumed to have an
       indefinite sequence of future DST transitions.
     * Fix text to name and char to name casts to perform string
       truncation correctly in multibyte encodings (Karl Schnaitter)
     * Fix memory copying bug in to_tsquery() (Heikki Linnakangas)
     * Ensure txid_current() reports the correct epoch when executed in
       hot standby (Simon Riggs)
     * Fix planner's handling of outer PlaceHolderVars within subqueries
       (Tom Lane)
       This bug concerns sub-SELECTs that reference variables coming from
       the nullable side of an outer join of the surrounding query. In
       9.1, queries affected by this bug would fail with "ERROR:
       Upper-level PlaceHolderVar found where not expected". But in 9.0
       and 8.4, you'd silently get possibly-wrong answers, since the value
       transmitted into the subquery wouldn't go to null when it should.
     * Fix slow session startup when pg_attribute is very large (Tom Lane)
       If pg_attribute exceeds one-fourth of shared_buffers, cache
       rebuilding code that is sometimes needed during session start would
       trigger the synchronized-scan logic, causing it to take many times
       longer than normal. The problem was particularly acute if many new
       sessions were starting at once.
     * Ensure sequential scans check for query cancel reasonably often
       (Merlin Moncure)
       A scan encountering many consecutive pages that contain no live
       tuples would not respond to interrupts meanwhile.
     * Ensure the Windows implementation of PGSemaphoreLock() clears
       ImmediateInterruptOK before returning (Tom Lane)
       This oversight meant that a query-cancel interrupt received later
       in the same query could be accepted at an unsafe time, with
       unpredictable but not good consequences.
     * Show whole-row variables safely when printing views or rules (Abbas
       Butt, Tom Lane)
       Corner cases involving ambiguous names (that is, the name could be
       either a table or column name of the query) were printed in an
       ambiguous way, risking that the view or rule would be interpreted
       differently after dump and reload. Avoid the ambiguous case by
       attaching a no-op cast.
     * Fix "COPY FROM" to properly handle null marker strings that
       correspond to invalid encoding (Tom Lane)
       A null marker string such as E'\\0' should work, and did work in
       the past, but the case got broken in 8.4.
     * Ensure autovacuum worker processes perform stack depth checking
       properly (Heikki Linnakangas)
       Previously, infinite recursion in a function invoked by
       auto-"ANALYZE" could crash worker processes.
     * Fix logging collector to not lose log coherency under high load
       (Andrew Dunstan)
       The collector previously could fail to reassemble large messages if
       it got too busy.
     * Fix logging collector to ensure it will restart file rotation after
       receiving SIGHUP (Tom Lane)
     * Fix WAL replay logic for GIN indexes to not fail if the index was
       subsequently dropped (Tom Lane)
     * Fix memory leak in PL/pgSQL's "RETURN NEXT" command (Joe Conway)
     * Fix PL/pgSQL's "GET DIAGNOSTICS" command when the target is the
       function's first variable (Tom Lane)
     * Fix potential access off the end of memory in psql's expanded
       display ("\x") mode (Peter Eisentraut)
     * Fix several performance problems in pg_dump when the database
       contains many objects (Jeff Janes, Tom Lane)
       pg_dump could get very slow if the database contained many schemas,
       or if many objects are in dependency loops, or if there are many
       owned sequences.
     * Fix pg_upgrade for the case that a database stored in a non-default
       tablespace contains a table in the cluster's default tablespace
       (Bruce Momjian)
     * In ecpg, fix rare memory leaks and possible overwrite of one byte
       after the sqlca_t structure (Peter Eisentraut)
     * Fix "contrib/dblink"'s dblink_exec() to not leak temporary database
       connections upon error (Tom Lane)
     * Fix "contrib/dblink" to report the correct connection name in error
       messages (Kyotaro Horiguchi)
     * Fix "contrib/vacuumlo" to use multiple transactions when dropping
       many large objects (Tim Lewis, Robert Haas, Tom Lane)
       This change avoids exceeding max_locks_per_transaction when many
       objects need to be dropped. The behavior can be adjusted with the
       new -l (limit) option.
     * Update time zone data files to tzdata release 2012c for DST law
       changes in Antarctica, Armenia, Chile, Cuba, Falkland Islands,
       Gaza, Haiti, Hebron, Morocco, Syria, and Tokelau Islands; also
       historical corrections for Canada.
     __________________________________________________________________

                                Release 9.0.7

     Release Date: 2012-02-27

   This release contains a variety of fixes from 9.0.6. For information
   about new features in the 9.0 major release, see the Section called
   Release 9.0.
     __________________________________________________________________

Migration to Version 9.0.7

   A dump/restore is not required for those running 9.0.X.

   However, if you are upgrading from a version earlier than 9.0.6, see
   the release notes for 9.0.6.
     __________________________________________________________________

Changes

     * Require execute permission on the trigger function for "CREATE
       TRIGGER" (Robert Haas)
       This missing check could allow another user to execute a trigger
       function with forged input data, by installing it on a table he
       owns. This is only of significance for trigger functions marked
       SECURITY DEFINER, since otherwise trigger functions run as the
       table owner anyway. (CVE-2012-0866)
     * Remove arbitrary limitation on length of common name in SSL
       certificates (Heikki Linnakangas)
       Both libpq and the server truncated the common name extracted from
       an SSL certificate at 32 bytes. Normally this would cause nothing
       worse than an unexpected verification failure, but there are some
       rather-implausible scenarios in which it might allow one
       certificate holder to impersonate another. The victim would have to
       have a common name exactly 32 bytes long, and the attacker would
       have to persuade a trusted CA to issue a certificate in which the
       common name has that string as a prefix. Impersonating a server
       would also require some additional exploit to redirect client
       connections. (CVE-2012-0867)
     * Convert newlines to spaces in names written in pg_dump comments
       (Robert Haas)
       pg_dump was incautious about sanitizing object names that are
       emitted within SQL comments in its output script. A name containing
       a newline would at least render the script syntactically incorrect.
       Maliciously crafted object names could present a SQL injection risk
       when the script is reloaded. (CVE-2012-0868)
     * Fix btree index corruption from insertions concurrent with
       vacuuming (Tom Lane)
       An index page split caused by an insertion could sometimes cause a
       concurrently-running "VACUUM" to miss removing index entries that
       it should remove. After the corresponding table rows are removed,
       the dangling index entries would cause errors (such as "could not
       read block N in file ...") or worse, silently wrong query results
       after unrelated rows are re-inserted at the now-free table
       locations. This bug has been present since release 8.2, but occurs
       so infrequently that it was not diagnosed until now. If you have
       reason to suspect that it has happened in your database, reindexing
       the affected index will fix things.
     * Fix transient zeroing of shared buffers during WAL replay (Tom
       Lane)
       The replay logic would sometimes zero and refill a shared buffer,
       so that the contents were transiently invalid. In hot standby mode
       this can result in a query that's executing in parallel seeing
       garbage data. Various symptoms could result from that, but the most
       common one seems to be "invalid memory alloc request size".
     * Fix postmaster to attempt restart after a hot-standby crash (Tom
       Lane)
       A logic error caused the postmaster to terminate, rather than
       attempt to restart the cluster, if any backend process crashed
       while operating in hot standby mode.
     * Fix "CLUSTER"/"VACUUM FULL" handling of toast values owned by
       recently-updated rows (Tom Lane)
       This oversight could lead to "duplicate key value violates unique
       constraint" errors being reported against the toast table's index
       during one of these commands.
     * Update per-column permissions, not only per-table permissions, when
       changing table owner (Tom Lane)
       Failure to do this meant that any previously granted column
       permissions were still shown as having been granted by the old
       owner. This meant that neither the new owner nor a superuser could
       revoke the now-untraceable-to-table-owner permissions.
     * Support foreign data wrappers and foreign servers in "REASSIGN
       OWNED" (Alvaro Herrera)
       This command failed with "unexpected classid" errors if it needed
       to change the ownership of any such objects.
     * Allow non-existent values for some settings in "ALTER USER/DATABASE
       SET" (Heikki Linnakangas)
       Allow default_text_search_config, default_tablespace, and
       temp_tablespaces to be set to names that are not known. This is
       because they might be known in another database where the setting
       is intended to be used, or for the tablespace cases because the
       tablespace might not be created yet. The same issue was previously
       recognized for search_path, and these settings now act like that
       one.
     * Avoid crashing when we have problems deleting table files
       post-commit (Tom Lane)
       Dropping a table should lead to deleting the underlying disk files
       only after the transaction commits. In event of failure then (for
       instance, because of wrong file permissions) the code is supposed
       to just emit a warning message and go on, since it's too late to
       abort the transaction. This logic got broken as of release 8.4,
       causing such situations to result in a PANIC and an unrestartable
       database.
     * Recover from errors occurring during WAL replay of "DROP
       TABLESPACE" (Tom Lane)
       Replay will attempt to remove the tablespace's directories, but
       there are various reasons why this might fail (for example,
       incorrect ownership or permissions on those directories). Formerly
       the replay code would panic, rendering the database unrestartable
       without manual intervention. It seems better to log the problem and
       continue, since the only consequence of failure to remove the
       directories is some wasted disk space.
     * Fix race condition in logging AccessExclusiveLocks for hot standby
       (Simon Riggs)
       Sometimes a lock would be logged as being held by "transaction
       zero". This is at least known to produce assertion failures on
       slave servers, and might be the cause of more serious problems.
     * Track the OID counter correctly during WAL replay, even when it
       wraps around (Tom Lane)
       Previously the OID counter would remain stuck at a high value until
       the system exited replay mode. The practical consequences of that
       are usually nil, but there are scenarios wherein a standby server
       that's been promoted to master might take a long time to advance
       the OID counter to a reasonable value once values are needed.
     * Prevent emitting misleading "consistent recovery state reached" log
       message at the beginning of crash recovery (Heikki Linnakangas)
     * Fix initial value of pg_stat_replication.replay_location (Fujii
       Masao)
       Previously, the value shown would be wrong until at least one WAL
       record had been replayed.
     * Fix regular expression back-references with * attached (Tom Lane)
       Rather than enforcing an exact string match, the code would
       effectively accept any string that satisfies the pattern
       sub-expression referenced by the back-reference symbol.
       A similar problem still afflicts back-references that are embedded
       in a larger quantified expression, rather than being the immediate
       subject of the quantifier. This will be addressed in a future
       PostgreSQL release.
     * Fix recently-introduced memory leak in processing of inet/cidr
       values (Heikki Linnakangas)
       A patch in the December 2011 releases of PostgreSQL caused memory
       leakage in these operations, which could be significant in
       scenarios such as building a btree index on such a column.
     * Fix dangling pointer after "CREATE TABLE AS"/"SELECT INTO" in a
       SQL-language function (Tom Lane)
       In most cases this only led to an assertion failure in
       assert-enabled builds, but worse consequences seem possible.
     * Avoid double close of file handle in syslogger on Windows (MauMau)
       Ordinarily this error was invisible, but it would cause an
       exception when running on a debug version of Windows.
     * Fix I/O-conversion-related memory leaks in plpgsql (Andres Freund,
       Jan Urbanski, Tom Lane)
       Certain operations would leak memory until the end of the current
       function.
     * Improve pg_dump's handling of inherited table columns (Tom Lane)
       pg_dump mishandled situations where a child column has a different
       default expression than its parent column. If the default is
       textually identical to the parent's default, but not actually the
       same (for instance, because of schema search path differences) it
       would not be recognized as different, so that after dump and
       restore the child would be allowed to inherit the parent's default.
       Child columns that are NOT NULL where their parent is not could
       also be restored subtly incorrectly.
     * Fix pg_restore's direct-to-database mode for INSERT-style table
       data (Tom Lane)
       Direct-to-database restores from archive files made with
       "--inserts" or "--column-inserts" options fail when using
       pg_restore from a release dated September or December 2011, as a
       result of an oversight in a fix for another problem. The archive
       file itself is not at fault, and text-mode output is okay.
     * Allow pg_upgrade to process tables containing regclass columns
       (Bruce Momjian)
       Since pg_upgrade now takes care to preserve pg_class OIDs, there
       was no longer any reason for this restriction.
     * Make libpq ignore ENOTDIR errors when looking for an SSL client
       certificate file (Magnus Hagander)
       This allows SSL connections to be established, though without a
       certificate, even when the user's home directory is set to
       something like /dev/null.
     * Fix some more field alignment issues in ecpg's SQLDA area (Zoltan
       Boszormenyi)
     * Allow AT option in ecpg DEALLOCATE statements (Michael Meskes)
       The infrastructure to support this has been there for awhile, but
       through an oversight there was still an error check rejecting the
       case.
     * Do not use the variable name when defining a varchar structure in
       ecpg (Michael Meskes)
     * Fix "contrib/auto_explain"'s JSON output mode to produce valid JSON
       (Andrew Dunstan)
       The output used brackets at the top level, when it should have used
       braces.
     * Fix error in "contrib/intarray"'s int[] & int[] operator (Guillaume
       Lelarge)
       If the smallest integer the two input arrays have in common is 1,
       and there are smaller values in either array, then 1 would be
       incorrectly omitted from the result.
     * Fix error detection in "contrib/pgcrypto"'s encrypt_iv() and
       decrypt_iv() (Marko Kreen)
       These functions failed to report certain types of invalid-input
       errors, and would instead return random garbage values for
       incorrect input.
     * Fix one-byte buffer overrun in "contrib/test_parser" (Paul Guyot)
       The code would try to read one more byte than it should, which
       would crash in corner cases. Since "contrib/test_parser" is only
       example code, this is not a security issue in itself, but bad
       example code is still bad.
     * Use __sync_lock_test_and_set() for spinlocks on ARM, if available
       (Martin Pitt)
       This function replaces our previous use of the SWPB instruction,
       which is deprecated and not available on ARMv6 and later. Reports
       suggest that the old code doesn't fail in an obvious way on recent
       ARM boards, but simply doesn't interlock concurrent accesses,
       leading to bizarre failures in multiprocess operation.
     * Use "-fexcess-precision=standard" option when building with gcc
       versions that accept it (Andrew Dunstan)
       This prevents assorted scenarios wherein recent versions of gcc
       will produce creative results.
     * Allow use of threaded Python on FreeBSD (Chris Rees)
       Our configure script previously believed that this combination
       wouldn't work; but FreeBSD fixed the problem, so remove that error
       check.
     __________________________________________________________________

                                Release 9.0.6

     Release Date: 2011-12-05

   This release contains a variety of fixes from 9.0.5. For information
   about new features in the 9.0 major release, see the Section called
   Release 9.0.
     __________________________________________________________________

Migration to Version 9.0.6

   A dump/restore is not required for those running 9.0.X.

   However, a longstanding error was discovered in the definition of the
   information_schema.referential_constraints view. If you rely on correct
   results from that view, you should replace its definition as explained
   in the first changelog item below.

   Also, if you are upgrading from a version earlier than 9.0.4, see the
   release notes for 9.0.4.
     __________________________________________________________________

Changes

     * Fix bugs in information_schema.referential_constraints view (Tom
       Lane)
       This view was being insufficiently careful about matching the
       foreign-key constraint to the depended-on primary or unique key
       constraint. That could result in failure to show a foreign key
       constraint at all, or showing it multiple times, or claiming that
       it depends on a different constraint than the one it really does.
       Since the view definition is installed by initdb, merely upgrading
       will not fix the problem. If you need to fix this in an existing
       installation, you can (as a superuser) drop the information_schema
       schema then re-create it by sourcing
       "SHAREDIR/information_schema.sql". (Run pg_config --sharedir if
       you're uncertain where "SHAREDIR" is.) This must be repeated in
       each database to be fixed.
     * Fix possible crash during "UPDATE" or "DELETE" that joins to the
       output of a scalar-returning function (Tom Lane)
       A crash could only occur if the target row had been concurrently
       updated, so this problem surfaced only intermittently.
     * Fix incorrect replay of WAL records for GIN index updates (Tom
       Lane)
       This could result in transiently failing to find index entries
       after a crash, or on a hot-standby server. The problem would be
       repaired by the next "VACUUM" of the index, however.
     * Fix TOAST-related data corruption during CREATE TABLE dest AS
       SELECT * FROM src or INSERT INTO dest SELECT * FROM src (Tom Lane)
       If a table has been modified by "ALTER TABLE ADD COLUMN", attempts
       to copy its data verbatim to another table could produce corrupt
       results in certain corner cases. The problem can only manifest in
       this precise form in 8.4 and later, but we patched earlier versions
       as well in case there are other code paths that could trigger the
       same bug.
     * Fix possible failures during hot standby startup (Simon Riggs)
     * Start hot standby faster when initial snapshot is incomplete (Simon
       Riggs)
     * Fix race condition during toast table access from stale syscache
       entries (Tom Lane)
       The typical symptom was transient errors like "missing chunk number
       0 for toast value NNNNN in pg_toast_2619", where the cited toast
       table would always belong to a system catalog.
     * Track dependencies of functions on items used in parameter default
       expressions (Tom Lane)
       Previously, a referenced object could be dropped without having
       dropped or modified the function, leading to misbehavior when the
       function was used. Note that merely installing this update will not
       fix the missing dependency entries; to do that, you'd need to
       "CREATE OR REPLACE" each such function afterwards. If you have
       functions whose defaults depend on non-built-in objects, doing so
       is recommended.
     * Allow inlining of set-returning SQL functions with multiple OUT
       parameters (Tom Lane)
     * Don't trust deferred-unique indexes for join removal (Tom Lane and
       Marti Raudsepp)
       A deferred uniqueness constraint might not hold intra-transaction,
       so assuming that it does could give incorrect query results.
     * Make DatumGetInetP() unpack inet datums that have a 1-byte header,
       and add a new macro, DatumGetInetPP(), that does not (Heikki
       Linnakangas)
       This change affects no core code, but might prevent crashes in
       add-on code that expects DatumGetInetP() to produce an unpacked
       datum as per usual convention.
     * Improve locale support in money type's input and output (Tom Lane)
       Aside from not supporting all standard lc_monetary formatting
       options, the input and output functions were inconsistent, meaning
       there were locales in which dumped money values could not be
       re-read.
     * Don't let transform_null_equals affect CASE foo WHEN NULL ...
       constructs (Heikki Linnakangas)
       transform_null_equals is only supposed to affect foo = NULL
       expressions written directly by the user, not equality checks
       generated internally by this form of CASE.
     * Change foreign-key trigger creation order to better support
       self-referential foreign keys (Tom Lane)
       For a cascading foreign key that references its own table, a row
       update will fire both the ON UPDATE trigger and the CHECK trigger
       as one event. The ON UPDATE trigger must execute first, else the
       CHECK will check a non-final state of the row and possibly throw an
       inappropriate error. However, the firing order of these triggers is
       determined by their names, which generally sort in creation order
       since the triggers have auto-generated names following the
       convention "RI_ConstraintTrigger_NNNN". A proper fix would require
       modifying that convention, which we will do in 9.2, but it seems
       risky to change it in existing releases. So this patch just changes
       the creation order of the triggers. Users encountering this type of
       error should drop and re-create the foreign key constraint to get
       its triggers into the right order.
     * Avoid floating-point underflow while tracking buffer allocation
       rate (Greg Matthews)
       While harmless in itself, on certain platforms this would result in
       annoying kernel log messages.
     * Preserve configuration file name and line number values when
       starting child processes under Windows (Tom Lane)
       Formerly, these would not be displayed correctly in the pg_settings
       view.
     * Fix incorrect field alignment in ecpg's SQLDA area (Zoltan
       Boszormenyi)
     * Preserve blank lines within commands in psql's command history
       (Robert Haas)
       The former behavior could cause problems if an empty line was
       removed from within a string literal, for example.
     * Fix pg_dump to dump user-defined casts between auto-generated
       types, such as table rowtypes (Tom Lane)
     * Assorted fixes for pg_upgrade (Bruce Momjian)
       Handle exclusion constraints correctly, avoid failures on Windows,
       don't complain about mismatched toast table names in 8.4 databases.
     * Use the preferred version of xsubpp to build PL/Perl, not
       necessarily the operating system's main copy (David Wheeler and
       Alex Hunsaker)
     * Fix incorrect coding in "contrib/dict_int" and "contrib/dict_xsyn"
       (Tom Lane)
       Some functions incorrectly assumed that memory returned by palloc()
       is guaranteed zeroed.
     * Fix assorted errors in "contrib/unaccent"'s configuration file
       parsing (Tom Lane)
     * Honor query cancel interrupts promptly in pgstatindex() (Robert
       Haas)
     * Fix incorrect quoting of log file name in Mac OS X start script
       (Sidar Lopez)
     * Ensure VPATH builds properly install all server header files (Peter
       Eisentraut)
     * Shorten file names reported in verbose error messages (Peter
       Eisentraut)
       Regular builds have always reported just the name of the C file
       containing the error message call, but VPATH builds formerly
       reported an absolute path name.
     * Fix interpretation of Windows timezone names for Central America
       (Tom Lane)
       Map "Central America Standard Time" to CST6, not CST6CDT, because
       DST is generally not observed anywhere in Central America.
     * Update time zone data files to tzdata release 2011n for DST law
       changes in Brazil, Cuba, Fiji, Palestine, Russia, and Samoa; also
       historical corrections for Alaska and British East Africa.
     __________________________________________________________________

                                Release 9.0.5

     Release Date: 2011-09-26

   This release contains a variety of fixes from 9.0.4. For information
   about new features in the 9.0 major release, see the Section called
   Release 9.0.
     __________________________________________________________________

Migration to Version 9.0.5

   A dump/restore is not required for those running 9.0.X.

   However, if you are upgrading from a version earlier than 9.0.4, see
   the release notes for 9.0.4.
     __________________________________________________________________

Changes

     * Fix catalog cache invalidation after a "VACUUM FULL" or "CLUSTER"
       on a system catalog (Tom Lane)
       In some cases the relocation of a system catalog row to another
       place would not be recognized by concurrent server processes,
       allowing catalog corruption to occur if they then tried to update
       that row. The worst-case outcome could be as bad as complete loss
       of a table.
     * Fix incorrect order of operations during sinval reset processing,
       and ensure that TOAST OIDs are preserved in system catalogs (Tom
       Lane)
       These mistakes could lead to transient failures after a "VACUUM
       FULL" or "CLUSTER" on a system catalog.
     * Fix bugs in indexing of in-doubt HOT-updated tuples (Tom Lane)
       These bugs could result in index corruption after reindexing a
       system catalog. They are not believed to affect user indexes.
     * Fix multiple bugs in GiST index page split processing (Heikki
       Linnakangas)
       The probability of occurrence was low, but these could lead to
       index corruption.
     * Fix possible buffer overrun in tsvector_concat() (Tom Lane)
       The function could underestimate the amount of memory needed for
       its result, leading to server crashes.
     * Fix crash in xml_recv when processing a "standalone" parameter (Tom
       Lane)
     * Make pg_options_to_table return NULL for an option with no value
       (Tom Lane)
       Previously such cases would result in a server crash.
     * Avoid possibly accessing off the end of memory in "ANALYZE" and in
       SJIS-2004 encoding conversion (Noah Misch)
       This fixes some very-low-probability server crash scenarios.
     * Protect pg_stat_reset_shared() against NULL input (Magnus Hagander)
     * Fix possible failure when a recovery conflict deadlock is detected
       within a sub-transaction (Tom Lane)
     * Avoid spurious conflicts while recycling btree index pages during
       hot standby (Noah Misch, Simon Riggs)
     * Shut down WAL receiver if it's still running at end of recovery
       (Heikki Linnakangas)
       The postmaster formerly panicked in this situation, but it's
       actually a legitimate case.
     * Fix race condition in relcache init file invalidation (Tom Lane)
       There was a window wherein a new backend process could read a stale
       init file but miss the inval messages that would tell it the data
       is stale. The result would be bizarre failures in catalog accesses,
       typically "could not read block 0 in file ..." later during
       startup.
     * Fix memory leak at end of a GiST index scan (Tom Lane)
       Commands that perform many separate GiST index scans, such as
       verification of a new GiST-based exclusion constraint on a table
       already containing many rows, could transiently require large
       amounts of memory due to this leak.
     * Fix memory leak when encoding conversion has to be done on incoming
       command strings and "LISTEN" is active (Tom Lane)
     * Fix incorrect memory accounting (leading to possible memory bloat)
       in tuplestores supporting holdable cursors and plpgsql's RETURN
       NEXT command (Tom Lane)
     * Fix trigger WHEN conditions when both BEFORE and AFTER triggers
       exist (Tom Lane)
       Evaluation of WHEN conditions for AFTER ROW UPDATE triggers could
       crash if there had been a BEFORE ROW trigger fired for the same
       update.
     * Fix performance problem when constructing a large, lossy bitmap
       (Tom Lane)
     * Fix join selectivity estimation for unique columns (Tom Lane)
       This fixes an erroneous planner heuristic that could lead to poor
       estimates of the result size of a join.
     * Fix nested PlaceHolderVar expressions that appear only in
       sub-select target lists (Tom Lane)
       This mistake could result in outputs of an outer join incorrectly
       appearing as NULL.
     * Allow the planner to assume that empty parent tables really are
       empty (Tom Lane)
       Normally an empty table is assumed to have a certain minimum size
       for planning purposes; but this heuristic seems to do more harm
       than good for the parent table of an inheritance hierarchy, which
       often is permanently empty.
     * Allow nested EXISTS queries to be optimized properly (Tom Lane)
     * Fix array- and path-creating functions to ensure padding bytes are
       zeroes (Tom Lane)
       This avoids some situations where the planner will think that
       semantically-equal constants are not equal, resulting in poor
       optimization.
     * Fix "EXPLAIN" to handle gating Result nodes within inner-indexscan
       subplans (Tom Lane)
       The usual symptom of this oversight was "bogus varno" errors.
     * Fix btree preprocessing of "indexedcol" IS NULL conditions (Dean
       Rasheed)
       Such a condition is unsatisfiable if combined with any other type
       of btree-indexable condition on the same index column. The case was
       handled incorrectly in 9.0.0 and later, leading to query output
       where there should be none.
     * Work around gcc 4.6.0 bug that breaks WAL replay (Tom Lane)
       This could lead to loss of committed transactions after a server
       crash.
     * Fix dump bug for VALUES in a view (Tom Lane)
     * Disallow SELECT FOR UPDATE/SHARE on sequences (Tom Lane)
       This operation doesn't work as expected and can lead to failures.
     * Fix "VACUUM" so that it always updates pg_class.reltuples/relpages
       (Tom Lane)
       This fixes some scenarios where autovacuum could make increasingly
       poor decisions about when to vacuum tables.
     * Defend against integer overflow when computing size of a hash table
       (Tom Lane)
     * Fix cases where "CLUSTER" might attempt to access already-removed
       TOAST data (Tom Lane)
     * Fix premature timeout failures during initial authentication
       transaction (Tom Lane)
     * Fix portability bugs in use of credentials control messages for
       "peer" authentication (Tom Lane)
     * Fix SSPI login when multiple roundtrips are required (Ahmed
       Shinwari, Magnus Hagander)
       The typical symptom of this problem was "The function requested is
       not supported" errors during SSPI login.
     * Fix failure when adding a new variable of a custom variable class
       to "postgresql.conf" (Tom Lane)
     * Throw an error if "pg_hba.conf" contains hostssl but SSL is
       disabled (Tom Lane)
       This was concluded to be more user-friendly than the previous
       behavior of silently ignoring such lines.
     * Fix failure when "DROP OWNED BY" attempts to remove default
       privileges on sequences (Shigeru Hanada)
     * Fix typo in pg_srand48 seed initialization (Andres Freund)
       This led to failure to use all bits of the provided seed. This
       function is not used on most platforms (only those without
       srandom), and the potential security exposure from a
       less-random-than-expected seed seems minimal in any case.
     * Avoid integer overflow when the sum of LIMIT and OFFSET values
       exceeds 2^63 (Heikki Linnakangas)
     * Add overflow checks to int4 and int8 versions of generate_series()
       (Robert Haas)
     * Fix trailing-zero removal in to_char() (Marti Raudsepp)
       In a format with FM and no digit positions after the decimal point,
       zeroes to the left of the decimal point could be removed
       incorrectly.
     * Fix pg_size_pretty() to avoid overflow for inputs close to 2^63
       (Tom Lane)
     * Weaken plpgsql's check for typmod matching in record values (Tom
       Lane)
       An overly enthusiastic check could lead to discarding length
       modifiers that should have been kept.
     * Correctly handle quotes in locale names during initdb (Heikki
       Linnakangas)
       The case can arise with some Windows locales, such as "People's
       Republic of China".
     * In pg_upgrade, avoid dumping orphaned temporary tables (Bruce
       Momjian)
       This prevents situations wherein table OID assignments could get
       out of sync between old and new installations.
     * Fix pg_upgrade to preserve toast tables' relfrozenxids during an
       upgrade from 8.3 (Bruce Momjian)
       Failure to do this could lead to "pg_clog" files being removed too
       soon after the upgrade.
     * In pg_upgrade, fix the -l (log) option to work on Windows (Bruce
       Momjian)
     * In pg_ctl, support silent mode for service registrations on Windows
       (MauMau)
     * Fix psql's counting of script file line numbers during COPY from a
       different file (Tom Lane)
     * Fix pg_restore's direct-to-database mode for
       standard_conforming_strings (Tom Lane)
       pg_restore could emit incorrect commands when restoring directly to
       a database server from an archive file that had been made with
       standard_conforming_strings set to on.
     * Be more user-friendly about unsupported cases for parallel
       pg_restore (Tom Lane)
       This change ensures that such cases are detected and reported
       before any restore actions have been taken.
     * Fix write-past-buffer-end and memory leak in libpq's LDAP service
       lookup code (Albe Laurenz)
     * In libpq, avoid failures when using nonblocking I/O and an SSL
       connection (Martin Pihlak, Tom Lane)
     * Improve libpq's handling of failures during connection startup (Tom
       Lane)
       In particular, the response to a server report of fork() failure
       during SSL connection startup is now saner.
     * Improve libpq's error reporting for SSL failures (Tom Lane)
     * Fix PQsetvalue() to avoid possible crash when adding a new tuple to
       a PGresult originally obtained from a server query (Andrew Chernow)
     * Make ecpglib write double values with 15 digits precision (Akira
       Kurosawa)
     * In ecpglib, be sure LC_NUMERIC setting is restored after an error
       (Michael Meskes)
     * Apply upstream fix for blowfish signed-character bug
       (CVE-2011-2483) (Tom Lane)
       "contrib/pg_crypto"'s blowfish encryption code could give wrong
       results on platforms where char is signed (which is most), leading
       to encrypted passwords being weaker than they should be.
     * Fix memory leak in "contrib/seg" (Heikki Linnakangas)
     * Fix pgstatindex() to give consistent results for empty indexes (Tom
       Lane)
     * Allow building with perl 5.14 (Alex Hunsaker)
     * Fix assorted issues with build and install file paths containing
       spaces (Tom Lane)
     * Update time zone data files to tzdata release 2011i for DST law
       changes in Canada, Egypt, Russia, Samoa, and South Sudan.
     __________________________________________________________________

                                Release 9.0.4

     Release Date: 2011-04-18

   This release contains a variety of fixes from 9.0.3. For information
   about new features in the 9.0 major release, see the Section called
   Release 9.0.
     __________________________________________________________________

Migration to Version 9.0.4

   A dump/restore is not required for those running 9.0.X.

   However, if your installation was upgraded from a previous major
   release by running pg_upgrade, you should take action to prevent
   possible data loss due to a now-fixed bug in pg_upgrade. The
   recommended solution is to run "VACUUM FREEZE" on all TOAST tables.
   More information is available at
   http://wiki.postgresql.org/wiki/20110408pg_upgrade_fix.
     __________________________________________________________________

Changes

     * Fix pg_upgrade's handling of TOAST tables (Bruce Momjian)
       The pg_class.relfrozenxid value for TOAST tables was not correctly
       copied into the new installation during pg_upgrade. This could
       later result in pg_clog files being discarded while they were still
       needed to validate tuples in the TOAST tables, leading to "could
       not access status of transaction" failures.
       This error poses a significant risk of data loss for installations
       that have been upgraded with pg_upgrade. This patch corrects the
       problem for future uses of pg_upgrade, but does not in itself cure
       the issue in installations that have been processed with a buggy
       version of pg_upgrade.
     * Suppress incorrect "PD_ALL_VISIBLE flag was incorrectly set"
       warning (Heikki Linnakangas)
       "VACUUM" would sometimes issue this warning in cases that are
       actually valid.
     * Use better SQLSTATE error codes for hot standby conflict cases
       (Tatsuo Ishii and Simon Riggs)
       All retryable conflict errors now have an error code that indicates
       that a retry is possible. Also, session closure due to the database
       being dropped on the master is now reported as
       ERRCODE_DATABASE_DROPPED, rather than ERRCODE_ADMIN_SHUTDOWN, so
       that connection poolers can handle the situation correctly.
     * Prevent intermittent hang in interactions of startup process with
       bgwriter process (Simon Riggs)
       This affected recovery in non-hot-standby cases.
     * Disallow including a composite type in itself (Tom Lane)
       This prevents scenarios wherein the server could recurse infinitely
       while processing the composite type. While there are some possible
       uses for such a structure, they don't seem compelling enough to
       justify the effort required to make sure it always works safely.
     * Avoid potential deadlock during catalog cache initialization
       (Nikhil Sontakke)
       In some cases the cache loading code would acquire share lock on a
       system index before locking the index's catalog. This could
       deadlock against processes trying to acquire exclusive locks in the
       other, more standard order.
     * Fix dangling-pointer problem in BEFORE ROW UPDATE trigger handling
       when there was a concurrent update to the target tuple (Tom Lane)
       This bug has been observed to result in intermittent "cannot
       extract system attribute from virtual tuple" failures while trying
       to do UPDATE RETURNING ctid. There is a very small probability of
       more serious errors, such as generating incorrect index entries for
       the updated tuple.
     * Disallow "DROP TABLE" when there are pending deferred trigger
       events for the table (Tom Lane)
       Formerly the "DROP" would go through, leading to "could not open
       relation with OID nnn" errors when the triggers were eventually
       fired.
     * Allow "replication" as a user name in "pg_hba.conf" (Andrew
       Dunstan)
       "replication" is special in the database name column, but it was
       mistakenly also treated as special in the user name column.
     * Prevent crash triggered by constant-false WHERE conditions during
       GEQO optimization (Tom Lane)
     * Improve planner's handling of semi-join and anti-join cases (Tom
       Lane)
     * Fix handling of SELECT FOR UPDATE in a sub-SELECT (Tom Lane)
       This bug typically led to "cannot extract system attribute from
       virtual tuple" errors.
     * Fix selectivity estimation for text search to account for NULLs
       (Jesper Krogh)
     * Fix get_actual_variable_range() to support hypothetical indexes
       injected by an index adviser plugin (Gurjeet Singh)
     * Fix PL/Python memory leak involving array slices (Daniel Popowich)
     * Allow libpq's SSL initialization to succeed when user's home
       directory is unavailable (Tom Lane)
       If the SSL mode is such that a root certificate file is not
       required, there is no need to fail. This change restores the
       behavior to what it was in pre-9.0 releases.
     * Fix libpq to return a useful error message for errors detected in
       conninfo_array_parse (Joseph Adams)
       A typo caused the library to return NULL, rather than the PGconn
       structure containing the error message, to the application.
     * Fix ecpg preprocessor's handling of float constants (Heikki
       Linnakangas)
     * Fix parallel pg_restore to handle comments on POST_DATA items
       correctly (Arnd Hannemann)
     * Fix pg_restore to cope with long lines (over 1KB) in TOC files (Tom
       Lane)
     * Put in more safeguards against crashing due to division-by-zero
       with overly enthusiastic compiler optimization (Aurelien Jarno)
     * Support use of dlopen() in FreeBSD and OpenBSD on MIPS (Tom Lane)
       There was a hard-wired assumption that this system function was not
       available on MIPS hardware on these systems. Use a compile-time
       test instead, since more recent versions have it.
     * Fix compilation failures on HP-UX (Heikki Linnakangas)
     * Avoid crash when trying to write to the Windows console very early
       in process startup (Rushabh Lathia)
     * Support building with MinGW 64 bit compiler for Windows (Andrew
       Dunstan)
     * Fix version-incompatibility problem with libintl on Windows
       (Hiroshi Inoue)
     * Fix usage of xcopy in Windows build scripts to work correctly under
       Windows 7 (Andrew Dunstan)
       This affects the build scripts only, not installation or usage.
     * Fix path separator used by pg_regress on Cygwin (Andrew Dunstan)
     * Update time zone data files to tzdata release 2011f for DST law
       changes in Chile, Cuba, Falkland Islands, Morocco, Samoa, and
       Turkey; also historical corrections for South Australia, Alaska,
       and Hawaii.
     __________________________________________________________________

                                Release 9.0.3

     Release Date: 2011-01-31

   This release contains a variety of fixes from 9.0.2. For information
   about new features in the 9.0 major release, see the Section called
   Release 9.0.
     __________________________________________________________________

Migration to Version 9.0.3

   A dump/restore is not required for those running 9.0.X.
     __________________________________________________________________

Changes

     * Before exiting walreceiver, ensure all the received WAL is fsync'd
       to disk (Heikki Linnakangas)
       Otherwise the standby server could replay some un-synced WAL,
       conceivably leading to data corruption if the system crashes just
       at that point.
     * Avoid excess fsync activity in walreceiver (Heikki Linnakangas)
     * Make "ALTER TABLE" revalidate uniqueness and exclusion constraints
       when needed (Noah Misch)
       This was broken in 9.0 by a change that was intended to suppress
       revalidation during "VACUUM FULL" and "CLUSTER", but
       unintentionally affected "ALTER TABLE" as well.
     * Fix EvalPlanQual for "UPDATE" of an inheritance tree in which the
       tables are not all alike (Tom Lane)
       Any variation in the table row types (including dropped columns
       present in only some child tables) would confuse the EvalPlanQual
       code, leading to misbehavior or even crashes. Since EvalPlanQual is
       only executed during concurrent updates to the same row, the
       problem was only seen intermittently.
     * Avoid failures when "EXPLAIN" tries to display a simple-form CASE
       expression (Tom Lane)
       If the CASE's test expression was a constant, the planner could
       simplify the CASE into a form that confused the expression-display
       code, resulting in "unexpected CASE WHEN clause" errors.
     * Fix assignment to an array slice that is before the existing range
       of subscripts (Tom Lane)
       If there was a gap between the newly added subscripts and the first
       pre-existing subscript, the code miscalculated how many entries
       needed to be copied from the old array's null bitmap, potentially
       leading to data corruption or crash.
     * Avoid unexpected conversion overflow in planner for very distant
       date values (Tom Lane)
       The date type supports a wider range of dates than can be
       represented by the timestamp types, but the planner assumed it
       could always convert a date to timestamp with impunity.
     * Fix PL/Python crash when an array contains null entries (Alex
       Hunsaker)
     * Remove ecpg's fixed length limit for constants defining an array
       dimension (Michael Meskes)
     * Fix erroneous parsing of tsquery values containing ... &
       !(subexpression) | ... (Tom Lane)
       Queries containing this combination of operators were not executed
       correctly. The same error existed in "contrib/intarray"'s query_int
       type and "contrib/ltree"'s ltxtquery type.
     * Fix buffer overrun in "contrib/intarray"'s input function for the
       query_int type (Apple)
       This bug is a security risk since the function's return address
       could be overwritten. Thanks to Apple Inc's security team for
       reporting this issue and supplying the fix. (CVE-2010-4015)
     * Fix bug in "contrib/seg"'s GiST picksplit algorithm (Alexander
       Korotkov)
       This could result in considerable inefficiency, though not actually
       incorrect answers, in a GiST index on a seg column. If you have
       such an index, consider "REINDEX"ing it after installing this
       update. (This is identical to the bug that was fixed in
       "contrib/cube" in the previous update.)
     __________________________________________________________________

                                Release 9.0.2

     Release Date: 2010-12-16

   This release contains a variety of fixes from 9.0.1. For information
   about new features in the 9.0 major release, see the Section called
   Release 9.0.
     __________________________________________________________________

Migration to Version 9.0.2

   A dump/restore is not required for those running 9.0.X.
     __________________________________________________________________

Changes

     * Force the default wal_sync_method to be fdatasync on Linux (Tom
       Lane, Marti Raudsepp)
       The default on Linux has actually been fdatasync for many years,
       but recent kernel changes caused PostgreSQL to choose open_datasync
       instead. This choice did not result in any performance improvement,
       and caused outright failures on certain filesystems, notably ext4
       with the data=journal mount option.
     * Fix "too many KnownAssignedXids" error during Hot Standby replay
       (Heikki Linnakangas)
     * Fix race condition in lock acquisition during Hot Standby (Simon
       Riggs)
     * Avoid unnecessary conflicts during Hot Standby (Simon Riggs)
       This fixes some cases where replay was considered to conflict with
       standby queries (causing delay of replay or possibly cancellation
       of the queries), but there was no real conflict.
     * Fix assorted bugs in WAL replay logic for GIN indexes (Tom Lane)
       This could result in "bad buffer id: 0" failures or corruption of
       index contents during replication.
     * Fix recovery from base backup when the starting checkpoint WAL
       record is not in the same WAL segment as its redo point (Jeff
       Davis)
     * Fix corner-case bug when streaming replication is enabled
       immediately after creating the master database cluster (Heikki
       Linnakangas)
     * Fix persistent slowdown of autovacuum workers when multiple workers
       remain active for a long time (Tom Lane)
       The effective vacuum_cost_limit for an autovacuum worker could drop
       to nearly zero if it processed enough tables, causing it to run
       extremely slowly.
     * Fix long-term memory leak in autovacuum launcher (Alvaro Herrera)
     * Avoid failure when trying to report an impending transaction
       wraparound condition from outside a transaction (Tom Lane)
       This oversight prevented recovery after transaction wraparound got
       too close, because database startup processing would fail.
     * Add support for detecting register-stack overrun on IA64 (Tom Lane)
       The IA64 architecture has two hardware stacks. Full prevention of
       stack-overrun failures requires checking both.
     * Add a check for stack overflow in copyObject() (Tom Lane)
       Certain code paths could crash due to stack overflow given a
       sufficiently complex query.
     * Fix detection of page splits in temporary GiST indexes (Heikki
       Linnakangas)
       It is possible to have a "concurrent" page split in a temporary
       index, if for example there is an open cursor scanning the index
       when an insertion is done. GiST failed to detect this case and
       hence could deliver wrong results when execution of the cursor
       continued.
     * Fix error checking during early connection processing (Tom Lane)
       The check for too many child processes was skipped in some cases,
       possibly leading to postmaster crash when attempting to add the new
       child process to fixed-size arrays.
     * Improve efficiency of window functions (Tom Lane)
       Certain cases where a large number of tuples needed to be read in
       advance, but work_mem was large enough to allow them all to be held
       in memory, were unexpectedly slow. percent_rank(), cume_dist() and
       ntile() in particular were subject to this problem.
     * Avoid memory leakage while "ANALYZE"'ing complex index expressions
       (Tom Lane)
     * Ensure an index that uses a whole-row Var still depends on its
       table (Tom Lane)
       An index declared like create index i on t (foo(t.*)) would not
       automatically get dropped when its table was dropped.
     * Add missing support in "DROP OWNED BY" for removing foreign data
       wrapper/server privileges belonging to a user (Heikki Linnakangas)
     * Do not "inline" a SQL function with multiple OUT parameters (Tom
       Lane)
       This avoids a possible crash due to loss of information about the
       expected result rowtype.
     * Fix crash when inline-ing a set-returning function whose argument
       list contains a reference to an inline-able user function (Tom
       Lane)
     * Behave correctly if ORDER BY, LIMIT, FOR UPDATE, or WITH is
       attached to the VALUES part of INSERT ... VALUES (Tom Lane)
     * Make the OFF keyword unreserved (Heikki Linnakangas)
       This prevents problems with using off as a variable name in
       PL/pgSQL. That worked before 9.0, but was now broken because
       PL/pgSQL now treats all core reserved words as reserved.
     * Fix constant-folding of COALESCE() expressions (Tom Lane)
       The planner would sometimes attempt to evaluate sub-expressions
       that in fact could never be reached, possibly leading to unexpected
       errors.
     * Fix "could not find pathkey item to sort" planner failure with
       comparison of whole-row Vars (Tom Lane)
     * Fix postmaster crash when connection acceptance (accept() or one of
       the calls made immediately after it) fails, and the postmaster was
       compiled with GSSAPI support (Alexander Chernikov)
     * Retry after receiving an invalid response packet from a RADIUS
       authentication server (Magnus Hagander)
       This fixes a low-risk potential denial of service condition.
     * Fix missed unlink of temporary files when log_temp_files is active
       (Tom Lane)
       If an error occurred while attempting to emit the log message, the
       unlink was not done, resulting in accumulation of temp files.
     * Add print functionality for InhRelation nodes (Tom Lane)
       This avoids a failure when debug_print_parse is enabled and certain
       types of query are executed.
     * Fix incorrect calculation of distance from a point to a horizontal
       line segment (Tom Lane)
       This bug affected several different geometric distance-measurement
       operators.
     * Fix incorrect calculation of transaction status in ecpg (Itagaki
       Takahiro)
     * Fix errors in psql's Unicode-escape support (Tom Lane)
     * Speed up parallel pg_restore when the archive contains many large
       objects (blobs) (Tom Lane)
     * Fix PL/pgSQL's handling of "simple" expressions to not fail in
       recursion or error-recovery cases (Tom Lane)
     * Fix PL/pgSQL's error reporting for no-such-column cases (Tom Lane)
       As of 9.0, it would sometimes report "missing FROM-clause entry for
       table foo" when "record foo has no field bar" would be more
       appropriate.
     * Fix PL/Python to honor typmod (i.e., length or precision
       restrictions) when assigning to tuple fields (Tom Lane)
       This fixes a regression from 8.4.
     * Fix PL/Python's handling of set-returning functions (Jan Urbanski)
       Attempts to call SPI functions within the iterator generating a set
       result would fail.
     * Fix bug in "contrib/cube"'s GiST picksplit algorithm (Alexander
       Korotkov)
       This could result in considerable inefficiency, though not actually
       incorrect answers, in a GiST index on a cube column. If you have
       such an index, consider "REINDEX"ing it after installing this
       update.
     * Don't emit "identifier will be truncated" notices in
       "contrib/dblink" except when creating new connections (Itagaki
       Takahiro)
     * Fix potential coredump on missing public key in "contrib/pgcrypto"
       (Marti Raudsepp)
     * Fix buffer overrun in "contrib/pg_upgrade" (Hernan Gonzalez)
     * Fix memory leak in "contrib/xml2"'s XPath query functions (Tom
       Lane)
     * Update time zone data files to tzdata release 2010o for DST law
       changes in Fiji and Samoa; also historical corrections for Hong
       Kong.
     __________________________________________________________________

                                Release 9.0.1

     Release Date: 2010-10-04

   This release contains a variety of fixes from 9.0.0. For information
   about new features in the 9.0 major release, see the Section called
   Release 9.0.
     __________________________________________________________________

Migration to Version 9.0.1

   A dump/restore is not required for those running 9.0.X.
     __________________________________________________________________

Changes

     * Use a separate interpreter for each calling SQL userid in PL/Perl
       and PL/Tcl (Tom Lane)
       This change prevents security problems that can be caused by
       subverting Perl or Tcl code that will be executed later in the same
       session under another SQL user identity (for example, within a
       SECURITY DEFINER function). Most scripting languages offer numerous
       ways that that might be done, such as redefining standard functions
       or operators called by the target function. Without this change,
       any SQL user with Perl or Tcl language usage rights can do
       essentially anything with the SQL privileges of the target
       function's owner.
       The cost of this change is that intentional communication among
       Perl and Tcl functions becomes more difficult. To provide an escape
       hatch, PL/PerlU and PL/TclU functions continue to use only one
       interpreter per session. This is not considered a security issue
       since all such functions execute at the trust level of a database
       superuser already.
       It is likely that third-party procedural languages that claim to
       offer trusted execution have similar security issues. We advise
       contacting the authors of any PL you are depending on for
       security-critical purposes.
       Our thanks to Tim Bunce for pointing out this issue
       (CVE-2010-3433).
     * Improve pg_get_expr() security fix so that the function can still
       be used on the output of a sub-select (Tom Lane)
     * Fix incorrect placement of placeholder evaluation (Tom Lane)
       This bug could result in query outputs being non-null when they
       should be null, in cases where the inner side of an outer join is a
       sub-select with non-strict expressions in its output list.
     * Fix join removal's handling of placeholder expressions (Tom Lane)
     * Fix possible duplicate scans of UNION ALL member relations (Tom
       Lane)
     * Prevent infinite loop in ProcessIncomingNotify() after unlistening
       (Jeff Davis)
     * Prevent show_session_authorization() from crashing within
       autovacuum processes (Tom Lane)
     * Re-allow input of Julian dates prior to 0001-01-01 AD (Tom Lane)
       Input such as 'J100000'::date worked before 8.4, but was
       unintentionally broken by added error-checking.
     * Make psql recognize "DISCARD ALL" as a command that should not be
       encased in a transaction block in autocommit-off mode (Itagaki
       Takahiro)
     * Update build infrastructure and documentation to reflect the source
       code repository's move from CVS to Git (Magnus Hagander and others)
     __________________________________________________________________

                                 Release 9.0

     Release Date: 2010-09-20
     __________________________________________________________________

Overview

   This release of PostgreSQL adds features that have been requested for
   years, such as easy-to-use replication, a mass permission-changing
   facility, and anonymous code blocks. While past major releases have
   been conservative in their scope, this release shows a bold new desire
   to provide facilities that new and existing users of PostgreSQL will
   embrace. This has all been done with few incompatibilities. Major
   enhancements include:

     * Built-in replication based on log shipping. This advance consists
       of two features: Streaming Replication, allowing continuous archive
       (WAL) files to be streamed over a network connection to a standby
       server, and Hot Standby, allowing continuous archive standby
       servers to execute read-only queries. The net effect is to support
       a single master with multiple read-only slave servers.
     * Easier database object permissions management. "GRANT"/"REVOKE IN
       SCHEMA" supports mass permissions changes on existing objects,
       while "ALTER DEFAULT PRIVILEGES" allows control of privileges for
       objects created in the future. Large objects (BLOBs) now support
       permissions management as well.
     * Broadly enhanced stored procedure support. The "DO" statement
       supports ad-hoc or "anonymous" code blocks. Functions can now be
       called using named parameters. PL/pgSQL is now installed by
       default, and PL/Perl and PL/Python have been enhanced in several
       ways, including support for Python3.
     * Full support for 64-bit Windows.
     * More advanced reporting queries, including additional windowing
       options (PRECEDING and FOLLOWING) and the ability to control the
       order in which values are fed to aggregate functions.
     * New trigger features, including SQL-standard-compliant per-column
       triggers and conditional trigger execution.
     * Deferrable unique constraints. Mass updates to unique keys are now
       possible without trickery.
     * Exclusion constraints. These provide a generalized version of
       unique constraints, allowing enforcement of complex conditions.
     * New and enhanced security features, including RADIUS
       authentication, LDAP authentication improvements, and a new contrib
       module "passwordcheck" for testing password strength.
     * New high-performance implementation of the "LISTEN"/"NOTIFY"
       feature. Pending events are now stored in a memory-based queue
       rather than a table. Also, a "payload" string can be sent with each
       event, rather than transmitting just an event name as before.
     * New implementation of "VACUUM FULL". This command now rewrites the
       entire table and indexes, rather than moving individual rows to
       compact space. It is substantially faster in most cases, and no
       longer results in index bloat.
     * New contrib module "pg_upgrade" to support in-place upgrades from
       8.3 or 8.4 to 9.0.
     * Multiple performance enhancements for specific types of queries,
       including elimination of unnecessary joins. This helps optimize
       some automatically-generated queries, such as those produced by
       object-relational mappers (ORMs).
     * "EXPLAIN" enhancements. The output is now available in JSON, XML,
       or YAML format, and includes buffer utilization and other data not
       previously available.
     * "hstore" improvements, including new functions and greater data
       capacity.

   The above items are explained in more detail in the sections below.
     __________________________________________________________________

Migration to Version 9.0

   A dump/restore using pg_dump, or use of pg_upgrade, is required for
   those wishing to migrate data from any previous release.

   Version 9.0 contains a number of changes that selectively break
   backwards compatibility in order to support new features and code
   quality improvements. In particular, users who make extensive use of
   PL/pgSQL, Point-In-Time Recovery (PITR), or Warm Standby should test
   their applications because of slight user-visible changes in those
   areas. Observe the following incompatibilities:
     __________________________________________________________________

Server Settings

     * Remove server parameter add_missing_from, which was defaulted to
       off for many years (Tom Lane)
     * Remove server parameter regex_flavor, which was defaulted to
       advanced for many years (Tom Lane)
     * archive_mode now only affects archive_command; a new setting,
       wal_level, affects the contents of the write-ahead log (Heikki
       Linnakangas)
     * log_temp_files now uses default file size units of kilobytes
       (Robert Haas)
     __________________________________________________________________

Queries

     * When querying a parent table, do not do any separate permission
       checks on child tables scanned as part of the query (Peter
       Eisentraut)
       The SQL standard specifies this behavior, and it is also much more
       convenient in practice than the former behavior of checking
       permissions on each child as well as the parent.
     __________________________________________________________________

Data Types

     * bytea output now appears in hex format by default (Peter
       Eisentraut)
       The server parameter bytea_output can be used to select the
       traditional output format if needed for compatibility.
     * Array input now considers only plain ASCII whitespace characters to
       be potentially ignorable; it will never ignore non-ASCII
       characters, even if they are whitespace according to some locales
       (Tom Lane)
       This avoids some corner cases where array values could be
       interpreted differently depending on the server's locale settings.
     * Improve standards compliance of SIMILAR TO patterns and SQL-style
       substring() patterns (Tom Lane)
       This includes treating ? and {...} as pattern metacharacters, while
       they were simple literal characters before; that corresponds to new
       features added in SQL:2008. Also, ^ and $ are now treated as simple
       literal characters; formerly they were treated as metacharacters,
       as if the pattern were following POSIX rather than SQL rules. Also,
       in SQL-standard substring(), use of parentheses for nesting no
       longer interferes with capturing of a substring. Also, processing
       of bracket expressions (character classes) is now more
       standards-compliant.
     * Reject negative length values in 3-parameter substring() for bit
       strings, per the SQL standard (Tom Lane)
     * Make date_trunc truncate rather than round when reducing precision
       of fractional seconds (Tom Lane)
       The code always acted this way for integer-based dates/times. Now
       float-based dates/times behave similarly.
     __________________________________________________________________

Object Renaming

     * Tighten enforcement of column name consistency during "RENAME" when
       a child table inherits the same column from multiple unrelated
       parents (KaiGai Kohei)
     * No longer automatically rename indexes and index columns when the
       underlying table columns are renamed (Tom Lane)
       Administrators can still rename such indexes and columns manually.
       This change will require an update of the JDBC driver, and possibly
       other drivers, so that unique indexes are correctly recognized
       after a rename.
     * "CREATE OR REPLACE FUNCTION" can no longer change the declared
       names of function parameters (Pavel Stehule)
       In order to avoid creating ambiguity in named-parameter calls, it
       is no longer allowed to change the aliases for input parameters in
       the declaration of an existing function (although names can still
       be assigned to previously unnamed parameters). You now have to
       "DROP" and recreate the function to do that.
     __________________________________________________________________

PL/pgSQL

     * PL/pgSQL now throws an error if a variable name conflicts with a
       column name used in a query (Tom Lane)
       The former behavior was to bind ambiguous names to PL/pgSQL
       variables in preference to query columns, which often resulted in
       surprising misbehavior. Throwing an error allows easy detection of
       ambiguous situations. Although it's recommended that functions
       encountering this type of error be modified to remove the conflict,
       the old behavior can be restored if necessary via the configuration
       parameter plpgsql.variable_conflict, or via the per-function option
       #variable_conflict.
     * PL/pgSQL no longer allows variable names that match certain SQL
       reserved words (Tom Lane)
       This is a consequence of aligning the PL/pgSQL parser to match the
       core SQL parser more closely. If necessary, variable names can be
       double-quoted to avoid this restriction.
     * PL/pgSQL now requires columns of composite results to match the
       expected type modifier as well as base type (Pavel Stehule, Tom
       Lane)
       For example, if a column of the result type is declared as
       NUMERIC(30,2), it is no longer acceptable to return a NUMERIC of
       some other precision in that column. Previous versions neglected to
       check the type modifier and would thus allow result rows that
       didn't actually conform to the declared restrictions.
     * PL/pgSQL now treats selection into composite fields more
       consistently (Tom Lane)
       Formerly, a statement like SELECT ... INTO rec.fld FROM ... was
       treated as a scalar assignment even if the record field "fld" was
       of composite type. Now it is treated as a record assignment, the
       same as when the INTO target is a regular variable of composite
       type. So the values to be assigned to the field's subfields should
       be written as separate columns of the "SELECT" list, not as a
       ROW(...) construct as in previous versions.
       If you need to do this in a way that will work in both 9.0 and
       previous releases, you can write something like rec.fld := ROW(...)
       FROM ....
     * Remove PL/pgSQL's RENAME declaration (Tom Lane)
       Instead of RENAME, use ALIAS, which can now create an alias for any
       variable, not only dollar sign parameter names (such as $1) as
       before.
     __________________________________________________________________

Other Incompatibilities

     * Deprecate use of => as an operator name (Robert Haas)
       Future versions of PostgreSQL will probably reject this operator
       name entirely, in order to support the SQL-standard notation for
       named function parameters. For the moment, it is still allowed, but
       a warning is emitted when such an operator is defined.
     * Remove support for platforms that don't have a working 64-bit
       integer data type (Tom Lane)
       It is believed all still-supported platforms have working 64-bit
       integer data types.
     __________________________________________________________________

Changes

   Version 9.0 has an unprecedented number of new major features, and over
   200 enhancements, improvements, new commands, new functions, and other
   changes.
     __________________________________________________________________

Server

Continuous Archiving and Streaming Replication

   PostgreSQL's existing standby-server capability has been expanded both
   to support read-only queries on standby servers and to greatly reduce
   the lag between master and standby servers. For many users, this will
   be a useful and low-administration form of replication, either for high
   availability or for horizontal scalability.

     * Allow a standby server to accept read-only queries (Simon Riggs,
       Heikki Linnakangas)
       This feature is called Hot Standby. There are new "postgresql.conf"
       and "recovery.conf" settings to control this feature, as well as
       extensive documentation.
     * Allow write-ahead log (WAL) data to be streamed to a standby server
       (Fujii Masao, Heikki Linnakangas)
       This feature is called Streaming Replication. Previously WAL data
       could be sent to standby servers only in units of entire WAL files
       (normally 16 megabytes each). Streaming Replication eliminates this
       inefficiency and allows updates on the master to be propagated to
       standby servers with very little delay. There are new
       "postgresql.conf" and "recovery.conf" settings to control this
       feature, as well as extensive documentation.
     * Add pg_last_xlog_receive_location() and
       pg_last_xlog_replay_location(), which can be used to monitor
       standby server WAL activity (Simon Riggs, Fujii Masao, Heikki
       Linnakangas)
     __________________________________________________________________

Performance

     * Allow per-tablespace values to be set for sequential and random
       page cost estimates (seq_page_cost/random_page_cost) via "ALTER
       TABLESPACE ... SET/RESET" (Robert Haas)
     * Improve performance and reliability of EvalPlanQual rechecks in
       join queries (Tom Lane)
       "UPDATE", "DELETE", and "SELECT FOR UPDATE/SHARE" queries that
       involve joins will now behave much better when encountering
       freshly-updated rows.
     * Improve performance of "TRUNCATE" when the table was created or
       truncated earlier in the same transaction (Tom Lane)
     * Improve performance of finding inheritance child tables (Tom Lane)
     __________________________________________________________________

Optimizer

     * Remove unnecessary outer joins (Robert Haas)
       Outer joins where the inner side is unique and not referenced above
       the join are unnecessary and are therefore now removed. This will
       accelerate many automatically generated queries, such as those
       created by object-relational mappers (ORMs).
     * Allow IS NOT NULL restrictions to use indexes (Tom Lane)
       This is particularly useful for finding MAX()/MIN() values in
       indexes that contain many null values.
     * Improve the optimizer's choices about when to use materialize
       nodes, and when to use sorting versus hashing for DISTINCT (Tom
       Lane)
     * Improve the optimizer's equivalence detection for expressions
       involving boolean <> operators (Tom Lane)
     __________________________________________________________________

GEQO

     * Use the same random seed every time GEQO plans a query (Andres
       Freund)
       While the Genetic Query Optimizer (GEQO) still selects random
       plans, it now always selects the same random plans for identical
       queries, thus giving more consistent performance. You can modify
       geqo_seed to experiment with alternative plans.
     * Improve GEQO plan selection (Tom Lane)
       This avoids the rare error "failed to make a valid plan", and
       should also improve planning speed.
     __________________________________________________________________

Optimizer Statistics

     * Improve "ANALYZE" to support inheritance-tree statistics (Tom Lane)
       This is particularly useful for partitioned tables. However,
       autovacuum does not yet automatically re-analyze parent tables when
       child tables change.
     * Improve autovacuum's detection of when re-analyze is necessary (Tom
       Lane)
     * Improve optimizer's estimation for greater/less-than comparisons
       (Tom Lane)
       When looking up statistics for greater/less-than comparisons, if
       the comparison value is in the first or last histogram bucket, use
       an index (if available) to fetch the current actual column minimum
       or maximum. This greatly improves the accuracy of estimates for
       comparison values near the ends of the data range, particularly if
       the range is constantly changing due to addition of new data.
     * Allow setting of number-of-distinct-values statistics using "ALTER
       TABLE" (Robert Haas)
       This allows users to override the estimated number or percentage of
       distinct values for a column. This statistic is normally computed
       by "ANALYZE", but the estimate can be poor, especially on tables
       with very large numbers of rows.
     __________________________________________________________________

Authentication

     * Add support for RADIUS (Remote Authentication Dial In User Service)
       authentication (Magnus Hagander)
     * Allow LDAP (Lightweight Directory Access Protocol) authentication
       to operate in "search/bind" mode (Robert Fleming, Magnus Hagander)
       This allows the user to be looked up first, then the system uses
       the DN (Distinguished Name) returned for that user.
     * Add samehost and samenet designations to "pg_hba.conf" (Stef
       Walter)
       These match the server's IP address and subnet address
       respectively.
     * Pass trusted SSL root certificate names to the client so the client
       can return an appropriate client certificate (Craig Ringer)
     __________________________________________________________________

Monitoring

     * Add the ability for clients to set an application name, which is
       displayed in pg_stat_activity (Dave Page)
       This allows administrators to characterize database traffic and
       troubleshoot problems by source application.
     * Add a SQLSTATE option (%e) to log_line_prefix (Guillaume Smet)
       This allows users to compile statistics on errors and messages by
       error code number.
     * Write to the Windows event log in UTF16 encoding (Itagaki Takahiro)
       Now there is true multilingual support for PostgreSQL log messages
       on Windows.
     __________________________________________________________________

Statistics Counters

     * Add pg_stat_reset_shared('bgwriter') to reset the cluster-wide
       shared statistics for the background writer (Greg Smith)
     * Add pg_stat_reset_single_table_counters() and
       pg_stat_reset_single_function_counters() to allow resetting the
       statistics counters for individual tables and functions (Magnus
       Hagander)
     __________________________________________________________________

Server Settings

     * Allow setting of configuration parameters based on database/role
       combinations (Alvaro Herrera)
       Previously only per-database and per-role settings were possible,
       not combinations. All role and database settings are now stored in
       the new pg_db_role_setting system catalog. A new psql command \drds
       shows these settings. The legacy system views pg_roles, pg_shadow,
       and pg_user do not show combination settings, and therefore no
       longer completely represent the configuration for a user or
       database.
     * Add server parameter bonjour, which controls whether a
       Bonjour-enabled server advertises itself via Bonjour (Tom Lane)
       The default is off, meaning it does not advertise. This allows
       packagers to distribute Bonjour-enabled builds without worrying
       that individual users might not want the feature.
     * Add server parameter enable_material, which controls the use of
       materialize nodes in the optimizer (Robert Haas)
       The default is on. When off, the optimizer will not add materialize
       nodes purely for performance reasons, though they will still be
       used when necessary for correctness.
     * Change server parameter log_temp_files to use default file size
       units of kilobytes (Robert Haas)
       Previously this setting was interpreted in bytes if no units were
       specified.
     * Log changes of parameter values when "postgresql.conf" is reloaded
       (Peter Eisentraut)
       This lets administrators and security staff audit changes of
       database settings, and is also very convenient for checking the
       effects of "postgresql.conf" edits.
     * Properly enforce superuser permissions for custom server parameters
       (Tom Lane)
       Non-superusers can no longer issue "ALTER ROLE"/"DATABASE SET" for
       parameters that are not currently known to the server. This allows
       the server to correctly check that superuser-only parameters are
       only set by superusers. Previously, the SET would be allowed and
       then ignored at session start, making superuser-only custom
       parameters much less useful than they should be.
     __________________________________________________________________

Queries

     * Perform "SELECT FOR UPDATE"/SHARE processing after applying LIMIT,
       so the number of rows returned is always predictable (Tom Lane)
       Previously, changes made by concurrent transactions could cause a
       "SELECT FOR UPDATE" to unexpectedly return fewer rows than
       specified by its LIMIT. FOR UPDATE in combination with ORDER BY can
       still produce surprising results, but that can be corrected by
       placing FOR UPDATE in a subquery.
     * Allow mixing of traditional and SQL-standard LIMIT/OFFSET syntax
       (Tom Lane)
     * Extend the supported frame options in window functions (Hitoshi
       Harada)
       Frames can now start with CURRENT ROW, and the ROWS n
       PRECEDING/FOLLOWING options are now supported.
     * Make "SELECT INTO" and "CREATE TABLE AS" return row counts to the
       client in their command tags (Boszormenyi Zoltan)
       This can save an entire round-trip to the client, allowing result
       counts and pagination to be calculated without an additional
       "COUNT" query.
     __________________________________________________________________

Unicode Strings

     * Support Unicode surrogate pairs (dual 16-bit representation) in U&
       strings and identifiers (Peter Eisentraut)
     * Support Unicode escapes in E'...' strings (Marko Kreen)
     __________________________________________________________________

Object Manipulation

     * Speed up "CREATE DATABASE" by deferring flushes to disk (Andres
       Freund, Greg Stark)
     * Allow comments on columns of tables, views, and composite types
       only, not other relation types such as indexes and TOAST tables
       (Tom Lane)
     * Allow the creation of enumerated types containing no values (Bruce
       Momjian)
     * Let values of columns having storage type MAIN remain on the main
       heap page unless the row cannot fit on a page (Kevin Grittner)
       Previously MAIN values were forced out to TOAST tables until the
       row size was less than one-quarter of the page size.
     __________________________________________________________________

ALTER TABLE

     * Implement IF EXISTS for ALTER TABLE DROP COLUMN and ALTER TABLE
       DROP CONSTRAINT (Andres Freund)
     * Allow "ALTER TABLE" commands that rewrite tables to skip WAL
       logging (Itagaki Takahiro)
       Such operations either produce a new copy of the table or are
       rolled back, so WAL archiving can be skipped, unless running in
       continuous archiving mode. This reduces I/O overhead and improves
       performance.
     * Fix failure of ALTER TABLE table ADD COLUMN col serial when done by
       non-owner of table (Tom Lane)
     __________________________________________________________________

CREATE TABLE

     * Add support for copying COMMENTS and STORAGE settings in "CREATE
       TABLE ... LIKE" commands (Itagaki Takahiro)
     * Add a shortcut for copying all properties in "CREATE TABLE ...
       LIKE" commands (Itagaki Takahiro)
     * Add the SQL-standard CREATE TABLE ... OF type command (Peter
       Eisentraut)
       This allows creation of a table that matches an existing composite
       type. Additional constraints and defaults can be specified in the
       command.
     __________________________________________________________________

Constraints

     * Add deferrable unique constraints (Dean Rasheed)
       This allows mass updates, such as UPDATE tab SET col = col + 1, to
       work reliably on columns that have unique indexes or are marked as
       primary keys. If the constraint is specified as DEFERRABLE it will
       be checked at the end of the statement, rather than after each row
       is updated. The constraint check can also be deferred until the end
       of the current transaction, allowing such updates to be spread over
       multiple SQL commands.
     * Add exclusion constraints (Jeff Davis)
       Exclusion constraints generalize uniqueness constraints by allowing
       arbitrary comparison operators, not just equality. They are created
       with the "CREATE TABLE CONSTRAINT ... EXCLUDE" clause. The most
       common use of exclusion constraints is to specify that column
       entries must not overlap, rather than simply not be equal. This is
       useful for time periods and other ranges, as well as arrays. This
       feature enhances checking of data integrity for many calendaring,
       time-management, and scientific applications.
     * Improve uniqueness-constraint violation error messages to report
       the values causing the failure (Itagaki Takahiro)
       For example, a uniqueness constraint violation might now report Key
       (x)=(2) already exists.
     __________________________________________________________________

Object Permissions

     * Add the ability to make mass permission changes across a whole
       schema using the new "GRANT"/"REVOKE IN SCHEMA" clause (Petr
       Jelinek)
       This simplifies management of object permissions and makes it
       easier to utilize database roles for application data security.
     * Add "ALTER DEFAULT PRIVILEGES" command to control privileges of
       objects created later (Petr Jelinek)
       This greatly simplifies the assignment of object privileges in a
       complex database application. Default privileges can be set for
       tables, views, sequences, and functions. Defaults may be assigned
       on a per-schema basis, or database-wide.
     * Add the ability to control large object (BLOB) permissions with
       "GRANT"/"REVOKE" (KaiGai Kohei)
       Formerly, any database user could read or modify any large object.
       Read and write permissions can now be granted and revoked per large
       object, and the ownership of large objects is tracked.
     __________________________________________________________________

Utility Operations

     * Make "LISTEN"/"NOTIFY" store pending events in a memory queue,
       rather than in a system table (Joachim Wieland)
       This substantially improves performance, while retaining the
       existing features of transactional support and guaranteed delivery.
     * Allow "NOTIFY" to pass an optional "payload" string to listeners
       (Joachim Wieland)
       This greatly improves the usefulness of "LISTEN"/"NOTIFY" as a
       general-purpose event queue system.
     * Allow "CLUSTER" on all per-database system catalogs (Tom Lane)
       Shared catalogs still cannot be clustered.
     __________________________________________________________________

COPY

     * Accept COPY ... CSV FORCE QUOTE * (Itagaki Takahiro)
       Now * can be used as shorthand for "all columns" in the FORCE QUOTE
       clause.
     * Add new "COPY" syntax that allows options to be specified inside
       parentheses (Robert Haas, Emmanuel Cecchet)
       This allows greater flexibility for future "COPY" options. The old
       syntax is still supported, but only for pre-existing options.
     __________________________________________________________________

EXPLAIN

     * Allow "EXPLAIN" to output in XML, JSON, or YAML format (Robert
       Haas, Greg Sabino Mullane)
       The new output formats are easily machine-readable, supporting the
       development of new tools for analysis of "EXPLAIN" output.
     * Add new BUFFERS option to report query buffer usage during "EXPLAIN
       ANALYZE" (Itagaki Takahiro)
       This allows better query profiling for individual queries. Buffer
       usage is no longer reported in the output for log_statement_stats
       and related settings.
     * Add hash usage information to "EXPLAIN" output (Robert Haas)
     * Add new "EXPLAIN" syntax that allows options to be specified inside
       parentheses (Robert Haas)
       This allows greater flexibility for future "EXPLAIN" options. The
       old syntax is still supported, but only for pre-existing options.
     __________________________________________________________________

VACUUM

     * Change "VACUUM FULL" to rewrite the entire table and rebuild its
       indexes, rather than moving individual rows around to compact space
       (Itagaki Takahiro, Tom Lane)
       The previous method was usually slower and caused index bloat. Note
       that the new method will use more disk space transiently during
       "VACUUM FULL"; potentially as much as twice the space normally
       occupied by the table and its indexes.
     * Add new "VACUUM" syntax that allows options to be specified inside
       parentheses (Itagaki Takahiro)
       This allows greater flexibility for future "VACUUM" options. The
       old syntax is still supported, but only for pre-existing options.
     __________________________________________________________________

Indexes

     * Allow an index to be named automatically by omitting the index name
       in "CREATE INDEX" (Tom Lane)
     * By default, multicolumn indexes are now named after all their
       columns; and index expression columns are now named based on their
       expressions (Tom Lane)
     * Reindexing shared system catalogs is now fully transactional and
       crash-safe (Tom Lane)
       Formerly, reindexing a shared index was only allowed in standalone
       mode, and a crash during the operation could leave the index in
       worse condition than it was before.
     * Add point_ops operator class for GiST (Teodor Sigaev)
       This feature permits GiST indexing of point columns. The index can
       be used for several types of queries such as "point" <@ "polygon"
       (point is in polygon). This should make many PostGIS queries
       faster.
     * Use red-black binary trees for GIN index creation (Teodor Sigaev)
       Red-black trees are self-balancing. This avoids slowdowns in cases
       where the input is in nonrandom order.
     __________________________________________________________________

Data Types

     * Allow bytea values to be written in hex notation (Peter Eisentraut)
       The server parameter bytea_output controls whether hex or
       traditional format is used for bytea output. Libpq's
       PQescapeByteaConn() function automatically uses the hex format when
       connected to PostgreSQL 9.0 or newer servers. However, pre-9.0
       libpq versions will not correctly process hex format from newer
       servers.
       The new hex format will be directly compatible with more
       applications that use binary data, allowing them to store and
       retrieve it without extra conversion. It is also significantly
       faster to read and write than the traditional format.
     * Allow server parameter extra_float_digits to be increased to 3 (Tom
       Lane)
       The previous maximum extra_float_digits setting was 2. There are
       cases where 3 digits are needed to dump and restore float4 values
       exactly. pg_dump will now use the setting of 3 when dumping from a
       server that allows it.
     * Tighten input checking for int2vector values (Caleb Welton)
     __________________________________________________________________

Full Text Search

     * Add prefix support in synonym dictionaries (Teodor Sigaev)
     * Add filtering dictionaries (Teodor Sigaev)
       Filtering dictionaries allow tokens to be modified then passed to
       subsequent dictionaries.
     * Allow underscores in email-address tokens (Teodor Sigaev)
     * Use more standards-compliant rules for parsing URL tokens (Tom
       Lane)
     __________________________________________________________________

Functions

     * Allow function calls to supply parameter names and match them to
       named parameters in the function definition (Pavel Stehule)
       For example, if a function is defined to take parameters a and b,
       it can be called with func(a := 7, b := 12) or func(b := 12, a :=
       7).
     * Support locale-specific regular expression processing with UTF-8
       server encoding (Tom Lane)
       Locale-specific regular expression functionality includes
       case-insensitive matching and locale-specific character classes.
       Previously, these features worked correctly for non-ASCII
       characters only if the database used a single-byte server encoding
       (such as LATIN1). They will still misbehave in multi-byte encodings
       other than UTF-8.
     * Add support for scientific notation in to_char() (EEEE
       specification) (Pavel Stehule, Brendan Jurd)
     * Make to_char() honor FM (fill mode) in Y, YY, and YYY
       specifications (Bruce Momjian, Tom Lane)
       It was already honored by YYYY.
     * Fix to_char() to output localized numeric and monetary strings in
       the correct encoding on Windows (Hiroshi Inoue, Itagaki Takahiro,
       Bruce Momjian)
     * Correct calculations of "overlaps" and "contains" operations for
       polygons (Teodor Sigaev)
       The polygon && (overlaps) operator formerly just checked to see if
       the two polygons' bounding boxes overlapped. It now does a more
       correct check. The polygon @> and <@ (contains/contained by)
       operators formerly checked to see if one polygon's vertexes were
       all contained in the other; this can wrongly report "true" for some
       non-convex polygons. Now they check that all line segments of one
       polygon are contained in the other.
     __________________________________________________________________

Aggregates

     * Allow aggregate functions to use ORDER BY (Andrew Gierth)
       For example, this is now supported: array_agg(a ORDER BY b). This
       is useful with aggregates for which the order of input values is
       significant, and eliminates the need to use a nonstandard subquery
       to determine the ordering.
     * Multi-argument aggregate functions can now use DISTINCT (Andrew
       Gierth)
     * Add the string_agg() aggregate function to combine values into a
       single string (Pavel Stehule)
     * Aggregate functions that are called with DISTINCT are now passed
       NULL values if the aggregate transition function is not marked as
       STRICT (Andrew Gierth)
       For example, agg(DISTINCT x) might pass a NULL x value to agg().
       This is more consistent with the behavior in non-DISTINCT cases.
     __________________________________________________________________

Bit Strings

     * Add get_bit() and set_bit() functions for bit strings, mirroring
       those for bytea (Leonardo F)
     * Implement OVERLAY() (replace) for bit strings and bytea (Leonardo
       F)
     __________________________________________________________________

Object Information Functions

     * Add pg_table_size() and pg_indexes_size() to provide a more
       user-friendly interface to the pg_relation_size() function (Bernd
       Helmle)
     * Add has_sequence_privilege() for sequence permission checking
       (Abhijit Menon-Sen)
     * Update the information_schema views to conform to SQL:2008 (Peter
       Eisentraut)
     * Make the information_schema views correctly display maximum octet
       lengths for char and varchar columns (Peter Eisentraut)
     * Speed up information_schema privilege views (Joachim Wieland)
     __________________________________________________________________

Function and Trigger Creation

     * Support execution of anonymous code blocks using the "DO" statement
       (Petr Jelinek, Joshua Tolley, Hannu Valtonen)
       This allows execution of server-side code without the need to
       create and delete a temporary function definition. Code can be
       executed in any language for which the user has permissions to
       define a function.
     * Implement SQL-standard-compliant per-column triggers (Itagaki
       Takahiro)
       Such triggers are fired only when the specified column(s) are
       affected by the query, e.g. appear in an "UPDATE"'s SET list.
     * Add the WHEN clause to "CREATE TRIGGER" to allow control over
       whether a trigger is fired (Itagaki Takahiro)
       While the same type of check can always be performed inside the
       trigger, doing it in an external WHEN clause can have performance
       benefits.
     __________________________________________________________________

Server-Side Languages

     * Add the OR REPLACE clause to "CREATE LANGUAGE" (Tom Lane)
       This is helpful to optionally install a language if it does not
       already exist, and is particularly helpful now that PL/pgSQL is
       installed by default.
     __________________________________________________________________

PL/pgSQL Server-Side Language

     * Install PL/pgSQL by default (Bruce Momjian)
       The language can still be removed from a particular database if the
       administrator has security or performance concerns about making it
       available.
     * Improve handling of cases where PL/pgSQL variable names conflict
       with identifiers used in queries within a function (Tom Lane)
       The default behavior is now to throw an error when there is a
       conflict, so as to avoid surprising behaviors. This can be
       modified, via the configuration parameter plpgsql.variable_conflict
       or the per-function option #variable_conflict, to allow either the
       variable or the query-supplied column to be used. In any case
       PL/pgSQL will no longer attempt to substitute variables in places
       where they would not be syntactically valid.
     * Make PL/pgSQL use the main lexer, rather than its own version (Tom
       Lane)
       This ensures accurate tracking of the main system's behavior for
       details such as string escaping. Some user-visible details, such as
       the set of keywords considered reserved in PL/pgSQL, have changed
       in consequence.
     * Avoid throwing an unnecessary error for an invalid record reference
       (Tom Lane)
       An error is now thrown only if the reference is actually fetched,
       rather than whenever the enclosing expression is reached. For
       example, many people have tried to do this in triggers:
if TG_OP = 'INSERT' and NEW.col1 = ... then
       This will now actually work as expected.
     * Improve PL/pgSQL's ability to handle row types with dropped columns
       (Pavel Stehule)
     * Allow input parameters to be assigned values within PL/pgSQL
       functions (Steve Prentice)
       Formerly, input parameters were treated as being declared CONST, so
       the function's code could not change their values. This restriction
       has been removed to simplify porting of functions from other DBMSes
       that do not impose the equivalent restriction. An input parameter
       now acts like a local variable initialized to the passed-in value.
     * Improve error location reporting in PL/pgSQL (Tom Lane)
     * Add "count" and ALL options to "MOVE FORWARD"/BACKWARD in PL/pgSQL
       (Pavel Stehule)
     * Allow PL/pgSQL's WHERE CURRENT OF to use a cursor variable (Tom
       Lane)
     * Allow PL/pgSQL's "OPEN cursor FOR EXECUTE" to use parameters (Pavel
       Stehule, Itagaki Takahiro)
       This is accomplished with a new USING clause.
     __________________________________________________________________

PL/Perl Server-Side Language

     * Add new PL/Perl functions: quote_literal(), quote_nullable(),
       quote_ident(), encode_bytea(), decode_bytea(), looks_like_number(),
       encode_array_literal(), encode_array_constructor() (Tim Bunce)
     * Add server parameter plperl.on_init to specify a PL/Perl
       initialization function (Tim Bunce)
       plperl.on_plperl_init and plperl.on_plperlu_init are also available
       for initialization that is specific to the trusted or untrusted
       language respectively.
     * Support "END" blocks in PL/Perl (Tim Bunce)
       "END" blocks do not currently allow database access.
     * Allow "use strict" in PL/Perl (Tim Bunce)
       Perl strict checks can also be globally enabled with the new server
       parameter plperl.use_strict.
     * Allow "require" in PL/Perl (Tim Bunce)
       This basically tests to see if the module is loaded, and if not,
       generates an error. It will not allow loading of modules that the
       administrator has not preloaded via the initialization parameters.
     * Allow "use feature" in PL/Perl if Perl version 5.10 or later is
       used (Tim Bunce)
     * Verify that PL/Perl return values are valid in the server encoding
       (Andrew Dunstan)
     __________________________________________________________________

PL/Python Server-Side Language

     * Add Unicode support in PL/Python (Peter Eisentraut)
       Strings are automatically converted from/to the server encoding as
       necessary.
     * Improve bytea support in PL/Python (Caleb Welton)
       Bytea values passed into PL/Python are now represented as binary,
       rather than the PostgreSQL bytea text format. Bytea values
       containing null bytes are now also output properly from PL/Python.
       Passing of boolean, integer, and float values was also improved.
     * Support arrays as parameters and return values in PL/Python (Peter
       Eisentraut)
     * Improve mapping of SQL domains to Python types (Peter Eisentraut)
     * Add Python 3 support to PL/Python (Peter Eisentraut)
       The new server-side language is called plpython3u. This cannot be
       used in the same session with the Python 2 server-side language.
     * Improve error location and exception reporting in PL/Python (Peter
       Eisentraut)
     __________________________________________________________________

Client Applications

     * Add an "--analyze-only" option to "vacuumdb", to analyze without
       vacuuming (Bruce Momjian)
     __________________________________________________________________

psql

     * Add support for quoting/escaping the values of psql variables as
       SQL strings or identifiers (Pavel Stehule, Robert Haas)
       For example, :'var' will produce the value of var quoted and
       properly escaped as a literal string, while :"var" will produce its
       value quoted and escaped as an identifier.
     * Ignore a leading UTF-8-encoded Unicode byte-order marker in script
       files read by psql (Itagaki Takahiro)
       This is enabled when the client encoding is UTF-8. It improves
       compatibility with certain editors, mostly on Windows, that insist
       on inserting such markers.
     * Fix "psql --file -" to properly honor "--single-transaction" (Bruce
       Momjian)
     * Avoid overwriting of psql's command-line history when two psql
       sessions are run concurrently (Tom Lane)
     * Improve psql's tab completion support (Itagaki Takahiro)
     * Show \timing output when it is enabled, regardless of "quiet" mode
       (Peter Eisentraut)
     __________________________________________________________________

psql Display

     * Improve display of wrapped columns in psql (Roger Leigh)
       This behavior is now the default. The previous formatting is
       available by using "\pset linestyle old-ascii".
     * Allow psql to use fancy Unicode line-drawing characters via "\pset
       linestyle unicode" (Roger Leigh)
     __________________________________________________________________

psql \d Commands

     * Make "\d" show child tables that inherit from the specified parent
       (Damien Clochard)
       "\d" shows only the number of child tables, while "\d+" shows the
       names of all child tables.
     * Show definitions of index columns in "\d index_name" (Khee Chin)
       The definition is useful for expression indexes.
     * Show a view's defining query only in "\d+", not in "\d" (Peter
       Eisentraut)
       Always including the query was deemed overly verbose.
     __________________________________________________________________

pg_dump

     * Make pg_dump/pg_restore "--clean" also remove large objects
       (Itagaki Takahiro)
     * Fix pg_dump to properly dump large objects when
       standard_conforming_strings is enabled (Tom Lane)
       The previous coding could fail when dumping to an archive file and
       then generating script output from pg_restore.
     * pg_restore now emits large-object data in hex format when
       generating script output (Tom Lane)
       This could cause compatibility problems if the script is then
       loaded into a pre-9.0 server. To work around that, restore directly
       to the server, instead.
     * Allow pg_dump to dump comments attached to columns of composite
       types (Taro Minowa (Higepon))
     * Make pg_dump "--verbose" output the pg_dump and server versions in
       text output mode (Jim Cox, Tom Lane)
       These were already provided in custom output mode.
     * pg_restore now complains if any command-line arguments remain after
       the switches and optional file name (Tom Lane)
       Previously, it silently ignored any such arguments.
     __________________________________________________________________

pg_ctl

     * Allow pg_ctl to be used safely to start the postmaster during a
       system reboot (Tom Lane)
       Previously, pg_ctl's parent process could have been mistakenly
       identified as a running postmaster based on a stale postmaster lock
       file, resulting in a transient failure to start the database.
     * Give pg_ctl the ability to initialize the database (by invoking
       initdb) (Zdenek Kotala)
     __________________________________________________________________

Development Tools

libpq

     * Add new libpq functions PQconnectdbParams() and
       PQconnectStartParams() (Guillaume Lelarge)
       These functions are similar to PQconnectdb() and PQconnectStart()
       except that they accept a null-terminated array of connection
       options, rather than requiring all options to be provided in a
       single string.
     * Add libpq functions PQescapeLiteral() and PQescapeIdentifier()
       (Robert Haas)
       These functions return appropriately quoted and escaped SQL string
       literals and identifiers. The caller is not required to
       pre-allocate the string result, as is required by
       PQescapeStringConn().
     * Add support for a per-user service file (".pg_service.conf"), which
       is checked before the site-wide service file (Peter Eisentraut)
     * Properly report an error if the specified libpq service cannot be
       found (Peter Eisentraut)
     * Add TCP keepalive settings in libpq (Tollef Fog Heen, Fujii Masao,
       Robert Haas)
       Keepalive settings were already supported on the server end of TCP
       connections.
     * Avoid extra system calls to block and unblock SIGPIPE in libpq, on
       platforms that offer alternative methods (Jeremy Kerr)
     * When a ".pgpass"-supplied password fails, mention where the
       password came from in the error message (Bruce Momjian)
     * Load all SSL certificates given in the client certificate file (Tom
       Lane)
       This improves support for indirectly-signed SSL certificates.
     __________________________________________________________________

ecpg

     * Add SQLDA (SQL Descriptor Area) support to ecpg (Boszormenyi
       Zoltan)
     * Add the "DESCRIBE" [ OUTPUT ] statement to ecpg (Boszormenyi
       Zoltan)
     * Add an ECPGtransactionStatus function to return the current
       transaction status (Bernd Helmle)
     * Add the string data type in ecpg Informix-compatibility mode
       (Boszormenyi Zoltan)
     * Allow ecpg to use new and old variable names without restriction
       (Michael Meskes)
     * Allow ecpg to use variable names in free() (Michael Meskes)
     * Make ecpg_dynamic_type() return zero for non-SQL3 data types
       (Michael Meskes)
       Previously it returned the negative of the data type OID. This
       could be confused with valid type OIDs, however.
     * Support long long types on platforms that already have 64-bit long
       (Michael Meskes)
     __________________________________________________________________

ecpg Cursors

     * Add out-of-scope cursor support in ecpg's native mode (Boszormenyi
       Zoltan)
       This allows "DECLARE" to use variables that are not in scope when
       "OPEN" is called. This facility already existed in ecpg's
       Informix-compatibility mode.
     * Allow dynamic cursor names in ecpg (Boszormenyi Zoltan)
     * Allow ecpg to use noise words FROM and IN in "FETCH" and "MOVE"
       (Boszormenyi Zoltan)
     __________________________________________________________________

Build Options

     * Enable client thread safety by default (Bruce Momjian)
       The thread-safety option can be disabled with configure
       "--disable-thread-safety".
     * Add support for controlling the Linux out-of-memory killer (Alex
       Hunsaker, Tom Lane)
       Now that "/proc/self/oom_adj" allows disabling of the Linux
       out-of-memory (OOM) killer, it's recommendable to disable OOM kills
       for the postmaster. It may then be desirable to re-enable OOM kills
       for the postmaster's child processes. The new compile-time option
       LINUX_OOM_ADJ allows the killer to be reactivated for child
       processes.
     __________________________________________________________________

Makefiles

     * New "Makefile" targets world, install-world, and installcheck-world
       (Andrew Dunstan)
       These are similar to the existing all, install, and installcheck
       targets, but they also build the HTML documentation, build and test
       "contrib", and test server-side languages and ecpg.
     * Add data and documentation installation location control to PGXS
       Makefiles (Mark Cave-Ayland)
     * Add Makefile rules to build the PostgreSQL documentation as a
       single HTML file or as a single plain-text file (Peter Eisentraut,
       Bruce Momjian)
     __________________________________________________________________

Windows

     * Support compiling on 64-bit Windows and running in 64-bit mode
       (Tsutomu Yamada, Magnus Hagander)
       This allows for large shared memory sizes on Windows.
     * Support server builds using Visual Studio 2008 (Magnus Hagander)
     __________________________________________________________________

Source Code

     * Distribute prebuilt documentation in a subdirectory tree, rather
       than as tar archive files inside the distribution tarball (Peter
       Eisentraut)
       For example, the prebuilt HTML documentation is now in
       "doc/src/sgml/html/"; the manual pages are packaged similarly.
     * Make the server's lexer reentrant (Tom Lane)
       This was needed for use of the lexer by PL/pgSQL.
     * Improve speed of memory allocation (Tom Lane, Greg Stark)
     * User-defined constraint triggers now have entries in pg_constraint
       as well as pg_trigger (Tom Lane)
       Because of this change, pg_constraint.pgconstrname is now redundant
       and has been removed.
     * Add system catalog columns pg_constraint.conindid and
       pg_trigger.tgconstrindid to better document the use of indexes for
       constraint enforcement (Tom Lane)
     * Allow multiple conditions to be communicated to backends using a
       single operating system signal (Fujii Masao)
       This allows new features to be added without a platform-specific
       constraint on the number of signal conditions.
     * Improve source code test coverage, including "contrib", PL/Python,
       and PL/Perl (Peter Eisentraut, Andrew Dunstan)
     * Remove the use of flat files for system table bootstrapping (Tom
       Lane, Alvaro Herrera)
       This improves performance when using many roles or databases, and
       eliminates some possible failure conditions.
     * Automatically generate the initial contents of pg_attribute for
       "bootstrapped" catalogs (John Naylor)
       This greatly simplifies changes to these catalogs.
     * Split the processing of "INSERT"/"UPDATE"/"DELETE" operations out
       of "execMain.c" (Marko Tiikkaja)
       Updates are now executed in a separate ModifyTable node. This
       change is necessary infrastructure for future improvements.
     * Simplify translation of psql's SQL help text (Peter Eisentraut)
     * Reduce the lengths of some file names so that all file paths in the
       distribution tarball are less than 100 characters (Tom Lane)
       Some decompression programs have problems with longer file paths.
     * Add a new ERRCODE_INVALID_PASSWORD SQLSTATE error code (Bruce
       Momjian)
     * With authors' permissions, remove the few remaining personal source
       code copyright notices (Bruce Momjian)
       The personal copyright notices were insignificant but the community
       occasionally had to answer questions about them.
     * Add new documentation section about running PostgreSQL in
       non-durable mode to improve performance (Bruce Momjian)
     * Restructure the HTML documentation "Makefile" rules to make their
       dependency checks work correctly, avoiding unnecessary rebuilds
       (Peter Eisentraut)
     * Use DocBook XSL stylesheets for man page building, rather than
       Docbook2X (Peter Eisentraut)
       This changes the set of tools needed to build the man pages.
     * Improve PL/Perl code structure (Tim Bunce)
     * Improve error context reports in PL/Perl (Alexey Klyukin)
     __________________________________________________________________

New Build Requirements

   Note that these requirements do not apply when building from a
   distribution tarball, since tarballs include the files that these
   programs are used to build.

     * Require Autoconf 2.63 to build configure (Peter Eisentraut)
     * Require Flex 2.5.31 or later to build from a CVS checkout (Tom
       Lane)
     * Require Perl version 5.8 or later to build from a CVS checkout
       (John Naylor, Andrew Dunstan)
     __________________________________________________________________

Portability

     * Use a more modern API for Bonjour (Tom Lane)
       Bonjour support now requires OS X 10.3 or later. The older API has
       been deprecated by Apple.
     * Add spinlock support for the SuperH architecture (Nobuhiro
       Iwamatsu)
     * Allow non-GCC compilers to use inline functions if they support
       them (Kurt Harriman)
     * Remove support for platforms that don't have a working 64-bit
       integer data type (Tom Lane)
     * Restructure use of LDFLAGS to be more consistent across platforms
       (Tom Lane)
       LDFLAGS is now used for linking both executables and shared
       libraries, and we add on LDFLAGS_EX when linking executables, or
       LDFLAGS_SL when linking shared libraries.
     __________________________________________________________________

Server Programming

     * Make backend header files safe to include in C++ (Kurt Harriman,
       Peter Eisentraut)
       These changes remove keyword conflicts that previously made C++
       usage difficult in backend code. However, there are still other
       complexities when using C++ for backend functions. extern "C" { }
       is still necessary in appropriate places, and memory management and
       error handling are still problematic.
     * Add AggCheckCallContext() for use in detecting if a C function is
       being called as an aggregate (Hitoshi Harada)
     * Change calling convention for SearchSysCache() and related
       functions to avoid hard-wiring the maximum number of cache keys
       (Robert Haas)
       Existing calls will still work for the moment, but can be expected
       to break in 9.1 or later if not converted to the new style.
     * Require calls of fastgetattr() and heap_getattr() backend macros to
       provide a non-NULL fourth argument (Robert Haas)
     * Custom typanalyze functions should no longer rely on
       VacAttrStats.attr to determine the type of data they will be passed
       (Tom Lane)
       This was changed to allow collection of statistics on index columns
       for which the storage type is different from the underlying column
       data type. There are new fields that tell the actual datatype being
       analyzed.
     __________________________________________________________________

Server Hooks

     * Add parser hooks for processing ColumnRef and ParamRef nodes (Tom
       Lane)
     * Add a ProcessUtility hook so loadable modules can control utility
       commands (Itagaki Takahiro)
     __________________________________________________________________

Binary Upgrade Support

     * Add "contrib/pg_upgrade" to support in-place upgrades (Bruce
       Momjian)
       This avoids the requirement of dumping/reloading the database when
       upgrading to a new major release of PostgreSQL, thus reducing
       downtime by orders of magnitude. It supports upgrades to 9.0 from
       PostgreSQL 8.3 and 8.4.
     * Add support for preserving relation relfilenode values during
       binary upgrades (Bruce Momjian)
     * Add support for preserving pg_type and pg_enum OIDs during binary
       upgrades (Bruce Momjian)
     * Move data files within tablespaces into PostgreSQL-version-specific
       subdirectories (Bruce Momjian)
       This simplifies binary upgrades.
     __________________________________________________________________

Contrib

     * Add multithreading option ("-j") to "contrib/pgbench" (Itagaki
       Takahiro)
       This allows multiple CPUs to be used by pgbench, reducing the risk
       of pgbench itself becoming the test bottleneck.
     * Add "\shell" and "\setshell" meta commands to "contrib/pgbench"
       (Michael Paquier)
     * New features for "contrib/dict_xsyn" (Sergey Karpov)
       The new options are matchorig, matchsynonyms, and keepsynonyms.
     * Add full text dictionary "contrib/unaccent" (Teodor Sigaev)
       This filtering dictionary removes accents from letters, which makes
       full-text searches over multiple languages much easier.
     * Add dblink_get_notify() to "contrib/dblink" (Marcus Kempe)
       This allows asynchronous notifications in dblink.
     * Improve "contrib/dblink"'s handling of dropped columns (Tom Lane)
       This affects dblink_build_sql_insert() and related functions. These
       functions now number columns according to logical not physical
       column numbers.
     * Greatly increase "contrib/hstore"'s data length limit, and add
       B-tree and hash support so GROUP BY and DISTINCT operations are
       possible on hstore columns (Andrew Gierth)
       New functions and operators were also added. These improvements
       make hstore a full-function key-value store embedded in PostgreSQL.
     * Add "contrib/passwordcheck" to support site-specific password
       strength policies (Laurenz Albe)
       The source code of this module should be modified to implement
       site-specific password policies.
     * Add "contrib/pg_archivecleanup" tool (Simon Riggs)
       This is designed to be used in the archive_cleanup_command server
       parameter, to remove no-longer-needed archive files.
     * Add query text to "contrib/auto_explain" output (Andrew Dunstan)
     * Add buffer access counters to "contrib/pg_stat_statements" (Itagaki
       Takahiro)
     * Update "contrib/start-scripts/linux" to use "/proc/self/oom_adj" to
       disable the Linux out-of-memory (OOM) killer (Alex Hunsaker, Tom
       Lane)
     __________________________________________________________________

                               Release 8.4.19

     Release Date: 2013-12-05

   This release contains a variety of fixes from 8.4.18. For information
   about new features in the 8.4 major release, see the Section called
   Release 8.4.
     __________________________________________________________________

Migration to Version 8.4.19

   A dump/restore is not required for those running 8.4.X.

   However, this release corrects a potential data corruption issue. See
   the first changelog entry below to find out whether your installation
   has been affected and what steps you can take if so.

   Also, if you are upgrading from a version earlier than 8.4.17, see the
   release notes for 8.4.17.
     __________________________________________________________________

Changes

     * Fix "VACUUM"'s tests to see whether it can update relfrozenxid
       (Andres Freund)
       In some cases "VACUUM" (either manual or autovacuum) could
       incorrectly advance a table's relfrozenxid value, allowing tuples
       to escape freezing, causing those rows to become invisible once
       2^31 transactions have elapsed. The probability of data loss is
       fairly low since multiple incorrect advancements would need to
       happen before actual loss occurs, but it's not zero. Users
       upgrading from release 8.4.8 or earlier are not affected, but all
       later versions contain the bug.
       The issue can be ameliorated by, after upgrading, vacuuming all
       tables in all databases while having vacuum_freeze_table_age set to
       zero. This will fix any latent corruption but will not be able to
       fix all pre-existing data errors. However, an installation can be
       presumed safe after performing this vacuuming if it has executed
       fewer than 2^31 update transactions in its lifetime (check this
       with SELECT txid_current() < 2^31).
     * Fix race condition in GIN index posting tree page deletion (Heikki
       Linnakangas)
       This could lead to transient wrong answers or query failures.
     * Avoid flattening a subquery whose SELECT list contains a volatile
       function wrapped inside a sub-SELECT (Tom Lane)
       This avoids unexpected results due to extra evaluations of the
       volatile function.
     * Fix planner's processing of non-simple-variable subquery outputs
       nested within outer joins (Tom Lane)
       This error could lead to incorrect plans for queries involving
       multiple levels of subqueries within JOIN syntax.
     * Fix premature deletion of temporary files (Andres Freund)
     * Fix possible read past end of memory in rule printing (Peter
       Eisentraut)
     * Fix array slicing of int2vector and oidvector values (Tom Lane)
       Expressions of this kind are now implicitly promoted to regular
       int2 or oid arrays.
     * Fix incorrect behaviors when using a SQL-standard, simple GMT
       offset timezone (Tom Lane)
       In some cases, the system would use the simple GMT offset value
       when it should have used the regular timezone setting that had
       prevailed before the simple offset was selected. This change also
       causes the timeofday function to honor the simple GMT offset zone.
     * Prevent possible misbehavior when logging translations of Windows
       error codes (Tom Lane)
     * Properly quote generated command lines in pg_ctl (Naoya Anzai and
       Tom Lane)
       This fix applies only to Windows.
     * Fix pg_dumpall to work when a source database sets
       default_transaction_read_only via "ALTER DATABASE SET" (Kevin
       Grittner)
       Previously, the generated script would fail during restore.
     * Fix ecpg's processing of lists of variables declared varchar
       (Zoltan Boszormenyi)
     * Make "contrib/lo" defend against incorrect trigger definitions
       (Marc Cousin)
     * Update time zone data files to tzdata release 2013h for DST law
       changes in Argentina, Brazil, Jordan, Libya, Liechtenstein,
       Morocco, and Palestine. Also, new timezone abbreviations WIB, WIT,
       WITA for Indonesia.
     __________________________________________________________________

                               Release 8.4.18

     Release Date: 2013-10-10

   This release contains a variety of fixes from 8.4.17. For information
   about new features in the 8.4 major release, see the Section called
   Release 8.4.
     __________________________________________________________________

Migration to Version 8.4.18

   A dump/restore is not required for those running 8.4.X.

   However, if you are upgrading from a version earlier than 8.4.17, see
   the release notes for 8.4.17.
     __________________________________________________________________

Changes

     * Prevent corruption of multi-byte characters when attempting to
       case-fold identifiers (Andrew Dunstan)
       PostgreSQL case-folds non-ASCII characters only when using a
       single-byte server encoding.
     * Fix memory leak caused by lo_open() failure (Heikki Linnakangas)
     * Fix memory overcommit bug when work_mem is using more than 24GB of
       memory (Stephen Frost)
     * Fix deadlock bug in libpq when using SSL (Stephen Frost)
     * Properly compute row estimates for boolean columns containing many
       NULL values (Andrew Gierth)
       Previously tests like col IS NOT TRUE and col IS NOT FALSE did not
       properly factor in NULL values when estimating plan costs.
     * Prevent pushing down WHERE clauses into unsafe UNION/INTERSECT
       subqueries (Tom Lane)
       Subqueries of a UNION or INTERSECT that contain set-returning
       functions or volatile functions in their SELECT lists could be
       improperly optimized, leading to run-time errors or incorrect query
       results.
     * Fix rare case of "failed to locate grouping columns" planner
       failure (Tom Lane)
     * Improve view dumping code's handling of dropped columns in
       referenced tables (Tom Lane)
     * Fix possible deadlock during concurrent "CREATE INDEX CONCURRENTLY"
       operations (Tom Lane)
     * Fix regexp_matches() handling of zero-length matches (Jeevan
       Chalke)
       Previously, zero-length matches like '^' could return too many
       matches.
     * Fix crash for overly-complex regular expressions (Heikki
       Linnakangas)
     * Fix regular expression match failures for back references combined
       with non-greedy quantifiers (Jeevan Chalke)
     * Prevent "CREATE FUNCTION" from checking "SET" variables unless
       function body checking is enabled (Tom Lane)
     * Fix pgp_pub_decrypt() so it works for secret keys with passwords
       (Marko Kreen)
     * Remove rare inaccurate warning during vacuum of index-less tables
       (Heikki Linnakangas)
     * Avoid possible failure when performing transaction control commands
       (e.g "ROLLBACK") in prepared queries (Tom Lane)
     * Ensure that floating-point data input accepts standard spellings of
       "infinity" on all platforms (Tom Lane)
       The C99 standard says that allowable spellings are inf, +inf, -inf,
       infinity, +infinity, and -infinity. Make sure we recognize these
       even if the platform's strtod function doesn't.
     * Expand ability to compare rows to records and arrays (Rafal
       Rzepecki, Tom Lane)
     * Update time zone data files to tzdata release 2013d for DST law
       changes in Israel, Morocco, Palestine, and Paraguay. Also,
       historical zone data corrections for Macquarie Island.
     __________________________________________________________________

                               Release 8.4.17

     Release Date: 2013-04-04

   This release contains a variety of fixes from 8.4.16. For information
   about new features in the 8.4 major release, see the Section called
   Release 8.4.
     __________________________________________________________________

Migration to Version 8.4.17

   A dump/restore is not required for those running 8.4.X.

   However, this release corrects several errors in management of GiST
   indexes. After installing this update, it is advisable to "REINDEX" any
   GiST indexes that meet one or more of the conditions described below.

   Also, if you are upgrading from a version earlier than 8.4.10, see the
   release notes for 8.4.10.
     __________________________________________________________________

Changes

     * Reset OpenSSL randomness state in each postmaster child process
       (Marko Kreen)
       This avoids a scenario wherein random numbers generated by
       "contrib/pgcrypto" functions might be relatively easy for another
       database user to guess. The risk is only significant when the
       postmaster is configured with ssl = on but most connections don't
       use SSL encryption. (CVE-2013-1900)
     * Fix GiST indexes to not use "fuzzy" geometric comparisons when it's
       not appropriate to do so (Alexander Korotkov)
       The core geometric types perform comparisons using "fuzzy"
       equality, but gist_box_same must do exact comparisons, else GiST
       indexes using it might become inconsistent. After installing this
       update, users should "REINDEX" any GiST indexes on box, polygon,
       circle, or point columns, since all of these use gist_box_same.
     * Fix erroneous range-union and penalty logic in GiST indexes that
       use "contrib/btree_gist" for variable-width data types, that is
       text, bytea, bit, and numeric columns (Tom Lane)
       These errors could result in inconsistent indexes in which some
       keys that are present would not be found by searches, and also in
       useless index bloat. Users are advised to "REINDEX" such indexes
       after installing this update.
     * Fix bugs in GiST page splitting code for multi-column indexes (Tom
       Lane)
       These errors could result in inconsistent indexes in which some
       keys that are present would not be found by searches, and also in
       indexes that are unnecessarily inefficient to search. Users are
       advised to "REINDEX" multi-column GiST indexes after installing
       this update.
     * Fix infinite-loop risk in regular expression compilation (Tom Lane,
       Don Porter)
     * Fix potential null-pointer dereference in regular expression
       compilation (Tom Lane)
     * Fix to_char() to use ASCII-only case-folding rules where
       appropriate (Tom Lane)
       This fixes misbehavior of some template patterns that should be
       locale-independent, but mishandled "I" and "i" in Turkish locales.
     * Fix unwanted rejection of timestamp 1999-12-31 24:00:00 (Tom Lane)
     * Remove useless "picksplit doesn't support secondary split" log
       messages (Josh Hansen, Tom Lane)
       This message seems to have been added in expectation of code that
       was never written, and probably never will be, since GiST's default
       handling of secondary splits is actually pretty good. So stop
       nagging end users about it.
     * Fix possible failure to send a session's last few transaction
       commit/abort counts to the statistics collector (Tom Lane)
     * Eliminate memory leaks in PL/Perl's spi_prepare() function (Alex
       Hunsaker, Tom Lane)
     * Fix pg_dumpall to handle database names containing "=" correctly
       (Heikki Linnakangas)
     * Avoid crash in pg_dump when an incorrect connection string is given
       (Heikki Linnakangas)
     * Ignore invalid indexes in pg_dump (Michael Paquier)
       Dumping invalid indexes can cause problems at restore time, for
       example if the reason the index creation failed was because it
       tried to enforce a uniqueness condition not satisfied by the
       table's data. Also, if the index creation is in fact still in
       progress, it seems reasonable to consider it to be an uncommitted
       DDL change, which pg_dump wouldn't be expected to dump anyway.
     * Fix "contrib/pg_trgm"'s similarity() function to return zero for
       trigram-less strings (Tom Lane)
       Previously it returned NaN due to internal division by zero.
     * Update time zone data files to tzdata release 2013b for DST law
       changes in Chile, Haiti, Morocco, Paraguay, and some Russian areas.
       Also, historical zone data corrections for numerous places.
       Also, update the time zone abbreviation files for recent changes in
       Russia and elsewhere: CHOT, GET, IRKT, KGT, KRAT, MAGT, MAWT, MSK,
       NOVT, OMST, TKT, VLAT, WST, YAKT, YEKT now follow their current
       meanings, and VOLT (Europe/Volgograd) and MIST
       (Antarctica/Macquarie) are added to the default abbreviations list.
     __________________________________________________________________

                               Release 8.4.16

     Release Date: 2013-02-07

   This release contains a variety of fixes from 8.4.15. For information
   about new features in the 8.4 major release, see the Section called
   Release 8.4.
     __________________________________________________________________

Migration to Version 8.4.16

   A dump/restore is not required for those running 8.4.X.

   However, if you are upgrading from a version earlier than 8.4.10, see
   the release notes for 8.4.10.
     __________________________________________________________________

Changes

     * Prevent execution of enum_recv from SQL (Tom Lane)
       The function was misdeclared, allowing a simple SQL command to
       crash the server. In principle an attacker might be able to use it
       to examine the contents of server memory. Our thanks to Sumit Soni
       (via Secunia SVCRP) for reporting this issue. (CVE-2013-0255)
     * Update minimum recovery point when truncating a relation file
       (Heikki Linnakangas)
       Once data has been discarded, it's no longer safe to stop recovery
       at an earlier point in the timeline.
     * Fix SQL grammar to allow subscripting or field selection from a
       sub-SELECT result (Tom Lane)
     * Protect against race conditions when scanning pg_tablespace
       (Stephen Frost, Tom Lane)
       "CREATE DATABASE" and "DROP DATABASE" could misbehave if there were
       concurrent updates of pg_tablespace entries.
     * Prevent "DROP OWNED" from trying to drop whole databases or
       tablespaces (Alvaro Herrera)
       For safety, ownership of these objects must be reassigned, not
       dropped.
     * Fix error in vacuum_freeze_table_age implementation (Andres Freund)
       In installations that have existed for more than
       vacuum_freeze_min_age transactions, this mistake prevented
       autovacuum from using partial-table scans, so that a full-table
       scan would always happen instead.
     * Prevent misbehavior when a RowExpr or XmlExpr is parse-analyzed
       twice (Andres Freund, Tom Lane)
       This mistake could be user-visible in contexts such as CREATE TABLE
       LIKE INCLUDING INDEXES.
     * Improve defenses against integer overflow in hashtable sizing
       calculations (Jeff Davis)
     * Reject out-of-range dates in to_date() (Hitoshi Harada)
     * Ensure that non-ASCII prompt strings are translated to the correct
       code page on Windows (Alexander Law, Noah Misch)
       This bug affected psql and some other client programs.
     * Fix possible crash in psql's "\?" command when not connected to a
       database (Meng Qingzhong)
     * Fix one-byte buffer overrun in libpq's PQprintTuples (Xi Wang)
       This ancient function is not used anywhere by PostgreSQL itself,
       but it might still be used by some client code.
     * Make ecpglib use translated messages properly (Chen Huajun)
     * Properly install ecpg_compat and pgtypes libraries on MSVC (Jiang
       Guiqing)
     * Rearrange configure's tests for supplied functions so it is not
       fooled by bogus exports from libedit/libreadline (Christoph Berg)
     * Ensure Windows build number increases over time (Magnus Hagander)
     * Make pgxs build executables with the right .exe suffix when
       cross-compiling for Windows (Zoltan Boszormenyi)
     * Add new timezone abbreviation FET (Tom Lane)
       This is now used in some eastern-European time zones.
     __________________________________________________________________

                               Release 8.4.15

     Release Date: 2012-12-06

   This release contains a variety of fixes from 8.4.14. For information
   about new features in the 8.4 major release, see the Section called
   Release 8.4.
     __________________________________________________________________

Migration to Version 8.4.15

   A dump/restore is not required for those running 8.4.X.

   However, if you are upgrading from a version earlier than 8.4.10, see
   the release notes for 8.4.10.
     __________________________________________________________________

Changes

     * Fix multiple bugs associated with "CREATE INDEX CONCURRENTLY"
       (Andres Freund, Tom Lane)
       Fix "CREATE INDEX CONCURRENTLY" to use in-place updates when
       changing the state of an index's pg_index row. This prevents race
       conditions that could cause concurrent sessions to miss updating
       the target index, thus resulting in corrupt concurrently-created
       indexes.
       Also, fix various other operations to ensure that they ignore
       invalid indexes resulting from a failed "CREATE INDEX CONCURRENTLY"
       command. The most important of these is "VACUUM", because an
       auto-vacuum could easily be launched on the table before corrective
       action can be taken to fix or remove the invalid index.
     * Avoid corruption of internal hash tables when out of memory
       (Hitoshi Harada)
     * Fix planning of non-strict equivalence clauses above outer joins
       (Tom Lane)
       The planner could derive incorrect constraints from a clause
       equating a non-strict construct to something else, for example
       WHERE COALESCE(foo, 0) = 0 when foo is coming from the nullable
       side of an outer join.
     * Improve planner's ability to prove exclusion constraints from
       equivalence classes (Tom Lane)
     * Fix partial-row matching in hashed subplans to handle cross-type
       cases correctly (Tom Lane)
       This affects multicolumn NOT IN subplans, such as WHERE (a, b) NOT
       IN (SELECT x, y FROM ...) when for instance b and y are int4 and
       int8 respectively. This mistake led to wrong answers or crashes
       depending on the specific datatypes involved.
     * Acquire buffer lock when re-fetching the old tuple for an AFTER ROW
       UPDATE/DELETE trigger (Andres Freund)
       In very unusual circumstances, this oversight could result in
       passing incorrect data to the precheck logic for a foreign-key
       enforcement trigger. That could result in a crash, or in an
       incorrect decision about whether to fire the trigger.
     * Fix "ALTER COLUMN TYPE" to handle inherited check constraints
       properly (Pavan Deolasee)
       This worked correctly in pre-8.4 releases, and now works correctly
       in 8.4 and later.
     * Fix "REASSIGN OWNED" to handle grants on tablespaces (Alvaro
       Herrera)
     * Ignore incorrect pg_attribute entries for system columns for views
       (Tom Lane)
       Views do not have any system columns. However, we forgot to remove
       such entries when converting a table to a view. That's fixed
       properly for 9.3 and later, but in previous branches we need to
       defend against existing mis-converted views.
     * Fix rule printing to dump INSERT INTO table DEFAULT VALUES
       correctly (Tom Lane)
     * Guard against stack overflow when there are too many
       UNION/INTERSECT/EXCEPT clauses in a query (Tom Lane)
     * Prevent platform-dependent failures when dividing the minimum
       possible integer value by -1 (Xi Wang, Tom Lane)
     * Fix possible access past end of string in date parsing (Hitoshi
       Harada)
     * Produce an understandable error message if the length of the path
       name for a Unix-domain socket exceeds the platform-specific limit
       (Tom Lane, Andrew Dunstan)
       Formerly, this would result in something quite unhelpful, such as
       "Non-recoverable failure in name resolution".
     * Fix memory leaks when sending composite column values to the client
       (Tom Lane)
     * Make pg_ctl more robust about reading the "postmaster.pid" file
       (Heikki Linnakangas)
       Fix race conditions and possible file descriptor leakage.
     * Fix possible crash in psql if incorrectly-encoded data is presented
       and the client_encoding setting is a client-only encoding, such as
       SJIS (Jiang Guiqing)
     * Fix bugs in the "restore.sql" script emitted by pg_dump in tar
       output format (Tom Lane)
       The script would fail outright on tables whose names include
       upper-case characters. Also, make the script capable of restoring
       data in "--inserts" mode as well as the regular COPY mode.
     * Fix pg_restore to accept POSIX-conformant tar files (Brian Weaver,
       Tom Lane)
       The original coding of pg_dump's tar output mode produced files
       that are not fully conformant with the POSIX standard. This has
       been corrected for version 9.3. This patch updates previous
       branches so that they will accept both the incorrect and the
       corrected formats, in hopes of avoiding compatibility problems when
       9.3 comes out.
     * Fix pg_resetxlog to locate "postmaster.pid" correctly when given a
       relative path to the data directory (Tom Lane)
       This mistake could lead to pg_resetxlog not noticing that there is
       an active postmaster using the data directory.
     * Fix libpq's lo_import() and lo_export() functions to report file
       I/O errors properly (Tom Lane)
     * Fix ecpg's processing of nested structure pointer variables
       (Muhammad Usama)
     * Make "contrib/pageinspect"'s btree page inspection functions take
       buffer locks while examining pages (Tom Lane)
     * Fix pgxs support for building loadable modules on AIX (Tom Lane)
       Building modules outside the original source tree didn't work on
       AIX.
     * Update time zone data files to tzdata release 2012j for DST law
       changes in Cuba, Israel, Jordan, Libya, Palestine, Western Samoa,
       and portions of Brazil.
     __________________________________________________________________

                               Release 8.4.14

     Release Date: 2012-09-24

   This release contains a variety of fixes from 8.4.13. For information
   about new features in the 8.4 major release, see the Section called
   Release 8.4.
     __________________________________________________________________

Migration to Version 8.4.14

   A dump/restore is not required for those running 8.4.X.

   However, if you are upgrading from a version earlier than 8.4.10, see
   the release notes for 8.4.10.
     __________________________________________________________________

Changes

     * Fix planner's assignment of executor parameters, and fix executor's
       rescan logic for CTE plan nodes (Tom Lane)
       These errors could result in wrong answers from queries that scan
       the same WITH subquery multiple times.
     * Improve page-splitting decisions in GiST indexes (Alexander
       Korotkov, Robert Haas, Tom Lane)
       Multi-column GiST indexes might suffer unexpected bloat due to this
       error.
     * Fix cascading privilege revoke to stop if privileges are still held
       (Tom Lane)
       If we revoke a grant option from some role "X", but "X" still holds
       that option via a grant from someone else, we should not
       recursively revoke the corresponding privilege from role(s) "Y"
       that "X" had granted it to.
     * Fix handling of SIGFPE when PL/Perl is in use (Andres Freund)
       Perl resets the process's SIGFPE handler to SIG_IGN, which could
       result in crashes later on. Restore the normal Postgres signal
       handler after initializing PL/Perl.
     * Prevent PL/Perl from crashing if a recursive PL/Perl function is
       redefined while being executed (Tom Lane)
     * Work around possible misoptimization in PL/Perl (Tom Lane)
       Some Linux distributions contain an incorrect version of
       "pthread.h" that results in incorrect compiled code in PL/Perl,
       leading to crashes if a PL/Perl function calls another one that
       throws an error.
     * Update time zone data files to tzdata release 2012f for DST law
       changes in Fiji
     __________________________________________________________________

                               Release 8.4.13

     Release Date: 2012-08-17

   This release contains a variety of fixes from 8.4.12. For information
   about new features in the 8.4 major release, see the Section called
   Release 8.4.
     __________________________________________________________________

Migration to Version 8.4.13

   A dump/restore is not required for those running 8.4.X.

   However, if you are upgrading from a version earlier than 8.4.10, see
   the release notes for 8.4.10.
     __________________________________________________________________

Changes

     * Prevent access to external files/URLs via XML entity references
       (Noah Misch, Tom Lane)
       xml_parse() would attempt to fetch external files or URLs as needed
       to resolve DTD and entity references in an XML value, thus allowing
       unprivileged database users to attempt to fetch data with the
       privileges of the database server. While the external data wouldn't
       get returned directly to the user, portions of it could be exposed
       in error messages if the data didn't parse as valid XML; and in any
       case the mere ability to check existence of a file might be useful
       to an attacker. (CVE-2012-3489)
     * Prevent access to external files/URLs via "contrib/xml2"'s
       xslt_process() (Peter Eisentraut)
       libxslt offers the ability to read and write both files and URLs
       through stylesheet commands, thus allowing unprivileged database
       users to both read and write data with the privileges of the
       database server. Disable that through proper use of libxslt's
       security options. (CVE-2012-3488)
       Also, remove xslt_process()'s ability to fetch documents and
       stylesheets from external files/URLs. While this was a documented
       "feature", it was long regarded as a bad idea. The fix for
       CVE-2012-3489 broke that capability, and rather than expend effort
       on trying to fix it, we're just going to summarily remove it.
     * Prevent too-early recycling of btree index pages (Noah Misch)
       When we allowed read-only transactions to skip assigning XIDs, we
       introduced the possibility that a deleted btree page could be
       recycled while a read-only transaction was still in flight to it.
       This would result in incorrect index search results. The
       probability of such an error occurring in the field seems very low
       because of the timing requirements, but nonetheless it should be
       fixed.
     * Fix crash-safety bug with newly-created-or-reset sequences (Tom
       Lane)
       If "ALTER SEQUENCE" was executed on a freshly created or reset
       sequence, and then precisely one nextval() call was made on it, and
       then the server crashed, WAL replay would restore the sequence to a
       state in which it appeared that no nextval() had been done, thus
       allowing the first sequence value to be returned again by the next
       nextval() call. In particular this could manifest for serial
       columns, since creation of a serial column's sequence includes an
       "ALTER SEQUENCE OWNED BY" step.
     * Ensure the "backup_label" file is fsync'd after pg_start_backup()
       (Dave Kerr)
     * Back-patch 9.1 improvement to compress the fsync request queue
       (Robert Haas)
       This improves performance during checkpoints. The 9.1 change has
       now seen enough field testing to seem safe to back-patch.
     * Only allow autovacuum to be auto-canceled by a directly blocked
       process (Tom Lane)
       The original coding could allow inconsistent behavior in some
       cases; in particular, an autovacuum could get canceled after less
       than deadlock_timeout grace period.
     * Improve logging of autovacuum cancels (Robert Haas)
     * Fix log collector so that log_truncate_on_rotation works during the
       very first log rotation after server start (Tom Lane)
     * Fix WITH attached to a nested set operation
       (UNION/INTERSECT/EXCEPT) (Tom Lane)
     * Ensure that a whole-row reference to a subquery doesn't include any
       extra GROUP BY or ORDER BY columns (Tom Lane)
     * Disallow copying whole-row references in CHECK constraints and
       index definitions during "CREATE TABLE" (Tom Lane)
       This situation can arise in "CREATE TABLE" with LIKE or INHERITS.
       The copied whole-row variable was incorrectly labeled with the row
       type of the original table not the new one. Rejecting the case
       seems reasonable for LIKE, since the row types might well diverge
       later. For INHERITS we should ideally allow it, with an implicit
       coercion to the parent table's row type; but that will require more
       work than seems safe to back-patch.
     * Fix memory leak in ARRAY(SELECT ...) subqueries (Heikki
       Linnakangas, Tom Lane)
     * Fix extraction of common prefixes from regular expressions (Tom
       Lane)
       The code could get confused by quantified parenthesized
       subexpressions, such as ^(foo)?bar. This would lead to incorrect
       index optimization of searches for such patterns.
     * Fix bugs with parsing signed "hh":"mm" and "hh":"mm":"ss" fields in
       interval constants (Amit Kapila, Tom Lane)
     * Report errors properly in "contrib/xml2"'s xslt_process() (Tom
       Lane)
     * Update time zone data files to tzdata release 2012e for DST law
       changes in Morocco and Tokelau
     __________________________________________________________________

                               Release 8.4.12

     Release Date: 2012-06-04

   This release contains a variety of fixes from 8.4.11. For information
   about new features in the 8.4 major release, see the Section called
   Release 8.4.
     __________________________________________________________________

Migration to Version 8.4.12

   A dump/restore is not required for those running 8.4.X.

   However, if you are upgrading from a version earlier than 8.4.10, see
   the release notes for 8.4.10.
     __________________________________________________________________

Changes

     * Fix incorrect password transformation in "contrib/pgcrypto"'s DES
       crypt() function (Solar Designer)
       If a password string contained the byte value 0x80, the remainder
       of the password was ignored, causing the password to be much weaker
       than it appeared. With this fix, the rest of the string is properly
       included in the DES hash. Any stored password values that are
       affected by this bug will thus no longer match, so the stored
       values may need to be updated. (CVE-2012-2143)
     * Ignore SECURITY DEFINER and SET attributes for a procedural
       language's call handler (Tom Lane)
       Applying such attributes to a call handler could crash the server.
       (CVE-2012-2655)
     * Allow numeric timezone offsets in timestamp input to be up to 16
       hours away from UTC (Tom Lane)
       Some historical time zones have offsets larger than 15 hours, the
       previous limit. This could result in dumped data values being
       rejected during reload.
     * Fix timestamp conversion to cope when the given time is exactly the
       last DST transition time for the current timezone (Tom Lane)
       This oversight has been there a long time, but was not noticed
       previously because most DST-using zones are presumed to have an
       indefinite sequence of future DST transitions.
     * Fix text to name and char to name casts to perform string
       truncation correctly in multibyte encodings (Karl Schnaitter)
     * Fix memory copying bug in to_tsquery() (Heikki Linnakangas)
     * Fix planner's handling of outer PlaceHolderVars within subqueries
       (Tom Lane)
       This bug concerns sub-SELECTs that reference variables coming from
       the nullable side of an outer join of the surrounding query. In
       9.1, queries affected by this bug would fail with "ERROR:
       Upper-level PlaceHolderVar found where not expected". But in 9.0
       and 8.4, you'd silently get possibly-wrong answers, since the value
       transmitted into the subquery wouldn't go to null when it should.
     * Fix slow session startup when pg_attribute is very large (Tom Lane)
       If pg_attribute exceeds one-fourth of shared_buffers, cache
       rebuilding code that is sometimes needed during session start would
       trigger the synchronized-scan logic, causing it to take many times
       longer than normal. The problem was particularly acute if many new
       sessions were starting at once.
     * Ensure sequential scans check for query cancel reasonably often
       (Merlin Moncure)
       A scan encountering many consecutive pages that contain no live
       tuples would not respond to interrupts meanwhile.
     * Ensure the Windows implementation of PGSemaphoreLock() clears
       ImmediateInterruptOK before returning (Tom Lane)
       This oversight meant that a query-cancel interrupt received later
       in the same query could be accepted at an unsafe time, with
       unpredictable but not good consequences.
     * Show whole-row variables safely when printing views or rules (Abbas
       Butt, Tom Lane)
       Corner cases involving ambiguous names (that is, the name could be
       either a table or column name of the query) were printed in an
       ambiguous way, risking that the view or rule would be interpreted
       differently after dump and reload. Avoid the ambiguous case by
       attaching a no-op cast.
     * Fix "COPY FROM" to properly handle null marker strings that
       correspond to invalid encoding (Tom Lane)
       A null marker string such as E'\\0' should work, and did work in
       the past, but the case got broken in 8.4.
     * Ensure autovacuum worker processes perform stack depth checking
       properly (Heikki Linnakangas)
       Previously, infinite recursion in a function invoked by
       auto-"ANALYZE" could crash worker processes.
     * Fix logging collector to not lose log coherency under high load
       (Andrew Dunstan)
       The collector previously could fail to reassemble large messages if
       it got too busy.
     * Fix logging collector to ensure it will restart file rotation after
       receiving SIGHUP (Tom Lane)
     * Fix WAL replay logic for GIN indexes to not fail if the index was
       subsequently dropped (Tom Lane)
     * Fix memory leak in PL/pgSQL's "RETURN NEXT" command (Joe Conway)
     * Fix PL/pgSQL's "GET DIAGNOSTICS" command when the target is the
       function's first variable (Tom Lane)
     * Fix potential access off the end of memory in psql's expanded
       display ("\x") mode (Peter Eisentraut)
     * Fix several performance problems in pg_dump when the database
       contains many objects (Jeff Janes, Tom Lane)
       pg_dump could get very slow if the database contained many schemas,
       or if many objects are in dependency loops, or if there are many
       owned sequences.
     * Fix "contrib/dblink"'s dblink_exec() to not leak temporary database
       connections upon error (Tom Lane)
     * Fix "contrib/dblink" to report the correct connection name in error
       messages (Kyotaro Horiguchi)
     * Update time zone data files to tzdata release 2012c for DST law
       changes in Antarctica, Armenia, Chile, Cuba, Falkland Islands,
       Gaza, Haiti, Hebron, Morocco, Syria, and Tokelau Islands; also
       historical corrections for Canada.
     __________________________________________________________________

                               Release 8.4.11

     Release Date: 2012-02-27

   This release contains a variety of fixes from 8.4.10. For information
   about new features in the 8.4 major release, see the Section called
   Release 8.4.
     __________________________________________________________________

Migration to Version 8.4.11

   A dump/restore is not required for those running 8.4.X.

   However, if you are upgrading from a version earlier than 8.4.10, see
   the release notes for 8.4.10.
     __________________________________________________________________

Changes

     * Require execute permission on the trigger function for "CREATE
       TRIGGER" (Robert Haas)
       This missing check could allow another user to execute a trigger
       function with forged input data, by installing it on a table he
       owns. This is only of significance for trigger functions marked
       SECURITY DEFINER, since otherwise trigger functions run as the
       table owner anyway. (CVE-2012-0866)
     * Remove arbitrary limitation on length of common name in SSL
       certificates (Heikki Linnakangas)
       Both libpq and the server truncated the common name extracted from
       an SSL certificate at 32 bytes. Normally this would cause nothing
       worse than an unexpected verification failure, but there are some
       rather-implausible scenarios in which it might allow one
       certificate holder to impersonate another. The victim would have to
       have a common name exactly 32 bytes long, and the attacker would
       have to persuade a trusted CA to issue a certificate in which the
       common name has that string as a prefix. Impersonating a server
       would also require some additional exploit to redirect client
       connections. (CVE-2012-0867)
     * Convert newlines to spaces in names written in pg_dump comments
       (Robert Haas)
       pg_dump was incautious about sanitizing object names that are
       emitted within SQL comments in its output script. A name containing
       a newline would at least render the script syntactically incorrect.
       Maliciously crafted object names could present a SQL injection risk
       when the script is reloaded. (CVE-2012-0868)
     * Fix btree index corruption from insertions concurrent with
       vacuuming (Tom Lane)
       An index page split caused by an insertion could sometimes cause a
       concurrently-running "VACUUM" to miss removing index entries that
       it should remove. After the corresponding table rows are removed,
       the dangling index entries would cause errors (such as "could not
       read block N in file ...") or worse, silently wrong query results
       after unrelated rows are re-inserted at the now-free table
       locations. This bug has been present since release 8.2, but occurs
       so infrequently that it was not diagnosed until now. If you have
       reason to suspect that it has happened in your database, reindexing
       the affected index will fix things.
     * Update per-column permissions, not only per-table permissions, when
       changing table owner (Tom Lane)
       Failure to do this meant that any previously granted column
       permissions were still shown as having been granted by the old
       owner. This meant that neither the new owner nor a superuser could
       revoke the now-untraceable-to-table-owner permissions.
     * Allow non-existent values for some settings in "ALTER USER/DATABASE
       SET" (Heikki Linnakangas)
       Allow default_text_search_config, default_tablespace, and
       temp_tablespaces to be set to names that are not known. This is
       because they might be known in another database where the setting
       is intended to be used, or for the tablespace cases because the
       tablespace might not be created yet. The same issue was previously
       recognized for search_path, and these settings now act like that
       one.
     * Avoid crashing when we have problems deleting table files
       post-commit (Tom Lane)
       Dropping a table should lead to deleting the underlying disk files
       only after the transaction commits. In event of failure then (for
       instance, because of wrong file permissions) the code is supposed
       to just emit a warning message and go on, since it's too late to
       abort the transaction. This logic got broken as of release 8.4,
       causing such situations to result in a PANIC and an unrestartable
       database.
     * Track the OID counter correctly during WAL replay, even when it
       wraps around (Tom Lane)
       Previously the OID counter would remain stuck at a high value until
       the system exited replay mode. The practical consequences of that
       are usually nil, but there are scenarios wherein a standby server
       that's been promoted to master might take a long time to advance
       the OID counter to a reasonable value once values are needed.
     * Fix regular expression back-references with * attached (Tom Lane)
       Rather than enforcing an exact string match, the code would
       effectively accept any string that satisfies the pattern
       sub-expression referenced by the back-reference symbol.
       A similar problem still afflicts back-references that are embedded
       in a larger quantified expression, rather than being the immediate
       subject of the quantifier. This will be addressed in a future
       PostgreSQL release.
     * Fix recently-introduced memory leak in processing of inet/cidr
       values (Heikki Linnakangas)
       A patch in the December 2011 releases of PostgreSQL caused memory
       leakage in these operations, which could be significant in
       scenarios such as building a btree index on such a column.
     * Fix dangling pointer after "CREATE TABLE AS"/"SELECT INTO" in a
       SQL-language function (Tom Lane)
       In most cases this only led to an assertion failure in
       assert-enabled builds, but worse consequences seem possible.
     * Avoid double close of file handle in syslogger on Windows (MauMau)
       Ordinarily this error was invisible, but it would cause an
       exception when running on a debug version of Windows.
     * Fix I/O-conversion-related memory leaks in plpgsql (Andres Freund,
       Jan Urbanski, Tom Lane)
       Certain operations would leak memory until the end of the current
       function.
     * Improve pg_dump's handling of inherited table columns (Tom Lane)
       pg_dump mishandled situations where a child column has a different
       default expression than its parent column. If the default is
       textually identical to the parent's default, but not actually the
       same (for instance, because of schema search path differences) it
       would not be recognized as different, so that after dump and
       restore the child would be allowed to inherit the parent's default.
       Child columns that are NOT NULL where their parent is not could
       also be restored subtly incorrectly.
     * Fix pg_restore's direct-to-database mode for INSERT-style table
       data (Tom Lane)
       Direct-to-database restores from archive files made with
       "--inserts" or "--column-inserts" options fail when using
       pg_restore from a release dated September or December 2011, as a
       result of an oversight in a fix for another problem. The archive
       file itself is not at fault, and text-mode output is okay.
     * Allow AT option in ecpg DEALLOCATE statements (Michael Meskes)
       The infrastructure to support this has been there for awhile, but
       through an oversight there was still an error check rejecting the
       case.
     * Fix error in "contrib/intarray"'s int[] & int[] operator (Guillaume
       Lelarge)
       If the smallest integer the two input arrays have in common is 1,
       and there are smaller values in either array, then 1 would be
       incorrectly omitted from the result.
     * Fix error detection in "contrib/pgcrypto"'s encrypt_iv() and
       decrypt_iv() (Marko Kreen)
       These functions failed to report certain types of invalid-input
       errors, and would instead return random garbage values for
       incorrect input.
     * Fix one-byte buffer overrun in "contrib/test_parser" (Paul Guyot)
       The code would try to read one more byte than it should, which
       would crash in corner cases. Since "contrib/test_parser" is only
       example code, this is not a security issue in itself, but bad
       example code is still bad.
     * Use __sync_lock_test_and_set() for spinlocks on ARM, if available
       (Martin Pitt)
       This function replaces our previous use of the SWPB instruction,
       which is deprecated and not available on ARMv6 and later. Reports
       suggest that the old code doesn't fail in an obvious way on recent
       ARM boards, but simply doesn't interlock concurrent accesses,
       leading to bizarre failures in multiprocess operation.
     * Use "-fexcess-precision=standard" option when building with gcc
       versions that accept it (Andrew Dunstan)
       This prevents assorted scenarios wherein recent versions of gcc
       will produce creative results.
     * Allow use of threaded Python on FreeBSD (Chris Rees)
       Our configure script previously believed that this combination
       wouldn't work; but FreeBSD fixed the problem, so remove that error
       check.
     __________________________________________________________________

                               Release 8.4.10

     Release Date: 2011-12-05

   This release contains a variety of fixes from 8.4.9. For information
   about new features in the 8.4 major release, see the Section called
   Release 8.4.
     __________________________________________________________________

Migration to Version 8.4.10

   A dump/restore is not required for those running 8.4.X.

   However, a longstanding error was discovered in the definition of the
   information_schema.referential_constraints view. If you rely on correct
   results from that view, you should replace its definition as explained
   in the first changelog item below.

   Also, if you are upgrading from a version earlier than 8.4.8, see the
   release notes for 8.4.8.
     __________________________________________________________________

Changes

     * Fix bugs in information_schema.referential_constraints view (Tom
       Lane)
       This view was being insufficiently careful about matching the
       foreign-key constraint to the depended-on primary or unique key
       constraint. That could result in failure to show a foreign key
       constraint at all, or showing it multiple times, or claiming that
       it depends on a different constraint than the one it really does.
       Since the view definition is installed by initdb, merely upgrading
       will not fix the problem. If you need to fix this in an existing
       installation, you can (as a superuser) drop the information_schema
       schema then re-create it by sourcing
       "SHAREDIR/information_schema.sql". (Run pg_config --sharedir if
       you're uncertain where "SHAREDIR" is.) This must be repeated in
       each database to be fixed.
     * Fix incorrect replay of WAL records for GIN index updates (Tom
       Lane)
       This could result in transiently failing to find index entries
       after a crash, or on a hot-standby server. The problem would be
       repaired by the next "VACUUM" of the index, however.
     * Fix TOAST-related data corruption during CREATE TABLE dest AS
       SELECT * FROM src or INSERT INTO dest SELECT * FROM src (Tom Lane)
       If a table has been modified by "ALTER TABLE ADD COLUMN", attempts
       to copy its data verbatim to another table could produce corrupt
       results in certain corner cases. The problem can only manifest in
       this precise form in 8.4 and later, but we patched earlier versions
       as well in case there are other code paths that could trigger the
       same bug.
     * Fix race condition during toast table access from stale syscache
       entries (Tom Lane)
       The typical symptom was transient errors like "missing chunk number
       0 for toast value NNNNN in pg_toast_2619", where the cited toast
       table would always belong to a system catalog.
     * Track dependencies of functions on items used in parameter default
       expressions (Tom Lane)
       Previously, a referenced object could be dropped without having
       dropped or modified the function, leading to misbehavior when the
       function was used. Note that merely installing this update will not
       fix the missing dependency entries; to do that, you'd need to
       "CREATE OR REPLACE" each such function afterwards. If you have
       functions whose defaults depend on non-built-in objects, doing so
       is recommended.
     * Allow inlining of set-returning SQL functions with multiple OUT
       parameters (Tom Lane)
     * Make DatumGetInetP() unpack inet datums that have a 1-byte header,
       and add a new macro, DatumGetInetPP(), that does not (Heikki
       Linnakangas)
       This change affects no core code, but might prevent crashes in
       add-on code that expects DatumGetInetP() to produce an unpacked
       datum as per usual convention.
     * Improve locale support in money type's input and output (Tom Lane)
       Aside from not supporting all standard lc_monetary formatting
       options, the input and output functions were inconsistent, meaning
       there were locales in which dumped money values could not be
       re-read.
     * Don't let transform_null_equals affect CASE foo WHEN NULL ...
       constructs (Heikki Linnakangas)
       transform_null_equals is only supposed to affect foo = NULL
       expressions written directly by the user, not equality checks
       generated internally by this form of CASE.
     * Change foreign-key trigger creation order to better support
       self-referential foreign keys (Tom Lane)
       For a cascading foreign key that references its own table, a row
       update will fire both the ON UPDATE trigger and the CHECK trigger
       as one event. The ON UPDATE trigger must execute first, else the
       CHECK will check a non-final state of the row and possibly throw an
       inappropriate error. However, the firing order of these triggers is
       determined by their names, which generally sort in creation order
       since the triggers have auto-generated names following the
       convention "RI_ConstraintTrigger_NNNN". A proper fix would require
       modifying that convention, which we will do in 9.2, but it seems
       risky to change it in existing releases. So this patch just changes
       the creation order of the triggers. Users encountering this type of
       error should drop and re-create the foreign key constraint to get
       its triggers into the right order.
     * Avoid floating-point underflow while tracking buffer allocation
       rate (Greg Matthews)
       While harmless in itself, on certain platforms this would result in
       annoying kernel log messages.
     * Preserve configuration file name and line number values when
       starting child processes under Windows (Tom Lane)
       Formerly, these would not be displayed correctly in the pg_settings
       view.
     * Preserve blank lines within commands in psql's command history
       (Robert Haas)
       The former behavior could cause problems if an empty line was
       removed from within a string literal, for example.
     * Fix pg_dump to dump user-defined casts between auto-generated
       types, such as table rowtypes (Tom Lane)
     * Use the preferred version of xsubpp to build PL/Perl, not
       necessarily the operating system's main copy (David Wheeler and
       Alex Hunsaker)
     * Fix incorrect coding in "contrib/dict_int" and "contrib/dict_xsyn"
       (Tom Lane)
       Some functions incorrectly assumed that memory returned by palloc()
       is guaranteed zeroed.
     * Honor query cancel interrupts promptly in pgstatindex() (Robert
       Haas)
     * Ensure VPATH builds properly install all server header files (Peter
       Eisentraut)
     * Shorten file names reported in verbose error messages (Peter
       Eisentraut)
       Regular builds have always reported just the name of the C file
       containing the error message call, but VPATH builds formerly
       reported an absolute path name.
     * Fix interpretation of Windows timezone names for Central America
       (Tom Lane)
       Map "Central America Standard Time" to CST6, not CST6CDT, because
       DST is generally not observed anywhere in Central America.
     * Update time zone data files to tzdata release 2011n for DST law
       changes in Brazil, Cuba, Fiji, Palestine, Russia, and Samoa; also
       historical corrections for Alaska and British East Africa.
     __________________________________________________________________

                                Release 8.4.9

     Release Date: 2011-09-26

   This release contains a variety of fixes from 8.4.8. For information
   about new features in the 8.4 major release, see the Section called
   Release 8.4.
     __________________________________________________________________

Migration to Version 8.4.9

   A dump/restore is not required for those running 8.4.X.

   However, if you are upgrading from a version earlier than 8.4.8, see
   the release notes for 8.4.8.
     __________________________________________________________________

Changes

     * Fix bugs in indexing of in-doubt HOT-updated tuples (Tom Lane)
       These bugs could result in index corruption after reindexing a
       system catalog. They are not believed to affect user indexes.
     * Fix multiple bugs in GiST index page split processing (Heikki
       Linnakangas)
       The probability of occurrence was low, but these could lead to
       index corruption.
     * Fix possible buffer overrun in tsvector_concat() (Tom Lane)
       The function could underestimate the amount of memory needed for
       its result, leading to server crashes.
     * Fix crash in xml_recv when processing a "standalone" parameter (Tom
       Lane)
     * Make pg_options_to_table return NULL for an option with no value
       (Tom Lane)
       Previously such cases would result in a server crash.
     * Avoid possibly accessing off the end of memory in "ANALYZE" and in
       SJIS-2004 encoding conversion (Noah Misch)
       This fixes some very-low-probability server crash scenarios.
     * Prevent intermittent hang in interactions of startup process with
       bgwriter process (Simon Riggs)
       This affected recovery in non-hot-standby cases.
     * Fix race condition in relcache init file invalidation (Tom Lane)
       There was a window wherein a new backend process could read a stale
       init file but miss the inval messages that would tell it the data
       is stale. The result would be bizarre failures in catalog accesses,
       typically "could not read block 0 in file ..." later during
       startup.
     * Fix memory leak at end of a GiST index scan (Tom Lane)
       Commands that perform many separate GiST index scans, such as
       verification of a new GiST-based exclusion constraint on a table
       already containing many rows, could transiently require large
       amounts of memory due to this leak.
     * Fix incorrect memory accounting (leading to possible memory bloat)
       in tuplestores supporting holdable cursors and plpgsql's RETURN
       NEXT command (Tom Lane)
     * Fix performance problem when constructing a large, lossy bitmap
       (Tom Lane)
     * Fix join selectivity estimation for unique columns (Tom Lane)
       This fixes an erroneous planner heuristic that could lead to poor
       estimates of the result size of a join.
     * Fix nested PlaceHolderVar expressions that appear only in
       sub-select target lists (Tom Lane)
       This mistake could result in outputs of an outer join incorrectly
       appearing as NULL.
     * Allow nested EXISTS queries to be optimized properly (Tom Lane)
     * Fix array- and path-creating functions to ensure padding bytes are
       zeroes (Tom Lane)
       This avoids some situations where the planner will think that
       semantically-equal constants are not equal, resulting in poor
       optimization.
     * Fix "EXPLAIN" to handle gating Result nodes within inner-indexscan
       subplans (Tom Lane)
       The usual symptom of this oversight was "bogus varno" errors.
     * Work around gcc 4.6.0 bug that breaks WAL replay (Tom Lane)
       This could lead to loss of committed transactions after a server
       crash.
     * Fix dump bug for VALUES in a view (Tom Lane)
     * Disallow SELECT FOR UPDATE/SHARE on sequences (Tom Lane)
       This operation doesn't work as expected and can lead to failures.
     * Fix "VACUUM" so that it always updates pg_class.reltuples/relpages
       (Tom Lane)
       This fixes some scenarios where autovacuum could make increasingly
       poor decisions about when to vacuum tables.
     * Defend against integer overflow when computing size of a hash table
       (Tom Lane)
     * Fix cases where "CLUSTER" might attempt to access already-removed
       TOAST data (Tom Lane)
     * Fix portability bugs in use of credentials control messages for
       "peer" authentication (Tom Lane)
     * Fix SSPI login when multiple roundtrips are required (Ahmed
       Shinwari, Magnus Hagander)
       The typical symptom of this problem was "The function requested is
       not supported" errors during SSPI login.
     * Throw an error if "pg_hba.conf" contains hostssl but SSL is
       disabled (Tom Lane)
       This was concluded to be more user-friendly than the previous
       behavior of silently ignoring such lines.
     * Fix typo in pg_srand48 seed initialization (Andres Freund)
       This led to failure to use all bits of the provided seed. This
       function is not used on most platforms (only those without
       srandom), and the potential security exposure from a
       less-random-than-expected seed seems minimal in any case.
     * Avoid integer overflow when the sum of LIMIT and OFFSET values
       exceeds 2^63 (Heikki Linnakangas)
     * Add overflow checks to int4 and int8 versions of generate_series()
       (Robert Haas)
     * Fix trailing-zero removal in to_char() (Marti Raudsepp)
       In a format with FM and no digit positions after the decimal point,
       zeroes to the left of the decimal point could be removed
       incorrectly.
     * Fix pg_size_pretty() to avoid overflow for inputs close to 2^63
       (Tom Lane)
     * Weaken plpgsql's check for typmod matching in record values (Tom
       Lane)
       An overly enthusiastic check could lead to discarding length
       modifiers that should have been kept.
     * Correctly handle quotes in locale names during initdb (Heikki
       Linnakangas)
       The case can arise with some Windows locales, such as "People's
       Republic of China".
     * Fix pg_upgrade to preserve toast tables' relfrozenxids during an
       upgrade from 8.3 (Bruce Momjian)
       Failure to do this could lead to "pg_clog" files being removed too
       soon after the upgrade.
     * In pg_ctl, support silent mode for service registrations on Windows
       (MauMau)
     * Fix psql's counting of script file line numbers during COPY from a
       different file (Tom Lane)
     * Fix pg_restore's direct-to-database mode for
       standard_conforming_strings (Tom Lane)
       pg_restore could emit incorrect commands when restoring directly to
       a database server from an archive file that had been made with
       standard_conforming_strings set to on.
     * Be more user-friendly about unsupported cases for parallel
       pg_restore (Tom Lane)
       This change ensures that such cases are detected and reported
       before any restore actions have been taken.
     * Fix write-past-buffer-end and memory leak in libpq's LDAP service
       lookup code (Albe Laurenz)
     * In libpq, avoid failures when using nonblocking I/O and an SSL
       connection (Martin Pihlak, Tom Lane)
     * Improve libpq's handling of failures during connection startup (Tom
       Lane)
       In particular, the response to a server report of fork() failure
       during SSL connection startup is now saner.
     * Improve libpq's error reporting for SSL failures (Tom Lane)
     * Fix PQsetvalue() to avoid possible crash when adding a new tuple to
       a PGresult originally obtained from a server query (Andrew Chernow)
     * Make ecpglib write double values with 15 digits precision (Akira
       Kurosawa)
     * In ecpglib, be sure LC_NUMERIC setting is restored after an error
       (Michael Meskes)
     * Apply upstream fix for blowfish signed-character bug
       (CVE-2011-2483) (Tom Lane)
       "contrib/pg_crypto"'s blowfish encryption code could give wrong
       results on platforms where char is signed (which is most), leading
       to encrypted passwords being weaker than they should be.
     * Fix memory leak in "contrib/seg" (Heikki Linnakangas)
     * Fix pgstatindex() to give consistent results for empty indexes (Tom
       Lane)
     * Allow building with perl 5.14 (Alex Hunsaker)
     * Update configure script's method for probing existence of system
       functions (Tom Lane)
       The version of autoconf we used in 8.3 and 8.2 could be fooled by
       compilers that perform link-time optimization.
     * Fix assorted issues with build and install file paths containing
       spaces (Tom Lane)
     * Update time zone data files to tzdata release 2011i for DST law
       changes in Canada, Egypt, Russia, Samoa, and South Sudan.
     __________________________________________________________________

                                Release 8.4.8

     Release Date: 2011-04-18

   This release contains a variety of fixes from 8.4.7. For information
   about new features in the 8.4 major release, see the Section called
   Release 8.4.
     __________________________________________________________________

Migration to Version 8.4.8

   A dump/restore is not required for those running 8.4.X.

   However, if your installation was upgraded from a previous major
   release by running pg_upgrade, you should take action to prevent
   possible data loss due to a now-fixed bug in pg_upgrade. The
   recommended solution is to run "VACUUM FREEZE" on all TOAST tables.
   More information is available at
   http://wiki.postgresql.org/wiki/20110408pg_upgrade_fix.

   Also, if you are upgrading from a version earlier than 8.4.2, see the
   release notes for 8.4.2.
     __________________________________________________________________

Changes

     * Fix pg_upgrade's handling of TOAST tables (Bruce Momjian)
       The pg_class.relfrozenxid value for TOAST tables was not correctly
       copied into the new installation during pg_upgrade. This could
       later result in pg_clog files being discarded while they were still
       needed to validate tuples in the TOAST tables, leading to "could
       not access status of transaction" failures.
       This error poses a significant risk of data loss for installations
       that have been upgraded with pg_upgrade. This patch corrects the
       problem for future uses of pg_upgrade, but does not in itself cure
       the issue in installations that have been processed with a buggy
       version of pg_upgrade.
     * Suppress incorrect "PD_ALL_VISIBLE flag was incorrectly set"
       warning (Heikki Linnakangas)
       "VACUUM" would sometimes issue this warning in cases that are
       actually valid.
     * Disallow including a composite type in itself (Tom Lane)
       This prevents scenarios wherein the server could recurse infinitely
       while processing the composite type. While there are some possible
       uses for such a structure, they don't seem compelling enough to
       justify the effort required to make sure it always works safely.
     * Avoid potential deadlock during catalog cache initialization
       (Nikhil Sontakke)
       In some cases the cache loading code would acquire share lock on a
       system index before locking the index's catalog. This could
       deadlock against processes trying to acquire exclusive locks in the
       other, more standard order.
     * Fix dangling-pointer problem in BEFORE ROW UPDATE trigger handling
       when there was a concurrent update to the target tuple (Tom Lane)
       This bug has been observed to result in intermittent "cannot
       extract system attribute from virtual tuple" failures while trying
       to do UPDATE RETURNING ctid. There is a very small probability of
       more serious errors, such as generating incorrect index entries for
       the updated tuple.
     * Disallow "DROP TABLE" when there are pending deferred trigger
       events for the table (Tom Lane)
       Formerly the "DROP" would go through, leading to "could not open
       relation with OID nnn" errors when the triggers were eventually
       fired.
     * Prevent crash triggered by constant-false WHERE conditions during
       GEQO optimization (Tom Lane)
     * Improve planner's handling of semi-join and anti-join cases (Tom
       Lane)
     * Fix selectivity estimation for text search to account for NULLs
       (Jesper Krogh)
     * Improve PL/pgSQL's ability to handle row types with dropped columns
       (Pavel Stehule)
       This is a back-patch of fixes previously made in 9.0.
     * Fix PL/Python memory leak involving array slices (Daniel Popowich)
     * Fix pg_restore to cope with long lines (over 1KB) in TOC files (Tom
       Lane)
     * Put in more safeguards against crashing due to division-by-zero
       with overly enthusiastic compiler optimization (Aurelien Jarno)
     * Support use of dlopen() in FreeBSD and OpenBSD on MIPS (Tom Lane)
       There was a hard-wired assumption that this system function was not
       available on MIPS hardware on these systems. Use a compile-time
       test instead, since more recent versions have it.
     * Fix compilation failures on HP-UX (Heikki Linnakangas)
     * Fix version-incompatibility problem with libintl on Windows
       (Hiroshi Inoue)
     * Fix usage of xcopy in Windows build scripts to work correctly under
       Windows 7 (Andrew Dunstan)
       This affects the build scripts only, not installation or usage.
     * Fix path separator used by pg_regress on Cygwin (Andrew Dunstan)
     * Update time zone data files to tzdata release 2011f for DST law
       changes in Chile, Cuba, Falkland Islands, Morocco, Samoa, and
       Turkey; also historical corrections for South Australia, Alaska,
       and Hawaii.
     __________________________________________________________________

                                Release 8.4.7

     Release Date: 2011-01-31

   This release contains a variety of fixes from 8.4.6. For information
   about new features in the 8.4 major release, see the Section called
   Release 8.4.
     __________________________________________________________________

Migration to Version 8.4.7

   A dump/restore is not required for those running 8.4.X. However, if you
   are upgrading from a version earlier than 8.4.2, see the release notes
   for 8.4.2.
     __________________________________________________________________

Changes

     * Avoid failures when "EXPLAIN" tries to display a simple-form CASE
       expression (Tom Lane)
       If the CASE's test expression was a constant, the planner could
       simplify the CASE into a form that confused the expression-display
       code, resulting in "unexpected CASE WHEN clause" errors.
     * Fix assignment to an array slice that is before the existing range
       of subscripts (Tom Lane)
       If there was a gap between the newly added subscripts and the first
       pre-existing subscript, the code miscalculated how many entries
       needed to be copied from the old array's null bitmap, potentially
       leading to data corruption or crash.
     * Avoid unexpected conversion overflow in planner for very distant
       date values (Tom Lane)
       The date type supports a wider range of dates than can be
       represented by the timestamp types, but the planner assumed it
       could always convert a date to timestamp with impunity.
     * Fix pg_restore's text output for large objects (BLOBs) when
       standard_conforming_strings is on (Tom Lane)
       Although restoring directly to a database worked correctly, string
       escaping was incorrect if pg_restore was asked for SQL text output
       and standard_conforming_strings had been enabled in the source
       database.
     * Fix erroneous parsing of tsquery values containing ... &
       !(subexpression) | ... (Tom Lane)
       Queries containing this combination of operators were not executed
       correctly. The same error existed in "contrib/intarray"'s query_int
       type and "contrib/ltree"'s ltxtquery type.
     * Fix buffer overrun in "contrib/intarray"'s input function for the
       query_int type (Apple)
       This bug is a security risk since the function's return address
       could be overwritten. Thanks to Apple Inc's security team for
       reporting this issue and supplying the fix. (CVE-2010-4015)
     * Fix bug in "contrib/seg"'s GiST picksplit algorithm (Alexander
       Korotkov)
       This could result in considerable inefficiency, though not actually
       incorrect answers, in a GiST index on a seg column. If you have
       such an index, consider "REINDEX"ing it after installing this
       update. (This is identical to the bug that was fixed in
       "contrib/cube" in the previous update.)
     __________________________________________________________________

                                Release 8.4.6

     Release Date: 2010-12-16

   This release contains a variety of fixes from 8.4.5. For information
   about new features in the 8.4 major release, see the Section called
   Release 8.4.
     __________________________________________________________________

Migration to Version 8.4.6

   A dump/restore is not required for those running 8.4.X. However, if you
   are upgrading from a version earlier than 8.4.2, see the release notes
   for 8.4.2.
     __________________________________________________________________

Changes

     * Force the default wal_sync_method to be fdatasync on Linux (Tom
       Lane, Marti Raudsepp)
       The default on Linux has actually been fdatasync for many years,
       but recent kernel changes caused PostgreSQL to choose open_datasync
       instead. This choice did not result in any performance improvement,
       and caused outright failures on certain filesystems, notably ext4
       with the data=journal mount option.
     * Fix assorted bugs in WAL replay logic for GIN indexes (Tom Lane)
       This could result in "bad buffer id: 0" failures or corruption of
       index contents during replication.
     * Fix recovery from base backup when the starting checkpoint WAL
       record is not in the same WAL segment as its redo point (Jeff
       Davis)
     * Fix persistent slowdown of autovacuum workers when multiple workers
       remain active for a long time (Tom Lane)
       The effective vacuum_cost_limit for an autovacuum worker could drop
       to nearly zero if it processed enough tables, causing it to run
       extremely slowly.
     * Add support for detecting register-stack overrun on IA64 (Tom Lane)
       The IA64 architecture has two hardware stacks. Full prevention of
       stack-overrun failures requires checking both.
     * Add a check for stack overflow in copyObject() (Tom Lane)
       Certain code paths could crash due to stack overflow given a
       sufficiently complex query.
     * Fix detection of page splits in temporary GiST indexes (Heikki
       Linnakangas)
       It is possible to have a "concurrent" page split in a temporary
       index, if for example there is an open cursor scanning the index
       when an insertion is done. GiST failed to detect this case and
       hence could deliver wrong results when execution of the cursor
       continued.
     * Fix error checking during early connection processing (Tom Lane)
       The check for too many child processes was skipped in some cases,
       possibly leading to postmaster crash when attempting to add the new
       child process to fixed-size arrays.
     * Improve efficiency of window functions (Tom Lane)
       Certain cases where a large number of tuples needed to be read in
       advance, but work_mem was large enough to allow them all to be held
       in memory, were unexpectedly slow. percent_rank(), cume_dist() and
       ntile() in particular were subject to this problem.
     * Avoid memory leakage while "ANALYZE"'ing complex index expressions
       (Tom Lane)
     * Ensure an index that uses a whole-row Var still depends on its
       table (Tom Lane)
       An index declared like create index i on t (foo(t.*)) would not
       automatically get dropped when its table was dropped.
     * Do not "inline" a SQL function with multiple OUT parameters (Tom
       Lane)
       This avoids a possible crash due to loss of information about the
       expected result rowtype.
     * Behave correctly if ORDER BY, LIMIT, FOR UPDATE, or WITH is
       attached to the VALUES part of INSERT ... VALUES (Tom Lane)
     * Fix constant-folding of COALESCE() expressions (Tom Lane)
       The planner would sometimes attempt to evaluate sub-expressions
       that in fact could never be reached, possibly leading to unexpected
       errors.
     * Fix postmaster crash when connection acceptance (accept() or one of
       the calls made immediately after it) fails, and the postmaster was
       compiled with GSSAPI support (Alexander Chernikov)
     * Fix missed unlink of temporary files when log_temp_files is active
       (Tom Lane)
       If an error occurred while attempting to emit the log message, the
       unlink was not done, resulting in accumulation of temp files.
     * Add print functionality for InhRelation nodes (Tom Lane)
       This avoids a failure when debug_print_parse is enabled and certain
       types of query are executed.
     * Fix incorrect calculation of distance from a point to a horizontal
       line segment (Tom Lane)
       This bug affected several different geometric distance-measurement
       operators.
     * Fix incorrect calculation of transaction status in ecpg (Itagaki
       Takahiro)
     * Fix PL/pgSQL's handling of "simple" expressions to not fail in
       recursion or error-recovery cases (Tom Lane)
     * Fix PL/Python's handling of set-returning functions (Jan Urbanski)
       Attempts to call SPI functions within the iterator generating a set
       result would fail.
     * Fix bug in "contrib/cube"'s GiST picksplit algorithm (Alexander
       Korotkov)
       This could result in considerable inefficiency, though not actually
       incorrect answers, in a GiST index on a cube column. If you have
       such an index, consider "REINDEX"ing it after installing this
       update.
     * Don't emit "identifier will be truncated" notices in
       "contrib/dblink" except when creating new connections (Itagaki
       Takahiro)
     * Fix potential coredump on missing public key in "contrib/pgcrypto"
       (Marti Raudsepp)
     * Fix memory leak in "contrib/xml2"'s XPath query functions (Tom
       Lane)
     * Update time zone data files to tzdata release 2010o for DST law
       changes in Fiji and Samoa; also historical corrections for Hong
       Kong.
     __________________________________________________________________

                                Release 8.4.5

     Release Date: 2010-10-04

   This release contains a variety of fixes from 8.4.4. For information
   about new features in the 8.4 major release, see the Section called
   Release 8.4.
     __________________________________________________________________

Migration to Version 8.4.5

   A dump/restore is not required for those running 8.4.X. However, if you
   are upgrading from a version earlier than 8.4.2, see the release notes
   for 8.4.2.
     __________________________________________________________________

Changes

     * Use a separate interpreter for each calling SQL userid in PL/Perl
       and PL/Tcl (Tom Lane)
       This change prevents security problems that can be caused by
       subverting Perl or Tcl code that will be executed later in the same
       session under another SQL user identity (for example, within a
       SECURITY DEFINER function). Most scripting languages offer numerous
       ways that that might be done, such as redefining standard functions
       or operators called by the target function. Without this change,
       any SQL user with Perl or Tcl language usage rights can do
       essentially anything with the SQL privileges of the target
       function's owner.
       The cost of this change is that intentional communication among
       Perl and Tcl functions becomes more difficult. To provide an escape
       hatch, PL/PerlU and PL/TclU functions continue to use only one
       interpreter per session. This is not considered a security issue
       since all such functions execute at the trust level of a database
       superuser already.
       It is likely that third-party procedural languages that claim to
       offer trusted execution have similar security issues. We advise
       contacting the authors of any PL you are depending on for
       security-critical purposes.
       Our thanks to Tim Bunce for pointing out this issue
       (CVE-2010-3433).
     * Prevent possible crashes in pg_get_expr() by disallowing it from
       being called with an argument that is not one of the system catalog
       columns it's intended to be used with (Heikki Linnakangas, Tom
       Lane)
     * Treat exit code 128 (ERROR_WAIT_NO_CHILDREN) as non-fatal on
       Windows (Magnus Hagander)
       Under high load, Windows processes will sometimes fail at startup
       with this error code. Formerly the postmaster treated this as a
       panic condition and restarted the whole database, but that seems to
       be an overreaction.
     * Fix incorrect placement of placeholder evaluation (Tom Lane)
       This bug could result in query outputs being non-null when they
       should be null, in cases where the inner side of an outer join is a
       sub-select with non-strict expressions in its output list.
     * Fix possible duplicate scans of UNION ALL member relations (Tom
       Lane)
     * Fix "cannot handle unplanned sub-select" error (Tom Lane)
       This occurred when a sub-select contains a join alias reference
       that expands into an expression containing another sub-select.
     * Fix mishandling of whole-row Vars that reference a view or
       sub-select and appear within a nested sub-select (Tom Lane)
     * Fix mishandling of cross-type IN comparisons (Tom Lane)
       This could result in failures if the planner tried to implement an
       IN join with a sort-then-unique-then-plain-join plan.
     * Fix computation of "ANALYZE" statistics for tsvector columns (Jan
       Urbanski)
       The original coding could produce incorrect statistics, leading to
       poor plan choices later.
     * Improve planner's estimate of memory used by array_agg(),
       string_agg(), and similar aggregate functions (Hitoshi Harada)
       The previous drastic underestimate could lead to out-of-memory
       failures due to inappropriate choice of a hash-aggregation plan.
     * Fix failure to mark cached plans as transient (Tom Lane)
       If a plan is prepared while "CREATE INDEX CONCURRENTLY" is in
       progress for one of the referenced tables, it is supposed to be
       re-planned once the index is ready for use. This was not happening
       reliably.
     * Reduce PANIC to ERROR in some occasionally-reported btree failure
       cases, and provide additional detail in the resulting error
       messages (Tom Lane)
       This should improve the system's robustness with corrupted indexes.
     * Fix incorrect search logic for partial-match queries with GIN
       indexes (Tom Lane)
       Cases involving AND/OR combination of several GIN index conditions
       didn't always give the right answer, and were sometimes much slower
       than necessary.
     * Prevent show_session_authorization() from crashing within
       autovacuum processes (Tom Lane)
     * Defend against functions returning setof record where not all the
       returned rows are actually of the same rowtype (Tom Lane)
     * Fix possible corruption of pending trigger event lists during
       subtransaction rollback (Tom Lane)
       This could lead to a crash or incorrect firing of triggers.
     * Fix possible failure when hashing a pass-by-reference function
       result (Tao Ma, Tom Lane)
     * Improve merge join's handling of NULLs in the join columns (Tom
       Lane)
       A merge join can now stop entirely upon reaching the first NULL, if
       the sort order is such that NULLs sort high.
     * Take care to fsync the contents of lockfiles (both "postmaster.pid"
       and the socket lockfile) while writing them (Tom Lane)
       This omission could result in corrupted lockfile contents if the
       machine crashes shortly after postmaster start. That could in turn
       prevent subsequent attempts to start the postmaster from
       succeeding, until the lockfile is manually removed.
     * Avoid recursion while assigning XIDs to heavily-nested
       subtransactions (Andres Freund, Robert Haas)
       The original coding could result in a crash if there was limited
       stack space.
     * Avoid holding open old WAL segments in the walwriter process
       (Magnus Hagander, Heikki Linnakangas)
       The previous coding would prevent removal of no-longer-needed
       segments.
     * Fix log_line_prefix's %i escape, which could produce junk early in
       backend startup (Tom Lane)
     * Prevent misinterpretation of partially-specified relation options
       for TOAST tables (Itagaki Takahiro)
       In particular, fillfactor would be read as zero if any other
       reloption had been set for the table, leading to serious bloat.
     * Fix inheritance count tracking in "ALTER TABLE ... ADD CONSTRAINT"
       (Robert Haas)
     * Fix possible data corruption in "ALTER TABLE ... SET TABLESPACE"
       when archiving is enabled (Jeff Davis)
     * Allow "CREATE DATABASE" and "ALTER DATABASE ... SET TABLESPACE" to
       be interrupted by query-cancel (Guillaume Lelarge)
     * Improve "CREATE INDEX"'s checking of whether proposed index
       expressions are immutable (Tom Lane)
     * Fix "REASSIGN OWNED" to handle operator classes and families (Asko
       Tiidumaa)
     * Fix possible core dump when comparing two empty tsquery values (Tom
       Lane)
     * Fix LIKE's handling of patterns containing % followed by _ (Tom
       Lane)
       We've fixed this before, but there were still some
       incorrectly-handled cases.
     * Re-allow input of Julian dates prior to 0001-01-01 AD (Tom Lane)
       Input such as 'J100000'::date worked before 8.4, but was
       unintentionally broken by added error-checking.
     * Fix PL/pgSQL to throw an error, not crash, if a cursor is closed
       within a FOR loop that is iterating over that cursor (Heikki
       Linnakangas)
     * In PL/Python, defend against null pointer results from
       PyCObject_AsVoidPtr and PyCObject_FromVoidPtr (Peter Eisentraut)
     * In libpq, fix full SSL certificate verification for the case where
       both host and hostaddr are specified (Tom Lane)
     * Make psql recognize "DISCARD ALL" as a command that should not be
       encased in a transaction block in autocommit-off mode (Itagaki
       Takahiro)
     * Fix some issues in pg_dump's handling of SQL/MED objects (Tom Lane)
       Notably, pg_dump would always fail if run by a non-superuser, which
       was not intended.
     * Improve pg_dump and pg_restore's handling of non-seekable archive
       files (Tom Lane, Robert Haas)
       This is important for proper functioning of parallel restore.
     * Improve parallel pg_restore's ability to cope with selective
       restore (-L option) (Tom Lane)
       The original code tended to fail if the -L file commanded a
       non-default restore ordering.
     * Fix ecpg to process data from RETURNING clauses correctly (Michael
       Meskes)
     * Fix some memory leaks in ecpg (Zoltan Boszormenyi)
     * Improve "contrib/dblink"'s handling of tables containing dropped
       columns (Tom Lane)
     * Fix connection leak after "duplicate connection name" errors in
       "contrib/dblink" (Itagaki Takahiro)
     * Fix "contrib/dblink" to handle connection names longer than 62
       bytes correctly (Itagaki Takahiro)
     * Add hstore(text, text) function to "contrib/hstore" (Robert Haas)
       This function is the recommended substitute for the now-deprecated
       => operator. It was back-patched so that future-proofed code can be
       used with older server versions. Note that the patch will be
       effective only after "contrib/hstore" is installed or reinstalled
       in a particular database. Users might prefer to execute the "CREATE
       FUNCTION" command by hand, instead.
     * Update build infrastructure and documentation to reflect the source
       code repository's move from CVS to Git (Magnus Hagander and others)
     * Update time zone data files to tzdata release 2010l for DST law
       changes in Egypt and Palestine; also historical corrections for
       Finland.
       This change also adds new names for two Micronesian timezones:
       Pacific/Chuuk is now preferred over Pacific/Truk (and the preferred
       abbreviation is CHUT not TRUT) and Pacific/Pohnpei is preferred
       over Pacific/Ponape.
     * Make Windows' "N. Central Asia Standard Time" timezone map to
       Asia/Novosibirsk, not Asia/Almaty (Magnus Hagander)
       Microsoft changed the DST behavior of this zone in the timezone
       update from KB976098. Asia/Novosibirsk is a better match to its new
       behavior.
     __________________________________________________________________

                                Release 8.4.4

     Release Date: 2010-05-17

   This release contains a variety of fixes from 8.4.3. For information
   about new features in the 8.4 major release, see the Section called
   Release 8.4.
     __________________________________________________________________

Migration to Version 8.4.4

   A dump/restore is not required for those running 8.4.X. However, if you
   are upgrading from a version earlier than 8.4.2, see the release notes
   for 8.4.2.
     __________________________________________________________________

Changes

     * Enforce restrictions in plperl using an opmask applied to the whole
       interpreter, instead of using "Safe.pm" (Tim Bunce, Andrew Dunstan)
       Recent developments have convinced us that "Safe.pm" is too
       insecure to rely on for making plperl trustable. This change
       removes use of "Safe.pm" altogether, in favor of using a separate
       interpreter with an opcode mask that is always applied. Pleasant
       side effects of the change include that it is now possible to use
       Perl's strict pragma in a natural way in plperl, and that Perl's $a
       and $b variables work as expected in sort routines, and that
       function compilation is significantly faster. (CVE-2010-1169)
     * Prevent PL/Tcl from executing untrustworthy code from pltcl_modules
       (Tom)
       PL/Tcl's feature for autoloading Tcl code from a database table
       could be exploited for trojan-horse attacks, because there was no
       restriction on who could create or insert into that table. This
       change disables the feature unless pltcl_modules is owned by a
       superuser. (However, the permissions on the table are not checked,
       so installations that really need a less-than-secure modules table
       can still grant suitable privileges to trusted non-superusers.)
       Also, prevent loading code into the unrestricted "normal" Tcl
       interpreter unless we are really going to execute a pltclu
       function. (CVE-2010-1170)
     * Fix data corruption during WAL replay of ALTER ... SET TABLESPACE
       (Tom)
       When archive_mode is on, ALTER ... SET TABLESPACE generates a WAL
       record whose replay logic was incorrect. It could write the data to
       the wrong place, leading to possibly-unrecoverable data corruption.
       Data corruption would be observed on standby slaves, and could
       occur on the master as well if a database crash and recovery
       occurred after committing the ALTER and before the next checkpoint.
     * Fix possible crash if a cache reset message is received during
       rebuild of a relcache entry (Heikki)
       This error was introduced in 8.4.3 while fixing a related failure.
     * Apply per-function GUC settings while running the language
       validator for the function (Itagaki Takahiro)
       This avoids failures if the function's code is invalid without the
       setting; an example is that SQL functions may not parse if the
       search_path is not correct.
     * Do constraint exclusion for inherited "UPDATE" and "DELETE" target
       tables when constraint_exclusion = partition (Tom)
       Due to an oversight, this setting previously only caused constraint
       exclusion to be checked in "SELECT" commands.
     * Do not allow an unprivileged user to reset superuser-only parameter
       settings (Alvaro)
       Previously, if an unprivileged user ran ALTER USER ... RESET ALL
       for himself, or ALTER DATABASE ... RESET ALL for a database he
       owns, this would remove all special parameter settings for the user
       or database, even ones that are only supposed to be changeable by a
       superuser. Now, the "ALTER" will only remove the parameters that
       the user has permission to change.
     * Avoid possible crash during backend shutdown if shutdown occurs
       when a CONTEXT addition would be made to log entries (Tom)
       In some cases the context-printing function would fail because the
       current transaction had already been rolled back when it came time
       to print a log message.
     * Fix erroneous handling of %r parameter in recovery_end_command
       (Heikki)
       The value always came out zero.
     * Ensure the archiver process responds to changes in archive_command
       as soon as possible (Tom)
     * Fix pl/pgsql's CASE statement to not fail when the case expression
       is a query that returns no rows (Tom)
     * Update pl/perl's "ppport.h" for modern Perl versions (Andrew)
     * Fix assorted memory leaks in pl/python (Andreas Freund, Tom)
     * Handle empty-string connect parameters properly in ecpg (Michael)
     * Prevent infinite recursion in psql when expanding a variable that
       refers to itself (Tom)
     * Fix psql's \copy to not add spaces around a dot within \copy
       (select ...) (Tom)
       Addition of spaces around the decimal point in a numeric literal
       would result in a syntax error.
     * Avoid formatting failure in psql when running in a locale context
       that doesn't match the client_encoding (Tom)
     * Fix unnecessary "GIN indexes do not support whole-index scans"
       errors for unsatisfiable queries using "contrib/intarray" operators
       (Tom)
     * Ensure that "contrib/pgstattuple" functions respond to cancel
       interrupts promptly (Tatsuhito Kasahara)
     * Make server startup deal properly with the case that shmget()
       returns EINVAL for an existing shared memory segment (Tom)
       This behavior has been observed on BSD-derived kernels including OS
       X. It resulted in an entirely-misleading startup failure
       complaining that the shared memory request size was too large.
     * Avoid possible crashes in syslogger process on Windows (Heikki)
     * Deal more robustly with incomplete time zone information in the
       Windows registry (Magnus)
     * Update the set of known Windows time zone names (Magnus)
     * Update time zone data files to tzdata release 2010j for DST law
       changes in Argentina, Australian Antarctic, Bangladesh, Mexico,
       Morocco, Pakistan, Palestine, Russia, Syria, Tunisia; also
       historical corrections for Taiwan.
       Also, add PKST (Pakistan Summer Time) to the default set of
       timezone abbreviations.
     __________________________________________________________________

                                Release 8.4.3

     Release Date: 2010-03-15

   This release contains a variety of fixes from 8.4.2. For information
   about new features in the 8.4 major release, see the Section called
   Release 8.4.
     __________________________________________________________________

Migration to Version 8.4.3

   A dump/restore is not required for those running 8.4.X. However, if you
   are upgrading from a version earlier than 8.4.2, see the release notes
   for 8.4.2.
     __________________________________________________________________

Changes

     * Add new configuration parameter ssl_renegotiation_limit to control
       how often we do session key renegotiation for an SSL connection
       (Magnus)
       This can be set to zero to disable renegotiation completely, which
       may be required if a broken SSL library is used. In particular,
       some vendors are shipping stopgap patches for CVE-2009-3555 that
       cause renegotiation attempts to fail.
     * Fix possible deadlock during backend startup (Tom)
     * Fix possible crashes due to not handling errors during relcache
       reload cleanly (Tom)
     * Fix possible crash due to use of dangling pointer to a cached plan
       (Tatsuo)
     * Fix possible crash due to overenthusiastic invalidation of cached
       plan for "ROLLBACK" (Tom)
     * Fix possible crashes when trying to recover from a failure in
       subtransaction start (Tom)
     * Fix server memory leak associated with use of savepoints and a
       client encoding different from server's encoding (Tom)
     * Fix incorrect WAL data emitted during end-of-recovery cleanup of a
       GIST index page split (Yoichi Hirai)
       This would result in index corruption, or even more likely an error
       during WAL replay, if we were unlucky enough to crash during
       end-of-recovery cleanup after having completed an incomplete GIST
       insertion.
     * Fix bug in WAL redo cleanup method for GIN indexes (Heikki)
     * Fix incorrect comparison of scan key in GIN index search (Teodor)
     * Make substring() for bit types treat any negative length as meaning
       "all the rest of the string" (Tom)
       The previous coding treated only -1 that way, and would produce an
       invalid result value for other negative values, possibly leading to
       a crash (CVE-2010-0442).
     * Fix integer-to-bit-string conversions to handle the first
       fractional byte correctly when the output bit width is wider than
       the given integer by something other than a multiple of 8 bits
       (Tom)
     * Fix some cases of pathologically slow regular expression matching
       (Tom)
     * Fix bug occurring when trying to inline a SQL function that returns
       a set of a composite type that contains dropped columns (Tom)
     * Fix bug with trying to update a field of an element of a
       composite-type array column (Tom)
     * Avoid failure when "EXPLAIN" has to print a FieldStore or
       assignment ArrayRef expression (Tom)
       These cases can arise now that "EXPLAIN VERBOSE" tries to print
       plan node target lists.
     * Avoid an unnecessary coercion failure in some cases where an
       undecorated literal string appears in a subquery within
       "UNION"/"INTERSECT"/"EXCEPT" (Tom)
       This fixes a regression for some cases that worked before 8.4.
     * Avoid undesirable rowtype compatibility check failures in some
       cases where a whole-row Var has a rowtype that contains dropped
       columns (Tom)
     * Fix the STOP WAL LOCATION entry in backup history files to report
       the next WAL segment's name when the end location is exactly at a
       segment boundary (Itagaki Takahiro)
     * Always pass the catalog ID to an option validator function
       specified in "CREATE FOREIGN DATA WRAPPER" (Martin Pihlak)
     * Fix some more cases of temporary-file leakage (Heikki)
       This corrects a problem introduced in the previous minor release.
       One case that failed is when a plpgsql function returning set is
       called within another function's exception handler.
     * Add support for doing FULL JOIN ON FALSE (Tom)
       This prevents a regression from pre-8.4 releases for some queries
       that can now be simplified to a constant-false join condition.
     * Improve constraint exclusion processing of boolean-variable cases,
       in particular make it possible to exclude a partition that has a
       "bool_column = false" constraint (Tom)
     * Prevent treating an INOUT cast as representing binary compatibility
       (Heikki)
     * Include column name in the message when warning about inability to
       grant or revoke column-level privileges (Stephen Frost)
       This is more useful than before and helps to prevent confusion when
       a "REVOKE" generates multiple messages, which formerly appeared to
       be duplicates.
     * When reading "pg_hba.conf" and related files, do not treat
       @something as a file inclusion request if the @ appears inside
       quote marks; also, never treat @ by itself as a file inclusion
       request (Tom)
       This prevents erratic behavior if a role or database name starts
       with @. If you need to include a file whose path name contains
       spaces, you can still do so, but you must write @"/path to/file"
       rather than putting the quotes around the whole construct.
     * Prevent infinite loop on some platforms if a directory is named as
       an inclusion target in "pg_hba.conf" and related files (Tom)
     * Fix possible infinite loop if SSL_read or SSL_write fails without
       setting errno (Tom)
       This is reportedly possible with some Windows versions of openssl.
     * Disallow GSSAPI authentication on local connections, since it
       requires a hostname to function correctly (Magnus)
     * Protect ecpg against applications freeing strings unexpectedly
       (Michael)
     * Make ecpg report the proper SQLSTATE if the connection disappears
       (Michael)
     * Fix translation of cell contents in psql \d output (Heikki)
     * Fix psql's numericlocale option to not format strings it shouldn't
       in latex and troff output formats (Heikki)
     * Fix a small per-query memory leak in psql (Tom)
     * Make psql return the correct exit status (3) when ON_ERROR_STOP and
       --single-transaction are both specified and an error occurs during
       the implied "COMMIT" (Bruce)
     * Fix pg_dump's output of permissions for foreign servers (Heikki)
     * Fix possible crash in parallel pg_restore due to out-of-range
       dependency IDs (Tom)
     * Fix plpgsql failure in one case where a composite column is set to
       NULL (Tom)
     * Fix possible failure when calling PL/Perl functions from PL/PerlU
       or vice versa (Tim Bunce)
     * Add volatile markings in PL/Python to avoid possible
       compiler-specific misbehavior (Zdenek Kotala)
     * Ensure PL/Tcl initializes the Tcl interpreter fully (Tom)
       The only known symptom of this oversight is that the Tcl clock
       command misbehaves if using Tcl 8.5 or later.
     * Prevent ExecutorEnd from being run on portals created within a
       failed transaction or subtransaction (Tom)
       This is known to cause issues when using "contrib/auto_explain".
     * Prevent crash in "contrib/dblink" when too many key columns are
       specified to a dblink_build_sql_* function (Rushabh Lathia, Joe
       Conway)
     * Allow zero-dimensional arrays in "contrib/ltree" operations (Tom)
       This case was formerly rejected as an error, but it's more
       convenient to treat it the same as a zero-element array. In
       particular this avoids unnecessary failures when an ltree operation
       is applied to the result of ARRAY(SELECT ...) and the sub-select
       returns no rows.
     * Fix assorted crashes in "contrib/xml2" caused by sloppy memory
       management (Tom)
     * Make building of "contrib/xml2" more robust on Windows (Andrew)
     * Fix race condition in Windows signal handling (Radu Ilie)
       One known symptom of this bug is that rows in pg_listener could be
       dropped under heavy load.
     * Make the configure script report failure if the C compiler does not
       provide a working 64-bit integer datatype (Tom)
       This case has been broken for some time, and no longer seems worth
       supporting, so just reject it at configure time instead.
     * Update time zone data files to tzdata release 2010e for DST law
       changes in Bangladesh, Chile, Fiji, Mexico, Paraguay, Samoa.
     __________________________________________________________________

                                Release 8.4.2

     Release Date: 2009-12-14

   This release contains a variety of fixes from 8.4.1. For information
   about new features in the 8.4 major release, see the Section called
   Release 8.4.
     __________________________________________________________________

Migration to Version 8.4.2

   A dump/restore is not required for those running 8.4.X. However, if you
   have any hash indexes, you should "REINDEX" them after updating to
   8.4.2, to repair possible damage.
     __________________________________________________________________

Changes

     * Protect against indirect security threats caused by index functions
       changing session-local state (Gurjeet Singh, Tom)
       This change prevents allegedly-immutable index functions from
       possibly subverting a superuser's session (CVE-2009-4136).
     * Reject SSL certificates containing an embedded null byte in the
       common name (CN) field (Magnus)
       This prevents unintended matching of a certificate to a server or
       client name during SSL validation (CVE-2009-4034).
     * Fix hash index corruption (Tom)
       The 8.4 change that made hash indexes keep entries sorted by hash
       value failed to update the bucket splitting and compaction routines
       to preserve the ordering. So application of either of those
       operations could lead to permanent corruption of an index, in the
       sense that searches might fail to find entries that are present. To
       deal with this, it is recommended to REINDEX any hash indexes you
       may have after installing this update.
     * Fix possible crash during backend-startup-time cache initialization
       (Tom)
     * Avoid crash on empty thesaurus dictionary (Tom)
     * Prevent signals from interrupting VACUUM at unsafe times (Alvaro)
       This fix prevents a PANIC if a VACUUM FULL is canceled after it's
       already committed its tuple movements, as well as transient errors
       if a plain VACUUM is interrupted after having truncated the table.
     * Fix possible crash due to integer overflow in hash table size
       calculation (Tom)
       This could occur with extremely large planner estimates for the
       size of a hashjoin's result.
     * Fix crash if a DROP is attempted on an internally-dependent object
       (Tom)
     * Fix very rare crash in inet/cidr comparisons (Chris Mikkelson)
     * Ensure that shared tuple-level locks held by prepared transactions
       are not ignored (Heikki)
     * Fix premature drop of temporary files used for a cursor that is
       accessed within a subtransaction (Heikki)
     * Fix memory leak in syslogger process when rotating to a new CSV
       logfile (Tom)
     * Fix memory leak in postmaster when re-parsing "pg_hba.conf" (Tom)
     * Fix Windows permission-downgrade logic (Jesse Morris)
       This fixes some cases where the database failed to start on
       Windows, often with misleading error messages such as "could not
       locate matching postgres executable".
     * Make FOR UPDATE/SHARE in the primary query not propagate into WITH
       queries (Tom)
       For example, in
WITH w AS (SELECT * FROM foo) SELECT * FROM w, bar ... FOR UPDATE
       the FOR UPDATE will now affect bar but not foo. This is more useful
       and consistent than the original 8.4 behavior, which tried to
       propagate FOR UPDATE into the WITH query but always failed due to
       assorted implementation restrictions. It also follows the design
       rule that WITH queries are executed as if independent of the main
       query.
     * Fix bug with a WITH RECURSIVE query immediately inside another one
       (Tom)
     * Fix concurrency bug in hash indexes (Tom)
       Concurrent insertions could cause index scans to transiently report
       wrong results.
     * Fix incorrect logic for GiST index page splits, when the split
       depends on a non-first column of the index (Paul Ramsey)
     * Fix wrong search results for a multi-column GIN index with
       fastupdate enabled (Teodor)
     * Fix bugs in WAL entry creation for GIN indexes (Tom)
       These bugs were masked when full_page_writes was on, but with it
       off a WAL replay failure was certain if a crash occurred before the
       next checkpoint.
     * Don't error out if recycling or removing an old WAL file fails at
       the end of checkpoint (Heikki)
       It's better to treat the problem as non-fatal and allow the
       checkpoint to complete. Future checkpoints will retry the removal.
       Such problems are not expected in normal operation, but have been
       seen to be caused by misdesigned Windows anti-virus and backup
       software.
     * Ensure WAL files aren't repeatedly archived on Windows (Heikki)
       This is another symptom that could happen if some other process
       interfered with deletion of a no-longer-needed file.
     * Fix PAM password processing to be more robust (Tom)
       The previous code is known to fail with the combination of the
       Linux pam_krb5 PAM module with Microsoft Active Directory as the
       domain controller. It might have problems elsewhere too, since it
       was making unjustified assumptions about what arguments the PAM
       stack would pass to it.
     * Raise the maximum authentication token (Kerberos ticket) size in
       GSSAPI and SSPI authentication methods (Ian Turner)
       While the old 2000-byte limit was more than enough for Unix
       Kerberos implementations, tickets issued by Windows Domain
       Controllers can be much larger.
     * Ensure that domain constraints are enforced in constructs like
       ARRAY[...]::domain, where the domain is over an array type (Heikki)
     * Fix foreign-key logic for some cases involving composite-type
       columns as foreign keys (Tom)
     * Ensure that a cursor's snapshot is not modified after it is created
       (Alvaro)
       This could lead to a cursor delivering wrong results if later
       operations in the same transaction modify the data the cursor is
       supposed to return.
     * Fix CREATE TABLE to properly merge default expressions coming from
       different inheritance parent tables (Tom)
       This used to work but was broken in 8.4.
     * Re-enable collection of access statistics for sequences (Akira
       Kurosawa)
       This used to work but was broken in 8.3.
     * Fix processing of ownership dependencies during CREATE OR REPLACE
       FUNCTION (Tom)
     * Fix incorrect handling of WHERE "x"="x" conditions (Tom)
       In some cases these could get ignored as redundant, but they aren't
       -- they're equivalent to "x" IS NOT NULL.
     * Fix incorrect plan construction when using hash aggregation to
       implement DISTINCT for textually identical volatile expressions
       (Tom)
     * Fix Assert failure for a volatile SELECT DISTINCT ON expression
       (Tom)
     * Fix ts_stat() to not fail on an empty tsvector value (Tom)
     * Make text search parser accept underscores in XML attributes
       (Peter)
     * Fix encoding handling in xml binary input (Heikki)
       If the XML header doesn't specify an encoding, we now assume UTF-8
       by default; the previous handling was inconsistent.
     * Fix bug with calling plperl from plperlu or vice versa (Tom)
       An error exit from the inner function could result in crashes due
       to failure to re-select the correct Perl interpreter for the outer
       function.
     * Fix session-lifespan memory leak when a PL/Perl function is
       redefined (Tom)
     * Ensure that Perl arrays are properly converted to PostgreSQL arrays
       when returned by a set-returning PL/Perl function (Andrew Dunstan,
       Abhijit Menon-Sen)
       This worked correctly already for non-set-returning functions.
     * Fix rare crash in exception processing in PL/Python (Peter)
     * Fix ecpg problem with comments in DECLARE CURSOR statements
       (Michael)
     * Fix ecpg to not treat recently-added keywords as reserved words
       (Tom)
       This affected the keywords CALLED, CATALOG, DEFINER, ENUM,
       FOLLOWING, INVOKER, OPTIONS, PARTITION, PRECEDING, RANGE, SECURITY,
       SERVER, UNBOUNDED, and WRAPPER.
     * Re-allow regular expression special characters in psql's \df
       function name parameter (Tom)
     * In "contrib/fuzzystrmatch", correct the calculation of levenshtein
       distances with non-default costs (Marcin Mank)
     * In "contrib/pg_standby", disable triggering failover with a signal
       on Windows (Fujii Masao)
       This never did anything useful, because Windows doesn't have
       Unix-style signals, but recent changes made it actually crash.
     * Put FREEZE and VERBOSE options in the right order in the VACUUM
       command that "contrib/vacuumdb" produces (Heikki)
     * Fix possible leak of connections when "contrib/dblink" encounters
       an error (Tatsuhito Kasahara)
     * Ensure psql's flex module is compiled with the correct system
       header definitions (Tom)
       This fixes build failures on platforms where --enable-largefile
       causes incompatible changes in the generated code.
     * Make the postmaster ignore any application_name parameter in
       connection request packets, to improve compatibility with future
       libpq versions (Tom)
     * Update the timezone abbreviation files to match current reality
       (Joachim Wieland)
       This includes adding IDT to the default timezone abbreviation set.
     * Update time zone data files to tzdata release 2009s for DST law
       changes in Antarctica, Argentina, Bangladesh, Fiji, Novokuznetsk,
       Pakistan, Palestine, Samoa, Syria; also historical corrections for
       Hong Kong.
     __________________________________________________________________

                                Release 8.4.1

     Release Date: 2009-09-09

   This release contains a variety of fixes from 8.4. For information
   about new features in the 8.4 major release, see the Section called
   Release 8.4.
     __________________________________________________________________

Migration to Version 8.4.1

   A dump/restore is not required for those running 8.4.X.
     __________________________________________________________________

Changes

     * Fix WAL page header initialization at the end of archive recovery
       (Heikki)
       This could lead to failure to process the WAL in a subsequent
       archive recovery.
     * Fix "cannot make new WAL entries during recovery" error (Tom)
     * Fix problem that could make expired rows visible after a crash
       (Tom)
       This bug involved a page status bit potentially not being set
       correctly after a server crash.
     * Disallow "RESET ROLE" and "RESET SESSION AUTHORIZATION" inside
       security-definer functions (Tom, Heikki)
       This covers a case that was missed in the previous patch that
       disallowed "SET ROLE" and "SET SESSION AUTHORIZATION" inside
       security-definer functions. (See CVE-2007-6600)
     * Make "LOAD" of an already-loaded loadable module into a no-op (Tom)
       Formerly, "LOAD" would attempt to unload and re-load the module,
       but this is unsafe and not all that useful.
     * Make window function PARTITION BY and ORDER BY items always be
       interpreted as simple expressions (Tom)
       In 8.4.0 these lists were parsed following the rules used for
       top-level GROUP BY and ORDER BY lists. But this was not correct per
       the SQL standard, and it led to possible circularity.
     * Fix several errors in planning of semi-joins (Tom)
       These led to wrong query results in some cases where IN or EXISTS
       was used together with another join.
     * Fix handling of whole-row references to subqueries that are within
       an outer join (Tom)
       An example is SELECT COUNT(ss.*) FROM ... LEFT JOIN (SELECT ...) ss
       ON .... Here, ss.* would be treated as ROW(NULL,NULL,...) for
       null-extended join rows, which is not the same as a simple NULL.
       Now it is treated as a simple NULL.
     * Fix Windows shared-memory allocation code (Tsutomu Yamada, Magnus)
       This bug led to the often-reported "could not reattach to shared
       memory" error message.
     * Fix locale handling with plperl (Heikki)
       This bug could cause the server's locale setting to change when a
       plperl function is called, leading to data corruption.
     * Fix handling of reloptions to ensure setting one option doesn't
       force default values for others (Itagaki Takahiro)
     * Ensure that a "fast shutdown" request will forcibly terminate open
       sessions, even if a "smart shutdown" was already in progress (Fujii
       Masao)
     * Avoid memory leak for array_agg() in GROUP BY queries (Tom)
     * Treat to_char(..., 'TH') as an uppercase ordinal suffix with
       'HH'/'HH12' (Heikki)
       It was previously handled as 'th' (lowercase).
     * Include the fractional part in the result of EXTRACT(second) and
       EXTRACT(milliseconds) for time and time with time zone inputs (Tom)
       This has always worked for floating-point datetime configurations,
       but was broken in the integer datetime code.
     * Fix overflow for INTERVAL 'x ms' when "x" is more than 2 million
       and integer datetimes are in use (Alex Hunsaker)
     * Improve performance when processing toasted values in index scans
       (Tom)
       This is particularly useful for PostGIS.
     * Fix a typo that disabled commit_delay (Jeff Janes)
     * Output early-startup messages to "postmaster.log" if the server is
       started in silent mode (Tom)
       Previously such error messages were discarded, leading to
       difficulty in debugging.
     * Remove translated FAQs (Peter)
       They are now on the wiki. The main FAQ was moved to the wiki some
       time ago.
     * Fix pg_ctl to not go into an infinite loop if "postgresql.conf" is
       empty (Jeff Davis)
     * Fix several errors in pg_dump's --binary-upgrade mode (Bruce, Tom)
       pg_dump --binary-upgrade is used by pg_migrator.
     * Fix "contrib/xml2"'s xslt_process() to properly handle the maximum
       number of parameters (twenty) (Tom)
     * Improve robustness of libpq's code to recover from errors during
       "COPY FROM STDIN" (Tom)
     * Avoid including conflicting readline and editline header files when
       both libraries are installed (Zdenek Kotala)
     * Work around gcc bug that causes "floating-point exception" instead
       of "division by zero" on some platforms (Tom)
     * Update time zone data files to tzdata release 2009l for DST law
       changes in Bangladesh, Egypt, Mauritius.
     __________________________________________________________________

                                 Release 8.4

     Release Date: 2009-07-01
     __________________________________________________________________

Overview

   After many years of development, PostgreSQL has become feature-complete
   in many areas. This release shows a targeted approach to adding
   features (e.g., authentication, monitoring, space reuse), and adds
   capabilities defined in the later SQL standards. The major areas of
   enhancement are:

     * Windowing Functions
     * Common Table Expressions and Recursive Queries
     * Default and variadic parameters for functions
     * Parallel Restore
     * Column Permissions
     * Per-database locale settings
     * Improved hash indexes
     * Improved join performance for EXISTS and NOT EXISTS queries
     * Easier-to-use Warm Standby
     * Automatic sizing of the Free Space Map
     * Visibility Map (greatly reduces vacuum overhead for slowly-changing
       tables)
     * Version-aware psql (backslash commands work against older servers)
     * Support SSL certificates for user authentication
     * Per-function runtime statistics
     * Easy editing of functions in psql
     * New contrib modules: pg_stat_statements, auto_explain, citext,
       btree_gin

   The above items are explained in more detail in the sections below.
     __________________________________________________________________

Migration to Version 8.4

   A dump/restore using pg_dump is required for those wishing to migrate
   data from any previous release.

   Observe the following incompatibilities:
     __________________________________________________________________

General

     * Use 64-bit integer datetimes by default (Neil Conway)
       Previously this was selected by configure's
       "--enable-integer-datetimes" option. To retain the old behavior,
       build with "--disable-integer-datetimes".
     * Remove ipcclean utility command (Bruce)
       The utility only worked on a few platforms. Users should use their
       operating system tools instead.
     __________________________________________________________________

Server Settings

     * Change default setting for log_min_messages to warning (previously
       it was notice) to reduce log file volume (Tom)
     * Change default setting for max_prepared_transactions to zero
       (previously it was 5) (Tom)
     * Make debug_print_parse, debug_print_rewritten, and debug_print_plan
       output appear at LOG message level, not DEBUG1 as formerly (Tom)
     * Make debug_pretty_print default to on (Tom)
     * Remove explain_pretty_print parameter (no longer needed) (Tom)
     * Make log_temp_files settable by superusers only, like other logging
       options (Simon Riggs)
     * Remove automatic appending of the epoch timestamp when no % escapes
       are present in log_filename (Robert Haas)
       This change was made because some users wanted a fixed log
       filename, for use with an external log rotation tool.
     * Remove log_restartpoints from "recovery.conf"; instead use
       log_checkpoints (Simon)
     * Remove krb_realm and krb_server_hostname; these are now set in
       "pg_hba.conf" instead (Magnus)
     * There are also significant changes in "pg_hba.conf", as described
       below.
     __________________________________________________________________

Queries

     * Change "TRUNCATE" and "LOCK" to apply to child tables of the
       specified table(s) (Peter)
       These commands now accept an ONLY option that prevents processing
       child tables; this option must be used if the old behavior is
       needed.
     * "SELECT DISTINCT" and UNION/INTERSECT/EXCEPT no longer always
       produce sorted output (Tom)
       Previously, these types of queries always removed duplicate rows by
       means of Sort/Unique processing (i.e., sort then remove adjacent
       duplicates). Now they can be implemented by hashing, which will not
       produce sorted output. If an application relied on the output being
       in sorted order, the recommended fix is to add an ORDER BY clause.
       As a short-term workaround, the previous behavior can be restored
       by disabling enable_hashagg, but that is a very
       performance-expensive fix. SELECT DISTINCT ON never uses hashing,
       however, so its behavior is unchanged.
     * Force child tables to inherit CHECK constraints from parents (Alex
       Hunsaker, Nikhil Sontakke, Tom)
       Formerly it was possible to drop such a constraint from a child
       table, allowing rows that violate the constraint to be visible when
       scanning the parent table. This was deemed inconsistent, as well as
       contrary to SQL standard.
     * Disallow negative LIMIT or OFFSET values, rather than treating them
       as zero (Simon)
     * Disallow "LOCK TABLE" outside a transaction block (Tom)
       Such an operation is useless because the lock would be released
       immediately.
     * Sequences now contain an additional start_value column (Zoltan
       Boszormenyi)
       This supports "ALTER SEQUENCE ... RESTART".
     __________________________________________________________________

Functions and Operators

     * Make numeric zero raised to a fractional power return 0, rather
       than throwing an error, and make numeric zero raised to the zero
       power return 1, rather than error (Bruce)
       This matches the longstanding float8 behavior.
     * Allow unary minus of floating-point values to produce minus zero
       (Tom)
       The changed behavior is more IEEE-standard compliant.
     * Throw an error if an escape character is the last character in a
       LIKE pattern (i.e., it has nothing to escape) (Tom)
       Previously, such an escape character was silently ignored, thus
       possibly masking application logic errors.
     * Remove ~=~ and ~<>~ operators formerly used for LIKE index
       comparisons (Tom)
       Pattern indexes now use the regular equality operator.
     * xpath() now passes its arguments to libxml without any changes
       (Andrew)
       This means that the XML argument must be a well-formed XML
       document. The previous coding attempted to allow XML fragments, but
       it did not work well.
     * Make xmlelement() format attribute values just like content values
       (Peter)
       Previously, attribute values were formatted according to the normal
       SQL output behavior, which is sometimes at odds with XML rules.
     * Rewrite memory management for libxml-using functions (Tom)
       This change should avoid some compatibility problems with use of
       libxml in PL/Perl and other add-on code.
     * Adopt a faster algorithm for hash functions (Kenneth Marshall,
       based on work of Bob Jenkins)
       Many of the built-in hash functions now deliver different results
       on little-endian and big-endian platforms.
     __________________________________________________________________

Temporal Functions and Operators

     * DateStyle no longer controls interval output formatting; instead
       there is a new variable IntervalStyle (Ron Mayer)
     * Improve consistency of handling of fractional seconds in timestamp
       and interval output (Ron Mayer)
       This may result in displaying a different number of fractional
       digits than before, or rounding instead of truncating.
     * Make to_char()'s localized month/day names depend on LC_TIME, not
       LC_MESSAGES (Euler Taveira de Oliveira)
     * Cause to_date() and to_timestamp() to more consistently report
       errors for invalid input (Brendan Jurd)
       Previous versions would often ignore or silently misread input that
       did not match the format string. Such cases will now result in an
       error.
     * Fix to_timestamp() to not require upper/lower case matching for
       meridian (AM/PM) and era (BC/AD) format designations (Brendan Jurd)
       For example, input value ad now matches the format string AD.
     __________________________________________________________________

Changes

   Below you will find a detailed account of the changes between
   PostgreSQL 8.4 and the previous major release.
     __________________________________________________________________

Performance

     * Improve optimizer statistics calculations (Jan Urbanski, Tom)
       In particular, estimates for full-text-search operators are greatly
       improved.
     * Allow "SELECT DISTINCT" and UNION/INTERSECT/EXCEPT to use hashing
       (Tom)
       This means that these types of queries no longer automatically
       produce sorted output.
     * Create explicit concepts of semi-joins and anti-joins (Tom)
       This work formalizes our previous ad-hoc treatment of IN (SELECT
       ...) clauses, and extends it to EXISTS and NOT EXISTS clauses. It
       should result in significantly better planning of EXISTS and NOT
       EXISTS queries. In general, logically equivalent IN and EXISTS
       clauses should now have similar performance, whereas previously IN
       often won.
     * Improve optimization of sub-selects beneath outer joins (Tom)
       Formerly, a sub-select or view could not be optimized very well if
       it appeared within the nullable side of an outer join and contained
       non-strict expressions (for instance, constants) in its result
       list.
     * Improve the performance of text_position() and related functions by
       using Boyer-Moore-Horspool searching (David Rowley)
       This is particularly helpful for long search patterns.
     * Reduce I/O load of writing the statistics collection file by
       writing the file only when requested (Martin Pihlak)
     * Improve performance for bulk inserts (Robert Haas, Simon)
     * Increase the default value of default_statistics_target from 10 to
       100 (Greg Sabino Mullane, Tom)
       The maximum value was also increased from 1000 to 10000.
     * Perform constraint_exclusion checking by default in queries
       involving inheritance or UNION ALL (Tom)
       A new constraint_exclusion setting, partition, was added to specify
       this behavior.
     * Allow I/O read-ahead for bitmap index scans (Greg Stark)
       The amount of read-ahead is controlled by effective_io_concurrency.
       This feature is available only if the kernel has posix_fadvise()
       support.
     * Inline simple set-returning SQL functions in FROM clauses (Richard
       Rowell)
     * Improve performance of multi-batch hash joins by providing a
       special case for join key values that are especially common in the
       outer relation (Bryce Cutt, Ramon Lawrence)
     * Reduce volume of temporary data in multi-batch hash joins by
       suppressing "physical tlist" optimization (Michael Henderson, Ramon
       Lawrence)
     * Avoid waiting for idle-in-transaction sessions during "CREATE INDEX
       CONCURRENTLY" (Simon)
     * Improve performance of shared cache invalidation (Tom)
     __________________________________________________________________

Server

Settings

     * Convert many "postgresql.conf" settings to enumerated values so
       that pg_settings can display the valid values (Magnus)
     * Add cursor_tuple_fraction parameter to control the fraction of a
       cursor's rows that the planner assumes will be fetched (Robert
       Hell)
     * Allow underscores in the names of custom variable classes in
       "postgresql.conf" (Tom)
     __________________________________________________________________

Authentication and security

     * Remove support for the (insecure) crypt authentication method
       (Magnus)
       This effectively obsoletes pre-PostgreSQL 7.2 client libraries, as
       there is no longer any non-plaintext password method that they can
       use.
     * Support regular expressions in "pg_ident.conf" (Magnus)
     * Allow Kerberos/GSSAPI parameters to be changed without restarting
       the postmaster (Magnus)
     * Support SSL certificate chains in server certificate file (Andrew
       Gierth)
       Including the full certificate chain makes the client able to
       verify the certificate without having all intermediate CA
       certificates present in the local store, which is often the case
       for commercial CAs.
     * Report appropriate error message for combination of MD5
       authentication and db_user_namespace enabled (Bruce)
     __________________________________________________________________

pg_hba.conf

     * Change all authentication options to use name=value syntax (Magnus)
       This makes incompatible changes to the ldap, pam and ident
       authentication methods. All "pg_hba.conf" entries with these
       methods need to be rewritten using the new format.
     * Remove the ident sameuser option, instead making that behavior the
       default if no usermap is specified (Magnus)
     * Allow a usermap parameter for all external authentication methods
       (Magnus)
       Previously a usermap was only supported for ident authentication.
     * Add clientcert option to control requesting of a client certificate
       (Magnus)
       Previously this was controlled by the presence of a root
       certificate file in the server's data directory.
     * Add cert authentication method to allow *user* authentication via
       SSL certificates (Magnus)
       Previously SSL certificates could only verify that the client had
       access to a certificate, not authenticate a user.
     * Allow krb5, gssapi and sspi realm and krb5 host settings to be
       specified in "pg_hba.conf" (Magnus)
       These override the settings in "postgresql.conf".
     * Add include_realm parameter for krb5, gssapi, and sspi methods
       (Magnus)
       This allows identical usernames from different realms to be
       authenticated as different database users using usermaps.
     * Parse "pg_hba.conf" fully when it is loaded, so that errors are
       reported immediately (Magnus)
       Previously, most errors in the file wouldn't be detected until
       clients tried to connect, so an erroneous file could render the
       system unusable. With the new behavior, if an error is detected
       during reload then the bad file is rejected and the postmaster
       continues to use its old copy.
     * Show all parsing errors in "pg_hba.conf" instead of aborting after
       the first one (Selena Deckelmann)
     * Support ident authentication over Unix-domain sockets on Solaris
       (Garick Hamlin)
     __________________________________________________________________

Continuous Archiving

     * Provide an option to pg_start_backup() to force its implied
       checkpoint to finish as quickly as possible (Tom)
       The default behavior avoids excess I/O consumption, but that is
       pointless if no concurrent query activity is going on.
     * Make pg_stop_backup() wait for modified WAL files to be archived
       (Simon)
       This guarantees that the backup is valid at the time
       pg_stop_backup() completes.
     * When archiving is enabled, rotate the last WAL segment at shutdown
       so that all transactions can be archived immediately (Guillaume
       Smet, Heikki)
     * Delay "smart" shutdown while a continuous archiving base backup is
       in progress (Laurenz Albe)
     * Cancel a continuous archiving base backup if "fast" shutdown is
       requested (Laurenz Albe)
     * Allow "recovery.conf" boolean variables to take the same range of
       string values as "postgresql.conf" boolean variables (Bruce)
     __________________________________________________________________

Monitoring

     * Add pg_conf_load_time() to report when the PostgreSQL configuration
       files were last loaded (George Gensure)
     * Add pg_terminate_backend() to safely terminate a backend (the
       SIGTERM signal works also) (Tom, Bruce)
       While it's always been possible to SIGTERM a single backend, this
       was previously considered unsupported; and testing of the case
       found some bugs that are now fixed.
     * Add ability to track user-defined functions' call counts and
       runtimes (Martin Pihlak)
       Function statistics appear in a new system view,
       pg_stat_user_functions. Tracking is controlled by the new parameter
       track_functions.
     * Allow specification of the maximum query string size in
       pg_stat_activity via new track_activity_query_size parameter
       (Thomas Lee)
     * Increase the maximum line length sent to syslog, in hopes of
       improving performance (Tom)
     * Add read-only configuration variables segment_size, wal_block_size,
       and wal_segment_size (Bernd Helmle)
     * When reporting a deadlock, report the text of all queries involved
       in the deadlock to the server log (Itagaki Takahiro)
     * Add pg_stat_get_activity(pid) function to return information about
       a specific process id (Magnus)
     * Allow the location of the server's statistics file to be specified
       via stats_temp_directory (Magnus)
       This allows the statistics file to be placed in a RAM-resident
       directory to reduce I/O requirements. On startup/shutdown, the file
       is copied to its traditional location ($PGDATA/global/) so it is
       preserved across restarts.
     __________________________________________________________________

Queries

     * Add support for WINDOW functions (Hitoshi Harada)
     * Add support for WITH clauses (CTEs), including WITH RECURSIVE
       (Yoshiyuki Asaba, Tatsuo Ishii, Tom)
     * Add "TABLE" command (Peter)
       TABLE tablename is a SQL standard short-hand for SELECT * FROM
       tablename.
     * Allow AS to be optional when specifying a "SELECT" (or RETURNING)
       column output label (Hiroshi Saito)
       This works so long as the column label is not any PostgreSQL
       keyword; otherwise AS is still needed.
     * Support set-returning functions in "SELECT" result lists even for
       functions that return their result via a tuplestore (Tom)
       In particular, this means that functions written in PL/pgSQL and
       other PL languages can now be called this way.
     * Support set-returning functions in the output of aggregation and
       grouping queries (Tom)
     * Allow "SELECT FOR UPDATE"/SHARE to work on inheritance trees (Tom)
     * Add infrastructure for SQL/MED (Martin Pihlak, Peter)
       There are no remote or external SQL/MED capabilities yet, but this
       change provides a standardized and future-proof system for managing
       connection information for modules like "dblink" and "plproxy".
     * Invalidate cached plans when referenced schemas, functions,
       operators, or operator classes are modified (Martin Pihlak, Tom)
       This improves the system's ability to respond to on-the-fly DDL
       changes.
     * Allow comparison of composite types and allow arrays of anonymous
       composite types (Tom)
       This allows constructs such as row(1, 1.1) = any (array[row(7,
       7.7), row(1, 1.0)]). This is particularly useful in recursive
       queries.
     * Add support for Unicode string literal and identifier
       specifications using code points, e.g. U&'d\0061t\+000061' (Peter)
     * Reject \000 in string literals and "COPY" data (Tom)
       Previously, this was accepted but had the effect of terminating the
       string contents.
     * Improve the parser's ability to report error locations (Tom)
       An error location is now reported for many semantic errors, such as
       mismatched datatypes, that previously could not be localized.
     __________________________________________________________________

TRUNCATE

     * Support statement-level ON TRUNCATE triggers (Simon)
     * Add RESTART/CONTINUE IDENTITY options for "TRUNCATE TABLE" (Zoltan
       Boszormenyi)
       The start value of a sequence can be changed by "ALTER SEQUENCE
       START WITH".
     * Allow "TRUNCATE tab1, tab1" to succeed (Bruce)
     * Add a separate "TRUNCATE" permission (Robert Haas)
     __________________________________________________________________

EXPLAIN

     * Make "EXPLAIN VERBOSE" show the output columns of each plan node
       (Tom)
       Previously "EXPLAIN VERBOSE" output an internal representation of
       the query plan. (That behavior is now available via
       debug_print_plan.)
     * Make "EXPLAIN" identify subplans and initplans with individual
       labels (Tom)
     * Make "EXPLAIN" honor debug_print_plan (Tom)
     * Allow "EXPLAIN" on "CREATE TABLE AS" (Peter)
     __________________________________________________________________

LIMIT/OFFSET

     * Allow sub-selects in LIMIT and OFFSET (Tom)
     * Add SQL-standard syntax for LIMIT/OFFSET capabilities (Peter)
       To wit, OFFSET num {ROW|ROWS} FETCH {FIRST|NEXT} [num] {ROW|ROWS}
       ONLY.
     __________________________________________________________________

Object Manipulation

     * Add support for column-level privileges (Stephen Frost, KaiGai
       Kohei)
     * Refactor multi-object "DROP" operations to reduce the need for
       CASCADE (Alex Hunsaker)
       For example, if table B has a dependency on table A, the command
       DROP TABLE A, B no longer requires the CASCADE option.
     * Fix various problems with concurrent "DROP" commands by ensuring
       that locks are taken before we begin to drop dependencies of an
       object (Tom)
     * Improve reporting of dependencies during "DROP" commands (Tom)
     * Add WITH [NO] DATA clause to "CREATE TABLE AS", per the SQL
       standard (Peter, Tom)
     * Add support for user-defined I/O conversion casts (Heikki)
     * Allow "CREATE AGGREGATE" to use an internal transition datatype
       (Tom)
     * Add LIKE clause to "CREATE TYPE" (Tom)
       This simplifies creation of data types that use the same internal
       representation as an existing type.
     * Allow specification of the type category and "preferred" status for
       user-defined base types (Tom)
       This allows more control over the coercion behavior of user-defined
       types.
     * Allow "CREATE OR REPLACE VIEW" to add columns to the end of a view
       (Robert Haas)
     __________________________________________________________________

ALTER

     * Add "ALTER TYPE RENAME" (Petr Jelinek)
     * Add "ALTER SEQUENCE ... RESTART" (with no parameter) to reset a
       sequence to its initial value (Zoltan Boszormenyi)
     * Modify the "ALTER TABLE" syntax to allow all reasonable
       combinations for tables, indexes, sequences, and views (Tom)
       This change allows the following new syntaxes:
          + "ALTER SEQUENCE OWNER TO"
          + "ALTER VIEW ALTER COLUMN SET/DROP DEFAULT"
          + "ALTER VIEW OWNER TO"
          + "ALTER VIEW SET SCHEMA"
       There is no actual new functionality here, but formerly you had to
       say "ALTER TABLE" to do these things, which was confusing.
     * Add support for the syntax "ALTER TABLE ... ALTER COLUMN ... SET
       DATA TYPE" (Peter)
       This is SQL-standard syntax for functionality that was already
       supported.
     * Make "ALTER TABLE SET WITHOUT OIDS" rewrite the table to physically
       remove OID values (Tom)
       Also, add "ALTER TABLE SET WITH OIDS" to rewrite the table to add
       OIDs.
     __________________________________________________________________

Database Manipulation

     * Improve reporting of "CREATE"/"DROP"/"RENAME DATABASE" failure when
       uncommitted prepared transactions are the cause (Tom)
     * Make LC_COLLATE and LC_CTYPE into per-database settings (Radek
       Strnad, Heikki)
       This makes collation similar to encoding, which was always
       configurable per database.
     * Improve checks that the database encoding, collation (LC_COLLATE),
       and character classes (LC_CTYPE) match (Heikki, Tom)
       Note in particular that a new database's encoding and locale
       settings can be changed only when copying from template0. This
       prevents possibly copying data that doesn't match the settings.
     * Add "ALTER DATABASE SET TABLESPACE" to move a database to a new
       tablespace (Guillaume Lelarge, Bernd Helmle)
     __________________________________________________________________

Utility Operations

     * Add a VERBOSE option to the "CLUSTER" command and clusterdb (Jim
       Cox)
     * Decrease memory requirements for recording pending trigger events
       (Tom)
     __________________________________________________________________

Indexes

     * Dramatically improve the speed of building and accessing hash
       indexes (Tom Raney, Shreya Bhargava)
       This allows hash indexes to be sometimes faster than btree indexes.
       However, hash indexes are still not crash-safe.
     * Make hash indexes store only the hash code, not the full value of
       the indexed column (Xiao Meng)
       This greatly reduces the size of hash indexes for long indexed
       values, improving performance.
     * Implement fast update option for GIN indexes (Teodor, Oleg)
       This option greatly improves update speed at a small penalty in
       search speed.
     * xxx_pattern_ops indexes can now be used for simple equality
       comparisons, not only for LIKE (Tom)
     __________________________________________________________________

Full Text Indexes

     * Remove the requirement to use @@@ when doing GIN weighted lookups
       on full text indexes (Tom, Teodor)
       The normal @@ text search operator can be used instead.
     * Add an optimizer selectivity function for @@ text search operations
       (Jan Urbanski)
     * Allow prefix matching in full text searches (Teodor Sigaev, Oleg
       Bartunov)
     * Support multi-column GIN indexes (Teodor Sigaev)
     * Improve support for Nepali language and Devanagari alphabet
       (Teodor)
     __________________________________________________________________

VACUUM

     * Track free space in separate per-relation "fork" files (Heikki)
       Free space discovered by "VACUUM" is now recorded in "*_fsm" files,
       rather than in a fixed-sized shared memory area. The max_fsm_pages
       and max_fsm_relations settings have been removed, greatly
       simplifying administration of free space management.
     * Add a visibility map to track pages that do not require vacuuming
       (Heikki)
       This allows "VACUUM" to avoid scanning all of a table when only a
       portion of the table needs vacuuming. The visibility map is stored
       in per-relation "fork" files.
     * Add vacuum_freeze_table_age parameter to control when "VACUUM"
       should ignore the visibility map and do a full table scan to freeze
       tuples (Heikki)
     * Track transaction snapshots more carefully (Alvaro)
       This improves "VACUUM"'s ability to reclaim space in the presence
       of long-running transactions.
     * Add ability to specify per-relation autovacuum and TOAST parameters
       in "CREATE TABLE" (Alvaro, Euler Taveira de Oliveira)
       Autovacuum options used to be stored in a system table.
     * Add --freeze option to vacuumdb (Bruce)
     __________________________________________________________________

Data Types

     * Add a CaseSensitive option for text search synonym dictionaries
       (Simon)
     * Improve the precision of NUMERIC division (Tom)
     * Add basic arithmetic operators for int2 with int8 (Tom)
       This eliminates the need for explicit casting in some situations.
     * Allow UUID input to accept an optional hyphen after every fourth
       digit (Robert Haas)
     * Allow on/off as input for the boolean data type (Itagaki Takahiro)
     * Allow spaces around NaN in the input string for type numeric (Sam
       Mason)
     __________________________________________________________________

Temporal Data Types

     * Reject year 0 BC and years 000 and 0000 (Tom)
       Previously these were interpreted as 1 BC. (Note: years 0 and 00
       are still assumed to be the year 2000.)
     * Include SGT (Singapore time) in the default list of known time zone
       abbreviations (Tom)
     * Support infinity and -infinity as values of type date (Tom)
     * Make parsing of interval literals more standard-compliant (Tom, Ron
       Mayer)
       For example, INTERVAL '1' YEAR now does what it's supposed to.
     * Allow interval fractional-seconds precision to be specified after
       the second keyword, for SQL standard compliance (Tom)
       Formerly the precision had to be specified after the keyword
       interval. (For backwards compatibility, this syntax is still
       supported, though deprecated.) Data type definitions will now be
       output using the standard format.
     * Support the IS0 8601 interval syntax (Ron Mayer, Kevin Grittner)
       For example, INTERVAL 'P1Y2M3DT4H5M6.7S' is now supported.
     * Add IntervalStyle parameter which controls how interval values are
       output (Ron Mayer)
       Valid values are: postgres, postgres_verbose, sql_standard,
       iso_8601. This setting also controls the handling of negative
       interval input when only some fields have positive/negative
       designations.
     * Improve consistency of handling of fractional seconds in timestamp
       and interval output (Ron Mayer)
     __________________________________________________________________

Arrays

     * Improve the handling of casts applied to ARRAY[] constructs, such
       as ARRAY[...]::integer[] (Brendan Jurd)
       Formerly PostgreSQL attempted to determine a data type for the
       ARRAY[] construct without reference to the ensuing cast. This could
       fail unnecessarily in many cases, in particular when the ARRAY[]
       construct was empty or contained only ambiguous entries such as
       NULL. Now the cast is consulted to determine the type that the
       array elements must be.
     * Make SQL-syntax ARRAY dimensions optional to match the SQL standard
       (Peter)
     * Add array_ndims() to return the number of dimensions of an array
       (Robert Haas)
     * Add array_length() to return the length of an array for a specified
       dimension (Jim Nasby, Robert Haas, Peter Eisentraut)
     * Add aggregate function array_agg(), which returns all aggregated
       values as a single array (Robert Haas, Jeff Davis, Peter)
     * Add unnest(), which converts an array to individual row values
       (Tom)
       This is the opposite of array_agg().
     * Add array_fill() to create arrays initialized with a value (Pavel
       Stehule)
     * Add generate_subscripts() to simplify generating the range of an
       array's subscripts (Pavel Stehule)
     __________________________________________________________________

Wide-Value Storage (TOAST)

     * Consider TOAST compression on values as short as 32 bytes
       (previously 256 bytes) (Greg Stark)
     * Require 25% minimum space savings before using TOAST compression
       (previously 20% for small values and any-savings-at-all for large
       values) (Greg)
     * Improve TOAST heuristics for rows that have a mix of large and
       small toastable fields, so that we prefer to push large values out
       of line and don't compress small values unnecessarily (Greg, Tom)
     __________________________________________________________________

Functions

     * Document that setseed() allows values from -1 to 1 (not just 0 to
       1), and enforce the valid range (Kris Jurka)
     * Add server-side function lo_import(filename, oid) (Tatsuo)
     * Add quote_nullable(), which behaves like quote_literal() but
       returns the string NULL for a null argument (Brendan Jurd)
     * Improve full text search headline() function to allow extracting
       several fragments of text (Sushant Sinha)
     * Add suppress_redundant_updates_trigger() trigger function to avoid
       overhead for non-data-changing updates (Andrew)
     * Add div(numeric, numeric) to perform numeric division without
       rounding (Tom)
     * Add timestamp and timestamptz versions of generate_series()
       (Hitoshi Harada)
     __________________________________________________________________

Object Information Functions

     * Implement current_query() for use by functions that need to know
       the currently running query (Tomas Doran)
     * Add pg_get_keywords() to return a list of the parser keywords (Dave
       Page)
     * Add pg_get_functiondef() to see a function's definition (Abhijit
       Menon-Sen)
     * Allow the second argument of pg_get_expr() to be zero when
       deparsing an expression that does not contain variables (Tom)
     * Modify pg_relation_size() to use regclass (Heikki)
       pg_relation_size(data_type_name) no longer works.
     * Add boot_val and reset_val columns to pg_settings output (Greg
       Smith)
     * Add source file name and line number columns to pg_settings output
       for variables set in a configuration file (Magnus, Alvaro)
       For security reasons, these columns are only visible to superusers.
     * Add support for CURRENT_CATALOG, CURRENT_SCHEMA, SET CATALOG, SET
       SCHEMA (Peter)
       These provide SQL-standard syntax for existing features.
     * Add pg_typeof() which returns the data type of any value (Brendan
       Jurd)
     * Make version() return information about whether the server is a 32-
       or 64-bit binary (Bruce)
     * Fix the behavior of information schema columns is_insertable_into
       and is_updatable to be consistent (Peter)
     * Improve the behavior of information schema datetime_precision
       columns (Peter)
       These columns now show zero for date columns, and 6 (the default
       precision) for time, timestamp, and interval without a declared
       precision, rather than showing null as formerly.
     * Convert remaining builtin set-returning functions to use OUT
       parameters (Jaime Casanova)
       This makes it possible to call these functions without specifying a
       column list: pg_show_all_settings(), pg_lock_status(),
       pg_prepared_xact(), pg_prepared_statement(), pg_cursor()
     * Make pg_*_is_visible() and has_*_privilege() functions return NULL
       for invalid OIDs, rather than reporting an error (Tom)
     * Extend has_*_privilege() functions to allow inquiring about the OR
       of multiple privileges in one call (Stephen Frost, Tom)
     * Add has_column_privilege() and has_any_column_privilege() functions
       (Stephen Frost, Tom)
     __________________________________________________________________

Function Creation

     * Support variadic functions (functions with a variable number of
       arguments) (Pavel Stehule)
       Only trailing arguments can be optional, and they all must be of
       the same data type.
     * Support default values for function arguments (Pavel Stehule)
     * Add "CREATE FUNCTION ... RETURNS TABLE" clause (Pavel Stehule)
     * Allow SQL-language functions to return the output of an
       "INSERT"/"UPDATE"/"DELETE" RETURNING clause (Tom)
     __________________________________________________________________

PL/pgSQL Server-Side Language

     * Support EXECUTE USING for easier insertion of data values into a
       dynamic query string (Pavel Stehule)
     * Allow looping over the results of a cursor using a FOR loop (Pavel
       Stehule)
     * Support RETURN QUERY EXECUTE (Pavel Stehule)
     * Improve the RAISE command (Pavel Stehule)
          + Support DETAIL and HINT fields
          + Support specification of the SQLSTATE error code
          + Support an exception name parameter
          + Allow RAISE without parameters in an exception block to
            re-throw the current error
     * Allow specification of SQLSTATE codes in EXCEPTION lists (Pavel
       Stehule)
       This is useful for handling custom SQLSTATE codes.
     * Support the CASE statement (Pavel Stehule)
     * Make "RETURN QUERY" set the special FOUND and "GET DIAGNOSTICS"
       ROW_COUNT variables (Pavel Stehule)
     * Make "FETCH" and "MOVE" set the "GET DIAGNOSTICS" ROW_COUNT
       variable (Andrew Gierth)
     * Make "EXIT" without a label always exit the innermost loop (Tom)
       Formerly, if there were a BEGIN block more closely nested than any
       loop, it would exit that block instead. The new behavior matches
       Oracle(TM) and is also what was previously stated by our own
       documentation.
     * Make processing of string literals and nested block comments match
       the main SQL parser's processing (Tom)
       In particular, the format string in "RAISE" now works the same as
       any other string literal, including being subject to
       standard_conforming_strings. This change also fixes other cases in
       which valid commands would fail when standard_conforming_strings is
       on.
     * Avoid memory leakage when the same function is called at varying
       exception-block nesting depths (Tom)
     __________________________________________________________________

Client Applications

     * Fix pg_ctl restart to preserve command-line arguments (Bruce)
     * Add -w/--no-password option that prevents password prompting in all
       utilities that have a -W/--password option (Peter)
     * Remove "-q" (quiet) option of createdb, createuser, dropdb,
       dropuser (Peter)
       These options have had no effect since PostgreSQL 8.3.
     __________________________________________________________________

psql

     * Remove verbose startup banner; now just suggest help (Joshua Drake)
     * Make help show common backslash commands (Greg Sabino Mullane)
     * Add \pset format wrapped mode to wrap output to the screen width,
       or file/pipe output too if \pset columns is set (Bryce Nesbitt)
     * Allow all supported spellings of boolean values in "\pset", rather
       than just on and off (Bruce)
       Formerly, any string other than "off" was silently taken to mean
       true. psql will now complain about unrecognized spellings (but
       still take them as true).
     * Use the pager for wide output (Bruce)
     * Require a space between a one-letter backslash command and its
       first argument (Bernd Helmle)
       This removes a historical source of ambiguity.
     * Improve tab completion support for schema-qualified and quoted
       identifiers (Greg Sabino Mullane)
     * Add optional on/off argument for "\timing" (David Fetter)
     * Display access control rights on multiple lines (Brendan Jurd,
       Andreas Scherbaum)
     * Make "\l" show database access privileges (Andrew Gilligan)
     * Make "\l+" show database sizes, if permissions allow (Andrew
       Gilligan)
     * Add the "\ef" command to edit function definitions (Abhijit
       Menon-Sen)
     __________________________________________________________________

psql \d* commands

     * Make "\d*" commands that do not have a pattern argument show system
       objects only if the S modifier is specified (Greg Sabino Mullane,
       Bruce)
       The former behavior was inconsistent across different variants of
       "\d", and in most cases it provided no easy way to see just user
       objects.
     * Improve "\d*" commands to work with older PostgreSQL server
       versions (back to 7.4), not only the current server version
       (Guillaume Lelarge)
     * Make "\d" show foreign-key constraints that reference the selected
       table (Kenneth D'Souza)
     * Make "\d" on a sequence show its column values (Euler Taveira de
       Oliveira)
     * Add column storage type and other relation options to the "\d+"
       display (Gregory Stark, Euler Taveira de Oliveira)
     * Show relation size in "\dt+" output (Dickson S. Guedes)
     * Show the possible values of enum types in "\dT+" (David Fetter)
     * Allow "\dC" to accept a wildcard pattern, which matches either
       datatype involved in the cast (Tom)
     * Add a function type column to "\df"'s output, and add options to
       list only selected types of functions (David Fetter)
     * Make "\df" not hide functions that take or return type cstring
       (Tom)
       Previously, such functions were hidden because most of them are
       datatype I/O functions, which were deemed uninteresting. The new
       policy about hiding system functions by default makes this wart
       unnecessary.
     __________________________________________________________________

pg_dump

     * Add a --no-tablespaces option to pg_dump/pg_dumpall/pg_restore so
       that dumps can be restored to clusters that have non-matching
       tablespace layouts (Gavin Roy)
     * Remove "-d" and "-D" options from pg_dump and pg_dumpall (Tom)
       These options were too frequently confused with the option to
       select a database name in other PostgreSQL client applications. The
       functionality is still available, but you must now spell out the
       long option name "--inserts" or "--column-inserts".
     * Remove "-i"/"--ignore-version" option from pg_dump and pg_dumpall
       (Tom)
       Use of this option does not throw an error, but it has no effect.
       This option was removed because the version checks are necessary
       for safety.
     * Disable statement_timeout during dump and restore (Joshua Drake)
     * Add pg_dump/pg_dumpall option "--lock-wait-timeout" (David Gould)
       This allows dumps to fail if unable to acquire a shared lock within
       the specified amount of time.
     * Reorder pg_dump --data-only output to dump tables referenced by
       foreign keys before the referencing tables (Tom)
       This allows data loads when foreign keys are already present. If
       circular references make a safe ordering impossible, a NOTICE is
       issued.
     * Allow pg_dump, pg_dumpall, and pg_restore to use a specified role
       (Benedek Laszlo)
     * Allow pg_restore to use multiple concurrent connections to do the
       restore (Andrew)
       The number of concurrent connections is controlled by the option
       --jobs. This is supported only for custom-format archives.
     __________________________________________________________________

Programming Tools

libpq

     * Allow the OID to be specified when importing a large object, via
       new function lo_import_with_oid() (Tatsuo)
     * Add "events" support (Andrew Chernow, Merlin Moncure)
       This adds the ability to register callbacks to manage private data
       associated with PGconn and PGresult objects.
     * Improve error handling to allow the return of multiple error
       messages as multi-line error reports (Magnus)
     * Make PQexecParams() and related functions return PGRES_EMPTY_QUERY
       for an empty query (Tom)
       They previously returned PGRES_COMMAND_OK.
     * Document how to avoid the overhead of WSACleanup() on Windows
       (Andrew Chernow)
     * Do not rely on Kerberos tickets to determine the default database
       username (Magnus)
       Previously, a Kerberos-capable build of libpq would use the
       principal name from any available Kerberos ticket as default
       database username, even if the connection wasn't using Kerberos
       authentication. This was deemed inconsistent and confusing. The
       default username is now determined the same way with or without
       Kerberos. Note however that the database username must still match
       the ticket when Kerberos authentication is used.
     __________________________________________________________________

libpq SSL (Secure Sockets Layer) support

     * Fix certificate validation for SSL connections (Magnus)
       libpq now supports verifying both the certificate and the name of
       the server when making SSL connections. If a root certificate is
       not available to use for verification, SSL connections will fail.
       The sslmode parameter is used to enable certificate verification
       and set the level of checking. The default is still not to do any
       verification, allowing connections to SSL-enabled servers without
       requiring a root certificate on the client.
     * Support wildcard server certificates (Magnus)
       If a certificate CN starts with *, it will be treated as a wildcard
       when matching the hostname, allowing the use of the same
       certificate for multiple servers.
     * Allow the file locations for client certificates to be specified
       (Mark Woodward, Alvaro, Magnus)
     * Add a PQinitOpenSSL function to allow greater control over
       OpenSSL/libcrypto initialization (Andrew Chernow)
     * Make libpq unregister its OpenSSL callbacks when no database
       connections remain open (Bruce, Magnus, Russell Smith)
       This is required for applications that unload the libpq library,
       otherwise invalid OpenSSL callbacks will remain.
     __________________________________________________________________

ecpg

     * Add localization support for messages (Euler Taveira de Oliveira)
     * ecpg parser is now automatically generated from the server parser
       (Michael)
       Previously the ecpg parser was hand-maintained.
     __________________________________________________________________

Server Programming Interface (SPI)

     * Add support for single-use plans with out-of-line parameters (Tom)
     * Add new SPI_OK_REWRITTEN return code for SPI_execute() (Heikki)
       This is used when a command is rewritten to another type of
       command.
     * Remove unnecessary inclusions from "executor/spi.h" (Tom)
       SPI-using modules might need to add some #include lines if they
       were depending on "spi.h" to include things for them.
     __________________________________________________________________

Build Options

     * Update build system to use Autoconf 2.61 (Peter)
     * Require GNU bison for source code builds (Peter)
       This has effectively been required for several years, but now there
       is no infrastructure claiming to support other parser tools.
     * Add pg_config --htmldir option (Peter)
     * Pass float4 by value inside the server (Zoltan Boszormenyi)
       Add configure option --disable-float4-byval to use the old
       behavior. External C functions that use old-style (version 0) call
       convention and pass or return float4 values will be broken by this
       change, so you may need the configure option if you have such
       functions and don't want to update them.
     * Pass float8, int8, and related datatypes by value inside the server
       on 64-bit platforms (Zoltan Boszormenyi)
       Add configure option --disable-float8-byval to use the old
       behavior. As above, this change might break old-style external C
       functions.
     * Add configure options --with-segsize, --with-blocksize,
       --with-wal-blocksize, --with-wal-segsize (Zdenek Kotala, Tom)
       This simplifies build-time control over several constants that
       previously could only be changed by editing "pg_config_manual.h".
     * Allow threaded builds on Solaris 2.5 (Bruce)
     * Use the system's getopt_long() on Solaris (Zdenek Kotala, Tom)
       This makes option processing more consistent with what Solaris
       users expect.
     * Add support for the Sun Studio compiler on Linux (Julius Stroffek)
     * Append the major version number to the backend gettext domain, and
       the soname major version number to libraries' gettext domain
       (Peter)
       This simplifies parallel installations of multiple versions.
     * Add support for code coverage testing with gcov (Michelle Caisse)
     * Allow out-of-tree builds on Mingw and Cygwin (Richard Evans)
     * Fix the use of Mingw as a cross-compiling source platform (Peter)
     __________________________________________________________________

Source Code

     * Support 64-bit time zone data files (Heikki)
       This adds support for daylight saving time (DST) calculations
       beyond the year 2038.
     * Deprecate use of platform's time_t data type (Tom)
       Some platforms have migrated to 64-bit time_t, some have not, and
       Windows can't make up its mind what it's doing. Define pg_time_t to
       have the same meaning as time_t, but always be 64 bits (unless the
       platform has no 64-bit integer type), and use that type in all
       module APIs and on-disk data formats.
     * Fix bug in handling of the time zone database when cross-compiling
       (Richard Evans)
     * Link backend object files in one step, rather than in stages
       (Peter)
     * Improve gettext support to allow better translation of plurals
       (Peter)
     * Add message translation support to the PL languages (Alvaro, Peter)
     * Add more DTrace probes (Robert Lor)
     * Enable DTrace support on Mac OS X Leopard and other non-Solaris
       platforms (Robert Lor)
     * Simplify and standardize conversions between C strings and text
       datums, by providing common functions for the purpose (Brendan
       Jurd, Tom)
     * Clean up the "include/catalog/" header files so that frontend
       programs can include them without including "postgres.h" (Zdenek
       Kotala)
     * Make name char-aligned, and suppress zero-padding of name entries
       in indexes (Tom)
     * Recover better if dynamically-loaded code executes exit() (Tom)
     * Add a hook to let plug-ins monitor the executor (Itagaki Takahiro)
     * Add a hook to allow the planner's statistics lookup behavior to be
       overridden (Simon Riggs)
     * Add shmem_startup_hook() for custom shared memory requirements
       (Tom)
     * Replace the index access method amgetmulti entry point with
       amgetbitmap, and extend the API for amgettuple to support run-time
       determination of operator lossiness (Heikki, Tom, Teodor)
       The API for GIN and GiST opclass consistent functions has been
       extended as well.
     * Add support for partial-match searches in GIN indexes (Teodor
       Sigaev, Oleg Bartunov)
     * Replace pg_class column reltriggers with boolean relhastriggers
       (Simon)
       Also remove unused pg_class columns relukeys, relfkeys, and
       relrefs.
     * Add a relistemp column to pg_class to ease identification of
       temporary tables (Tom)
     * Move platform FAQs into the main documentation (Peter)
     * Prevent parser input files from being built with any conflicts
       (Peter)
     * Add support for the KOI8U (Ukrainian) encoding (Peter)
     * Add Japanese message translations (Japan PostgreSQL Users Group)
       This used to be maintained as a separate project.
     * Fix problem when setting LC_MESSAGES on MSVC-built systems (Hiroshi
       Inoue, Hiroshi Saito, Magnus)
     __________________________________________________________________

Contrib

     * Add "contrib/auto_explain" to automatically run "EXPLAIN" on
       queries exceeding a specified duration (Itagaki Takahiro, Tom)
     * Add "contrib/btree_gin" to allow GIN indexes to handle more
       datatypes (Oleg, Teodor)
     * Add "contrib/citext" to provide a case-insensitive, multibyte-aware
       text data type (David Wheeler)
     * Add "contrib/pg_stat_statements" for server-wide tracking of
       statement execution statistics (Itagaki Takahiro)
     * Add duration and query mode options to "contrib/pgbench" (Itagaki
       Takahiro)
     * Make "contrib/pgbench" use table names pgbench_accounts,
       pgbench_branches, pgbench_history, and pgbench_tellers, rather than
       just accounts, branches, history, and tellers (Tom)
       This is to reduce the risk of accidentally destroying real data by
       running pgbench.
     * Fix "contrib/pgstattuple" to handle tables and indexes with over 2
       billion pages (Tatsuhito Kasahara)
     * In "contrib/fuzzystrmatch", add a version of the Levenshtein
       string-distance function that allows the user to specify the costs
       of insertion, deletion, and substitution (Volkan Yazici)
     * Make "contrib/ltree" support multibyte encodings (laser)
     * Enable "contrib/dblink" to use connection information stored in the
       SQL/MED catalogs (Joe Conway)
     * Improve "contrib/dblink"'s reporting of errors from the remote
       server (Joe Conway)
     * Make "contrib/dblink" set client_encoding to match the local
       database's encoding (Joe Conway)
       This prevents encoding problems when communicating with a remote
       database that uses a different encoding.
     * Make sure "contrib/dblink" uses a password supplied by the user,
       and not accidentally taken from the server's ".pgpass" file (Joe
       Conway)
       This is a minor security enhancement.
     * Add fsm_page_contents() to "contrib/pageinspect" (Heikki)
     * Modify get_raw_page() to support free space map ("*_fsm") files.
       Also update "contrib/pg_freespacemap".
     * Add support for multibyte encodings to "contrib/pg_trgm" (Teodor)
     * Rewrite "contrib/intagg" to use new functions array_agg() and
       unnest() (Tom)
     * Make "contrib/pg_standby" recover all available WAL before failover
       (Fujii Masao, Simon, Heikki)
       To make this work safely, you now need to set the new
       recovery_end_command option in "recovery.conf" to clean up the
       trigger file after failover. pg_standby will no longer remove the
       trigger file itself.
     * "contrib/pg_standby"'s "-l" option is now a no-op, because it is
       unsafe to use a symlink (Simon)
     __________________________________________________________________

                               Release 8.3.23

     Release Date: 2013-02-07

   This release contains a variety of fixes from 8.3.22. For information
   about new features in the 8.3 major release, see the Section called
   Release 8.3.

   This is expected to be the last PostgreSQL release in the 8.3.X series.
   Users are encouraged to update to a newer release branch soon.
     __________________________________________________________________

Migration to Version 8.3.23

   A dump/restore is not required for those running 8.3.X.

   However, if you are upgrading from a version earlier than 8.3.17, see
   the release notes for 8.3.17.
     __________________________________________________________________

Changes

     * Prevent execution of enum_recv from SQL (Tom Lane)
       The function was misdeclared, allowing a simple SQL command to
       crash the server. In principle an attacker might be able to use it
       to examine the contents of server memory. Our thanks to Sumit Soni
       (via Secunia SVCRP) for reporting this issue. (CVE-2013-0255)
     * Fix SQL grammar to allow subscripting or field selection from a
       sub-SELECT result (Tom Lane)
     * Protect against race conditions when scanning pg_tablespace
       (Stephen Frost, Tom Lane)
       "CREATE DATABASE" and "DROP DATABASE" could misbehave if there were
       concurrent updates of pg_tablespace entries.
     * Prevent "DROP OWNED" from trying to drop whole databases or
       tablespaces (Alvaro Herrera)
       For safety, ownership of these objects must be reassigned, not
       dropped.
     * Prevent misbehavior when a RowExpr or XmlExpr is parse-analyzed
       twice (Andres Freund, Tom Lane)
       This mistake could be user-visible in contexts such as CREATE TABLE
       LIKE INCLUDING INDEXES.
     * Improve defenses against integer overflow in hashtable sizing
       calculations (Jeff Davis)
     * Ensure that non-ASCII prompt strings are translated to the correct
       code page on Windows (Alexander Law, Noah Misch)
       This bug affected psql and some other client programs.
     * Fix possible crash in psql's "\?" command when not connected to a
       database (Meng Qingzhong)
     * Fix one-byte buffer overrun in libpq's PQprintTuples (Xi Wang)
       This ancient function is not used anywhere by PostgreSQL itself,
       but it might still be used by some client code.
     * Rearrange configure's tests for supplied functions so it is not
       fooled by bogus exports from libedit/libreadline (Christoph Berg)
     * Ensure Windows build number increases over time (Magnus Hagander)
     * Make pgxs build executables with the right .exe suffix when
       cross-compiling for Windows (Zoltan Boszormenyi)
     * Add new timezone abbreviation FET (Tom Lane)
       This is now used in some eastern-European time zones.
     __________________________________________________________________

                               Release 8.3.22

     Release Date: 2012-12-06

   This release contains a variety of fixes from 8.3.21. For information
   about new features in the 8.3 major release, see the Section called
   Release 8.3.

   The PostgreSQL community will stop releasing updates for the 8.3.X
   release series in February 2013. Users are encouraged to update to a
   newer release branch soon.
     __________________________________________________________________

Migration to Version 8.3.22

   A dump/restore is not required for those running 8.3.X.

   However, if you are upgrading from a version earlier than 8.3.17, see
   the release notes for 8.3.17.
     __________________________________________________________________

Changes

     * Fix multiple bugs associated with "CREATE INDEX CONCURRENTLY"
       (Andres Freund, Tom Lane)
       Fix "CREATE INDEX CONCURRENTLY" to use in-place updates when
       changing the state of an index's pg_index row. This prevents race
       conditions that could cause concurrent sessions to miss updating
       the target index, thus resulting in corrupt concurrently-created
       indexes.
       Also, fix various other operations to ensure that they ignore
       invalid indexes resulting from a failed "CREATE INDEX CONCURRENTLY"
       command. The most important of these is "VACUUM", because an
       auto-vacuum could easily be launched on the table before corrective
       action can be taken to fix or remove the invalid index.
     * Avoid corruption of internal hash tables when out of memory
       (Hitoshi Harada)
     * Fix planning of non-strict equivalence clauses above outer joins
       (Tom Lane)
       The planner could derive incorrect constraints from a clause
       equating a non-strict construct to something else, for example
       WHERE COALESCE(foo, 0) = 0 when foo is coming from the nullable
       side of an outer join.
     * Improve planner's ability to prove exclusion constraints from
       equivalence classes (Tom Lane)
     * Fix partial-row matching in hashed subplans to handle cross-type
       cases correctly (Tom Lane)
       This affects multicolumn NOT IN subplans, such as WHERE (a, b) NOT
       IN (SELECT x, y FROM ...) when for instance b and y are int4 and
       int8 respectively. This mistake led to wrong answers or crashes
       depending on the specific datatypes involved.
     * Acquire buffer lock when re-fetching the old tuple for an AFTER ROW
       UPDATE/DELETE trigger (Andres Freund)
       In very unusual circumstances, this oversight could result in
       passing incorrect data to the precheck logic for a foreign-key
       enforcement trigger. That could result in a crash, or in an
       incorrect decision about whether to fire the trigger.
     * Fix "REASSIGN OWNED" to handle grants on tablespaces (Alvaro
       Herrera)
     * Ignore incorrect pg_attribute entries for system columns for views
       (Tom Lane)
       Views do not have any system columns. However, we forgot to remove
       such entries when converting a table to a view. That's fixed
       properly for 9.3 and later, but in previous branches we need to
       defend against existing mis-converted views.
     * Fix rule printing to dump INSERT INTO table DEFAULT VALUES
       correctly (Tom Lane)
     * Guard against stack overflow when there are too many
       UNION/INTERSECT/EXCEPT clauses in a query (Tom Lane)
     * Prevent platform-dependent failures when dividing the minimum
       possible integer value by -1 (Xi Wang, Tom Lane)
     * Fix possible access past end of string in date parsing (Hitoshi
       Harada)
     * Produce an understandable error message if the length of the path
       name for a Unix-domain socket exceeds the platform-specific limit
       (Tom Lane, Andrew Dunstan)
       Formerly, this would result in something quite unhelpful, such as
       "Non-recoverable failure in name resolution".
     * Fix memory leaks when sending composite column values to the client
       (Tom Lane)
     * Make pg_ctl more robust about reading the "postmaster.pid" file
       (Heikki Linnakangas)
       Fix race conditions and possible file descriptor leakage.
     * Fix possible crash in psql if incorrectly-encoded data is presented
       and the client_encoding setting is a client-only encoding, such as
       SJIS (Jiang Guiqing)
     * Fix bugs in the "restore.sql" script emitted by pg_dump in tar
       output format (Tom Lane)
       The script would fail outright on tables whose names include
       upper-case characters. Also, make the script capable of restoring
       data in "--inserts" mode as well as the regular COPY mode.
     * Fix pg_restore to accept POSIX-conformant tar files (Brian Weaver,
       Tom Lane)
       The original coding of pg_dump's tar output mode produced files
       that are not fully conformant with the POSIX standard. This has
       been corrected for version 9.3. This patch updates previous
       branches so that they will accept both the incorrect and the
       corrected formats, in hopes of avoiding compatibility problems when
       9.3 comes out.
     * Fix pg_resetxlog to locate "postmaster.pid" correctly when given a
       relative path to the data directory (Tom Lane)
       This mistake could lead to pg_resetxlog not noticing that there is
       an active postmaster using the data directory.
     * Fix libpq's lo_import() and lo_export() functions to report file
       I/O errors properly (Tom Lane)
     * Fix ecpg's processing of nested structure pointer variables
       (Muhammad Usama)
     * Make "contrib/pageinspect"'s btree page inspection functions take
       buffer locks while examining pages (Tom Lane)
     * Fix pgxs support for building loadable modules on AIX (Tom Lane)
       Building modules outside the original source tree didn't work on
       AIX.
     * Update time zone data files to tzdata release 2012j for DST law
       changes in Cuba, Israel, Jordan, Libya, Palestine, Western Samoa,
       and portions of Brazil.
     __________________________________________________________________

                               Release 8.3.21

     Release Date: 2012-09-24

   This release contains a variety of fixes from 8.3.20. For information
   about new features in the 8.3 major release, see the Section called
   Release 8.3.

   The PostgreSQL community will stop releasing updates for the 8.3.X
   release series in February 2013. Users are encouraged to update to a
   newer release branch soon.
     __________________________________________________________________

Migration to Version 8.3.21

   A dump/restore is not required for those running 8.3.X.

   However, if you are upgrading from a version earlier than 8.3.17, see
   the release notes for 8.3.17.
     __________________________________________________________________

Changes

     * Improve page-splitting decisions in GiST indexes (Alexander
       Korotkov, Robert Haas, Tom Lane)
       Multi-column GiST indexes might suffer unexpected bloat due to this
       error.
     * Fix cascading privilege revoke to stop if privileges are still held
       (Tom Lane)
       If we revoke a grant option from some role "X", but "X" still holds
       that option via a grant from someone else, we should not
       recursively revoke the corresponding privilege from role(s) "Y"
       that "X" had granted it to.
     * Fix handling of SIGFPE when PL/Perl is in use (Andres Freund)
       Perl resets the process's SIGFPE handler to SIG_IGN, which could
       result in crashes later on. Restore the normal Postgres signal
       handler after initializing PL/Perl.
     * Prevent PL/Perl from crashing if a recursive PL/Perl function is
       redefined while being executed (Tom Lane)
     * Work around possible misoptimization in PL/Perl (Tom Lane)
       Some Linux distributions contain an incorrect version of
       "pthread.h" that results in incorrect compiled code in PL/Perl,
       leading to crashes if a PL/Perl function calls another one that
       throws an error.
     * Update time zone data files to tzdata release 2012f for DST law
       changes in Fiji
     __________________________________________________________________

                               Release 8.3.20

     Release Date: 2012-08-17

   This release contains a variety of fixes from 8.3.19. For information
   about new features in the 8.3 major release, see the Section called
   Release 8.3.

   The PostgreSQL community will stop releasing updates for the 8.3.X
   release series in February 2013. Users are encouraged to update to a
   newer release branch soon.
     __________________________________________________________________

Migration to Version 8.3.20

   A dump/restore is not required for those running 8.3.X.

   However, if you are upgrading from a version earlier than 8.3.17, see
   the release notes for 8.3.17.
     __________________________________________________________________

Changes

     * Prevent access to external files/URLs via XML entity references
       (Noah Misch, Tom Lane)
       xml_parse() would attempt to fetch external files or URLs as needed
       to resolve DTD and entity references in an XML value, thus allowing
       unprivileged database users to attempt to fetch data with the
       privileges of the database server. While the external data wouldn't
       get returned directly to the user, portions of it could be exposed
       in error messages if the data didn't parse as valid XML; and in any
       case the mere ability to check existence of a file might be useful
       to an attacker. (CVE-2012-3489)
     * Prevent access to external files/URLs via "contrib/xml2"'s
       xslt_process() (Peter Eisentraut)
       libxslt offers the ability to read and write both files and URLs
       through stylesheet commands, thus allowing unprivileged database
       users to both read and write data with the privileges of the
       database server. Disable that through proper use of libxslt's
       security options. (CVE-2012-3488)
       Also, remove xslt_process()'s ability to fetch documents and
       stylesheets from external files/URLs. While this was a documented
       "feature", it was long regarded as a bad idea. The fix for
       CVE-2012-3489 broke that capability, and rather than expend effort
       on trying to fix it, we're just going to summarily remove it.
     * Prevent too-early recycling of btree index pages (Noah Misch)
       When we allowed read-only transactions to skip assigning XIDs, we
       introduced the possibility that a deleted btree page could be
       recycled while a read-only transaction was still in flight to it.
       This would result in incorrect index search results. The
       probability of such an error occurring in the field seems very low
       because of the timing requirements, but nonetheless it should be
       fixed.
     * Fix crash-safety bug with newly-created-or-reset sequences (Tom
       Lane)
       If "ALTER SEQUENCE" was executed on a freshly created or reset
       sequence, and then precisely one nextval() call was made on it, and
       then the server crashed, WAL replay would restore the sequence to a
       state in which it appeared that no nextval() had been done, thus
       allowing the first sequence value to be returned again by the next
       nextval() call. In particular this could manifest for serial
       columns, since creation of a serial column's sequence includes an
       "ALTER SEQUENCE OWNED BY" step.
     * Ensure the "backup_label" file is fsync'd after pg_start_backup()
       (Dave Kerr)
     * Back-patch 9.1 improvement to compress the fsync request queue
       (Robert Haas)
       This improves performance during checkpoints. The 9.1 change has
       now seen enough field testing to seem safe to back-patch.
     * Only allow autovacuum to be auto-canceled by a directly blocked
       process (Tom Lane)
       The original coding could allow inconsistent behavior in some
       cases; in particular, an autovacuum could get canceled after less
       than deadlock_timeout grace period.
     * Improve logging of autovacuum cancels (Robert Haas)
     * Fix log collector so that log_truncate_on_rotation works during the
       very first log rotation after server start (Tom Lane)
     * Ensure that a whole-row reference to a subquery doesn't include any
       extra GROUP BY or ORDER BY columns (Tom Lane)
     * Disallow copying whole-row references in CHECK constraints and
       index definitions during "CREATE TABLE" (Tom Lane)
       This situation can arise in "CREATE TABLE" with LIKE or INHERITS.
       The copied whole-row variable was incorrectly labeled with the row
       type of the original table not the new one. Rejecting the case
       seems reasonable for LIKE, since the row types might well diverge
       later. For INHERITS we should ideally allow it, with an implicit
       coercion to the parent table's row type; but that will require more
       work than seems safe to back-patch.
     * Fix memory leak in ARRAY(SELECT ...) subqueries (Heikki
       Linnakangas, Tom Lane)
     * Fix extraction of common prefixes from regular expressions (Tom
       Lane)
       The code could get confused by quantified parenthesized
       subexpressions, such as ^(foo)?bar. This would lead to incorrect
       index optimization of searches for such patterns.
     * Report errors properly in "contrib/xml2"'s xslt_process() (Tom
       Lane)
     * Update time zone data files to tzdata release 2012e for DST law
       changes in Morocco and Tokelau
     __________________________________________________________________

                               Release 8.3.19

     Release Date: 2012-06-04

   This release contains a variety of fixes from 8.3.18. For information
   about new features in the 8.3 major release, see the Section called
   Release 8.3.
     __________________________________________________________________

Migration to Version 8.3.19

   A dump/restore is not required for those running 8.3.X.

   However, if you are upgrading from a version earlier than 8.3.17, see
   the release notes for 8.3.17.
     __________________________________________________________________

Changes

     * Fix incorrect password transformation in "contrib/pgcrypto"'s DES
       crypt() function (Solar Designer)
       If a password string contained the byte value 0x80, the remainder
       of the password was ignored, causing the password to be much weaker
       than it appeared. With this fix, the rest of the string is properly
       included in the DES hash. Any stored password values that are
       affected by this bug will thus no longer match, so the stored
       values may need to be updated. (CVE-2012-2143)
     * Ignore SECURITY DEFINER and SET attributes for a procedural
       language's call handler (Tom Lane)
       Applying such attributes to a call handler could crash the server.
       (CVE-2012-2655)
     * Allow numeric timezone offsets in timestamp input to be up to 16
       hours away from UTC (Tom Lane)
       Some historical time zones have offsets larger than 15 hours, the
       previous limit. This could result in dumped data values being
       rejected during reload.
     * Fix timestamp conversion to cope when the given time is exactly the
       last DST transition time for the current timezone (Tom Lane)
       This oversight has been there a long time, but was not noticed
       previously because most DST-using zones are presumed to have an
       indefinite sequence of future DST transitions.
     * Fix text to name and char to name casts to perform string
       truncation correctly in multibyte encodings (Karl Schnaitter)
     * Fix memory copying bug in to_tsquery() (Heikki Linnakangas)
     * Fix slow session startup when pg_attribute is very large (Tom Lane)
       If pg_attribute exceeds one-fourth of shared_buffers, cache
       rebuilding code that is sometimes needed during session start would
       trigger the synchronized-scan logic, causing it to take many times
       longer than normal. The problem was particularly acute if many new
       sessions were starting at once.
     * Ensure sequential scans check for query cancel reasonably often
       (Merlin Moncure)
       A scan encountering many consecutive pages that contain no live
       tuples would not respond to interrupts meanwhile.
     * Ensure the Windows implementation of PGSemaphoreLock() clears
       ImmediateInterruptOK before returning (Tom Lane)
       This oversight meant that a query-cancel interrupt received later
       in the same query could be accepted at an unsafe time, with
       unpredictable but not good consequences.
     * Show whole-row variables safely when printing views or rules (Abbas
       Butt, Tom Lane)
       Corner cases involving ambiguous names (that is, the name could be
       either a table or column name of the query) were printed in an
       ambiguous way, risking that the view or rule would be interpreted
       differently after dump and reload. Avoid the ambiguous case by
       attaching a no-op cast.
     * Ensure autovacuum worker processes perform stack depth checking
       properly (Heikki Linnakangas)
       Previously, infinite recursion in a function invoked by
       auto-"ANALYZE" could crash worker processes.
     * Fix logging collector to not lose log coherency under high load
       (Andrew Dunstan)
       The collector previously could fail to reassemble large messages if
       it got too busy.
     * Fix logging collector to ensure it will restart file rotation after
       receiving SIGHUP (Tom Lane)
     * Fix PL/pgSQL's "GET DIAGNOSTICS" command when the target is the
       function's first variable (Tom Lane)
     * Fix several performance problems in pg_dump when the database
       contains many objects (Jeff Janes, Tom Lane)
       pg_dump could get very slow if the database contained many schemas,
       or if many objects are in dependency loops, or if there are many
       owned sequences.
     * Fix "contrib/dblink"'s dblink_exec() to not leak temporary database
       connections upon error (Tom Lane)
     * Update time zone data files to tzdata release 2012c for DST law
       changes in Antarctica, Armenia, Chile, Cuba, Falkland Islands,
       Gaza, Haiti, Hebron, Morocco, Syria, and Tokelau Islands; also
       historical corrections for Canada.
     __________________________________________________________________

                               Release 8.3.18

     Release Date: 2012-02-27

   This release contains a variety of fixes from 8.3.17. For information
   about new features in the 8.3 major release, see the Section called
   Release 8.3.
     __________________________________________________________________

Migration to Version 8.3.18

   A dump/restore is not required for those running 8.3.X.

   However, if you are upgrading from a version earlier than 8.3.17, see
   the release notes for 8.3.17.
     __________________________________________________________________

Changes

     * Require execute permission on the trigger function for "CREATE
       TRIGGER" (Robert Haas)
       This missing check could allow another user to execute a trigger
       function with forged input data, by installing it on a table he
       owns. This is only of significance for trigger functions marked
       SECURITY DEFINER, since otherwise trigger functions run as the
       table owner anyway. (CVE-2012-0866)
     * Convert newlines to spaces in names written in pg_dump comments
       (Robert Haas)
       pg_dump was incautious about sanitizing object names that are
       emitted within SQL comments in its output script. A name containing
       a newline would at least render the script syntactically incorrect.
       Maliciously crafted object names could present a SQL injection risk
       when the script is reloaded. (CVE-2012-0868)
     * Fix btree index corruption from insertions concurrent with
       vacuuming (Tom Lane)
       An index page split caused by an insertion could sometimes cause a
       concurrently-running "VACUUM" to miss removing index entries that
       it should remove. After the corresponding table rows are removed,
       the dangling index entries would cause errors (such as "could not
       read block N in file ...") or worse, silently wrong query results
       after unrelated rows are re-inserted at the now-free table
       locations. This bug has been present since release 8.2, but occurs
       so infrequently that it was not diagnosed until now. If you have
       reason to suspect that it has happened in your database, reindexing
       the affected index will fix things.
     * Allow non-existent values for some settings in "ALTER USER/DATABASE
       SET" (Heikki Linnakangas)
       Allow default_text_search_config, default_tablespace, and
       temp_tablespaces to be set to names that are not known. This is
       because they might be known in another database where the setting
       is intended to be used, or for the tablespace cases because the
       tablespace might not be created yet. The same issue was previously
       recognized for search_path, and these settings now act like that
       one.
     * Track the OID counter correctly during WAL replay, even when it
       wraps around (Tom Lane)
       Previously the OID counter would remain stuck at a high value until
       the system exited replay mode. The practical consequences of that
       are usually nil, but there are scenarios wherein a standby server
       that's been promoted to master might take a long time to advance
       the OID counter to a reasonable value once values are needed.
     * Fix regular expression back-references with * attached (Tom Lane)
       Rather than enforcing an exact string match, the code would
       effectively accept any string that satisfies the pattern
       sub-expression referenced by the back-reference symbol.
       A similar problem still afflicts back-references that are embedded
       in a larger quantified expression, rather than being the immediate
       subject of the quantifier. This will be addressed in a future
       PostgreSQL release.
     * Fix recently-introduced memory leak in processing of inet/cidr
       values (Heikki Linnakangas)
       A patch in the December 2011 releases of PostgreSQL caused memory
       leakage in these operations, which could be significant in
       scenarios such as building a btree index on such a column.
     * Avoid double close of file handle in syslogger on Windows (MauMau)
       Ordinarily this error was invisible, but it would cause an
       exception when running on a debug version of Windows.
     * Fix I/O-conversion-related memory leaks in plpgsql (Andres Freund,
       Jan Urbanski, Tom Lane)
       Certain operations would leak memory until the end of the current
       function.
     * Improve pg_dump's handling of inherited table columns (Tom Lane)
       pg_dump mishandled situations where a child column has a different
       default expression than its parent column. If the default is
       textually identical to the parent's default, but not actually the
       same (for instance, because of schema search path differences) it
       would not be recognized as different, so that after dump and
       restore the child would be allowed to inherit the parent's default.
       Child columns that are NOT NULL where their parent is not could
       also be restored subtly incorrectly.
     * Fix pg_restore's direct-to-database mode for INSERT-style table
       data (Tom Lane)
       Direct-to-database restores from archive files made with
       "--inserts" or "--column-inserts" options fail when using
       pg_restore from a release dated September or December 2011, as a
       result of an oversight in a fix for another problem. The archive
       file itself is not at fault, and text-mode output is okay.
     * Fix error in "contrib/intarray"'s int[] & int[] operator (Guillaume
       Lelarge)
       If the smallest integer the two input arrays have in common is 1,
       and there are smaller values in either array, then 1 would be
       incorrectly omitted from the result.
     * Fix error detection in "contrib/pgcrypto"'s encrypt_iv() and
       decrypt_iv() (Marko Kreen)
       These functions failed to report certain types of invalid-input
       errors, and would instead return random garbage values for
       incorrect input.
     * Fix one-byte buffer overrun in "contrib/test_parser" (Paul Guyot)
       The code would try to read one more byte than it should, which
       would crash in corner cases. Since "contrib/test_parser" is only
       example code, this is not a security issue in itself, but bad
       example code is still bad.
     * Use __sync_lock_test_and_set() for spinlocks on ARM, if available
       (Martin Pitt)
       This function replaces our previous use of the SWPB instruction,
       which is deprecated and not available on ARMv6 and later. Reports
       suggest that the old code doesn't fail in an obvious way on recent
       ARM boards, but simply doesn't interlock concurrent accesses,
       leading to bizarre failures in multiprocess operation.
     * Use "-fexcess-precision=standard" option when building with gcc
       versions that accept it (Andrew Dunstan)
       This prevents assorted scenarios wherein recent versions of gcc
       will produce creative results.
     * Allow use of threaded Python on FreeBSD (Chris Rees)
       Our configure script previously believed that this combination
       wouldn't work; but FreeBSD fixed the problem, so remove that error
       check.
     __________________________________________________________________

                               Release 8.3.17

     Release Date: 2011-12-05

   This release contains a variety of fixes from 8.3.16. For information
   about new features in the 8.3 major release, see the Section called
   Release 8.3.
     __________________________________________________________________

Migration to Version 8.3.17

   A dump/restore is not required for those running 8.3.X.

   However, a longstanding error was discovered in the definition of the
   information_schema.referential_constraints view. If you rely on correct
   results from that view, you should replace its definition as explained
   in the first changelog item below.

   Also, if you are upgrading from a version earlier than 8.3.8, see the
   release notes for 8.3.8.
     __________________________________________________________________

Changes

     * Fix bugs in information_schema.referential_constraints view (Tom
       Lane)
       This view was being insufficiently careful about matching the
       foreign-key constraint to the depended-on primary or unique key
       constraint. That could result in failure to show a foreign key
       constraint at all, or showing it multiple times, or claiming that
       it depends on a different constraint than the one it really does.
       Since the view definition is installed by initdb, merely upgrading
       will not fix the problem. If you need to fix this in an existing
       installation, you can (as a superuser) drop the information_schema
       schema then re-create it by sourcing
       "SHAREDIR/information_schema.sql". (Run pg_config --sharedir if
       you're uncertain where "SHAREDIR" is.) This must be repeated in
       each database to be fixed.
     * Fix TOAST-related data corruption during CREATE TABLE dest AS
       SELECT * FROM src or INSERT INTO dest SELECT * FROM src (Tom Lane)
       If a table has been modified by "ALTER TABLE ADD COLUMN", attempts
       to copy its data verbatim to another table could produce corrupt
       results in certain corner cases. The problem can only manifest in
       this precise form in 8.4 and later, but we patched earlier versions
       as well in case there are other code paths that could trigger the
       same bug.
     * Fix race condition during toast table access from stale syscache
       entries (Tom Lane)
       The typical symptom was transient errors like "missing chunk number
       0 for toast value NNNNN in pg_toast_2619", where the cited toast
       table would always belong to a system catalog.
     * Make DatumGetInetP() unpack inet datums that have a 1-byte header,
       and add a new macro, DatumGetInetPP(), that does not (Heikki
       Linnakangas)
       This change affects no core code, but might prevent crashes in
       add-on code that expects DatumGetInetP() to produce an unpacked
       datum as per usual convention.
     * Improve locale support in money type's input and output (Tom Lane)
       Aside from not supporting all standard lc_monetary formatting
       options, the input and output functions were inconsistent, meaning
       there were locales in which dumped money values could not be
       re-read.
     * Don't let transform_null_equals affect CASE foo WHEN NULL ...
       constructs (Heikki Linnakangas)
       transform_null_equals is only supposed to affect foo = NULL
       expressions written directly by the user, not equality checks
       generated internally by this form of CASE.
     * Change foreign-key trigger creation order to better support
       self-referential foreign keys (Tom Lane)
       For a cascading foreign key that references its own table, a row
       update will fire both the ON UPDATE trigger and the CHECK trigger
       as one event. The ON UPDATE trigger must execute first, else the
       CHECK will check a non-final state of the row and possibly throw an
       inappropriate error. However, the firing order of these triggers is
       determined by their names, which generally sort in creation order
       since the triggers have auto-generated names following the
       convention "RI_ConstraintTrigger_NNNN". A proper fix would require
       modifying that convention, which we will do in 9.2, but it seems
       risky to change it in existing releases. So this patch just changes
       the creation order of the triggers. Users encountering this type of
       error should drop and re-create the foreign key constraint to get
       its triggers into the right order.
     * Avoid floating-point underflow while tracking buffer allocation
       rate (Greg Matthews)
       While harmless in itself, on certain platforms this would result in
       annoying kernel log messages.
     * Preserve blank lines within commands in psql's command history
       (Robert Haas)
       The former behavior could cause problems if an empty line was
       removed from within a string literal, for example.
     * Fix pg_dump to dump user-defined casts between auto-generated
       types, such as table rowtypes (Tom Lane)
     * Use the preferred version of xsubpp to build PL/Perl, not
       necessarily the operating system's main copy (David Wheeler and
       Alex Hunsaker)
     * Fix incorrect coding in "contrib/dict_int" and "contrib/dict_xsyn"
       (Tom Lane)
       Some functions incorrectly assumed that memory returned by palloc()
       is guaranteed zeroed.
     * Honor query cancel interrupts promptly in pgstatindex() (Robert
       Haas)
     * Ensure VPATH builds properly install all server header files (Peter
       Eisentraut)
     * Shorten file names reported in verbose error messages (Peter
       Eisentraut)
       Regular builds have always reported just the name of the C file
       containing the error message call, but VPATH builds formerly
       reported an absolute path name.
     * Fix interpretation of Windows timezone names for Central America
       (Tom Lane)
       Map "Central America Standard Time" to CST6, not CST6CDT, because
       DST is generally not observed anywhere in Central America.
     * Update time zone data files to tzdata release 2011n for DST law
       changes in Brazil, Cuba, Fiji, Palestine, Russia, and Samoa; also
       historical corrections for Alaska and British East Africa.
     __________________________________________________________________

                               Release 8.3.16

     Release Date: 2011-09-26

   This release contains a variety of fixes from 8.3.15. For information
   about new features in the 8.3 major release, see the Section called
   Release 8.3.
     __________________________________________________________________

Migration to Version 8.3.16

   A dump/restore is not required for those running 8.3.X. However, if you
   are upgrading from a version earlier than 8.3.8, see the release notes
   for 8.3.8.
     __________________________________________________________________

Changes

     * Fix bugs in indexing of in-doubt HOT-updated tuples (Tom Lane)
       These bugs could result in index corruption after reindexing a
       system catalog. They are not believed to affect user indexes.
     * Fix multiple bugs in GiST index page split processing (Heikki
       Linnakangas)
       The probability of occurrence was low, but these could lead to
       index corruption.
     * Fix possible buffer overrun in tsvector_concat() (Tom Lane)
       The function could underestimate the amount of memory needed for
       its result, leading to server crashes.
     * Fix crash in xml_recv when processing a "standalone" parameter (Tom
       Lane)
     * Avoid possibly accessing off the end of memory in "ANALYZE" and in
       SJIS-2004 encoding conversion (Noah Misch)
       This fixes some very-low-probability server crash scenarios.
     * Fix race condition in relcache init file invalidation (Tom Lane)
       There was a window wherein a new backend process could read a stale
       init file but miss the inval messages that would tell it the data
       is stale. The result would be bizarre failures in catalog accesses,
       typically "could not read block 0 in file ..." later during
       startup.
     * Fix memory leak at end of a GiST index scan (Tom Lane)
       Commands that perform many separate GiST index scans, such as
       verification of a new GiST-based exclusion constraint on a table
       already containing many rows, could transiently require large
       amounts of memory due to this leak.
     * Fix performance problem when constructing a large, lossy bitmap
       (Tom Lane)
     * Fix array- and path-creating functions to ensure padding bytes are
       zeroes (Tom Lane)
       This avoids some situations where the planner will think that
       semantically-equal constants are not equal, resulting in poor
       optimization.
     * Work around gcc 4.6.0 bug that breaks WAL replay (Tom Lane)
       This could lead to loss of committed transactions after a server
       crash.
     * Fix dump bug for VALUES in a view (Tom Lane)
     * Disallow SELECT FOR UPDATE/SHARE on sequences (Tom Lane)
       This operation doesn't work as expected and can lead to failures.
     * Defend against integer overflow when computing size of a hash table
       (Tom Lane)
     * Fix cases where "CLUSTER" might attempt to access already-removed
       TOAST data (Tom Lane)
     * Fix portability bugs in use of credentials control messages for
       "peer" authentication (Tom Lane)
     * Fix SSPI login when multiple roundtrips are required (Ahmed
       Shinwari, Magnus Hagander)
       The typical symptom of this problem was "The function requested is
       not supported" errors during SSPI login.
     * Fix typo in pg_srand48 seed initialization (Andres Freund)
       This led to failure to use all bits of the provided seed. This
       function is not used on most platforms (only those without
       srandom), and the potential security exposure from a
       less-random-than-expected seed seems minimal in any case.
     * Avoid integer overflow when the sum of LIMIT and OFFSET values
       exceeds 2^63 (Heikki Linnakangas)
     * Add overflow checks to int4 and int8 versions of generate_series()
       (Robert Haas)
     * Fix trailing-zero removal in to_char() (Marti Raudsepp)
       In a format with FM and no digit positions after the decimal point,
       zeroes to the left of the decimal point could be removed
       incorrectly.
     * Fix pg_size_pretty() to avoid overflow for inputs close to 2^63
       (Tom Lane)
     * In pg_ctl, support silent mode for service registrations on Windows
       (MauMau)
     * Fix psql's counting of script file line numbers during COPY from a
       different file (Tom Lane)
     * Fix pg_restore's direct-to-database mode for
       standard_conforming_strings (Tom Lane)
       pg_restore could emit incorrect commands when restoring directly to
       a database server from an archive file that had been made with
       standard_conforming_strings set to on.
     * Fix write-past-buffer-end and memory leak in libpq's LDAP service
       lookup code (Albe Laurenz)
     * In libpq, avoid failures when using nonblocking I/O and an SSL
       connection (Martin Pihlak, Tom Lane)
     * Improve libpq's handling of failures during connection startup (Tom
       Lane)
       In particular, the response to a server report of fork() failure
       during SSL connection startup is now saner.
     * Improve libpq's error reporting for SSL failures (Tom Lane)
     * Make ecpglib write double values with 15 digits precision (Akira
       Kurosawa)
     * In ecpglib, be sure LC_NUMERIC setting is restored after an error
       (Michael Meskes)
     * Apply upstream fix for blowfish signed-character bug
       (CVE-2011-2483) (Tom Lane)
       "contrib/pg_crypto"'s blowfish encryption code could give wrong
       results on platforms where char is signed (which is most), leading
       to encrypted passwords being weaker than they should be.
     * Fix memory leak in "contrib/seg" (Heikki Linnakangas)
     * Fix pgstatindex() to give consistent results for empty indexes (Tom
       Lane)
     * Allow building with perl 5.14 (Alex Hunsaker)
     * Update configure script's method for probing existence of system
       functions (Tom Lane)
       The version of autoconf we used in 8.3 and 8.2 could be fooled by
       compilers that perform link-time optimization.
     * Fix assorted issues with build and install file paths containing
       spaces (Tom Lane)
     * Update time zone data files to tzdata release 2011i for DST law
       changes in Canada, Egypt, Russia, Samoa, and South Sudan.
     __________________________________________________________________

                               Release 8.3.15

     Release Date: 2011-04-18

   This release contains a variety of fixes from 8.3.14. For information
   about new features in the 8.3 major release, see the Section called
   Release 8.3.
     __________________________________________________________________

Migration to Version 8.3.15

   A dump/restore is not required for those running 8.3.X. However, if you
   are upgrading from a version earlier than 8.3.8, see the release notes
   for 8.3.8.
     __________________________________________________________________

Changes

     * Disallow including a composite type in itself (Tom Lane)
       This prevents scenarios wherein the server could recurse infinitely
       while processing the composite type. While there are some possible
       uses for such a structure, they don't seem compelling enough to
       justify the effort required to make sure it always works safely.
     * Avoid potential deadlock during catalog cache initialization
       (Nikhil Sontakke)
       In some cases the cache loading code would acquire share lock on a
       system index before locking the index's catalog. This could
       deadlock against processes trying to acquire exclusive locks in the
       other, more standard order.
     * Fix dangling-pointer problem in BEFORE ROW UPDATE trigger handling
       when there was a concurrent update to the target tuple (Tom Lane)
       This bug has been observed to result in intermittent "cannot
       extract system attribute from virtual tuple" failures while trying
       to do UPDATE RETURNING ctid. There is a very small probability of
       more serious errors, such as generating incorrect index entries for
       the updated tuple.
     * Disallow "DROP TABLE" when there are pending deferred trigger
       events for the table (Tom Lane)
       Formerly the "DROP" would go through, leading to "could not open
       relation with OID nnn" errors when the triggers were eventually
       fired.
     * Fix PL/Python memory leak involving array slices (Daniel Popowich)
     * Fix pg_restore to cope with long lines (over 1KB) in TOC files (Tom
       Lane)
     * Put in more safeguards against crashing due to division-by-zero
       with overly enthusiastic compiler optimization (Aurelien Jarno)
     * Support use of dlopen() in FreeBSD and OpenBSD on MIPS (Tom Lane)
       There was a hard-wired assumption that this system function was not
       available on MIPS hardware on these systems. Use a compile-time
       test instead, since more recent versions have it.
     * Fix compilation failures on HP-UX (Heikki Linnakangas)
     * Fix version-incompatibility problem with libintl on Windows
       (Hiroshi Inoue)
     * Fix usage of xcopy in Windows build scripts to work correctly under
       Windows 7 (Andrew Dunstan)
       This affects the build scripts only, not installation or usage.
     * Fix path separator used by pg_regress on Cygwin (Andrew Dunstan)
     * Update time zone data files to tzdata release 2011f for DST law
       changes in Chile, Cuba, Falkland Islands, Morocco, Samoa, and
       Turkey; also historical corrections for South Australia, Alaska,
       and Hawaii.
     __________________________________________________________________

                               Release 8.3.14

     Release Date: 2011-01-31

   This release contains a variety of fixes from 8.3.13. For information
   about new features in the 8.3 major release, see the Section called
   Release 8.3.
     __________________________________________________________________

Migration to Version 8.3.14

   A dump/restore is not required for those running 8.3.X. However, if you
   are upgrading from a version earlier than 8.3.8, see the release notes
   for 8.3.8.
     __________________________________________________________________

Changes

     * Avoid failures when "EXPLAIN" tries to display a simple-form CASE
       expression (Tom Lane)
       If the CASE's test expression was a constant, the planner could
       simplify the CASE into a form that confused the expression-display
       code, resulting in "unexpected CASE WHEN clause" errors.
     * Fix assignment to an array slice that is before the existing range
       of subscripts (Tom Lane)
       If there was a gap between the newly added subscripts and the first
       pre-existing subscript, the code miscalculated how many entries
       needed to be copied from the old array's null bitmap, potentially
       leading to data corruption or crash.
     * Avoid unexpected conversion overflow in planner for very distant
       date values (Tom Lane)
       The date type supports a wider range of dates than can be
       represented by the timestamp types, but the planner assumed it
       could always convert a date to timestamp with impunity.
     * Fix pg_restore's text output for large objects (BLOBs) when
       standard_conforming_strings is on (Tom Lane)
       Although restoring directly to a database worked correctly, string
       escaping was incorrect if pg_restore was asked for SQL text output
       and standard_conforming_strings had been enabled in the source
       database.
     * Fix erroneous parsing of tsquery values containing ... &
       !(subexpression) | ... (Tom Lane)
       Queries containing this combination of operators were not executed
       correctly. The same error existed in "contrib/intarray"'s query_int
       type and "contrib/ltree"'s ltxtquery type.
     * Fix buffer overrun in "contrib/intarray"'s input function for the
       query_int type (Apple)
       This bug is a security risk since the function's return address
       could be overwritten. Thanks to Apple Inc's security team for
       reporting this issue and supplying the fix. (CVE-2010-4015)
     * Fix bug in "contrib/seg"'s GiST picksplit algorithm (Alexander
       Korotkov)
       This could result in considerable inefficiency, though not actually
       incorrect answers, in a GiST index on a seg column. If you have
       such an index, consider "REINDEX"ing it after installing this
       update. (This is identical to the bug that was fixed in
       "contrib/cube" in the previous update.)
     __________________________________________________________________

                               Release 8.3.13

     Release Date: 2010-12-16

   This release contains a variety of fixes from 8.3.12. For information
   about new features in the 8.3 major release, see the Section called
   Release 8.3.
     __________________________________________________________________

Migration to Version 8.3.13

   A dump/restore is not required for those running 8.3.X. However, if you
   are upgrading from a version earlier than 8.3.8, see the release notes
   for 8.3.8.
     __________________________________________________________________

Changes

     * Force the default wal_sync_method to be fdatasync on Linux (Tom
       Lane, Marti Raudsepp)
       The default on Linux has actually been fdatasync for many years,
       but recent kernel changes caused PostgreSQL to choose open_datasync
       instead. This choice did not result in any performance improvement,
       and caused outright failures on certain filesystems, notably ext4
       with the data=journal mount option.
     * Fix assorted bugs in WAL replay logic for GIN indexes (Tom Lane)
       This could result in "bad buffer id: 0" failures or corruption of
       index contents during replication.
     * Fix recovery from base backup when the starting checkpoint WAL
       record is not in the same WAL segment as its redo point (Jeff
       Davis)
     * Fix persistent slowdown of autovacuum workers when multiple workers
       remain active for a long time (Tom Lane)
       The effective vacuum_cost_limit for an autovacuum worker could drop
       to nearly zero if it processed enough tables, causing it to run
       extremely slowly.
     * Add support for detecting register-stack overrun on IA64 (Tom Lane)
       The IA64 architecture has two hardware stacks. Full prevention of
       stack-overrun failures requires checking both.
     * Add a check for stack overflow in copyObject() (Tom Lane)
       Certain code paths could crash due to stack overflow given a
       sufficiently complex query.
     * Fix detection of page splits in temporary GiST indexes (Heikki
       Linnakangas)
       It is possible to have a "concurrent" page split in a temporary
       index, if for example there is an open cursor scanning the index
       when an insertion is done. GiST failed to detect this case and
       hence could deliver wrong results when execution of the cursor
       continued.
     * Avoid memory leakage while "ANALYZE"'ing complex index expressions
       (Tom Lane)
     * Ensure an index that uses a whole-row Var still depends on its
       table (Tom Lane)
       An index declared like create index i on t (foo(t.*)) would not
       automatically get dropped when its table was dropped.
     * Do not "inline" a SQL function with multiple OUT parameters (Tom
       Lane)
       This avoids a possible crash due to loss of information about the
       expected result rowtype.
     * Behave correctly if ORDER BY, LIMIT, FOR UPDATE, or WITH is
       attached to the VALUES part of INSERT ... VALUES (Tom Lane)
     * Fix constant-folding of COALESCE() expressions (Tom Lane)
       The planner would sometimes attempt to evaluate sub-expressions
       that in fact could never be reached, possibly leading to unexpected
       errors.
     * Fix postmaster crash when connection acceptance (accept() or one of
       the calls made immediately after it) fails, and the postmaster was
       compiled with GSSAPI support (Alexander Chernikov)
     * Fix missed unlink of temporary files when log_temp_files is active
       (Tom Lane)
       If an error occurred while attempting to emit the log message, the
       unlink was not done, resulting in accumulation of temp files.
     * Add print functionality for InhRelation nodes (Tom Lane)
       This avoids a failure when debug_print_parse is enabled and certain
       types of query are executed.
     * Fix incorrect calculation of distance from a point to a horizontal
       line segment (Tom Lane)
       This bug affected several different geometric distance-measurement
       operators.
     * Fix PL/pgSQL's handling of "simple" expressions to not fail in
       recursion or error-recovery cases (Tom Lane)
     * Fix PL/Python's handling of set-returning functions (Jan Urbanski)
       Attempts to call SPI functions within the iterator generating a set
       result would fail.
     * Fix bug in "contrib/cube"'s GiST picksplit algorithm (Alexander
       Korotkov)
       This could result in considerable inefficiency, though not actually
       incorrect answers, in a GiST index on a cube column. If you have
       such an index, consider "REINDEX"ing it after installing this
       update.
     * Don't emit "identifier will be truncated" notices in
       "contrib/dblink" except when creating new connections (Itagaki
       Takahiro)
     * Fix potential coredump on missing public key in "contrib/pgcrypto"
       (Marti Raudsepp)
     * Fix memory leak in "contrib/xml2"'s XPath query functions (Tom
       Lane)
     * Update time zone data files to tzdata release 2010o for DST law
       changes in Fiji and Samoa; also historical corrections for Hong
       Kong.
     __________________________________________________________________

                               Release 8.3.12

     Release Date: 2010-10-04

   This release contains a variety of fixes from 8.3.11. For information
   about new features in the 8.3 major release, see the Section called
   Release 8.3.
     __________________________________________________________________

Migration to Version 8.3.12

   A dump/restore is not required for those running 8.3.X. However, if you
   are upgrading from a version earlier than 8.3.8, see the release notes
   for 8.3.8.
     __________________________________________________________________

Changes

     * Use a separate interpreter for each calling SQL userid in PL/Perl
       and PL/Tcl (Tom Lane)
       This change prevents security problems that can be caused by
       subverting Perl or Tcl code that will be executed later in the same
       session under another SQL user identity (for example, within a
       SECURITY DEFINER function). Most scripting languages offer numerous
       ways that that might be done, such as redefining standard functions
       or operators called by the target function. Without this change,
       any SQL user with Perl or Tcl language usage rights can do
       essentially anything with the SQL privileges of the target
       function's owner.
       The cost of this change is that intentional communication among
       Perl and Tcl functions becomes more difficult. To provide an escape
       hatch, PL/PerlU and PL/TclU functions continue to use only one
       interpreter per session. This is not considered a security issue
       since all such functions execute at the trust level of a database
       superuser already.
       It is likely that third-party procedural languages that claim to
       offer trusted execution have similar security issues. We advise
       contacting the authors of any PL you are depending on for
       security-critical purposes.
       Our thanks to Tim Bunce for pointing out this issue
       (CVE-2010-3433).
     * Prevent possible crashes in pg_get_expr() by disallowing it from
       being called with an argument that is not one of the system catalog
       columns it's intended to be used with (Heikki Linnakangas, Tom
       Lane)
     * Treat exit code 128 (ERROR_WAIT_NO_CHILDREN) as non-fatal on
       Windows (Magnus Hagander)
       Under high load, Windows processes will sometimes fail at startup
       with this error code. Formerly the postmaster treated this as a
       panic condition and restarted the whole database, but that seems to
       be an overreaction.
     * Fix incorrect usage of non-strict OR joinclauses in Append
       indexscans (Tom Lane)
       This is a back-patch of an 8.4 fix that was missed in the 8.3
       branch. This corrects an error introduced in 8.3.8 that could cause
       incorrect results for outer joins when the inner relation is an
       inheritance tree or UNION ALL subquery.
     * Fix possible duplicate scans of UNION ALL member relations (Tom
       Lane)
     * Fix "cannot handle unplanned sub-select" error (Tom Lane)
       This occurred when a sub-select contains a join alias reference
       that expands into an expression containing another sub-select.
     * Fix failure to mark cached plans as transient (Tom Lane)
       If a plan is prepared while "CREATE INDEX CONCURRENTLY" is in
       progress for one of the referenced tables, it is supposed to be
       re-planned once the index is ready for use. This was not happening
       reliably.
     * Reduce PANIC to ERROR in some occasionally-reported btree failure
       cases, and provide additional detail in the resulting error
       messages (Tom Lane)
       This should improve the system's robustness with corrupted indexes.
     * Prevent show_session_authorization() from crashing within
       autovacuum processes (Tom Lane)
     * Defend against functions returning setof record where not all the
       returned rows are actually of the same rowtype (Tom Lane)
     * Fix possible failure when hashing a pass-by-reference function
       result (Tao Ma, Tom Lane)
     * Improve merge join's handling of NULLs in the join columns (Tom
       Lane)
       A merge join can now stop entirely upon reaching the first NULL, if
       the sort order is such that NULLs sort high.
     * Take care to fsync the contents of lockfiles (both "postmaster.pid"
       and the socket lockfile) while writing them (Tom Lane)
       This omission could result in corrupted lockfile contents if the
       machine crashes shortly after postmaster start. That could in turn
       prevent subsequent attempts to start the postmaster from
       succeeding, until the lockfile is manually removed.
     * Avoid recursion while assigning XIDs to heavily-nested
       subtransactions (Andres Freund, Robert Haas)
       The original coding could result in a crash if there was limited
       stack space.
     * Avoid holding open old WAL segments in the walwriter process
       (Magnus Hagander, Heikki Linnakangas)
       The previous coding would prevent removal of no-longer-needed
       segments.
     * Fix log_line_prefix's %i escape, which could produce junk early in
       backend startup (Tom Lane)
     * Fix possible data corruption in "ALTER TABLE ... SET TABLESPACE"
       when archiving is enabled (Jeff Davis)
     * Allow "CREATE DATABASE" and "ALTER DATABASE ... SET TABLESPACE" to
       be interrupted by query-cancel (Guillaume Lelarge)
     * Fix "REASSIGN OWNED" to handle operator classes and families (Asko
       Tiidumaa)
     * Fix possible core dump when comparing two empty tsquery values (Tom
       Lane)
     * Fix LIKE's handling of patterns containing % followed by _ (Tom
       Lane)
       We've fixed this before, but there were still some
       incorrectly-handled cases.
     * In PL/Python, defend against null pointer results from
       PyCObject_AsVoidPtr and PyCObject_FromVoidPtr (Peter Eisentraut)
     * Make psql recognize "DISCARD ALL" as a command that should not be
       encased in a transaction block in autocommit-off mode (Itagaki
       Takahiro)
     * Fix ecpg to process data from RETURNING clauses correctly (Michael
       Meskes)
     * Improve "contrib/dblink"'s handling of tables containing dropped
       columns (Tom Lane)
     * Fix connection leak after "duplicate connection name" errors in
       "contrib/dblink" (Itagaki Takahiro)
     * Fix "contrib/dblink" to handle connection names longer than 62
       bytes correctly (Itagaki Takahiro)
     * Add hstore(text, text) function to "contrib/hstore" (Robert Haas)
       This function is the recommended substitute for the now-deprecated
       => operator. It was back-patched so that future-proofed code can be
       used with older server versions. Note that the patch will be
       effective only after "contrib/hstore" is installed or reinstalled
       in a particular database. Users might prefer to execute the "CREATE
       FUNCTION" command by hand, instead.
     * Update build infrastructure and documentation to reflect the source
       code repository's move from CVS to Git (Magnus Hagander and others)
     * Update time zone data files to tzdata release 2010l for DST law
       changes in Egypt and Palestine; also historical corrections for
       Finland.
       This change also adds new names for two Micronesian timezones:
       Pacific/Chuuk is now preferred over Pacific/Truk (and the preferred
       abbreviation is CHUT not TRUT) and Pacific/Pohnpei is preferred
       over Pacific/Ponape.
     * Make Windows' "N. Central Asia Standard Time" timezone map to
       Asia/Novosibirsk, not Asia/Almaty (Magnus Hagander)
       Microsoft changed the DST behavior of this zone in the timezone
       update from KB976098. Asia/Novosibirsk is a better match to its new
       behavior.
     __________________________________________________________________

                               Release 8.3.11

     Release Date: 2010-05-17

   This release contains a variety of fixes from 8.3.10. For information
   about new features in the 8.3 major release, see the Section called
   Release 8.3.
     __________________________________________________________________

Migration to Version 8.3.11

   A dump/restore is not required for those running 8.3.X. However, if you
   are upgrading from a version earlier than 8.3.8, see the release notes
   for 8.3.8.
     __________________________________________________________________

Changes

     * Enforce restrictions in plperl using an opmask applied to the whole
       interpreter, instead of using "Safe.pm" (Tim Bunce, Andrew Dunstan)
       Recent developments have convinced us that "Safe.pm" is too
       insecure to rely on for making plperl trustable. This change
       removes use of "Safe.pm" altogether, in favor of using a separate
       interpreter with an opcode mask that is always applied. Pleasant
       side effects of the change include that it is now possible to use
       Perl's strict pragma in a natural way in plperl, and that Perl's $a
       and $b variables work as expected in sort routines, and that
       function compilation is significantly faster. (CVE-2010-1169)
     * Prevent PL/Tcl from executing untrustworthy code from pltcl_modules
       (Tom)
       PL/Tcl's feature for autoloading Tcl code from a database table
       could be exploited for trojan-horse attacks, because there was no
       restriction on who could create or insert into that table. This
       change disables the feature unless pltcl_modules is owned by a
       superuser. (However, the permissions on the table are not checked,
       so installations that really need a less-than-secure modules table
       can still grant suitable privileges to trusted non-superusers.)
       Also, prevent loading code into the unrestricted "normal" Tcl
       interpreter unless we are really going to execute a pltclu
       function. (CVE-2010-1170)
     * Fix possible crash if a cache reset message is received during
       rebuild of a relcache entry (Heikki)
       This error was introduced in 8.3.10 while fixing a related failure.
     * Apply per-function GUC settings while running the language
       validator for the function (Itagaki Takahiro)
       This avoids failures if the function's code is invalid without the
       setting; an example is that SQL functions may not parse if the
       search_path is not correct.
     * Do not allow an unprivileged user to reset superuser-only parameter
       settings (Alvaro)
       Previously, if an unprivileged user ran ALTER USER ... RESET ALL
       for himself, or ALTER DATABASE ... RESET ALL for a database he
       owns, this would remove all special parameter settings for the user
       or database, even ones that are only supposed to be changeable by a
       superuser. Now, the "ALTER" will only remove the parameters that
       the user has permission to change.
     * Avoid possible crash during backend shutdown if shutdown occurs
       when a CONTEXT addition would be made to log entries (Tom)
       In some cases the context-printing function would fail because the
       current transaction had already been rolled back when it came time
       to print a log message.
     * Ensure the archiver process responds to changes in archive_command
       as soon as possible (Tom)
     * Update pl/perl's "ppport.h" for modern Perl versions (Andrew)
     * Fix assorted memory leaks in pl/python (Andreas Freund, Tom)
     * Prevent infinite recursion in psql when expanding a variable that
       refers to itself (Tom)
     * Fix psql's \copy to not add spaces around a dot within \copy
       (select ...) (Tom)
       Addition of spaces around the decimal point in a numeric literal
       would result in a syntax error.
     * Fix unnecessary "GIN indexes do not support whole-index scans"
       errors for unsatisfiable queries using "contrib/intarray" operators
       (Tom)
     * Ensure that "contrib/pgstattuple" functions respond to cancel
       interrupts promptly (Tatsuhito Kasahara)
     * Make server startup deal properly with the case that shmget()
       returns EINVAL for an existing shared memory segment (Tom)
       This behavior has been observed on BSD-derived kernels including OS
       X. It resulted in an entirely-misleading startup failure
       complaining that the shared memory request size was too large.
     * Avoid possible crashes in syslogger process on Windows (Heikki)
     * Deal more robustly with incomplete time zone information in the
       Windows registry (Magnus)
     * Update the set of known Windows time zone names (Magnus)
     * Update time zone data files to tzdata release 2010j for DST law
       changes in Argentina, Australian Antarctic, Bangladesh, Mexico,
       Morocco, Pakistan, Palestine, Russia, Syria, Tunisia; also
       historical corrections for Taiwan.
       Also, add PKST (Pakistan Summer Time) to the default set of
       timezone abbreviations.
     __________________________________________________________________

                               Release 8.3.10

     Release Date: 2010-03-15

   This release contains a variety of fixes from 8.3.9. For information
   about new features in the 8.3 major release, see the Section called
   Release 8.3.
     __________________________________________________________________

Migration to Version 8.3.10

   A dump/restore is not required for those running 8.3.X. However, if you
   are upgrading from a version earlier than 8.3.8, see the release notes
   for 8.3.8.
     __________________________________________________________________

Changes

     * Add new configuration parameter ssl_renegotiation_limit to control
       how often we do session key renegotiation for an SSL connection
       (Magnus)
       This can be set to zero to disable renegotiation completely, which
       may be required if a broken SSL library is used. In particular,
       some vendors are shipping stopgap patches for CVE-2009-3555 that
       cause renegotiation attempts to fail.
     * Fix possible deadlock during backend startup (Tom)
     * Fix possible crashes due to not handling errors during relcache
       reload cleanly (Tom)
     * Fix possible crash due to use of dangling pointer to a cached plan
       (Tatsuo)
     * Fix possible crashes when trying to recover from a failure in
       subtransaction start (Tom)
     * Fix server memory leak associated with use of savepoints and a
       client encoding different from server's encoding (Tom)
     * Fix incorrect WAL data emitted during end-of-recovery cleanup of a
       GIST index page split (Yoichi Hirai)
       This would result in index corruption, or even more likely an error
       during WAL replay, if we were unlucky enough to crash during
       end-of-recovery cleanup after having completed an incomplete GIST
       insertion.
     * Make substring() for bit types treat any negative length as meaning
       "all the rest of the string" (Tom)
       The previous coding treated only -1 that way, and would produce an
       invalid result value for other negative values, possibly leading to
       a crash (CVE-2010-0442).
     * Fix integer-to-bit-string conversions to handle the first
       fractional byte correctly when the output bit width is wider than
       the given integer by something other than a multiple of 8 bits
       (Tom)
     * Fix some cases of pathologically slow regular expression matching
       (Tom)
     * Fix assorted crashes in xml processing caused by sloppy memory
       management (Tom)
       This is a back-patch of changes first applied in 8.4. The 8.3 code
       was known buggy, but the new code was sufficiently different to not
       want to back-patch it until it had gotten some field testing.
     * Fix bug with trying to update a field of an element of a
       composite-type array column (Tom)
     * Fix the STOP WAL LOCATION entry in backup history files to report
       the next WAL segment's name when the end location is exactly at a
       segment boundary (Itagaki Takahiro)
     * Fix some more cases of temporary-file leakage (Heikki)
       This corrects a problem introduced in the previous minor release.
       One case that failed is when a plpgsql function returning set is
       called within another function's exception handler.
     * Improve constraint exclusion processing of boolean-variable cases,
       in particular make it possible to exclude a partition that has a
       "bool_column = false" constraint (Tom)
     * When reading "pg_hba.conf" and related files, do not treat
       @something as a file inclusion request if the @ appears inside
       quote marks; also, never treat @ by itself as a file inclusion
       request (Tom)
       This prevents erratic behavior if a role or database name starts
       with @. If you need to include a file whose path name contains
       spaces, you can still do so, but you must write @"/path to/file"
       rather than putting the quotes around the whole construct.
     * Prevent infinite loop on some platforms if a directory is named as
       an inclusion target in "pg_hba.conf" and related files (Tom)
     * Fix possible infinite loop if SSL_read or SSL_write fails without
       setting errno (Tom)
       This is reportedly possible with some Windows versions of openssl.
     * Disallow GSSAPI authentication on local connections, since it
       requires a hostname to function correctly (Magnus)
     * Make ecpg report the proper SQLSTATE if the connection disappears
       (Michael)
     * Fix psql's numericlocale option to not format strings it shouldn't
       in latex and troff output formats (Heikki)
     * Make psql return the correct exit status (3) when ON_ERROR_STOP and
       --single-transaction are both specified and an error occurs during
       the implied "COMMIT" (Bruce)
     * Fix plpgsql failure in one case where a composite column is set to
       NULL (Tom)
     * Fix possible failure when calling PL/Perl functions from PL/PerlU
       or vice versa (Tim Bunce)
     * Add volatile markings in PL/Python to avoid possible
       compiler-specific misbehavior (Zdenek Kotala)
     * Ensure PL/Tcl initializes the Tcl interpreter fully (Tom)
       The only known symptom of this oversight is that the Tcl clock
       command misbehaves if using Tcl 8.5 or later.
     * Prevent crash in "contrib/dblink" when too many key columns are
       specified to a dblink_build_sql_* function (Rushabh Lathia, Joe
       Conway)
     * Allow zero-dimensional arrays in "contrib/ltree" operations (Tom)
       This case was formerly rejected as an error, but it's more
       convenient to treat it the same as a zero-element array. In
       particular this avoids unnecessary failures when an ltree operation
       is applied to the result of ARRAY(SELECT ...) and the sub-select
       returns no rows.
     * Fix assorted crashes in "contrib/xml2" caused by sloppy memory
       management (Tom)
     * Make building of "contrib/xml2" more robust on Windows (Andrew)
     * Fix race condition in Windows signal handling (Radu Ilie)
       One known symptom of this bug is that rows in pg_listener could be
       dropped under heavy load.
     * Update time zone data files to tzdata release 2010e for DST law
       changes in Bangladesh, Chile, Fiji, Mexico, Paraguay, Samoa.
     __________________________________________________________________

                                Release 8.3.9

     Release Date: 2009-12-14

   This release contains a variety of fixes from 8.3.8. For information
   about new features in the 8.3 major release, see the Section called
   Release 8.3.
     __________________________________________________________________

Migration to Version 8.3.9

   A dump/restore is not required for those running 8.3.X. However, if you
   are upgrading from a version earlier than 8.3.8, see the release notes
   for 8.3.8.
     __________________________________________________________________

Changes

     * Protect against indirect security threats caused by index functions
       changing session-local state (Gurjeet Singh, Tom)
       This change prevents allegedly-immutable index functions from
       possibly subverting a superuser's session (CVE-2009-4136).
     * Reject SSL certificates containing an embedded null byte in the
       common name (CN) field (Magnus)
       This prevents unintended matching of a certificate to a server or
       client name during SSL validation (CVE-2009-4034).
     * Fix possible crash during backend-startup-time cache initialization
       (Tom)
     * Avoid crash on empty thesaurus dictionary (Tom)
     * Prevent signals from interrupting VACUUM at unsafe times (Alvaro)
       This fix prevents a PANIC if a VACUUM FULL is canceled after it's
       already committed its tuple movements, as well as transient errors
       if a plain VACUUM is interrupted after having truncated the table.
     * Fix possible crash due to integer overflow in hash table size
       calculation (Tom)
       This could occur with extremely large planner estimates for the
       size of a hashjoin's result.
     * Fix very rare crash in inet/cidr comparisons (Chris Mikkelson)
     * Ensure that shared tuple-level locks held by prepared transactions
       are not ignored (Heikki)
     * Fix premature drop of temporary files used for a cursor that is
       accessed within a subtransaction (Heikki)
     * Fix memory leak in syslogger process when rotating to a new CSV
       logfile (Tom)
     * Fix Windows permission-downgrade logic (Jesse Morris)
       This fixes some cases where the database failed to start on
       Windows, often with misleading error messages such as "could not
       locate matching postgres executable".
     * Fix incorrect logic for GiST index page splits, when the split
       depends on a non-first column of the index (Paul Ramsey)
     * Don't error out if recycling or removing an old WAL file fails at
       the end of checkpoint (Heikki)
       It's better to treat the problem as non-fatal and allow the
       checkpoint to complete. Future checkpoints will retry the removal.
       Such problems are not expected in normal operation, but have been
       seen to be caused by misdesigned Windows anti-virus and backup
       software.
     * Ensure WAL files aren't repeatedly archived on Windows (Heikki)
       This is another symptom that could happen if some other process
       interfered with deletion of a no-longer-needed file.
     * Fix PAM password processing to be more robust (Tom)
       The previous code is known to fail with the combination of the
       Linux pam_krb5 PAM module with Microsoft Active Directory as the
       domain controller. It might have problems elsewhere too, since it
       was making unjustified assumptions about what arguments the PAM
       stack would pass to it.
     * Raise the maximum authentication token (Kerberos ticket) size in
       GSSAPI and SSPI authentication methods (Ian Turner)
       While the old 2000-byte limit was more than enough for Unix
       Kerberos implementations, tickets issued by Windows Domain
       Controllers can be much larger.
     * Re-enable collection of access statistics for sequences (Akira
       Kurosawa)
       This used to work but was broken in 8.3.
     * Fix processing of ownership dependencies during CREATE OR REPLACE
       FUNCTION (Tom)
     * Fix incorrect handling of WHERE "x"="x" conditions (Tom)
       In some cases these could get ignored as redundant, but they aren't
       -- they're equivalent to "x" IS NOT NULL.
     * Make text search parser accept underscores in XML attributes
       (Peter)
     * Fix encoding handling in xml binary input (Heikki)
       If the XML header doesn't specify an encoding, we now assume UTF-8
       by default; the previous handling was inconsistent.
     * Fix bug with calling plperl from plperlu or vice versa (Tom)
       An error exit from the inner function could result in crashes due
       to failure to re-select the correct Perl interpreter for the outer
       function.
     * Fix session-lifespan memory leak when a PL/Perl function is
       redefined (Tom)
     * Ensure that Perl arrays are properly converted to PostgreSQL arrays
       when returned by a set-returning PL/Perl function (Andrew Dunstan,
       Abhijit Menon-Sen)
       This worked correctly already for non-set-returning functions.
     * Fix rare crash in exception processing in PL/Python (Peter)
     * In "contrib/pg_standby", disable triggering failover with a signal
       on Windows (Fujii Masao)
       This never did anything useful, because Windows doesn't have
       Unix-style signals, but recent changes made it actually crash.
     * Ensure psql's flex module is compiled with the correct system
       header definitions (Tom)
       This fixes build failures on platforms where --enable-largefile
       causes incompatible changes in the generated code.
     * Make the postmaster ignore any application_name parameter in
       connection request packets, to improve compatibility with future
       libpq versions (Tom)
     * Update the timezone abbreviation files to match current reality
       (Joachim Wieland)
       This includes adding IDT and SGT to the default timezone
       abbreviation set.
     * Update time zone data files to tzdata release 2009s for DST law
       changes in Antarctica, Argentina, Bangladesh, Fiji, Novokuznetsk,
       Pakistan, Palestine, Samoa, Syria; also historical corrections for
       Hong Kong.
     __________________________________________________________________

                                Release 8.3.8

     Release Date: 2009-09-09

   This release contains a variety of fixes from 8.3.7. For information
   about new features in the 8.3 major release, see the Section called
   Release 8.3.
     __________________________________________________________________

Migration to Version 8.3.8

   A dump/restore is not required for those running 8.3.X. However, if you
   have any hash indexes on interval columns, you must "REINDEX" them
   after updating to 8.3.8. Also, if you are upgrading from a version
   earlier than 8.3.5, see the release notes for 8.3.5.
     __________________________________________________________________

Changes

     * Fix Windows shared-memory allocation code (Tsutomu Yamada, Magnus)
       This bug led to the often-reported "could not reattach to shared
       memory" error message.
     * Force WAL segment switch during pg_start_backup() (Heikki)
       This avoids corner cases that could render a base backup unusable.
     * Disallow "RESET ROLE" and "RESET SESSION AUTHORIZATION" inside
       security-definer functions (Tom, Heikki)
       This covers a case that was missed in the previous patch that
       disallowed "SET ROLE" and "SET SESSION AUTHORIZATION" inside
       security-definer functions. (See CVE-2007-6600)
     * Make "LOAD" of an already-loaded loadable module into a no-op (Tom)
       Formerly, "LOAD" would attempt to unload and re-load the module,
       but this is unsafe and not all that useful.
     * Disallow empty passwords during LDAP authentication (Magnus)
     * Fix handling of sub-SELECTs appearing in the arguments of an
       outer-level aggregate function (Tom)
     * Fix bugs associated with fetching a whole-row value from the output
       of a Sort or Materialize plan node (Tom)
     * Prevent synchronize_seqscans from changing the results of
       scrollable and WITH HOLD cursors (Tom)
     * Revert planner change that disabled partial-index and constraint
       exclusion optimizations when there were more than 100 clauses in an
       AND or OR list (Tom)
     * Fix hash calculation for data type interval (Tom)
       This corrects wrong results for hash joins on interval values. It
       also changes the contents of hash indexes on interval columns. If
       you have any such indexes, you must "REINDEX" them after updating.
     * Treat to_char(..., 'TH') as an uppercase ordinal suffix with
       'HH'/'HH12' (Heikki)
       It was previously handled as 'th' (lowercase).
     * Fix overflow for INTERVAL 'x ms' when "x" is more than 2 million
       and integer datetimes are in use (Alex Hunsaker)
     * Fix calculation of distance between a point and a line segment
       (Tom)
       This led to incorrect results from a number of geometric operators.
     * Fix money data type to work in locales where currency amounts have
       no fractional digits, e.g. Japan (Itagaki Takahiro)
     * Fix LIKE for case where pattern contains %_ (Tom)
     * Properly round datetime input like
       00:12:57.9999999999999999999999999999 (Tom)
     * Fix memory leaks in XML operations (Tom)
     * Fix poor choice of page split point in GiST R-tree operator classes
       (Teodor)
     * Ensure that a "fast shutdown" request will forcibly terminate open
       sessions, even if a "smart shutdown" was already in progress (Fujii
       Masao)
     * Avoid performance degradation in bulk inserts into GIN indexes when
       the input values are (nearly) in sorted order (Tom)
     * Correctly enforce NOT NULL domain constraints in some contexts in
       PL/pgSQL (Tom)
     * Fix portability issues in plperl initialization (Andrew Dunstan)
     * Fix pg_ctl to not go into an infinite loop if "postgresql.conf" is
       empty (Jeff Davis)
     * Improve pg_dump's efficiency when there are many large objects
       (Tamas Vincze)
     * Use SIGUSR1, not SIGQUIT, as the failover signal for pg_standby
       (Heikki)
     * Make pg_standby's maxretries option behave as documented (Fujii
       Masao)
     * Make "contrib/hstore" throw an error when a key or value is too
       long to fit in its data structure, rather than silently truncating
       it (Andrew Gierth)
     * Fix "contrib/xml2"'s xslt_process() to properly handle the maximum
       number of parameters (twenty) (Tom)
     * Improve robustness of libpq's code to recover from errors during
       "COPY FROM STDIN" (Tom)
     * Avoid including conflicting readline and editline header files when
       both libraries are installed (Zdenek Kotala)
     * Update time zone data files to tzdata release 2009l for DST law
       changes in Bangladesh, Egypt, Jordan, Pakistan, Argentina/San_Luis,
       Cuba, Jordan (historical correction only), Mauritius, Morocco,
       Palestine, Syria, Tunisia.
     __________________________________________________________________

                                Release 8.3.7

     Release Date: 2009-03-16

   This release contains a variety of fixes from 8.3.6. For information
   about new features in the 8.3 major release, see the Section called
   Release 8.3.
     __________________________________________________________________

Migration to Version 8.3.7

   A dump/restore is not required for those running 8.3.X. However, if you
   are upgrading from a version earlier than 8.3.5, see the release notes
   for 8.3.5.
     __________________________________________________________________

Changes

     * Prevent error recursion crashes when encoding conversion fails
       (Tom)
       This change extends fixes made in the last two minor releases for
       related failure scenarios. The previous fixes were narrowly
       tailored for the original problem reports, but we have now
       recognized that *any* error thrown by an encoding conversion
       function could potentially lead to infinite recursion while trying
       to report the error. The solution therefore is to disable
       translation and encoding conversion and report the plain-ASCII form
       of any error message, if we find we have gotten into a recursive
       error reporting situation. (CVE-2009-0922)
     * Disallow "CREATE CONVERSION" with the wrong encodings for the
       specified conversion function (Heikki)
       This prevents one possible scenario for encoding conversion
       failure. The previous change is a backstop to guard against other
       kinds of failures in the same area.
     * Fix xpath() to not modify the path expression unless necessary, and
       to make a saner attempt at it when necessary (Andrew)
       The SQL standard suggests that xpath should work on data that is a
       document fragment, but libxml doesn't support that, and indeed it's
       not clear that this is sensible according to the XPath standard.
       xpath attempted to work around this mismatch by modifying both the
       data and the path expression, but the modification was buggy and
       could cause valid searches to fail. Now, xpath checks whether the
       data is in fact a well-formed document, and if so invokes libxml
       with no change to the data or path expression. Otherwise, a
       different modification method that is somewhat less likely to fail
       is used.

     Note: The new modification method is still not 100% satisfactory,
     and it seems likely that no real solution is possible. This patch
     should therefore be viewed as a band-aid to keep from breaking
     existing applications unnecessarily. It is likely that PostgreSQL
     8.4 will simply reject use of xpath on data that is not a
     well-formed document.
     * Fix core dump when to_char() is given format codes that are
       inappropriate for the type of the data argument (Tom)
     * Fix possible failure in text search when C locale is used with a
       multi-byte encoding (Teodor)
       Crashes were possible on platforms where wchar_t is narrower than
       int; Windows in particular.
     * Fix extreme inefficiency in text search parser's handling of an
       email-like string containing multiple @ characters (Heikki)
     * Fix planner problem with sub-"SELECT" in the output list of a
       larger subquery (Tom)
       The known symptom of this bug is a "failed to locate grouping
       columns" error that is dependent on the datatype involved; but
       there could be other issues as well.
     * Fix decompilation of CASE WHEN with an implicit coercion (Tom)
       This mistake could lead to Assert failures in an Assert-enabled
       build, or an "unexpected CASE WHEN clause" error message in other
       cases, when trying to examine or dump a view.
     * Fix possible misassignment of the owner of a TOAST table's rowtype
       (Tom)
       If "CLUSTER" or a rewriting variant of "ALTER TABLE" were executed
       by someone other than the table owner, the pg_type entry for the
       table's TOAST table would end up marked as owned by that someone.
       This caused no immediate problems, since the permissions on the
       TOAST rowtype aren't examined by any ordinary database operation.
       However, it could lead to unexpected failures if one later tried to
       drop the role that issued the command (in 8.1 or 8.2), or "owner of
       data type appears to be invalid" warnings from pg_dump after having
       done so (in 8.3).
     * Change "UNLISTEN" to exit quickly if the current session has never
       executed any "LISTEN" command (Tom)
       Most of the time this is not a particularly useful optimization,
       but since "DISCARD ALL" invokes "UNLISTEN", the previous coding
       caused a substantial performance problem for applications that made
       heavy use of "DISCARD ALL".
     * Fix PL/pgSQL to not treat INTO after "INSERT" as an INTO-variables
       clause anywhere in the string, not only at the start; in
       particular, don't fail for "INSERT INTO" within "CREATE RULE" (Tom)
     * Clean up PL/pgSQL error status variables fully at block exit
       (Ashesh Vashi and Dave Page)
       This is not a problem for PL/pgSQL itself, but the omission could
       cause the PL/pgSQL Debugger to crash while examining the state of a
       function.
     * Retry failed calls to CallNamedPipe() on Windows (Steve Marshall,
       Magnus)
       It appears that this function can sometimes fail transiently; we
       previously treated any failure as a hard error, which could confuse
       "LISTEN"/"NOTIFY" as well as other operations.
     * Add MUST (Mauritius Island Summer Time) to the default list of
       known timezone abbreviations (Xavier Bugaud)
     __________________________________________________________________

                                Release 8.3.6

     Release Date: 2009-02-02

   This release contains a variety of fixes from 8.3.5. For information
   about new features in the 8.3 major release, see the Section called
   Release 8.3.
     __________________________________________________________________

Migration to Version 8.3.6

   A dump/restore is not required for those running 8.3.X. However, if you
   are upgrading from a version earlier than 8.3.5, see the release notes
   for 8.3.5.
     __________________________________________________________________

Changes

     * Make "DISCARD ALL" release advisory locks, in addition to
       everything it already did (Tom)
       This was decided to be the most appropriate behavior. This could
       affect existing applications, however.
     * Fix whole-index GiST scans to work correctly (Teodor)
       This error could cause rows to be lost if a table is clustered on a
       GiST index.
     * Fix crash of xmlconcat(NULL) (Peter)
     * Fix possible crash in ispell dictionary if high-bit-set characters
       are used as flags (Teodor)
       This is known to be done by one widely available Norwegian
       dictionary, and the same condition may exist in others.
     * Fix misordering of pg_dump output for composite types (Tom)
       The most likely problem was for user-defined operator classes to be
       dumped after indexes or views that needed them.
     * Improve handling of URLs in headline() function (Teodor)
     * Improve handling of overlength headlines in headline() function
       (Teodor)
     * Prevent possible Assert failure or misconversion if an encoding
       conversion is created with the wrong conversion function for the
       specified pair of encodings (Tom, Heikki)
     * Fix possible Assert failure if a statement executed in PL/pgSQL is
       rewritten into another kind of statement, for example if an
       "INSERT" is rewritten into an "UPDATE" (Heikki)
     * Ensure that a snapshot is available to datatype input functions
       (Tom)
       This primarily affects domains that are declared with CHECK
       constraints involving user-defined stable or immutable functions.
       Such functions typically fail if no snapshot has been set.
     * Make it safer for SPI-using functions to be used within datatype
       I/O; in particular, to be used in domain check constraints (Tom)
     * Avoid unnecessary locking of small tables in "VACUUM" (Heikki)
     * Fix a problem that sometimes kept "ALTER TABLE ENABLE/DISABLE RULE"
       from being recognized by active sessions (Tom)
     * Fix a problem that made UPDATE RETURNING tableoid return zero
       instead of the correct OID (Tom)
     * Allow functions declared as taking ANYARRAY to work on the
       pg_statistic columns of that type (Tom)
       This used to work, but was unintentionally broken in 8.3.
     * Fix planner misestimation of selectivity when transitive equality
       is applied to an outer-join clause (Tom)
       This could result in bad plans for queries like ... from a left
       join b on a.a1 = b.b1 where a.a1 = 42 ...
     * Improve optimizer's handling of long IN lists (Tom)
       This change avoids wasting large amounts of time on such lists when
       constraint exclusion is enabled.
     * Prevent synchronous scan during GIN index build (Tom)
       Because GIN is optimized for inserting tuples in increasing TID
       order, choosing to use a synchronous scan could slow the build by a
       factor of three or more.
     * Ensure that the contents of a holdable cursor don't depend on the
       contents of TOAST tables (Tom)
       Previously, large field values in a cursor result might be
       represented as TOAST pointers, which would fail if the referenced
       table got dropped before the cursor is read, or if the large value
       is deleted and then vacuumed away. This cannot happen with an
       ordinary cursor, but it could with a cursor that is held past its
       creating transaction.
     * Fix memory leak when a set-returning function is terminated without
       reading its whole result (Tom)
     * Fix encoding conversion problems in XML functions when the database
       encoding isn't UTF-8 (Tom)
     * Fix "contrib/dblink"'s dblink_get_result(text,bool) function (Joe)
     * Fix possible garbage output from "contrib/sslinfo" functions (Tom)
     * Fix incorrect behavior of "contrib/tsearch2" compatibility trigger
       when it's fired more than once in a command (Teodor)
     * Fix possible mis-signaling in autovacuum (Heikki)
     * Support running as a service on Windows 7 beta (Dave and Magnus)
     * Fix ecpg's handling of varchar structs (Michael)
     * Fix configure script to properly report failure when unable to
       obtain linkage information for PL/Perl (Andrew)
     * Make all documentation reference pgsql-bugs and/or pgsql-hackers as
       appropriate, instead of the now-decommissioned pgsql-ports and
       pgsql-patches mailing lists (Tom)
     * Update time zone data files to tzdata release 2009a (for Kathmandu
       and historical DST corrections in Switzerland, Cuba)
     __________________________________________________________________

                                Release 8.3.5

     Release Date: 2008-11-03

   This release contains a variety of fixes from 8.3.4. For information
   about new features in the 8.3 major release, see the Section called
   Release 8.3.
     __________________________________________________________________

Migration to Version 8.3.5

   A dump/restore is not required for those running 8.3.X. However, if you
   are upgrading from a version earlier than 8.3.1, see the release notes
   for 8.3.1. Also, if you were running a previous 8.3.X release, it is
   recommended to "REINDEX" all GiST indexes after the upgrade.
     __________________________________________________________________

Changes

     * Fix GiST index corruption due to marking the wrong index entry
       "dead" after a deletion (Teodor)
       This would result in index searches failing to find rows they
       should have found. Corrupted indexes can be fixed with "REINDEX".
     * Fix backend crash when the client encoding cannot represent a
       localized error message (Tom)
       We have addressed similar issues before, but it would still fail if
       the "character has no equivalent" message itself couldn't be
       converted. The fix is to disable localization and send the plain
       ASCII error message when we detect such a situation.
     * Fix possible crash in bytea-to-XML mapping (Michael McMaster)
     * Fix possible crash when deeply nested functions are invoked from a
       trigger (Tom)
     * Improve optimization of "expression" IN ("expression-list") queries
       (Tom, per an idea from Robert Haas)
       Cases in which there are query variables on the right-hand side had
       been handled less efficiently in 8.2.x and 8.3.x than in prior
       versions. The fix restores 8.1 behavior for such cases.
     * Fix mis-expansion of rule queries when a sub-SELECT appears in a
       function call in FROM, a multi-row VALUES list, or a RETURNING list
       (Tom)
       The usual symptom of this problem is an "unrecognized node type"
       error.
     * Fix Assert failure during rescan of an IS NULL search of a GiST
       index (Teodor)
     * Fix memory leak during rescan of a hashed aggregation plan (Neil)
     * Ensure an error is reported when a newly-defined PL/pgSQL trigger
       function is invoked as a normal function (Tom)
     * Force a checkpoint before "CREATE DATABASE" starts to copy files
       (Heikki)
       This prevents a possible failure if files had recently been deleted
       in the source database.
     * Prevent possible collision of relfilenode numbers when moving a
       table to another tablespace with "ALTER SET TABLESPACE" (Heikki)
       The command tried to re-use the existing filename, instead of
       picking one that is known unused in the destination directory.
     * Fix incorrect text search headline generation when single query
       item matches first word of text (Sushant Sinha)
     * Fix improper display of fractional seconds in interval values when
       using a non-ISO datestyle in an "--enable-integer-datetimes" build
       (Ron Mayer)
     * Make ILIKE compare characters case-insensitively even when they're
       escaped (Andrew)
     * Ensure "DISCARD" is handled properly by statement logging (Tom)
     * Fix incorrect logging of last-completed-transaction time during
       PITR recovery (Tom)
     * Ensure SPI_getvalue and SPI_getbinval behave correctly when the
       passed tuple and tuple descriptor have different numbers of columns
       (Tom)
       This situation is normal when a table has had columns added or
       removed, but these two functions didn't handle it properly. The
       only likely consequence is an incorrect error indication.
     * Mark SessionReplicationRole as PGDLLIMPORT so it can be used by
       Slony on Windows (Magnus)
     * Fix small memory leak when using libpq's gsslib parameter (Magnus)
       The space used by the parameter string was not freed at connection
       close.
     * Ensure libgssapi is linked into libpq if needed (Markus Schaaf)
     * Fix ecpg's parsing of "CREATE ROLE" (Michael)
     * Fix recent breakage of pg_ctl restart (Tom)
     * Ensure "pg_control" is opened in binary mode (Itagaki Takahiro)
       pg_controldata and pg_resetxlog did this incorrectly, and so could
       fail on Windows.
     * Update time zone data files to tzdata release 2008i (for DST law
       changes in Argentina, Brazil, Mauritius, Syria)
     __________________________________________________________________

                                Release 8.3.4

     Release Date: 2008-09-22

   This release contains a variety of fixes from 8.3.3. For information
   about new features in the 8.3 major release, see the Section called
   Release 8.3.
     __________________________________________________________________

Migration to Version 8.3.4

   A dump/restore is not required for those running 8.3.X. However, if you
   are upgrading from a version earlier than 8.3.1, see the release notes
   for 8.3.1.
     __________________________________________________________________

Changes

     * Fix bug in btree WAL recovery code (Heikki)
       Recovery failed if the WAL ended partway through a page split
       operation.
     * Fix potential use of wrong cutoff XID for HOT page pruning (Alvaro)
       This error created a risk of corruption in system catalogs that are
       consulted by "VACUUM": dead tuple versions might be removed too
       soon. The impact of this on actual database operations would be
       minimal, since the system doesn't follow MVCC rules while examining
       catalogs, but it might result in transiently wrong output from
       pg_dump or other client programs.
     * Fix potential miscalculation of datfrozenxid (Alvaro)
       This error may explain some recent reports of failure to remove old
       pg_clog data.
     * Fix incorrect HOT updates after pg_class is reindexed (Tom)
       Corruption of pg_class could occur if REINDEX TABLE pg_class was
       followed in the same session by an ALTER TABLE RENAME or ALTER
       TABLE SET SCHEMA command.
     * Fix missed "combo cid" case (Karl Schnaitter)
       This error made rows incorrectly invisible to a transaction in
       which they had been deleted by multiple subtransactions that all
       aborted.
     * Prevent autovacuum from crashing if the table it's currently
       checking is deleted at just the wrong time (Alvaro)
     * Widen local lock counters from 32 to 64 bits (Tom)
       This responds to reports that the counters could overflow in
       sufficiently long transactions, leading to unexpected "lock is
       already held" errors.
     * Fix possible duplicate output of tuples during a GiST index scan
       (Teodor)
     * Regenerate foreign key checking queries from scratch when either
       table is modified (Tom)
       Previously, 8.3 would attempt to replan the query, but would work
       from previously generated query text. This led to failures if a
       table or column was renamed.
     * Fix missed permissions checks when a view contains a simple UNION
       ALL construct (Heikki)
       Permissions for the referenced tables were checked properly, but
       not permissions for the view itself.
     * Add checks in executor startup to ensure that the tuples produced
       by an "INSERT" or "UPDATE" will match the target table's current
       rowtype (Tom)
       This situation is believed to be impossible in 8.3, but it can
       happen in prior releases, so a check seems prudent.
     * Fix possible repeated drops during "DROP OWNED" (Tom)
       This would typically result in strange errors such as "cache lookup
       failed for relation NNN".
     * Fix several memory leaks in XML operations (Kris Jurka, Tom)
     * Fix xmlserialize() to raise error properly for unacceptable target
       data type (Tom)
     * Fix a couple of places that mis-handled multibyte characters in
       text search configuration file parsing (Tom)
       Certain characters occurring in configuration files would always
       cause "invalid byte sequence for encoding" failures.
     * Provide file name and line number location for all errors reported
       in text search configuration files (Tom)
     * Fix AT TIME ZONE to first try to interpret its timezone argument as
       a timezone abbreviation, and only try it as a full timezone name if
       that fails, rather than the other way around as formerly (Tom)
       The timestamp input functions have always resolved ambiguous zone
       names in this order. Making AT TIME ZONE do so as well improves
       consistency, and fixes a compatibility bug introduced in 8.1: in
       ambiguous cases we now behave the same as 8.0 and before did, since
       in the older versions AT TIME ZONE accepted *only* abbreviations.
     * Fix datetime input functions to correctly detect integer overflow
       when running on a 64-bit platform (Tom)
     * Prevent integer overflows during units conversion when displaying a
       configuration parameter that has units (Tom)
     * Improve performance of writing very long log messages to syslog
       (Tom)
     * Allow spaces in the suffix part of an LDAP URL in "pg_hba.conf"
       (Tom)
     * Fix bug in backwards scanning of a cursor on a SELECT DISTINCT ON
       query (Tom)
     * Fix planner bug that could improperly push down IS NULL tests below
       an outer join (Tom)
       This was triggered by occurrence of IS NULL tests for the same
       relation in all arms of an upper OR clause.
     * Fix planner bug with nested sub-select expressions (Tom)
       If the outer sub-select has no direct dependency on the parent
       query, but the inner one does, the outer value might not get
       recalculated for new parent query rows.
     * Fix planner to estimate that GROUP BY expressions yielding boolean
       results always result in two groups, regardless of the expressions'
       contents (Tom)
       This is very substantially more accurate than the regular GROUP BY
       estimate for certain boolean tests like "col" IS NULL.
     * Fix PL/pgSQL to not fail when a FOR loop's target variable is a
       record containing composite-type fields (Tom)
     * Fix PL/Tcl to behave correctly with Tcl 8.5, and to be more careful
       about the encoding of data sent to or from Tcl (Tom)
     * Improve performance of PQescapeBytea() (Rudolf Leitgeb)
     * On Windows, work around a Microsoft bug by preventing libpq from
       trying to send more than 64kB per system call (Magnus)
     * Fix ecpg to handle variables properly in "SET" commands (Michael)
     * Improve pg_dump and pg_restore's error reporting after failure to
       send a SQL command (Tom)
     * Fix pg_ctl to properly preserve postmaster command-line arguments
       across a restart (Bruce)
     * Fix erroneous WAL file cutoff point calculation in pg_standby
       (Simon)
     * Update time zone data files to tzdata release 2008f (for DST law
       changes in Argentina, Bahamas, Brazil, Mauritius, Morocco,
       Pakistan, Palestine, and Paraguay)
     __________________________________________________________________

                                Release 8.3.3

     Release Date: 2008-06-12

   This release contains one serious and one minor bug fix over 8.3.2. For
   information about new features in the 8.3 major release, see the
   Section called Release 8.3.
     __________________________________________________________________

Migration to Version 8.3.3

   A dump/restore is not required for those running 8.3.X. However, if you
   are upgrading from a version earlier than 8.3.1, see the release notes
   for 8.3.1.
     __________________________________________________________________

Changes

     * Make pg_get_ruledef() parenthesize negative constants (Tom)
       Before this fix, a negative constant in a view or rule might be
       dumped as, say, -42::integer, which is subtly incorrect: it should
       be (-42)::integer due to operator precedence rules. Usually this
       would make little difference, but it could interact with another
       recent patch to cause PostgreSQL to reject what had been a valid
       "SELECT DISTINCT" view query. Since this could result in pg_dump
       output failing to reload, it is being treated as a high-priority
       fix. The only released versions in which dump output is actually
       incorrect are 8.3.1 and 8.2.7.
     * Make "ALTER AGGREGATE ... OWNER TO" update pg_shdepend (Tom)
       This oversight could lead to problems if the aggregate was later
       involved in a "DROP OWNED" or "REASSIGN OWNED" operation.
     __________________________________________________________________

                                Release 8.3.2

     Release Date: never released

   This release contains a variety of fixes from 8.3.1. For information
   about new features in the 8.3 major release, see the Section called
   Release 8.3.
     __________________________________________________________________

Migration to Version 8.3.2

   A dump/restore is not required for those running 8.3.X. However, if you
   are upgrading from a version earlier than 8.3.1, see the release notes
   for 8.3.1.
     __________________________________________________________________

Changes

     * Fix ERRORDATA_STACK_SIZE exceeded crash that occurred on Windows
       when using UTF-8 database encoding and a different client encoding
       (Tom)
     * Fix incorrect archive truncation point calculation for the %r macro
       in recovery_command parameters (Simon)
       This could lead to data loss if a warm-standby script relied on %r
       to decide when to throw away WAL segment files.
     * Fix "ALTER TABLE ADD COLUMN ... PRIMARY KEY" so that the new column
       is correctly checked to see if it's been initialized to all
       non-nulls (Brendan Jurd)
       Previous versions neglected to check this requirement at all.
     * Fix "REASSIGN OWNED" so that it works on procedural languages too
       (Alvaro)
     * Fix problems with "SELECT FOR UPDATE/SHARE" occurring as a subquery
       in a query with a non-"SELECT" top-level operation (Tom)
     * Fix possible "CREATE TABLE" failure when inheriting the "same"
       constraint from multiple parent relations that inherited that
       constraint from a common ancestor (Tom)
     * Fix pg_get_ruledef() to show the alias, if any, attached to the
       target table of an "UPDATE" or "DELETE" (Tom)
     * Restore the pre-8.3 behavior that an out-of-range block number in a
       TID being used in a TidScan plan results in silently not matching
       any rows (Tom)
       8.3.0 and 8.3.1 threw an error instead.
     * Fix GIN bug that could result in a too many LWLocks taken failure
       (Teodor)
     * Fix broken GiST comparison function for tsquery (Teodor)
     * Fix tsvector_update_trigger() and ts_stat() to accept domains over
       the types they expect to work with (Tom)
     * Fix failure to support enum data types as foreign keys (Tom)
     * Avoid possible crash when decompressing corrupted data (Zdenek
       Kotala)
     * Fix race conditions between delayed unlinks and "DROP DATABASE"
       (Heikki)
       In the worst case this could result in deleting a newly created
       table in a new database that happened to get the same OID as the
       recently-dropped one; but of course that is an extremely
       low-probability scenario.
     * Repair two places where SIGTERM exit of a backend could leave
       corrupted state in shared memory (Tom)
       Neither case is very important if SIGTERM is used to shut down the
       whole database cluster together, but there was a problem if someone
       tried to SIGTERM individual backends.
     * Fix possible crash due to incorrect plan generated for an x IN
       (SELECT y FROM ...) clause when "x" and "y" have different data
       types; and make sure the behavior is semantically correct when the
       conversion from "y"'s type to "x"'s type is lossy (Tom)
     * Fix oversight that prevented the planner from substituting known
       Param values as if they were constants (Tom)
       This mistake partially disabled optimization of unnamed
       extended-Query statements in 8.3.0 and 8.3.1: in particular the
       LIKE-to-indexscan optimization would never be applied if the LIKE
       pattern was passed as a parameter, and constraint exclusion
       depending on a parameter value didn't work either.
     * Fix planner failure when an indexable MIN or MAX aggregate is used
       with DISTINCT or ORDER BY (Tom)
     * Fix planner to ensure it never uses a "physical tlist" for a plan
       node that is feeding a Sort node (Tom)
       This led to the sort having to push around more data than it really
       needed to, since unused column values were included in the sorted
       data.
     * Avoid unnecessary copying of query strings (Tom)
       This fixes a performance problem introduced in 8.3.0 when a very
       large number of commands are submitted as a single query string.
     * Make TransactionIdIsCurrentTransactionId() use binary search
       instead of linear search when checking child-transaction XIDs
       (Heikki)
       This fixes some cases in which 8.3.0 was significantly slower than
       earlier releases.
     * Fix conversions between ISO-8859-5 and other encodings to handle
       Cyrillic "Yo" characters (e and E with two dots) (Sergey Burladyan)
     * Fix several datatype input functions, notably array_in(), that were
       allowing unused bytes in their results to contain uninitialized,
       unpredictable values (Tom)
       This could lead to failures in which two apparently identical
       literal values were not seen as equal, resulting in the parser
       complaining about unmatched ORDER BY and DISTINCT expressions.
     * Fix a corner case in regular-expression substring matching
       (substring(string from pattern)) (Tom)
       The problem occurs when there is a match to the pattern overall but
       the user has specified a parenthesized subexpression and that
       subexpression hasn't got a match. An example is substring('foo'
       from 'foo(bar)?'). This should return NULL, since (bar) isn't
       matched, but it was mistakenly returning the whole-pattern match
       instead (ie, foo).
     * Prevent cancellation of an auto-vacuum that was launched to prevent
       XID wraparound (Alvaro)
     * Improve "ANALYZE"'s handling of in-doubt tuples (those inserted or
       deleted by a not-yet-committed transaction) so that the counts it
       reports to the stats collector are more likely to be correct (Pavan
       Deolasee)
     * Fix initdb to reject a relative path for its --xlogdir (-X) option
       (Tom)
     * Make psql print tab characters as an appropriate number of spaces,
       rather than \x09 as was done in 8.3.0 and 8.3.1 (Bruce)
     * Update time zone data files to tzdata release 2008c (for DST law
       changes in Morocco, Iraq, Choibalsan, Pakistan, Syria, Cuba, and
       Argentina/San_Luis)
     * Add ECPGget_PGconn() function to ecpglib (Michael)
     * Fix incorrect result from ecpg's PGTYPEStimestamp_sub() function
       (Michael)
     * Fix handling of continuation line markers in ecpg (Michael)
     * Fix possible crashes in "contrib/cube" functions (Tom)
     * Fix core dump in "contrib/xml2"'s xpath_table() function when the
       input query returns a NULL value (Tom)
     * Fix "contrib/xml2"'s makefile to not override CFLAGS, and make it
       auto-configure properly for libxslt present or not (Tom)
     __________________________________________________________________

                                Release 8.3.1

     Release Date: 2008-03-17

   This release contains a variety of fixes from 8.3.0. For information
   about new features in the 8.3 major release, see the Section called
   Release 8.3.
     __________________________________________________________________

Migration to Version 8.3.1

   A dump/restore is not required for those running 8.3.X. However, you
   might need to "REINDEX" indexes on textual columns after updating, if
   you are affected by the Windows locale issue described below.
     __________________________________________________________________

Changes

     * Fix character string comparison for Windows locales that consider
       different character combinations as equal (Tom)
       This fix applies only on Windows and only when using UTF-8 database
       encoding. The same fix was made for all other cases over two years
       ago, but Windows with UTF-8 uses a separate code path that was not
       updated. If you are using a locale that considers some
       non-identical strings as equal, you may need to "REINDEX" to fix
       existing indexes on textual columns.
     * Repair corner-case bugs in "VACUUM FULL" (Tom)
       A potential deadlock between concurrent "VACUUM FULL" operations on
       different system catalogs was introduced in 8.2. This has now been
       corrected. 8.3 made this worse because the deadlock could occur
       within a critical code section, making it a PANIC rather than just
       ERROR condition.
       Also, a "VACUUM FULL" that failed partway through vacuuming a
       system catalog could result in cache corruption in concurrent
       database sessions.
       Another "VACUUM FULL" bug introduced in 8.3 could result in a crash
       or out-of-memory report when dealing with pages containing no live
       tuples.
     * Fix misbehavior of foreign key checks involving character or bit
       columns (Tom)
       If the referencing column were of a different but compatible type
       (for instance varchar), the constraint was enforced incorrectly.
     * Avoid needless deadlock failures in no-op foreign-key checks
       (Stephan Szabo, Tom)
     * Fix possible core dump when re-planning a prepared query (Tom)
       This bug affected only protocol-level prepare operations, not SQL
       "PREPARE", and so tended to be seen only with JDBC, DBI, and other
       client-side drivers that use prepared statements heavily.
     * Fix possible failure when re-planning a query that calls an
       SPI-using function (Tom)
     * Fix failure in row-wise comparisons involving columns of different
       datatypes (Tom)
     * Fix longstanding "LISTEN"/"NOTIFY" race condition (Tom)
       In rare cases a session that had just executed a "LISTEN" might not
       get a notification, even though one would be expected because the
       concurrent transaction executing "NOTIFY" was observed to commit
       later.
       A side effect of the fix is that a transaction that has executed a
       not-yet-committed "LISTEN" command will not see any row in
       pg_listener for the "LISTEN", should it choose to look; formerly it
       would have. This behavior was never documented one way or the
       other, but it is possible that some applications depend on the old
       behavior.
     * Disallow "LISTEN" and "UNLISTEN" within a prepared transaction
       (Tom)
       This was formerly allowed but trying to do it had various
       unpleasant consequences, notably that the originating backend could
       not exit as long as an "UNLISTEN" remained uncommitted.
     * Disallow dropping a temporary table within a prepared transaction
       (Heikki)
       This was correctly disallowed by 8.1, but the check was
       inadvertently broken in 8.2 and 8.3.
     * Fix rare crash when an error occurs during a query using a hash
       index (Heikki)
     * Fix incorrect comparison of tsquery values (Teodor)
     * Fix incorrect behavior of LIKE with non-ASCII characters in
       single-byte encodings (Rolf Jentsch)
     * Disable xmlvalidate (Tom)
       This function should have been removed before 8.3 release, but was
       inadvertently left in the source code. It poses a small security
       risk since unprivileged users could use it to read the first few
       characters of any file accessible to the server.
     * Fix memory leaks in certain usages of set-returning functions
       (Neil)
     * Make encode(bytea, 'escape') convert all high-bit-set byte values
       into \"nnn" octal escape sequences (Tom)
       This is necessary to avoid encoding problems when the database
       encoding is multi-byte. This change could pose compatibility issues
       for applications that are expecting specific results from encode.
     * Fix input of datetime values for February 29 in years BC (Tom)
       The former coding was mistaken about which years were leap years.
     * Fix "unrecognized node type" error in some variants of "ALTER
       OWNER" (Tom)
     * Avoid tablespace permissions errors in "CREATE TABLE LIKE INCLUDING
       INDEXES" (Tom)
     * Ensure pg_stat_activity.waiting flag is cleared when a lock wait is
       aborted (Tom)
     * Fix handling of process permissions on Windows Vista (Dave, Magnus)
       In particular, this fix allows starting the server as the
       Administrator user.
     * Update time zone data files to tzdata release 2008a (in particular,
       recent Chile changes); adjust timezone abbreviation VET (Venezuela)
       to mean UTC-4:30, not UTC-4:00 (Tom)
     * Fix ecpg problems with arrays (Michael)
     * Fix pg_ctl to correctly extract the postmaster's port number from
       command-line options (Itagaki Takahiro, Tom)
       Previously, pg_ctl start -w could try to contact the postmaster on
       the wrong port, leading to bogus reports of startup failure.
     * Use "-fwrapv" to defend against possible misoptimization in recent
       gcc versions (Tom)
       This is known to be necessary when building PostgreSQL with gcc 4.3
       or later.
     * Enable building "contrib/uuid-ossp" with MSVC (Hiroshi Saito)
     __________________________________________________________________

                                 Release 8.3

     Release Date: 2008-02-04
     __________________________________________________________________

Overview

   With significant new functionality and performance enhancements, this
   release represents a major leap forward for PostgreSQL. This was made
   possible by a growing community that has dramatically accelerated the
   pace of development. This release adds the following major features:

     * Full text search is integrated into the core database system
     * Support for the SQL/XML standard, including new operators and an
       XML data type
     * Enumerated data types (ENUM)
     * Arrays of composite types
     * Universally Unique Identifier (UUID) data type
     * Add control over whether NULLs sort first or last
     * Updatable cursors
     * Server configuration parameters can now be set on a per-function
       basis
     * User-defined types can now have type modifiers
     * Automatically re-plan cached queries when table definitions change
       or statistics are updated
     * Numerous improvements in logging and statistics collection
     * Support Security Service Provider Interface (SSPI) for
       authentication on Windows
     * Support multiple concurrent autovacuum processes, and other
       autovacuum improvements
     * Allow the whole PostgreSQL distribution to be compiled with
       Microsoft Visual C++

   Major performance improvements are listed below. Most of these
   enhancements are automatic and do not require user changes or tuning:

     * Asynchronous commit delays writes to WAL during transaction commit
     * Checkpoint writes can be spread over a longer time period to smooth
       the I/O spike during each checkpoint
     * Heap-Only Tuples (HOT) accelerate space reuse for most "UPDATE"s
       and "DELETE"s
     * Just-in-time background writer strategy improves disk write
       efficiency
     * Using non-persistent transaction IDs for read-only transactions
       reduces overhead and "VACUUM" requirements
     * Per-field and per-row storage overhead has been reduced
     * Large sequential scans no longer force out frequently used cached
       pages
     * Concurrent large sequential scans can now share disk reads
     * ORDER BY ... LIMIT can be done without sorting

   The above items are explained in more detail in the sections below.
     __________________________________________________________________

Migration to Version 8.3

   A dump/restore using pg_dump is required for those wishing to migrate
   data from any previous release.

   Observe the following incompatibilities:
     __________________________________________________________________

General

     * Non-character data types are no longer automatically cast to TEXT
       (Peter, Tom)
       Previously, if a non-character value was supplied to an operator or
       function that requires text input, it was automatically cast to
       text, for most (though not all) built-in data types. This no longer
       happens: an explicit cast to text is now required for all
       non-character-string types. For example, these expressions formerly
       worked:
substr(current_date, 1, 4)
23 LIKE '2%'
       but will now draw "function does not exist" and "operator does not
       exist" errors respectively. Use an explicit cast instead:
substr(current_date::text, 1, 4)
23::text LIKE '2%'
       (Of course, you can use the more verbose CAST() syntax too.) The
       reason for the change is that these automatic casts too often
       caused surprising behavior. An example is that in previous
       releases, this expression was accepted but did not do what was
       expected:
current_date < 2017-11-17
       This is actually comparing a date to an integer, which should be
       (and now is) rejected -- but in the presence of automatic casts
       both sides were cast to text and a textual comparison was done,
       because the text < text operator was able to match the expression
       when no other < operator could.
       Types char(n) and varchar(n) still cast to text automatically.
       Also, automatic casting to text still works for inputs to the
       concatenation (||) operator, so long as least one input is a
       character-string type.
     * Full text search features from "contrib/tsearch2" have been moved
       into the core server, with some minor syntax changes
       "contrib/tsearch2" now contains a compatibility interface.
     * ARRAY(SELECT ...), where the "SELECT" returns no rows, now returns
       an empty array, rather than NULL (Tom)
     * The array type name for a base data type is no longer always the
       base type's name with an underscore prefix
       The old naming convention is still honored when possible, but
       application code should no longer depend on it. Instead use the new
       pg_type.typarray column to identify the array data type associated
       with a given type.
     * ORDER BY ... USING "operator" must now use a less-than or
       greater-than "operator" that is defined in a btree operator class
       This restriction was added to prevent inconsistent results.
     * "SET LOCAL" changes now persist until the end of the outermost
       transaction, unless rolled back (Tom)
       Previously "SET LOCAL"'s effects were lost after subtransaction
       commit ("RELEASE SAVEPOINT" or exit from a PL/pgSQL exception
       block).
     * Commands rejected in transaction blocks are now also rejected in
       multiple-statement query strings (Tom)
       For example, "BEGIN; DROP DATABASE; COMMIT" will now be rejected
       even if submitted as a single query message.
     * "ROLLBACK" outside a transaction block now issues NOTICE instead of
       WARNING (Bruce)
     * Prevent "NOTIFY"/"LISTEN"/"UNLISTEN" from accepting
       schema-qualified names (Bruce)
       Formerly, these commands accepted schema.relation but ignored the
       schema part, which was confusing.
     * "ALTER SEQUENCE" no longer affects the sequence's currval() state
       (Tom)
     * Foreign keys now must match indexable conditions for
       cross-data-type references (Tom)
       This improves semantic consistency and helps avoid performance
       problems.
     * Restrict object size functions to users who have reasonable
       permissions to view such information (Tom)
       For example, pg_database_size() now requires CONNECT permission,
       which is granted to everyone by default. pg_tablespace_size()
       requires CREATE permission in the tablespace, or is allowed if the
       tablespace is the default tablespace for the database.
     * Remove the undocumented !!= (not in) operator (Tom)
       NOT IN (SELECT ...) is the proper way to perform this operation.
     * Internal hashing functions are now more uniformly-distributed (Tom)
       If application code was computing and storing hash values using
       internal PostgreSQL hashing functions, the hash values must be
       regenerated.
     * C-code conventions for handling variable-length data values have
       changed (Greg Stark, Tom)
       The new SET_VARSIZE() macro *must* be used to set the length of
       generated varlena values. Also, it might be necessary to expand
       ("de-TOAST") input values in more cases.
     * Continuous archiving no longer reports each successful archive
       operation to the server logs unless DEBUG level is used (Simon)
     __________________________________________________________________

Configuration Parameters

     * Numerous changes in administrative server parameters
       bgwriter_lru_percent, bgwriter_all_percent, bgwriter_all_maxpages,
       stats_start_collector, and stats_reset_on_server_start are removed.
       redirect_stderr is renamed to logging_collector.
       stats_command_string is renamed to track_activities.
       stats_block_level and stats_row_level are merged into track_counts.
       A new boolean configuration parameter, archive_mode, controls
       archiving. Autovacuum's default settings have changed.
     * Remove stats_start_collector parameter (Tom)
       We now always start the collector process, unless UDP socket
       creation fails.
     * Remove stats_reset_on_server_start parameter (Tom)
       This was removed because pg_stat_reset() can be used for this
       purpose.
     * Commenting out a parameter in "postgresql.conf" now causes it to
       revert to its default value (Joachim Wieland)
       Previously, commenting out an entry left the parameter's value
       unchanged until the next server restart.
     __________________________________________________________________

Character Encodings

     * Add more checks for invalidly-encoded data (Andrew)
       This change plugs some holes that existed in literal backslash
       escape string processing and "COPY" escape processing. Now the
       de-escaped string is rechecked to see if the result created an
       invalid multi-byte character.
     * Disallow database encodings that are inconsistent with the server's
       locale setting (Tom)
       On most platforms, C locale is the only locale that will work with
       any database encoding. Other locale settings imply a specific
       encoding and will misbehave if the database encoding is something
       different. (Typical symptoms include bogus textual sort order and
       wrong results from upper() or lower().) The server now rejects
       attempts to create databases that have an incompatible encoding.
     * Ensure that chr() cannot create invalidly-encoded values (Andrew)
       In UTF8-encoded databases the argument of chr() is now treated as a
       Unicode code point. In other multi-byte encodings chr()'s argument
       must designate a 7-bit ASCII character. Zero is no longer accepted.
       ascii() has been adjusted to match.
     * Adjust convert() behavior to ensure encoding validity (Andrew)
       The two argument form of convert() has been removed. The three
       argument form now takes a bytea first argument and returns a bytea.
       To cover the loss of functionality, three new functions have been
       added:
          + convert_from(bytea, name) returns text -- converts the first
            argument from the named encoding to the database encoding
          + convert_to(text, name) returns bytea -- converts the first
            argument from the database encoding to the named encoding
          + length(bytea, name) returns integer -- gives the length of the
            first argument in characters in the named encoding
     * Remove convert(argument USING conversion_name) (Andrew)
       Its behavior did not match the SQL standard.
     * Make JOHAB encoding client-only (Tatsuo)
       JOHAB is not safe as a server-side encoding.
     __________________________________________________________________

Changes

   Below you will find a detailed account of the changes between
   PostgreSQL 8.3 and the previous major release.
     __________________________________________________________________

Performance

     * Asynchronous commit delays writes to WAL during transaction commit
       (Simon)
       This feature dramatically increases performance for short
       data-modifying transactions. The disadvantage is that because disk
       writes are delayed, if the database or operating system crashes
       before data is written to the disk, committed data will be lost.
       This feature is useful for applications that can accept some data
       loss. Unlike turning off fsync, using asynchronous commit does not
       put database consistency at risk; the worst case is that after a
       crash the last few reportedly-committed transactions might not be
       committed after all. This feature is enabled by turning off
       synchronous_commit (which can be done per-session or
       per-transaction, if some transactions are critical and others are
       not). wal_writer_delay can be adjusted to control the maximum delay
       before transactions actually reach disk.
     * Checkpoint writes can be spread over a longer time period to smooth
       the I/O spike during each checkpoint (Itagaki Takahiro and Heikki
       Linnakangas)
       Previously all modified buffers were forced to disk as quickly as
       possible during a checkpoint, causing an I/O spike that decreased
       server performance. This new approach spreads out disk writes
       during checkpoints, reducing peak I/O usage. (User-requested and
       shutdown checkpoints are still written as quickly as possible.)
     * Heap-Only Tuples (HOT) accelerate space reuse for most "UPDATE"s
       and "DELETE"s (Pavan Deolasee, with ideas from many others)
       "UPDATE"s and "DELETE"s leave dead tuples behind, as do failed
       "INSERT"s. Previously only "VACUUM" could reclaim space taken by
       dead tuples. With HOT dead tuple space can be automatically
       reclaimed at the time of "INSERT" or "UPDATE" if no changes are
       made to indexed columns. This allows for more consistent
       performance. Also, HOT avoids adding duplicate index entries.
     * Just-in-time background writer strategy improves disk write
       efficiency (Greg Smith, Itagaki Takahiro)
       This greatly reduces the need for manual tuning of the background
       writer.
     * Per-field and per-row storage overhead have been reduced (Greg
       Stark, Heikki Linnakangas)
       Variable-length data types with data values less than 128 bytes
       long will see a storage decrease of 3 to 6 bytes. For example, two
       adjacent char(1) fields now use 4 bytes instead of 16. Row headers
       are also 4 bytes shorter than before.
     * Using non-persistent transaction IDs for read-only transactions
       reduces overhead and "VACUUM" requirements (Florian Pflug)
       Non-persistent transaction IDs do not increment the global
       transaction counter. Therefore, they reduce the load on pg_clog and
       increase the time between forced vacuums to prevent transaction ID
       wraparound. Other performance improvements were also made that
       should improve concurrency.
     * Avoid incrementing the command counter after a read-only command
       (Tom)
       There was formerly a hard limit of 2^32 (4 billion) commands per
       transaction. Now only commands that actually changed the database
       count, so while this limit still exists, it should be significantly
       less annoying.
     * Create a dedicated WAL writer process to off-load work from
       backends (Simon)
     * Skip unnecessary WAL writes for "CLUSTER" and "COPY" (Simon)
       Unless WAL archiving is enabled, the system now avoids WAL writes
       for "CLUSTER" and just fsync()s the table at the end of the
       command. It also does the same for "COPY" if the table was created
       in the same transaction.
     * Large sequential scans no longer force out frequently used cached
       pages (Simon, Heikki, Tom)
     * Concurrent large sequential scans can now share disk reads (Jeff
       Davis)
       This is accomplished by starting the new sequential scan in the
       middle of the table (where another sequential scan is already
       in-progress) and wrapping around to the beginning to finish. This
       can affect the order of returned rows in a query that does not
       specify ORDER BY. The synchronize_seqscans configuration parameter
       can be used to disable this if necessary.
     * ORDER BY ... LIMIT can be done without sorting (Greg Stark)
       This is done by sequentially scanning the table and tracking just
       the "top N" candidate rows, rather than performing a full sort of
       the entire table. This is useful when there is no matching index
       and the LIMIT is not large.
     * Put a rate limit on messages sent to the statistics collector by
       backends (Tom)
       This reduces overhead for short transactions, but might sometimes
       increase the delay before statistics are tallied.
     * Improve hash join performance for cases with many NULLs (Tom)
     * Speed up operator lookup for cases with non-exact datatype matches
       (Tom)
     __________________________________________________________________

Server

     * Autovacuum is now enabled by default (Alvaro)
       Several changes were made to eliminate disadvantages of having
       autovacuum enabled, thereby justifying the change in default.
       Several other autovacuum parameter defaults were also modified.
     * Support multiple concurrent autovacuum processes (Alvaro, Itagaki
       Takahiro)
       This allows multiple vacuums to run concurrently. This prevents
       vacuuming of a large table from delaying vacuuming of smaller
       tables.
     * Automatically re-plan cached queries when table definitions change
       or statistics are updated (Tom)
       Previously PL/pgSQL functions that referenced temporary tables
       would fail if the temporary table was dropped and recreated between
       function invocations, unless EXECUTE was used. This improvement
       fixes that problem and many related issues.
     * Add a temp_tablespaces parameter to control the tablespaces for
       temporary tables and files (Jaime Casanova, Albert Cervera, Bernd
       Helmle)
       This parameter defines a list of tablespaces to be used. This
       enables spreading the I/O load across multiple tablespaces. A
       random tablespace is chosen each time a temporary object is
       created. Temporary files are no longer stored in per-database
       "pgsql_tmp/" directories but in per-tablespace directories.
     * Place temporary tables' TOAST tables in special schemas named
       pg_toast_temp_nnn (Tom)
       This allows low-level code to recognize these tables as temporary,
       which enables various optimizations such as not WAL-logging changes
       and using local rather than shared buffers for access. This also
       fixes a bug wherein backends unexpectedly held open file references
       to temporary TOAST tables.
     * Fix problem that a constant flow of new connection requests could
       indefinitely delay the postmaster from completing a shutdown or a
       crash restart (Tom)
     * Guard against a very-low-probability data loss scenario by
       preventing re-use of a deleted table's relfilenode until after the
       next checkpoint (Heikki)
     * Fix "CREATE CONSTRAINT TRIGGER" to convert old-style foreign key
       trigger definitions into regular foreign key constraints (Tom)
       This will ease porting of foreign key constraints carried forward
       from pre-7.3 databases, if they were never converted using
       "contrib/adddepend".
     * Fix DEFAULT NULL to override inherited defaults (Tom)
       DEFAULT NULL was formerly considered a noise phrase, but it should
       (and now does) override non-null defaults that would otherwise be
       inherited from a parent table or domain.
     * Add new encodings EUC_JIS_2004 and SHIFT_JIS_2004 (Tatsuo)
       These new encodings can be converted to and from UTF-8.
     * Change server startup log message from "database system is ready"
       to "database system is ready to accept connections", and adjust its
       timing
       The message now appears only when the postmaster is really ready to
       accept connections.
     __________________________________________________________________

Monitoring

     * Add log_autovacuum_min_duration parameter to support configurable
       logging of autovacuum activity (Simon, Alvaro)
     * Add log_lock_waits parameter to log lock waiting (Simon)
     * Add log_temp_files parameter to log temporary file usage (Bill
       Moran)
     * Add log_checkpoints parameter to improve logging of checkpoints
       (Greg Smith, Heikki)
     * log_line_prefix now supports %s and %c escapes in all processes
       (Andrew)
       Previously these escapes worked only for user sessions, not for
       background database processes.
     * Add log_restartpoints to control logging of point-in-time recovery
       restart points (Simon)
     * Last transaction end time is now logged at end of recovery and at
       each logged restart point (Simon)
     * Autovacuum now reports its activity start time in pg_stat_activity
       (Tom)
     * Allow server log output in comma-separated value (CSV) format (Arul
       Shaji, Greg Smith, Andrew Dunstan)
       CSV-format log files can easily be loaded into a database table for
       subsequent analysis.
     * Use PostgreSQL-supplied timezone support for formatting timestamps
       displayed in the server log (Tom)
       This avoids Windows-specific problems with localized time zone
       names that are in the wrong encoding. There is a new log_timezone
       parameter that controls the timezone used in log messages,
       independently of the client-visible timezone parameter.
     * New system view pg_stat_bgwriter displays statistics about
       background writer activity (Magnus)
     * Add new columns for database-wide tuple statistics to
       pg_stat_database (Magnus)
     * Add an xact_start (transaction start time) column to
       pg_stat_activity (Neil)
       This makes it easier to identify long-running transactions.
     * Add n_live_tuples and n_dead_tuples columns to pg_stat_all_tables
       and related views (Glen Parker)
     * Merge stats_block_level and stats_row_level parameters into a
       single parameter track_counts, which controls all messages sent to
       the statistics collector process (Tom)
     * Rename stats_command_string parameter to track_activities (Tom)
     * Fix statistical counting of live and dead tuples to recognize that
       committed and aborted transactions have different effects (Tom)
     __________________________________________________________________

Authentication

     * Support Security Service Provider Interface (SSPI) for
       authentication on Windows (Magnus)
     * Support GSSAPI authentication (Henry Hotz, Magnus)
       This should be preferred to native Kerberos authentication because
       GSSAPI is an industry standard.
     * Support a global SSL configuration file (Victor Wagner)
     * Add ssl_ciphers parameter to control accepted SSL ciphers (Victor
       Wagner)
     * Add a Kerberos realm parameter, krb_realm (Magnus)
     __________________________________________________________________

Write-Ahead Log (WAL) and Continuous Archiving

     * Change the timestamps recorded in transaction WAL records from
       time_t to TimestampTz representation (Tom)
       This provides sub-second resolution in WAL, which can be useful for
       point-in-time recovery.
     * Reduce WAL disk space needed by warm standby servers (Simon)
       This change allows a warm standby server to pass the name of the
       earliest still-needed WAL file to the recovery script, allowing
       automatic removal of no-longer-needed WAL files. This is done using
       %r in the restore_command parameter of "recovery.conf".
     * New boolean configuration parameter, archive_mode, controls
       archiving (Simon)
       Previously setting archive_command to an empty string turned off
       archiving. Now archive_mode turns archiving on and off,
       independently of archive_command. This is useful for stopping
       archiving temporarily.
     __________________________________________________________________

Queries

     * Full text search is integrated into the core database system
       (Teodor, Oleg)
       Text search has been improved, moved into the core code, and is now
       installed by default. "contrib/tsearch2" now contains a
       compatibility interface.
     * Add control over whether NULLs sort first or last (Teodor, Tom)
       The syntax is ORDER BY ... NULLS FIRST/LAST.
     * Allow per-column ascending/descending (ASC/DESC) ordering options
       for indexes (Teodor, Tom)
       Previously a query using ORDER BY with mixed ASC/DESC specifiers
       could not fully use an index. Now an index can be fully used in
       such cases if the index was created with matching ASC/DESC
       specifications. NULL sort order within an index can be controlled,
       too.
     * Allow col IS NULL to use an index (Teodor)
     * Updatable cursors (Arul Shaji, Tom)
       This eliminates the need to reference a primary key to "UPDATE" or
       "DELETE" rows returned by a cursor. The syntax is UPDATE/DELETE
       WHERE CURRENT OF.
     * Allow FOR UPDATE in cursors (Arul Shaji, Tom)
     * Create a general mechanism that supports casts to and from the
       standard string types (TEXT, VARCHAR, CHAR) for *every* datatype,
       by invoking the datatype's I/O functions (Tom)
       Previously, such casts were available only for types that had
       specialized function(s) for the purpose. These new casts are
       assignment-only in the to-string direction, explicit-only in the
       other direction, and therefore should create no surprising
       behavior.
     * Allow UNION and related constructs to return a domain type, when
       all inputs are of that domain type (Tom)
       Formerly, the output would be considered to be of the domain's base
       type.
     * Allow limited hashing when using two different data types (Tom)
       This allows hash joins, hash indexes, hashed subplans, and hash
       aggregation to be used in situations involving cross-data-type
       comparisons, if the data types have compatible hash functions.
       Currently, cross-data-type hashing support exists for
       smallint/integer/bigint, and for float4/float8.
     * Improve optimizer logic for detecting when variables are equal in a
       WHERE clause (Tom)
       This allows mergejoins to work with descending sort orders, and
       improves recognition of redundant sort columns.
     * Improve performance when planning large inheritance trees in cases
       where most tables are excluded by constraints (Tom)
     __________________________________________________________________

Object Manipulation

     * Arrays of composite types (David Fetter, Andrew, Tom)
       In addition to arrays of explicitly-declared composite types,
       arrays of the rowtypes of regular tables and views are now
       supported, except for rowtypes of system catalogs, sequences, and
       TOAST tables.
     * Server configuration parameters can now be set on a per-function
       basis (Tom)
       For example, functions can now set their own search_path to prevent
       unexpected behavior if a different search_path exists at run-time.
       Security definer functions should set search_path to avoid security
       loopholes.
     * "CREATE/ALTER FUNCTION" now supports COST and ROWS options (Tom)
       COST allows specification of the cost of a function call. ROWS
       allows specification of the average number or rows returned by a
       set-returning function. These values are used by the optimizer in
       choosing the best plan.
     * Implement "CREATE TABLE LIKE ... INCLUDING INDEXES" (Trevor
       Hardcastle, Nikhil Sontakke, Neil)
     * Allow "CREATE INDEX CONCURRENTLY" to ignore transactions in other
       databases (Simon)
     * Add "ALTER VIEW ... RENAME TO" and "ALTER SEQUENCE ... RENAME TO"
       (David Fetter, Neil)
       Previously this could only be done via "ALTER TABLE ... RENAME TO".
     * Make "CREATE/DROP/RENAME DATABASE" wait briefly for conflicting
       backends to exit before failing (Tom)
       This increases the likelihood that these commands will succeed.
     * Allow triggers and rules to be deactivated in groups using a
       configuration parameter, for replication purposes (Jan)
       This allows replication systems to disable triggers and rewrite
       rules as a group without modifying the system catalogs directly.
       The behavior is controlled by "ALTER TABLE" and a new parameter
       session_replication_role.
     * User-defined types can now have type modifiers (Teodor, Tom)
       This allows a user-defined type to take a modifier, like ssnum(7).
       Previously only built-in data types could have modifiers.
     __________________________________________________________________

Utility Commands

     * Non-superuser database owners now are able to add trusted
       procedural languages to their databases by default (Jeremy Drake)
       While this is reasonably safe, some administrators might wish to
       revoke the privilege. It is controlled by
       pg_pltemplate.tmpldbacreate.
     * Allow a session's current parameter setting to be used as the
       default for future sessions (Tom)
       This is done with SET ... FROM CURRENT in "CREATE/ALTER FUNCTION",
       "ALTER DATABASE", or "ALTER ROLE".
     * Implement new commands "DISCARD ALL", "DISCARD PLANS", "DISCARD
       TEMPORARY", "CLOSE ALL", and "DEALLOCATE ALL" (Marko Kreen, Neil)
       These commands simplify resetting a database session to its initial
       state, and are particularly useful for connection-pooling software.
     * Make "CLUSTER" MVCC-safe (Heikki Linnakangas)
       Formerly, "CLUSTER" would discard all tuples that were committed
       dead, even if there were still transactions that should be able to
       see them under MVCC visibility rules.
     * Add new "CLUSTER" syntax: CLUSTER table USING index (Holger
       Schurig)
       The old "CLUSTER" syntax is still supported, but the new form is
       considered more logical.
     * Fix "EXPLAIN" so it can show complex plans more accurately (Tom)
       References to subplan outputs are now always shown correctly,
       instead of using ?columnN? for complicated cases.
     * Limit the amount of information reported when a user is dropped
       (Alvaro)
       Previously, dropping (or attempting to drop) a user who owned many
       objects could result in large NOTICE or ERROR messages listing all
       these objects; this caused problems for some client applications.
       The length of the message is now limited, although a full list is
       still sent to the server log.
     __________________________________________________________________

Data Types

     * Support for the SQL/XML standard, including new operators and an
       XML data type (Nikolay Samokhvalov, Pavel Stehule, Peter)
     * Enumerated data types (ENUM) (Tom Dunstan)
       This feature provides convenient support for fields that have a
       small, fixed set of allowed values. An example of creating an ENUM
       type is CREATE TYPE mood AS ENUM ('sad', 'ok', 'happy').
     * Universally Unique Identifier (UUID) data type (Gevik Babakhani,
       Neil)
       This closely matches RFC 4122.
     * Widen the MONEY data type to 64 bits (D'Arcy Cain)
       This greatly increases the range of supported MONEY values.
     * Fix float4/float8 to handle Infinity and NAN (Not A Number)
       consistently (Bruce)
       The code formerly was not consistent about distinguishing Infinity
       from overflow conditions.
     * Allow leading and trailing whitespace during input of boolean
       values (Neil)
     * Prevent "COPY" from using digits and lowercase letters as
       delimiters (Tom)
     __________________________________________________________________

Functions

     * Add new regular expression functions regexp_matches(),
       regexp_split_to_array(), and regexp_split_to_table() (Jeremy Drake,
       Neil)
       These functions provide extraction of regular expression
       subexpressions and allow splitting a string using a POSIX regular
       expression.
     * Add lo_truncate() for large object truncation (Kris Jurka)
     * Implement width_bucket() for the float8 data type (Neil)
     * Add pg_stat_clear_snapshot() to discard statistics snapshots
       collected during the current transaction (Tom)
       The first request for statistics in a transaction takes a
       statistics snapshot that does not change during the transaction.
       This function allows the snapshot to be discarded and a new
       snapshot loaded during the next statistics query. This is
       particularly useful for PL/pgSQL functions, which are confined to a
       single transaction.
     * Add isodow option to EXTRACT() and date_part() (Bruce)
       This returns the day of the week, with Sunday as seven. (dow
       returns Sunday as zero.)
     * Add ID (ISO day of week) and IDDD (ISO day of year) format codes
       for to_char(), to_date(), and to_timestamp() (Brendan Jurd)
     * Make to_timestamp() and to_date() assume TM (trim) option for
       potentially variable-width fields (Bruce)
       This matches Oracle's behavior.
     * Fix off-by-one conversion error in to_date()/to_timestamp() D
       (non-ISO day of week) fields (Bruce)
     * Make setseed() return void, rather than a useless integer value
       (Neil)
     * Add a hash function for NUMERIC (Neil)
       This allows hash indexes and hash-based plans to be used with
       NUMERIC columns.
     * Improve efficiency of LIKE/ILIKE, especially for multi-byte
       character sets like UTF-8 (Andrew, Itagaki Takahiro)
     * Make currtid() functions require SELECT privileges on the target
       table (Tom)
     * Add several txid_*() functions to query active transaction IDs
       (Jan)
       This is useful for various replication solutions.
     __________________________________________________________________

PL/pgSQL Server-Side Language

     * Add scrollable cursor support, including directional control in
       "FETCH" (Pavel Stehule)
     * Allow IN as an alternative to FROM in PL/pgSQL's "FETCH" statement,
       for consistency with the backend's "FETCH" command (Pavel Stehule)
     * Add "MOVE" to PL/pgSQL (Magnus, Pavel Stehule, Neil)
     * Implement "RETURN QUERY" (Pavel Stehule, Neil)
       This adds convenient syntax for PL/pgSQL set-returning functions
       that want to return the result of a query. "RETURN QUERY" is easier
       and more efficient than a loop around "RETURN NEXT".
     * Allow function parameter names to be qualified with the function's
       name (Tom)
       For example, myfunc.myvar. This is particularly useful for
       specifying variables in a query where the variable name might match
       a column name.
     * Make qualification of variables with block labels work properly
       (Tom)
       Formerly, outer-level block labels could unexpectedly interfere
       with recognition of inner-level record or row references.
     * Tighten requirements for FOR loop STEP values (Tom)
       Prevent non-positive STEP values, and handle loop overflows.
     * Improve accuracy when reporting syntax error locations (Tom)
     __________________________________________________________________

Other Server-Side Languages

     * Allow type-name arguments to PL/Perl spi_prepare() to be data type
       aliases in addition to names found in pg_type (Andrew)
     * Allow type-name arguments to PL/Python plpy.prepare() to be data
       type aliases in addition to names found in pg_type (Andrew)
     * Allow type-name arguments to PL/Tcl spi_prepare to be data type
       aliases in addition to names found in pg_type (Andrew)
     * Enable PL/PythonU to compile on Python 2.5 (Marko Kreen)
     * Support a true PL/Python boolean type in compatible Python versions
       (Python 2.3 and later) (Marko Kreen)
     * Fix PL/Tcl problems with thread-enabled "libtcl" spawning multiple
       threads within the backend (Steve Marshall, Paul Bayer, Doug
       Knight)
       This caused all sorts of unpleasantness.
     __________________________________________________________________

psql

     * List disabled triggers separately in \d output (Brendan Jurd)
     * In \d patterns, always match $ literally (Tom)
     * Show aggregate return types in \da output (Greg Sabino Mullane)
     * Add the function's volatility status to the output of \df+ (Neil)
     * Add \prompt capability (Chad Wagner)
     * Allow \pset, \t, and \x to specify on or off, rather than just
       toggling (Chad Wagner)
     * Add \sleep capability (Jan)
     * Enable \timing output for \copy (Andrew)
     * Improve \timing resolution on Windows (Itagaki Takahiro)
     * Flush \o output after each backslash command (Tom)
     * Correctly detect and report errors while reading a -f input file
       (Peter)
     * Remove -u option (this option has long been deprecated) (Tom)
     __________________________________________________________________

pg_dump

     * Add --tablespaces-only and --roles-only options to pg_dumpall (Dave
       Page)
     * Add an output file option to pg_dumpall (Dave Page)
       This is primarily useful on Windows, where output redirection of
       child pg_dump processes does not work.
     * Allow pg_dumpall to accept an initial-connection database name
       rather than the default template1 (Dave Page)
     * In -n and -t switches, always match $ literally (Tom)
     * Improve performance when a database has thousands of objects (Tom)
     * Remove -u option (this option has long been deprecated) (Tom)
     __________________________________________________________________

Other Client Applications

     * In initdb, allow the location of the "pg_xlog" directory to be
       specified (Euler Taveira de Oliveira)
     * Enable server core dump generation in pg_regress on supported
       operating systems (Andrew)
     * Add a -t (timeout) parameter to pg_ctl (Bruce)
       This controls how long pg_ctl will wait when waiting for server
       startup or shutdown. Formerly the timeout was hard-wired as 60
       seconds.
     * Add a pg_ctl option to control generation of server core dumps
       (Andrew)
     * Allow Control-C to cancel clusterdb, reindexdb, and vacuumdb
       (Itagaki Takahiro, Magnus)
     * Suppress command tag output for createdb, createuser, dropdb, and
       dropuser (Peter)
       The --quiet option is ignored and will be removed in 8.4. Progress
       messages when acting on all databases now go to stdout instead of
       stderr because they are not actually errors.
     __________________________________________________________________

libpq

     * Interpret the dbName parameter of PQsetdbLogin() as a conninfo
       string if it contains an equals sign (Andrew)
       This allows use of conninfo strings in client programs that still
       use PQsetdbLogin().
     * Support a global SSL configuration file (Victor Wagner)
     * Add environment variable PGSSLKEY to control SSL hardware keys
       (Victor Wagner)
     * Add lo_truncate() for large object truncation (Kris Jurka)
     * Add PQconnectionNeedsPassword() that returns true if the server
       required a password but none was supplied (Joe Conway, Tom)
       If this returns true after a failed connection attempt, a client
       application should prompt the user for a password. In the past
       applications have had to check for a specific error message string
       to decide whether a password is needed; that approach is now
       deprecated.
     * Add PQconnectionUsedPassword() that returns true if the supplied
       password was actually used (Joe Conway, Tom)
       This is useful in some security contexts where it is important to
       know whether a user-supplied password is actually valid.
     __________________________________________________________________

ecpg

     * Use V3 frontend/backend protocol (Michael)
       This adds support for server-side prepared statements.
     * Use native threads, instead of pthreads, on Windows (Magnus)
     * Improve thread-safety of ecpglib (Itagaki Takahiro)
     * Make the ecpg libraries export only necessary API symbols (Michael)
     __________________________________________________________________

Windows Port

     * Allow the whole PostgreSQL distribution to be compiled with
       Microsoft Visual C++ (Magnus and others)
       This allows Windows-based developers to use familiar development
       and debugging tools. Windows executables made with Visual C++ might
       also have better stability and performance than those made with
       other tool sets. The client-only Visual C++ build scripts have been
       removed.
     * Drastically reduce postmaster's memory usage when it has many child
       processes (Magnus)
     * Allow regression tests to be started by an administrative user
       (Magnus)
     * Add native shared memory implementation (Magnus)
     __________________________________________________________________

Server Programming Interface (SPI)

     * Add cursor-related functionality in SPI (Pavel Stehule)
       Allow access to the cursor-related planning options, and add
       "FETCH"/"MOVE" routines.
     * Allow execution of cursor commands through SPI_execute (Tom)
       The macro SPI_ERROR_CURSOR still exists but will never be returned.
     * SPI plan pointers are now declared as SPIPlanPtr instead of void *
       (Tom)
       This does not break application code, but switching is recommended
       to help catch simple programming mistakes.
     __________________________________________________________________

Build Options

     * Add configure option --enable-profiling to enable code profiling
       (works only with gcc) (Korry Douglas and Nikhil Sontakke)
     * Add configure option --with-system-tzdata to use the operating
       system's time zone database (Peter)
     * Fix PGXS so extensions can be built against PostgreSQL
       installations whose pg_config program does not appear first in the
       PATH (Tom)
     * Support "gmake draft" when building the SGML documentation (Bruce)
       Unless draft is used, the documentation build will now be repeated
       if necessary to ensure the index is up-to-date.
     __________________________________________________________________

Source Code

     * Rename macro DLLIMPORT to PGDLLIMPORT to avoid conflicting with
       third party includes (like Tcl) that define DLLIMPORT (Magnus)
     * Create "operator families" to improve planning of queries involving
       cross-data-type comparisons (Tom)
     * Update GIN extractQuery() API to allow signalling that nothing can
       satisfy the query (Teodor)
     * Move NAMEDATALEN definition from "postgres_ext.h" to
       "pg_config_manual.h" (Peter)
     * Provide strlcpy() and strlcat() on all platforms, and replace
       error-prone uses of strncpy(), strncat(), etc (Peter)
     * Create hooks to let an external plugin monitor (or even replace)
       the planner and create plans for hypothetical situations (Gurjeet
       Singh, Tom)
     * Create a function variable join_search_hook to let plugins override
       the join search order portion of the planner (Julius Stroffek)
     * Add tas() support for Renesas' M32R processor (Kazuhiro Inaoka)
     * quote_identifier() and pg_dump no longer quote keywords that are
       unreserved according to the grammar (Tom)
     * Change the on-disk representation of the NUMERIC data type so that
       the sign_dscale word comes before the weight (Tom)
     * Use SYSV semaphores rather than POSIX on Darwin >= 6.0, i.e., OS X
       10.2 and up (Chris Marcellino)
     * Add acronym and NFS documentation sections (Bruce)
     * "Postgres" is now documented as an accepted alias for "PostgreSQL"
       (Peter)
     * Add documentation about preventing database server spoofing when
       the server is down (Bruce)
     __________________________________________________________________

Contrib

     * Move "contrib" "README" content into the main PostgreSQL
       documentation (Albert Cervera i Areny)
     * Add "contrib/pageinspect" module for low-level page inspection
       (Simon, Heikki)
     * Add "contrib/pg_standby" module for controlling warm standby
       operation (Simon)
     * Add "contrib/uuid-ossp" module for generating UUID values using the
       OSSP UUID library (Peter)
       Use configure --with-ossp-uuid to activate. This takes advantage of
       the new UUID builtin type.
     * Add "contrib/dict_int", "contrib/dict_xsyn", and
       "contrib/test_parser" modules to provide sample add-on text search
       dictionary templates and parsers (Sergey Karpov)
     * Allow contrib/pgbench to set the fillfactor (Pavan Deolasee)
     * Add timestamps to contrib/pgbench -l (Greg Smith)
     * Add usage count statistics to "contrib/pgbuffercache" (Greg Smith)
     * Add GIN support for "contrib/hstore" (Teodor)
     * Add GIN support for "contrib/pg_trgm" (Guillaume Smet, Teodor)
     * Update OS/X startup scripts in "contrib/start-scripts" (Mark
       Cotner, David Fetter)
     * Restrict pgrowlocks() and dblink_get_pkey() to users who have
       SELECT privilege on the target table (Tom)
     * Restrict "contrib/pgstattuple" functions to superusers (Tom)
     * "contrib/xml2" is deprecated and planned for removal in 8.4 (Peter)
       The new XML support in core PostgreSQL supersedes this module.
     __________________________________________________________________

                               Release 8.2.23

     Release Date: 2011-12-05

   This release contains a variety of fixes from 8.2.22. For information
   about new features in the 8.2 major release, see the Section called
   Release 8.2.

   This is expected to be the last PostgreSQL release in the 8.2.X series.
   Users are encouraged to update to a newer release branch soon.
     __________________________________________________________________

Migration to Version 8.2.23

   A dump/restore is not required for those running 8.2.X.

   However, a longstanding error was discovered in the definition of the
   information_schema.referential_constraints view. If you rely on correct
   results from that view, you should replace its definition as explained
   in the first changelog item below.

   Also, if you are upgrading from a version earlier than 8.2.14, see the
   release notes for 8.2.14.
     __________________________________________________________________

Changes

     * Fix bugs in information_schema.referential_constraints view (Tom
       Lane)
       This view was being insufficiently careful about matching the
       foreign-key constraint to the depended-on primary or unique key
       constraint. That could result in failure to show a foreign key
       constraint at all, or showing it multiple times, or claiming that
       it depends on a different constraint than the one it really does.
       Since the view definition is installed by initdb, merely upgrading
       will not fix the problem. If you need to fix this in an existing
       installation, you can (as a superuser) drop the information_schema
       schema then re-create it by sourcing
       "SHAREDIR/information_schema.sql". (Run pg_config --sharedir if
       you're uncertain where "SHAREDIR" is.) This must be repeated in
       each database to be fixed.
     * Fix TOAST-related data corruption during CREATE TABLE dest AS
       SELECT * FROM src or INSERT INTO dest SELECT * FROM src (Tom Lane)
       If a table has been modified by "ALTER TABLE ADD COLUMN", attempts
       to copy its data verbatim to another table could produce corrupt
       results in certain corner cases. The problem can only manifest in
       this precise form in 8.4 and later, but we patched earlier versions
       as well in case there are other code paths that could trigger the
       same bug.
     * Fix race condition during toast table access from stale syscache
       entries (Tom Lane)
       The typical symptom was transient errors like "missing chunk number
       0 for toast value NNNNN in pg_toast_2619", where the cited toast
       table would always belong to a system catalog.
     * Improve locale support in money type's input and output (Tom Lane)
       Aside from not supporting all standard lc_monetary formatting
       options, the input and output functions were inconsistent, meaning
       there were locales in which dumped money values could not be
       re-read.
     * Don't let transform_null_equals affect CASE foo WHEN NULL ...
       constructs (Heikki Linnakangas)
       transform_null_equals is only supposed to affect foo = NULL
       expressions written directly by the user, not equality checks
       generated internally by this form of CASE.
     * Change foreign-key trigger creation order to better support
       self-referential foreign keys (Tom Lane)
       For a cascading foreign key that references its own table, a row
       update will fire both the ON UPDATE trigger and the CHECK trigger
       as one event. The ON UPDATE trigger must execute first, else the
       CHECK will check a non-final state of the row and possibly throw an
       inappropriate error. However, the firing order of these triggers is
       determined by their names, which generally sort in creation order
       since the triggers have auto-generated names following the
       convention "RI_ConstraintTrigger_NNNN". A proper fix would require
       modifying that convention, which we will do in 9.2, but it seems
       risky to change it in existing releases. So this patch just changes
       the creation order of the triggers. Users encountering this type of
       error should drop and re-create the foreign key constraint to get
       its triggers into the right order.
     * Preserve blank lines within commands in psql's command history
       (Robert Haas)
       The former behavior could cause problems if an empty line was
       removed from within a string literal, for example.
     * Use the preferred version of xsubpp to build PL/Perl, not
       necessarily the operating system's main copy (David Wheeler and
       Alex Hunsaker)
     * Honor query cancel interrupts promptly in pgstatindex() (Robert
       Haas)
     * Ensure VPATH builds properly install all server header files (Peter
       Eisentraut)
     * Shorten file names reported in verbose error messages (Peter
       Eisentraut)
       Regular builds have always reported just the name of the C file
       containing the error message call, but VPATH builds formerly
       reported an absolute path name.
     * Fix interpretation of Windows timezone names for Central America
       (Tom Lane)
       Map "Central America Standard Time" to CST6, not CST6CDT, because
       DST is generally not observed anywhere in Central America.
     * Update time zone data files to tzdata release 2011n for DST law
       changes in Brazil, Cuba, Fiji, Palestine, Russia, and Samoa; also
       historical corrections for Alaska and British East Africa.
     __________________________________________________________________

                               Release 8.2.22

     Release Date: 2011-09-26

   This release contains a variety of fixes from 8.2.21. For information
   about new features in the 8.2 major release, see the Section called
   Release 8.2.

   The PostgreSQL community will stop releasing updates for the 8.2.X
   release series in December 2011. Users are encouraged to update to a
   newer release branch soon.
     __________________________________________________________________

Migration to Version 8.2.22

   A dump/restore is not required for those running 8.2.X. However, if you
   are upgrading from a version earlier than 8.2.14, see the release notes
   for 8.2.14.
     __________________________________________________________________

Changes

     * Fix multiple bugs in GiST index page split processing (Heikki
       Linnakangas)
       The probability of occurrence was low, but these could lead to
       index corruption.
     * Avoid possibly accessing off the end of memory in "ANALYZE" (Noah
       Misch)
       This fixes a very-low-probability server crash scenario.
     * Fix race condition in relcache init file invalidation (Tom Lane)
       There was a window wherein a new backend process could read a stale
       init file but miss the inval messages that would tell it the data
       is stale. The result would be bizarre failures in catalog accesses,
       typically "could not read block 0 in file ..." later during
       startup.
     * Fix memory leak at end of a GiST index scan (Tom Lane)
       Commands that perform many separate GiST index scans, such as
       verification of a new GiST-based exclusion constraint on a table
       already containing many rows, could transiently require large
       amounts of memory due to this leak.
     * Fix performance problem when constructing a large, lossy bitmap
       (Tom Lane)
     * Fix array- and path-creating functions to ensure padding bytes are
       zeroes (Tom Lane)
       This avoids some situations where the planner will think that
       semantically-equal constants are not equal, resulting in poor
       optimization.
     * Work around gcc 4.6.0 bug that breaks WAL replay (Tom Lane)
       This could lead to loss of committed transactions after a server
       crash.
     * Fix dump bug for VALUES in a view (Tom Lane)
     * Disallow SELECT FOR UPDATE/SHARE on sequences (Tom Lane)
       This operation doesn't work as expected and can lead to failures.
     * Defend against integer overflow when computing size of a hash table
       (Tom Lane)
     * Fix portability bugs in use of credentials control messages for
       "peer" authentication (Tom Lane)
     * Fix typo in pg_srand48 seed initialization (Andres Freund)
       This led to failure to use all bits of the provided seed. This
       function is not used on most platforms (only those without
       srandom), and the potential security exposure from a
       less-random-than-expected seed seems minimal in any case.
     * Avoid integer overflow when the sum of LIMIT and OFFSET values
       exceeds 2^63 (Heikki Linnakangas)
     * Add overflow checks to int4 and int8 versions of generate_series()
       (Robert Haas)
     * Fix trailing-zero removal in to_char() (Marti Raudsepp)
       In a format with FM and no digit positions after the decimal point,
       zeroes to the left of the decimal point could be removed
       incorrectly.
     * Fix pg_size_pretty() to avoid overflow for inputs close to 2^63
       (Tom Lane)
     * Fix psql's counting of script file line numbers during COPY from a
       different file (Tom Lane)
     * Fix pg_restore's direct-to-database mode for
       standard_conforming_strings (Tom Lane)
       pg_restore could emit incorrect commands when restoring directly to
       a database server from an archive file that had been made with
       standard_conforming_strings set to on.
     * Fix write-past-buffer-end and memory leak in libpq's LDAP service
       lookup code (Albe Laurenz)
     * In libpq, avoid failures when using nonblocking I/O and an SSL
       connection (Martin Pihlak, Tom Lane)
     * Improve libpq's handling of failures during connection startup (Tom
       Lane)
       In particular, the response to a server report of fork() failure
       during SSL connection startup is now saner.
     * Make ecpglib write double values with 15 digits precision (Akira
       Kurosawa)
     * Apply upstream fix for blowfish signed-character bug
       (CVE-2011-2483) (Tom Lane)
       "contrib/pg_crypto"'s blowfish encryption code could give wrong
       results on platforms where char is signed (which is most), leading
       to encrypted passwords being weaker than they should be.
     * Fix memory leak in "contrib/seg" (Heikki Linnakangas)
     * Fix pgstatindex() to give consistent results for empty indexes (Tom
       Lane)
     * Allow building with perl 5.14 (Alex Hunsaker)
     * Update configure script's method for probing existence of system
       functions (Tom Lane)
       The version of autoconf we used in 8.3 and 8.2 could be fooled by
       compilers that perform link-time optimization.
     * Fix assorted issues with build and install file paths containing
       spaces (Tom Lane)
     * Update time zone data files to tzdata release 2011i for DST law
       changes in Canada, Egypt, Russia, Samoa, and South Sudan.
     __________________________________________________________________

                               Release 8.2.21

     Release Date: 2011-04-18

   This release contains a variety of fixes from 8.2.20. For information
   about new features in the 8.2 major release, see the Section called
   Release 8.2.
     __________________________________________________________________

Migration to Version 8.2.21

   A dump/restore is not required for those running 8.2.X. However, if you
   are upgrading from a version earlier than 8.2.14, see the release notes
   for 8.2.14.
     __________________________________________________________________

Changes

     * Avoid potential deadlock during catalog cache initialization
       (Nikhil Sontakke)
       In some cases the cache loading code would acquire share lock on a
       system index before locking the index's catalog. This could
       deadlock against processes trying to acquire exclusive locks in the
       other, more standard order.
     * Fix dangling-pointer problem in BEFORE ROW UPDATE trigger handling
       when there was a concurrent update to the target tuple (Tom Lane)
       This bug has been observed to result in intermittent "cannot
       extract system attribute from virtual tuple" failures while trying
       to do UPDATE RETURNING ctid. There is a very small probability of
       more serious errors, such as generating incorrect index entries for
       the updated tuple.
     * Disallow "DROP TABLE" when there are pending deferred trigger
       events for the table (Tom Lane)
       Formerly the "DROP" would go through, leading to "could not open
       relation with OID nnn" errors when the triggers were eventually
       fired.
     * Fix PL/Python memory leak involving array slices (Daniel Popowich)
     * Fix pg_restore to cope with long lines (over 1KB) in TOC files (Tom
       Lane)
     * Put in more safeguards against crashing due to division-by-zero
       with overly enthusiastic compiler optimization (Aurelien Jarno)
     * Support use of dlopen() in FreeBSD and OpenBSD on MIPS (Tom Lane)
       There was a hard-wired assumption that this system function was not
       available on MIPS hardware on these systems. Use a compile-time
       test instead, since more recent versions have it.
     * Fix compilation failures on HP-UX (Heikki Linnakangas)
     * Fix path separator used by pg_regress on Cygwin (Andrew Dunstan)
     * Update time zone data files to tzdata release 2011f for DST law
       changes in Chile, Cuba, Falkland Islands, Morocco, Samoa, and
       Turkey; also historical corrections for South Australia, Alaska,
       and Hawaii.
     __________________________________________________________________

                               Release 8.2.20

     Release Date: 2011-01-31

   This release contains a variety of fixes from 8.2.19. For information
   about new features in the 8.2 major release, see the Section called
   Release 8.2.
     __________________________________________________________________

Migration to Version 8.2.20

   A dump/restore is not required for those running 8.2.X. However, if you
   are upgrading from a version earlier than 8.2.14, see the release notes
   for 8.2.14.
     __________________________________________________________________

Changes

     * Avoid failures when "EXPLAIN" tries to display a simple-form CASE
       expression (Tom Lane)
       If the CASE's test expression was a constant, the planner could
       simplify the CASE into a form that confused the expression-display
       code, resulting in "unexpected CASE WHEN clause" errors.
     * Fix assignment to an array slice that is before the existing range
       of subscripts (Tom Lane)
       If there was a gap between the newly added subscripts and the first
       pre-existing subscript, the code miscalculated how many entries
       needed to be copied from the old array's null bitmap, potentially
       leading to data corruption or crash.
     * Avoid unexpected conversion overflow in planner for very distant
       date values (Tom Lane)
       The date type supports a wider range of dates than can be
       represented by the timestamp types, but the planner assumed it
       could always convert a date to timestamp with impunity.
     * Fix pg_restore's text output for large objects (BLOBs) when
       standard_conforming_strings is on (Tom Lane)
       Although restoring directly to a database worked correctly, string
       escaping was incorrect if pg_restore was asked for SQL text output
       and standard_conforming_strings had been enabled in the source
       database.
     * Fix erroneous parsing of tsquery values containing ... &
       !(subexpression) | ... (Tom Lane)
       Queries containing this combination of operators were not executed
       correctly. The same error existed in "contrib/intarray"'s query_int
       type and "contrib/ltree"'s ltxtquery type.
     * Fix buffer overrun in "contrib/intarray"'s input function for the
       query_int type (Apple)
       This bug is a security risk since the function's return address
       could be overwritten. Thanks to Apple Inc's security team for
       reporting this issue and supplying the fix. (CVE-2010-4015)
     * Fix bug in "contrib/seg"'s GiST picksplit algorithm (Alexander
       Korotkov)
       This could result in considerable inefficiency, though not actually
       incorrect answers, in a GiST index on a seg column. If you have
       such an index, consider "REINDEX"ing it after installing this
       update. (This is identical to the bug that was fixed in
       "contrib/cube" in the previous update.)
     __________________________________________________________________

                               Release 8.2.19

     Release Date: 2010-12-16

   This release contains a variety of fixes from 8.2.18. For information
   about new features in the 8.2 major release, see the Section called
   Release 8.2.
     __________________________________________________________________

Migration to Version 8.2.19

   A dump/restore is not required for those running 8.2.X. However, if you
   are upgrading from a version earlier than 8.2.14, see the release notes
   for 8.2.14.
     __________________________________________________________________

Changes

     * Force the default wal_sync_method to be fdatasync on Linux (Tom
       Lane, Marti Raudsepp)
       The default on Linux has actually been fdatasync for many years,
       but recent kernel changes caused PostgreSQL to choose open_datasync
       instead. This choice did not result in any performance improvement,
       and caused outright failures on certain filesystems, notably ext4
       with the data=journal mount option.
     * Fix assorted bugs in WAL replay logic for GIN indexes (Tom Lane)
       This could result in "bad buffer id: 0" failures or corruption of
       index contents during replication.
     * Fix recovery from base backup when the starting checkpoint WAL
       record is not in the same WAL segment as its redo point (Jeff
       Davis)
     * Add support for detecting register-stack overrun on IA64 (Tom Lane)
       The IA64 architecture has two hardware stacks. Full prevention of
       stack-overrun failures requires checking both.
     * Add a check for stack overflow in copyObject() (Tom Lane)
       Certain code paths could crash due to stack overflow given a
       sufficiently complex query.
     * Fix detection of page splits in temporary GiST indexes (Heikki
       Linnakangas)
       It is possible to have a "concurrent" page split in a temporary
       index, if for example there is an open cursor scanning the index
       when an insertion is done. GiST failed to detect this case and
       hence could deliver wrong results when execution of the cursor
       continued.
     * Avoid memory leakage while "ANALYZE"'ing complex index expressions
       (Tom Lane)
     * Ensure an index that uses a whole-row Var still depends on its
       table (Tom Lane)
       An index declared like create index i on t (foo(t.*)) would not
       automatically get dropped when its table was dropped.
     * Do not "inline" a SQL function with multiple OUT parameters (Tom
       Lane)
       This avoids a possible crash due to loss of information about the
       expected result rowtype.
     * Behave correctly if ORDER BY, LIMIT, FOR UPDATE, or WITH is
       attached to the VALUES part of INSERT ... VALUES (Tom Lane)
     * Fix constant-folding of COALESCE() expressions (Tom Lane)
       The planner would sometimes attempt to evaluate sub-expressions
       that in fact could never be reached, possibly leading to unexpected
       errors.
     * Add print functionality for InhRelation nodes (Tom Lane)
       This avoids a failure when debug_print_parse is enabled and certain
       types of query are executed.
     * Fix incorrect calculation of distance from a point to a horizontal
       line segment (Tom Lane)
       This bug affected several different geometric distance-measurement
       operators.
     * Fix PL/pgSQL's handling of "simple" expressions to not fail in
       recursion or error-recovery cases (Tom Lane)
     * Fix PL/Python's handling of set-returning functions (Jan Urbanski)
       Attempts to call SPI functions within the iterator generating a set
       result would fail.
     * Fix bug in "contrib/cube"'s GiST picksplit algorithm (Alexander
       Korotkov)
       This could result in considerable inefficiency, though not actually
       incorrect answers, in a GiST index on a cube column. If you have
       such an index, consider "REINDEX"ing it after installing this
       update.
     * Don't emit "identifier will be truncated" notices in
       "contrib/dblink" except when creating new connections (Itagaki
       Takahiro)
     * Fix potential coredump on missing public key in "contrib/pgcrypto"
       (Marti Raudsepp)
     * Fix memory leak in "contrib/xml2"'s XPath query functions (Tom
       Lane)
     * Update time zone data files to tzdata release 2010o for DST law
       changes in Fiji and Samoa; also historical corrections for Hong
       Kong.
     __________________________________________________________________

                               Release 8.2.18

     Release Date: 2010-10-04

   This release contains a variety of fixes from 8.2.17. For information
   about new features in the 8.2 major release, see the Section called
   Release 8.2.
     __________________________________________________________________

Migration to Version 8.2.18

   A dump/restore is not required for those running 8.2.X. However, if you
   are upgrading from a version earlier than 8.2.14, see the release notes
   for 8.2.14.
     __________________________________________________________________

Changes

     * Use a separate interpreter for each calling SQL userid in PL/Perl
       and PL/Tcl (Tom Lane)
       This change prevents security problems that can be caused by
       subverting Perl or Tcl code that will be executed later in the same
       session under another SQL user identity (for example, within a
       SECURITY DEFINER function). Most scripting languages offer numerous
       ways that that might be done, such as redefining standard functions
       or operators called by the target function. Without this change,
       any SQL user with Perl or Tcl language usage rights can do
       essentially anything with the SQL privileges of the target
       function's owner.
       The cost of this change is that intentional communication among
       Perl and Tcl functions becomes more difficult. To provide an escape
       hatch, PL/PerlU and PL/TclU functions continue to use only one
       interpreter per session. This is not considered a security issue
       since all such functions execute at the trust level of a database
       superuser already.
       It is likely that third-party procedural languages that claim to
       offer trusted execution have similar security issues. We advise
       contacting the authors of any PL you are depending on for
       security-critical purposes.
       Our thanks to Tim Bunce for pointing out this issue
       (CVE-2010-3433).
     * Prevent possible crashes in pg_get_expr() by disallowing it from
       being called with an argument that is not one of the system catalog
       columns it's intended to be used with (Heikki Linnakangas, Tom
       Lane)
     * Fix Windows shared-memory allocation code (Tsutomu Yamada, Magnus
       Hagander)
       This bug led to the often-reported "could not reattach to shared
       memory" error message. This is a back-patch of a fix that was
       applied to newer branches some time ago.
     * Treat exit code 128 (ERROR_WAIT_NO_CHILDREN) as non-fatal on
       Windows (Magnus Hagander)
       Under high load, Windows processes will sometimes fail at startup
       with this error code. Formerly the postmaster treated this as a
       panic condition and restarted the whole database, but that seems to
       be an overreaction.
     * Fix possible duplicate scans of UNION ALL member relations (Tom
       Lane)
     * Fix "cannot handle unplanned sub-select" error (Tom Lane)
       This occurred when a sub-select contains a join alias reference
       that expands into an expression containing another sub-select.
     * Reduce PANIC to ERROR in some occasionally-reported btree failure
       cases, and provide additional detail in the resulting error
       messages (Tom Lane)
       This should improve the system's robustness with corrupted indexes.
     * Prevent show_session_authorization() from crashing within
       autovacuum processes (Tom Lane)
     * Defend against functions returning setof record where not all the
       returned rows are actually of the same rowtype (Tom Lane)
     * Fix possible failure when hashing a pass-by-reference function
       result (Tao Ma, Tom Lane)
     * Take care to fsync the contents of lockfiles (both "postmaster.pid"
       and the socket lockfile) while writing them (Tom Lane)
       This omission could result in corrupted lockfile contents if the
       machine crashes shortly after postmaster start. That could in turn
       prevent subsequent attempts to start the postmaster from
       succeeding, until the lockfile is manually removed.
     * Avoid recursion while assigning XIDs to heavily-nested
       subtransactions (Andres Freund, Robert Haas)
       The original coding could result in a crash if there was limited
       stack space.
     * Fix log_line_prefix's %i escape, which could produce junk early in
       backend startup (Tom Lane)
     * Fix possible data corruption in "ALTER TABLE ... SET TABLESPACE"
       when archiving is enabled (Jeff Davis)
     * Allow "CREATE DATABASE" and "ALTER DATABASE ... SET TABLESPACE" to
       be interrupted by query-cancel (Guillaume Lelarge)
     * In PL/Python, defend against null pointer results from
       PyCObject_AsVoidPtr and PyCObject_FromVoidPtr (Peter Eisentraut)
     * Improve "contrib/dblink"'s handling of tables containing dropped
       columns (Tom Lane)
     * Fix connection leak after "duplicate connection name" errors in
       "contrib/dblink" (Itagaki Takahiro)
     * Fix "contrib/dblink" to handle connection names longer than 62
       bytes correctly (Itagaki Takahiro)
     * Add hstore(text, text) function to "contrib/hstore" (Robert Haas)
       This function is the recommended substitute for the now-deprecated
       => operator. It was back-patched so that future-proofed code can be
       used with older server versions. Note that the patch will be
       effective only after "contrib/hstore" is installed or reinstalled
       in a particular database. Users might prefer to execute the "CREATE
       FUNCTION" command by hand, instead.
     * Update build infrastructure and documentation to reflect the source
       code repository's move from CVS to Git (Magnus Hagander and others)
     * Update time zone data files to tzdata release 2010l for DST law
       changes in Egypt and Palestine; also historical corrections for
       Finland.
       This change also adds new names for two Micronesian timezones:
       Pacific/Chuuk is now preferred over Pacific/Truk (and the preferred
       abbreviation is CHUT not TRUT) and Pacific/Pohnpei is preferred
       over Pacific/Ponape.
     * Make Windows' "N. Central Asia Standard Time" timezone map to
       Asia/Novosibirsk, not Asia/Almaty (Magnus Hagander)
       Microsoft changed the DST behavior of this zone in the timezone
       update from KB976098. Asia/Novosibirsk is a better match to its new
       behavior.
     __________________________________________________________________

                               Release 8.2.17

     Release Date: 2010-05-17

   This release contains a variety of fixes from 8.2.16. For information
   about new features in the 8.2 major release, see the Section called
   Release 8.2.
     __________________________________________________________________

Migration to Version 8.2.17

   A dump/restore is not required for those running 8.2.X. However, if you
   are upgrading from a version earlier than 8.2.14, see the release notes
   for 8.2.14.
     __________________________________________________________________

Changes

     * Enforce restrictions in plperl using an opmask applied to the whole
       interpreter, instead of using "Safe.pm" (Tim Bunce, Andrew Dunstan)
       Recent developments have convinced us that "Safe.pm" is too
       insecure to rely on for making plperl trustable. This change
       removes use of "Safe.pm" altogether, in favor of using a separate
       interpreter with an opcode mask that is always applied. Pleasant
       side effects of the change include that it is now possible to use
       Perl's strict pragma in a natural way in plperl, and that Perl's $a
       and $b variables work as expected in sort routines, and that
       function compilation is significantly faster. (CVE-2010-1169)
     * Prevent PL/Tcl from executing untrustworthy code from pltcl_modules
       (Tom)
       PL/Tcl's feature for autoloading Tcl code from a database table
       could be exploited for trojan-horse attacks, because there was no
       restriction on who could create or insert into that table. This
       change disables the feature unless pltcl_modules is owned by a
       superuser. (However, the permissions on the table are not checked,
       so installations that really need a less-than-secure modules table
       can still grant suitable privileges to trusted non-superusers.)
       Also, prevent loading code into the unrestricted "normal" Tcl
       interpreter unless we are really going to execute a pltclu
       function. (CVE-2010-1170)
     * Fix possible crash if a cache reset message is received during
       rebuild of a relcache entry (Heikki)
       This error was introduced in 8.2.16 while fixing a related failure.
     * Do not allow an unprivileged user to reset superuser-only parameter
       settings (Alvaro)
       Previously, if an unprivileged user ran ALTER USER ... RESET ALL
       for himself, or ALTER DATABASE ... RESET ALL for a database he
       owns, this would remove all special parameter settings for the user
       or database, even ones that are only supposed to be changeable by a
       superuser. Now, the "ALTER" will only remove the parameters that
       the user has permission to change.
     * Avoid possible crash during backend shutdown if shutdown occurs
       when a CONTEXT addition would be made to log entries (Tom)
       In some cases the context-printing function would fail because the
       current transaction had already been rolled back when it came time
       to print a log message.
     * Update pl/perl's "ppport.h" for modern Perl versions (Andrew)
     * Fix assorted memory leaks in pl/python (Andreas Freund, Tom)
     * Prevent infinite recursion in psql when expanding a variable that
       refers to itself (Tom)
     * Fix psql's \copy to not add spaces around a dot within \copy
       (select ...) (Tom)
       Addition of spaces around the decimal point in a numeric literal
       would result in a syntax error.
     * Ensure that "contrib/pgstattuple" functions respond to cancel
       interrupts promptly (Tatsuhito Kasahara)
     * Make server startup deal properly with the case that shmget()
       returns EINVAL for an existing shared memory segment (Tom)
       This behavior has been observed on BSD-derived kernels including OS
       X. It resulted in an entirely-misleading startup failure
       complaining that the shared memory request size was too large.
     * Avoid possible crashes in syslogger process on Windows (Heikki)
     * Deal more robustly with incomplete time zone information in the
       Windows registry (Magnus)
     * Update the set of known Windows time zone names (Magnus)
     * Update time zone data files to tzdata release 2010j for DST law
       changes in Argentina, Australian Antarctic, Bangladesh, Mexico,
       Morocco, Pakistan, Palestine, Russia, Syria, Tunisia; also
       historical corrections for Taiwan.
       Also, add PKST (Pakistan Summer Time) to the default set of
       timezone abbreviations.
     __________________________________________________________________

                               Release 8.2.16

     Release Date: 2010-03-15

   This release contains a variety of fixes from 8.2.15. For information
   about new features in the 8.2 major release, see the Section called
   Release 8.2.
     __________________________________________________________________

Migration to Version 8.2.16

   A dump/restore is not required for those running 8.2.X. However, if you
   are upgrading from a version earlier than 8.2.14, see the release notes
   for 8.2.14.
     __________________________________________________________________

Changes

     * Add new configuration parameter ssl_renegotiation_limit to control
       how often we do session key renegotiation for an SSL connection
       (Magnus)
       This can be set to zero to disable renegotiation completely, which
       may be required if a broken SSL library is used. In particular,
       some vendors are shipping stopgap patches for CVE-2009-3555 that
       cause renegotiation attempts to fail.
     * Fix possible deadlock during backend startup (Tom)
     * Fix possible crashes due to not handling errors during relcache
       reload cleanly (Tom)
     * Fix possible crashes when trying to recover from a failure in
       subtransaction start (Tom)
     * Fix server memory leak associated with use of savepoints and a
       client encoding different from server's encoding (Tom)
     * Fix incorrect WAL data emitted during end-of-recovery cleanup of a
       GIST index page split (Yoichi Hirai)
       This would result in index corruption, or even more likely an error
       during WAL replay, if we were unlucky enough to crash during
       end-of-recovery cleanup after having completed an incomplete GIST
       insertion.
     * Make substring() for bit types treat any negative length as meaning
       "all the rest of the string" (Tom)
       The previous coding treated only -1 that way, and would produce an
       invalid result value for other negative values, possibly leading to
       a crash (CVE-2010-0442).
     * Fix integer-to-bit-string conversions to handle the first
       fractional byte correctly when the output bit width is wider than
       the given integer by something other than a multiple of 8 bits
       (Tom)
     * Fix some cases of pathologically slow regular expression matching
       (Tom)
     * Fix the STOP WAL LOCATION entry in backup history files to report
       the next WAL segment's name when the end location is exactly at a
       segment boundary (Itagaki Takahiro)
     * Fix some more cases of temporary-file leakage (Heikki)
       This corrects a problem introduced in the previous minor release.
       One case that failed is when a plpgsql function returning set is
       called within another function's exception handler.
     * Improve constraint exclusion processing of boolean-variable cases,
       in particular make it possible to exclude a partition that has a
       "bool_column = false" constraint (Tom)
     * When reading "pg_hba.conf" and related files, do not treat
       @something as a file inclusion request if the @ appears inside
       quote marks; also, never treat @ by itself as a file inclusion
       request (Tom)
       This prevents erratic behavior if a role or database name starts
       with @. If you need to include a file whose path name contains
       spaces, you can still do so, but you must write @"/path to/file"
       rather than putting the quotes around the whole construct.
     * Prevent infinite loop on some platforms if a directory is named as
       an inclusion target in "pg_hba.conf" and related files (Tom)
     * Fix possible infinite loop if SSL_read or SSL_write fails without
       setting errno (Tom)
       This is reportedly possible with some Windows versions of openssl.
     * Fix psql's numericlocale option to not format strings it shouldn't
       in latex and troff output formats (Heikki)
     * Make psql return the correct exit status (3) when ON_ERROR_STOP and
       --single-transaction are both specified and an error occurs during
       the implied "COMMIT" (Bruce)
     * Fix plpgsql failure in one case where a composite column is set to
       NULL (Tom)
     * Fix possible failure when calling PL/Perl functions from PL/PerlU
       or vice versa (Tim Bunce)
     * Add volatile markings in PL/Python to avoid possible
       compiler-specific misbehavior (Zdenek Kotala)
     * Ensure PL/Tcl initializes the Tcl interpreter fully (Tom)
       The only known symptom of this oversight is that the Tcl clock
       command misbehaves if using Tcl 8.5 or later.
     * Prevent crash in "contrib/dblink" when too many key columns are
       specified to a dblink_build_sql_* function (Rushabh Lathia, Joe
       Conway)
     * Fix assorted crashes in "contrib/xml2" caused by sloppy memory
       management (Tom)
     * Make building of "contrib/xml2" more robust on Windows (Andrew)
     * Fix race condition in Windows signal handling (Radu Ilie)
       One known symptom of this bug is that rows in pg_listener could be
       dropped under heavy load.
     * Update time zone data files to tzdata release 2010e for DST law
       changes in Bangladesh, Chile, Fiji, Mexico, Paraguay, Samoa.
     __________________________________________________________________

                               Release 8.2.15

     Release Date: 2009-12-14

   This release contains a variety of fixes from 8.2.14. For information
   about new features in the 8.2 major release, see the Section called
   Release 8.2.
     __________________________________________________________________

Migration to Version 8.2.15

   A dump/restore is not required for those running 8.2.X. However, if you
   are upgrading from a version earlier than 8.2.14, see the release notes
   for 8.2.14.
     __________________________________________________________________

Changes

     * Protect against indirect security threats caused by index functions
       changing session-local state (Gurjeet Singh, Tom)
       This change prevents allegedly-immutable index functions from
       possibly subverting a superuser's session (CVE-2009-4136).
     * Reject SSL certificates containing an embedded null byte in the
       common name (CN) field (Magnus)
       This prevents unintended matching of a certificate to a server or
       client name during SSL validation (CVE-2009-4034).
     * Fix possible crash during backend-startup-time cache initialization
       (Tom)
     * Prevent signals from interrupting VACUUM at unsafe times (Alvaro)
       This fix prevents a PANIC if a VACUUM FULL is canceled after it's
       already committed its tuple movements, as well as transient errors
       if a plain VACUUM is interrupted after having truncated the table.
     * Fix possible crash due to integer overflow in hash table size
       calculation (Tom)
       This could occur with extremely large planner estimates for the
       size of a hashjoin's result.
     * Fix very rare crash in inet/cidr comparisons (Chris Mikkelson)
     * Ensure that shared tuple-level locks held by prepared transactions
       are not ignored (Heikki)
     * Fix premature drop of temporary files used for a cursor that is
       accessed within a subtransaction (Heikki)
     * Fix incorrect logic for GiST index page splits, when the split
       depends on a non-first column of the index (Paul Ramsey)
     * Don't error out if recycling or removing an old WAL file fails at
       the end of checkpoint (Heikki)
       It's better to treat the problem as non-fatal and allow the
       checkpoint to complete. Future checkpoints will retry the removal.
       Such problems are not expected in normal operation, but have been
       seen to be caused by misdesigned Windows anti-virus and backup
       software.
     * Ensure WAL files aren't repeatedly archived on Windows (Heikki)
       This is another symptom that could happen if some other process
       interfered with deletion of a no-longer-needed file.
     * Fix PAM password processing to be more robust (Tom)
       The previous code is known to fail with the combination of the
       Linux pam_krb5 PAM module with Microsoft Active Directory as the
       domain controller. It might have problems elsewhere too, since it
       was making unjustified assumptions about what arguments the PAM
       stack would pass to it.
     * Fix processing of ownership dependencies during CREATE OR REPLACE
       FUNCTION (Tom)
     * Fix bug with calling plperl from plperlu or vice versa (Tom)
       An error exit from the inner function could result in crashes due
       to failure to re-select the correct Perl interpreter for the outer
       function.
     * Fix session-lifespan memory leak when a PL/Perl function is
       redefined (Tom)
     * Ensure that Perl arrays are properly converted to PostgreSQL arrays
       when returned by a set-returning PL/Perl function (Andrew Dunstan,
       Abhijit Menon-Sen)
       This worked correctly already for non-set-returning functions.
     * Fix rare crash in exception processing in PL/Python (Peter)
     * Ensure psql's flex module is compiled with the correct system
       header definitions (Tom)
       This fixes build failures on platforms where --enable-largefile
       causes incompatible changes in the generated code.
     * Make the postmaster ignore any application_name parameter in
       connection request packets, to improve compatibility with future
       libpq versions (Tom)
     * Update the timezone abbreviation files to match current reality
       (Joachim Wieland)
       This includes adding IDT and SGT to the default timezone
       abbreviation set.
     * Update time zone data files to tzdata release 2009s for DST law
       changes in Antarctica, Argentina, Bangladesh, Fiji, Novokuznetsk,
       Pakistan, Palestine, Samoa, Syria; also historical corrections for
       Hong Kong.
     __________________________________________________________________

                               Release 8.2.14

     Release Date: 2009-09-09

   This release contains a variety of fixes from 8.2.13. For information
   about new features in the 8.2 major release, see the Section called
   Release 8.2.
     __________________________________________________________________

Migration to Version 8.2.14

   A dump/restore is not required for those running 8.2.X. However, if you
   have any hash indexes on interval columns, you must "REINDEX" them
   after updating to 8.2.14. Also, if you are upgrading from a version
   earlier than 8.2.11, see the release notes for 8.2.11.
     __________________________________________________________________

Changes

     * Force WAL segment switch during pg_start_backup() (Heikki)
       This avoids corner cases that could render a base backup unusable.
     * Disallow "RESET ROLE" and "RESET SESSION AUTHORIZATION" inside
       security-definer functions (Tom, Heikki)
       This covers a case that was missed in the previous patch that
       disallowed "SET ROLE" and "SET SESSION AUTHORIZATION" inside
       security-definer functions. (See CVE-2007-6600)
     * Make "LOAD" of an already-loaded loadable module into a no-op (Tom)
       Formerly, "LOAD" would attempt to unload and re-load the module,
       but this is unsafe and not all that useful.
     * Disallow empty passwords during LDAP authentication (Magnus)
     * Fix handling of sub-SELECTs appearing in the arguments of an
       outer-level aggregate function (Tom)
     * Fix bugs associated with fetching a whole-row value from the output
       of a Sort or Materialize plan node (Tom)
     * Revert planner change that disabled partial-index and constraint
       exclusion optimizations when there were more than 100 clauses in an
       AND or OR list (Tom)
     * Fix hash calculation for data type interval (Tom)
       This corrects wrong results for hash joins on interval values. It
       also changes the contents of hash indexes on interval columns. If
       you have any such indexes, you must "REINDEX" them after updating.
     * Treat to_char(..., 'TH') as an uppercase ordinal suffix with
       'HH'/'HH12' (Heikki)
       It was previously handled as 'th' (lowercase).
     * Fix overflow for INTERVAL 'x ms' when "x" is more than 2 million
       and integer datetimes are in use (Alex Hunsaker)
     * Fix calculation of distance between a point and a line segment
       (Tom)
       This led to incorrect results from a number of geometric operators.
     * Fix money data type to work in locales where currency amounts have
       no fractional digits, e.g. Japan (Itagaki Takahiro)
     * Properly round datetime input like
       00:12:57.9999999999999999999999999999 (Tom)
     * Fix poor choice of page split point in GiST R-tree operator classes
       (Teodor)
     * Avoid performance degradation in bulk inserts into GIN indexes when
       the input values are (nearly) in sorted order (Tom)
     * Correctly enforce NOT NULL domain constraints in some contexts in
       PL/pgSQL (Tom)
     * Fix portability issues in plperl initialization (Andrew Dunstan)
     * Fix pg_ctl to not go into an infinite loop if "postgresql.conf" is
       empty (Jeff Davis)
     * Make "contrib/hstore" throw an error when a key or value is too
       long to fit in its data structure, rather than silently truncating
       it (Andrew Gierth)
     * Fix "contrib/xml2"'s xslt_process() to properly handle the maximum
       number of parameters (twenty) (Tom)
     * Improve robustness of libpq's code to recover from errors during
       "COPY FROM STDIN" (Tom)
     * Avoid including conflicting readline and editline header files when
       both libraries are installed (Zdenek Kotala)
     * Update time zone data files to tzdata release 2009l for DST law
       changes in Bangladesh, Egypt, Jordan, Pakistan, Argentina/San_Luis,
       Cuba, Jordan (historical correction only), Mauritius, Morocco,
       Palestine, Syria, Tunisia.
     __________________________________________________________________

                               Release 8.2.13

     Release Date: 2009-03-16

   This release contains a variety of fixes from 8.2.12. For information
   about new features in the 8.2 major release, see the Section called
   Release 8.2.
     __________________________________________________________________

Migration to Version 8.2.13

   A dump/restore is not required for those running 8.2.X. However, if you
   are upgrading from a version earlier than 8.2.11, see the release notes
   for 8.2.11.
     __________________________________________________________________

Changes

     * Prevent error recursion crashes when encoding conversion fails
       (Tom)
       This change extends fixes made in the last two minor releases for
       related failure scenarios. The previous fixes were narrowly
       tailored for the original problem reports, but we have now
       recognized that *any* error thrown by an encoding conversion
       function could potentially lead to infinite recursion while trying
       to report the error. The solution therefore is to disable
       translation and encoding conversion and report the plain-ASCII form
       of any error message, if we find we have gotten into a recursive
       error reporting situation. (CVE-2009-0922)
     * Disallow "CREATE CONVERSION" with the wrong encodings for the
       specified conversion function (Heikki)
       This prevents one possible scenario for encoding conversion
       failure. The previous change is a backstop to guard against other
       kinds of failures in the same area.
     * Fix core dump when to_char() is given format codes that are
       inappropriate for the type of the data argument (Tom)
     * Fix possible failure in "contrib/tsearch2" when C locale is used
       with a multi-byte encoding (Teodor)
       Crashes were possible on platforms where wchar_t is narrower than
       int; Windows in particular.
     * Fix extreme inefficiency in "contrib/tsearch2" parser's handling of
       an email-like string containing multiple @ characters (Heikki)
     * Fix decompilation of CASE WHEN with an implicit coercion (Tom)
       This mistake could lead to Assert failures in an Assert-enabled
       build, or an "unexpected CASE WHEN clause" error message in other
       cases, when trying to examine or dump a view.
     * Fix possible misassignment of the owner of a TOAST table's rowtype
       (Tom)
       If "CLUSTER" or a rewriting variant of "ALTER TABLE" were executed
       by someone other than the table owner, the pg_type entry for the
       table's TOAST table would end up marked as owned by that someone.
       This caused no immediate problems, since the permissions on the
       TOAST rowtype aren't examined by any ordinary database operation.
       However, it could lead to unexpected failures if one later tried to
       drop the role that issued the command (in 8.1 or 8.2), or "owner of
       data type appears to be invalid" warnings from pg_dump after having
       done so (in 8.3).
     * Fix PL/pgSQL to not treat INTO after "INSERT" as an INTO-variables
       clause anywhere in the string, not only at the start; in
       particular, don't fail for "INSERT INTO" within "CREATE RULE" (Tom)
     * Clean up PL/pgSQL error status variables fully at block exit
       (Ashesh Vashi and Dave Page)
       This is not a problem for PL/pgSQL itself, but the omission could
       cause the PL/pgSQL Debugger to crash while examining the state of a
       function.
     * Retry failed calls to CallNamedPipe() on Windows (Steve Marshall,
       Magnus)
       It appears that this function can sometimes fail transiently; we
       previously treated any failure as a hard error, which could confuse
       "LISTEN"/"NOTIFY" as well as other operations.
     * Add MUST (Mauritius Island Summer Time) to the default list of
       known timezone abbreviations (Xavier Bugaud)
     __________________________________________________________________

                               Release 8.2.12

     Release Date: 2009-02-02

   This release contains a variety of fixes from 8.2.11. For information
   about new features in the 8.2 major release, see the Section called
   Release 8.2.
     __________________________________________________________________

Migration to Version 8.2.12

   A dump/restore is not required for those running 8.2.X. However, if you
   are upgrading from a version earlier than 8.2.11, see the release notes
   for 8.2.11.
     __________________________________________________________________

Changes

     * Improve handling of URLs in headline() function (Teodor)
     * Improve handling of overlength headlines in headline() function
       (Teodor)
     * Prevent possible Assert failure or misconversion if an encoding
       conversion is created with the wrong conversion function for the
       specified pair of encodings (Tom, Heikki)
     * Fix possible Assert failure if a statement executed in PL/pgSQL is
       rewritten into another kind of statement, for example if an
       "INSERT" is rewritten into an "UPDATE" (Heikki)
     * Ensure that a snapshot is available to datatype input functions
       (Tom)
       This primarily affects domains that are declared with CHECK
       constraints involving user-defined stable or immutable functions.
       Such functions typically fail if no snapshot has been set.
     * Make it safer for SPI-using functions to be used within datatype
       I/O; in particular, to be used in domain check constraints (Tom)
     * Avoid unnecessary locking of small tables in "VACUUM" (Heikki)
     * Fix a problem that made UPDATE RETURNING tableoid return zero
       instead of the correct OID (Tom)
     * Fix planner misestimation of selectivity when transitive equality
       is applied to an outer-join clause (Tom)
       This could result in bad plans for queries like ... from a left
       join b on a.a1 = b.b1 where a.a1 = 42 ...
     * Improve optimizer's handling of long IN lists (Tom)
       This change avoids wasting large amounts of time on such lists when
       constraint exclusion is enabled.
     * Ensure that the contents of a holdable cursor don't depend on the
       contents of TOAST tables (Tom)
       Previously, large field values in a cursor result might be
       represented as TOAST pointers, which would fail if the referenced
       table got dropped before the cursor is read, or if the large value
       is deleted and then vacuumed away. This cannot happen with an
       ordinary cursor, but it could with a cursor that is held past its
       creating transaction.
     * Fix memory leak when a set-returning function is terminated without
       reading its whole result (Tom)
     * Fix "contrib/dblink"'s dblink_get_result(text,bool) function (Joe)
     * Fix possible garbage output from "contrib/sslinfo" functions (Tom)
     * Fix configure script to properly report failure when unable to
       obtain linkage information for PL/Perl (Andrew)
     * Make all documentation reference pgsql-bugs and/or pgsql-hackers as
       appropriate, instead of the now-decommissioned pgsql-ports and
       pgsql-patches mailing lists (Tom)
     * Update time zone data files to tzdata release 2009a (for Kathmandu
       and historical DST corrections in Switzerland, Cuba)
     __________________________________________________________________

                               Release 8.2.11

     Release Date: 2008-11-03

   This release contains a variety of fixes from 8.2.10. For information
   about new features in the 8.2 major release, see the Section called
   Release 8.2.
     __________________________________________________________________

Migration to Version 8.2.11

   A dump/restore is not required for those running 8.2.X. However, if you
   are upgrading from a version earlier than 8.2.7, see the release notes
   for 8.2.7. Also, if you were running a previous 8.2.X release, it is
   recommended to "REINDEX" all GiST indexes after the upgrade.
     __________________________________________________________________

Changes

     * Fix GiST index corruption due to marking the wrong index entry
       "dead" after a deletion (Teodor)
       This would result in index searches failing to find rows they
       should have found. Corrupted indexes can be fixed with "REINDEX".
     * Fix backend crash when the client encoding cannot represent a
       localized error message (Tom)
       We have addressed similar issues before, but it would still fail if
       the "character has no equivalent" message itself couldn't be
       converted. The fix is to disable localization and send the plain
       ASCII error message when we detect such a situation.
     * Fix possible crash when deeply nested functions are invoked from a
       trigger (Tom)
     * Improve optimization of "expression" IN ("expression-list") queries
       (Tom, per an idea from Robert Haas)
       Cases in which there are query variables on the right-hand side had
       been handled less efficiently in 8.2.x and 8.3.x than in prior
       versions. The fix restores 8.1 behavior for such cases.
     * Fix mis-expansion of rule queries when a sub-SELECT appears in a
       function call in FROM, a multi-row VALUES list, or a RETURNING list
       (Tom)
       The usual symptom of this problem is an "unrecognized node type"
       error.
     * Fix memory leak during rescan of a hashed aggregation plan (Neil)
     * Ensure an error is reported when a newly-defined PL/pgSQL trigger
       function is invoked as a normal function (Tom)
     * Prevent possible collision of relfilenode numbers when moving a
       table to another tablespace with "ALTER SET TABLESPACE" (Heikki)
       The command tried to re-use the existing filename, instead of
       picking one that is known unused in the destination directory.
     * Fix incorrect tsearch2 headline generation when single query item
       matches first word of text (Sushant Sinha)
     * Fix improper display of fractional seconds in interval values when
       using a non-ISO datestyle in an "--enable-integer-datetimes" build
       (Ron Mayer)
     * Ensure SPI_getvalue and SPI_getbinval behave correctly when the
       passed tuple and tuple descriptor have different numbers of columns
       (Tom)
       This situation is normal when a table has had columns added or
       removed, but these two functions didn't handle it properly. The
       only likely consequence is an incorrect error indication.
     * Fix ecpg's parsing of "CREATE ROLE" (Michael)
     * Fix recent breakage of pg_ctl restart (Tom)
     * Ensure "pg_control" is opened in binary mode (Itagaki Takahiro)
       pg_controldata and pg_resetxlog did this incorrectly, and so could
       fail on Windows.
     * Update time zone data files to tzdata release 2008i (for DST law
       changes in Argentina, Brazil, Mauritius, Syria)
     __________________________________________________________________

                               Release 8.2.10

     Release Date: 2008-09-22

   This release contains a variety of fixes from 8.2.9. For information
   about new features in the 8.2 major release, see the Section called
   Release 8.2.
     __________________________________________________________________

Migration to Version 8.2.10

   A dump/restore is not required for those running 8.2.X. However, if you
   are upgrading from a version earlier than 8.2.7, see the release notes
   for 8.2.7.
     __________________________________________________________________

Changes

     * Fix bug in btree WAL recovery code (Heikki)
       Recovery failed if the WAL ended partway through a page split
       operation.
     * Fix potential miscalculation of datfrozenxid (Alvaro)
       This error may explain some recent reports of failure to remove old
       pg_clog data.
     * Widen local lock counters from 32 to 64 bits (Tom)
       This responds to reports that the counters could overflow in
       sufficiently long transactions, leading to unexpected "lock is
       already held" errors.
     * Fix possible duplicate output of tuples during a GiST index scan
       (Teodor)
     * Fix missed permissions checks when a view contains a simple UNION
       ALL construct (Heikki)
       Permissions for the referenced tables were checked properly, but
       not permissions for the view itself.
     * Add checks in executor startup to ensure that the tuples produced
       by an "INSERT" or "UPDATE" will match the target table's current
       rowtype (Tom)
       "ALTER COLUMN TYPE", followed by re-use of a previously cached
       plan, could produce this type of situation. The check protects
       against data corruption and/or crashes that could ensue.
     * Fix possible repeated drops during "DROP OWNED" (Tom)
       This would typically result in strange errors such as "cache lookup
       failed for relation NNN".
     * Fix AT TIME ZONE to first try to interpret its timezone argument as
       a timezone abbreviation, and only try it as a full timezone name if
       that fails, rather than the other way around as formerly (Tom)
       The timestamp input functions have always resolved ambiguous zone
       names in this order. Making AT TIME ZONE do so as well improves
       consistency, and fixes a compatibility bug introduced in 8.1: in
       ambiguous cases we now behave the same as 8.0 and before did, since
       in the older versions AT TIME ZONE accepted *only* abbreviations.
     * Fix datetime input functions to correctly detect integer overflow
       when running on a 64-bit platform (Tom)
     * Prevent integer overflows during units conversion when displaying a
       configuration parameter that has units (Tom)
     * Improve performance of writing very long log messages to syslog
       (Tom)
     * Allow spaces in the suffix part of an LDAP URL in "pg_hba.conf"
       (Tom)
     * Fix bug in backwards scanning of a cursor on a SELECT DISTINCT ON
       query (Tom)
     * Fix planner bug with nested sub-select expressions (Tom)
       If the outer sub-select has no direct dependency on the parent
       query, but the inner one does, the outer value might not get
       recalculated for new parent query rows.
     * Fix planner to estimate that GROUP BY expressions yielding boolean
       results always result in two groups, regardless of the expressions'
       contents (Tom)
       This is very substantially more accurate than the regular GROUP BY
       estimate for certain boolean tests like "col" IS NULL.
     * Fix PL/pgSQL to not fail when a FOR loop's target variable is a
       record containing composite-type fields (Tom)
     * Fix PL/Tcl to behave correctly with Tcl 8.5, and to be more careful
       about the encoding of data sent to or from Tcl (Tom)
     * On Windows, work around a Microsoft bug by preventing libpq from
       trying to send more than 64kB per system call (Magnus)
     * Improve pg_dump and pg_restore's error reporting after failure to
       send a SQL command (Tom)
     * Fix pg_ctl to properly preserve postmaster command-line arguments
       across a restart (Bruce)
     * Update time zone data files to tzdata release 2008f (for DST law
       changes in Argentina, Bahamas, Brazil, Mauritius, Morocco,
       Pakistan, Palestine, and Paraguay)
     __________________________________________________________________

                                Release 8.2.9

     Release Date: 2008-06-12

   This release contains one serious and one minor bug fix over 8.2.8. For
   information about new features in the 8.2 major release, see the
   Section called Release 8.2.
     __________________________________________________________________

Migration to Version 8.2.9

   A dump/restore is not required for those running 8.2.X. However, if you
   are upgrading from a version earlier than 8.2.7, see the release notes
   for 8.2.7.
     __________________________________________________________________

Changes

     * Make pg_get_ruledef() parenthesize negative constants (Tom)
       Before this fix, a negative constant in a view or rule might be
       dumped as, say, -42::integer, which is subtly incorrect: it should
       be (-42)::integer due to operator precedence rules. Usually this
       would make little difference, but it could interact with another
       recent patch to cause PostgreSQL to reject what had been a valid
       "SELECT DISTINCT" view query. Since this could result in pg_dump
       output failing to reload, it is being treated as a high-priority
       fix. The only released versions in which dump output is actually
       incorrect are 8.3.1 and 8.2.7.
     * Make "ALTER AGGREGATE ... OWNER TO" update pg_shdepend (Tom)
       This oversight could lead to problems if the aggregate was later
       involved in a "DROP OWNED" or "REASSIGN OWNED" operation.
     __________________________________________________________________

                                Release 8.2.8

     Release Date: never released

   This release contains a variety of fixes from 8.2.7. For information
   about new features in the 8.2 major release, see the Section called
   Release 8.2.
     __________________________________________________________________

Migration to Version 8.2.8

   A dump/restore is not required for those running 8.2.X. However, if you
   are upgrading from a version earlier than 8.2.7, see the release notes
   for 8.2.7.
     __________________________________________________________________

Changes

     * Fix ERRORDATA_STACK_SIZE exceeded crash that occurred on Windows
       when using UTF-8 database encoding and a different client encoding
       (Tom)
     * Fix "ALTER TABLE ADD COLUMN ... PRIMARY KEY" so that the new column
       is correctly checked to see if it's been initialized to all
       non-nulls (Brendan Jurd)
       Previous versions neglected to check this requirement at all.
     * Fix possible "CREATE TABLE" failure when inheriting the "same"
       constraint from multiple parent relations that inherited that
       constraint from a common ancestor (Tom)
     * Fix pg_get_ruledef() to show the alias, if any, attached to the
       target table of an "UPDATE" or "DELETE" (Tom)
     * Fix GIN bug that could result in a too many LWLocks taken failure
       (Teodor)
     * Avoid possible crash when decompressing corrupted data (Zdenek
       Kotala)
     * Repair two places where SIGTERM exit of a backend could leave
       corrupted state in shared memory (Tom)
       Neither case is very important if SIGTERM is used to shut down the
       whole database cluster together, but there was a problem if someone
       tried to SIGTERM individual backends.
     * Fix conversions between ISO-8859-5 and other encodings to handle
       Cyrillic "Yo" characters (e and E with two dots) (Sergey Burladyan)
     * Fix several datatype input functions, notably array_in(), that were
       allowing unused bytes in their results to contain uninitialized,
       unpredictable values (Tom)
       This could lead to failures in which two apparently identical
       literal values were not seen as equal, resulting in the parser
       complaining about unmatched ORDER BY and DISTINCT expressions.
     * Fix a corner case in regular-expression substring matching
       (substring(string from pattern)) (Tom)
       The problem occurs when there is a match to the pattern overall but
       the user has specified a parenthesized subexpression and that
       subexpression hasn't got a match. An example is substring('foo'
       from 'foo(bar)?'). This should return NULL, since (bar) isn't
       matched, but it was mistakenly returning the whole-pattern match
       instead (ie, foo).
     * Update time zone data files to tzdata release 2008c (for DST law
       changes in Morocco, Iraq, Choibalsan, Pakistan, Syria, Cuba, and
       Argentina/San_Luis)
     * Fix incorrect result from ecpg's PGTYPEStimestamp_sub() function
       (Michael)
     * Fix broken GiST comparison function for "contrib/tsearch2"'s
       tsquery type (Teodor)
     * Fix possible crashes in "contrib/cube" functions (Tom)
     * Fix core dump in "contrib/xml2"'s xpath_table() function when the
       input query returns a NULL value (Tom)
     * Fix "contrib/xml2"'s makefile to not override CFLAGS (Tom)
     * Fix DatumGetBool macro to not fail with gcc 4.3 (Tom)
       This problem affects "old style" (V0) C functions that return
       boolean. The fix is already in 8.3, but the need to back-patch it
       was not realized at the time.
     __________________________________________________________________

                                Release 8.2.7

     Release Date: 2008-03-17

   This release contains a variety of fixes from 8.2.6. For information
   about new features in the 8.2 major release, see the Section called
   Release 8.2.
     __________________________________________________________________

Migration to Version 8.2.7

   A dump/restore is not required for those running 8.2.X. However, you
   might need to "REINDEX" indexes on textual columns after updating, if
   you are affected by the Windows locale issue described below.
     __________________________________________________________________

Changes

     * Fix character string comparison for Windows locales that consider
       different character combinations as equal (Tom)
       This fix applies only on Windows and only when using UTF-8 database
       encoding. The same fix was made for all other cases over two years
       ago, but Windows with UTF-8 uses a separate code path that was not
       updated. If you are using a locale that considers some
       non-identical strings as equal, you may need to "REINDEX" to fix
       existing indexes on textual columns.
     * Repair potential deadlock between concurrent "VACUUM FULL"
       operations on different system catalogs (Tom)
     * Fix longstanding "LISTEN"/"NOTIFY" race condition (Tom)
       In rare cases a session that had just executed a "LISTEN" might not
       get a notification, even though one would be expected because the
       concurrent transaction executing "NOTIFY" was observed to commit
       later.
       A side effect of the fix is that a transaction that has executed a
       not-yet-committed "LISTEN" command will not see any row in
       pg_listener for the "LISTEN", should it choose to look; formerly it
       would have. This behavior was never documented one way or the
       other, but it is possible that some applications depend on the old
       behavior.
     * Disallow "LISTEN" and "UNLISTEN" within a prepared transaction
       (Tom)
       This was formerly allowed but trying to do it had various
       unpleasant consequences, notably that the originating backend could
       not exit as long as an "UNLISTEN" remained uncommitted.
     * Disallow dropping a temporary table within a prepared transaction
       (Heikki)
       This was correctly disallowed by 8.1, but the check was
       inadvertently broken in 8.2.
     * Fix rare crash when an error occurs during a query using a hash
       index (Heikki)
     * Fix memory leaks in certain usages of set-returning functions
       (Neil)
     * Fix input of datetime values for February 29 in years BC (Tom)
       The former coding was mistaken about which years were leap years.
     * Fix "unrecognized node type" error in some variants of "ALTER
       OWNER" (Tom)
     * Ensure pg_stat_activity.waiting flag is cleared when a lock wait is
       aborted (Tom)
     * Fix handling of process permissions on Windows Vista (Dave, Magnus)
       In particular, this fix allows starting the server as the
       Administrator user.
     * Update time zone data files to tzdata release 2008a (in particular,
       recent Chile changes); adjust timezone abbreviation VET (Venezuela)
       to mean UTC-4:30, not UTC-4:00 (Tom)
     * Fix pg_ctl to correctly extract the postmaster's port number from
       command-line options (Itagaki Takahiro, Tom)
       Previously, pg_ctl start -w could try to contact the postmaster on
       the wrong port, leading to bogus reports of startup failure.
     * Use "-fwrapv" to defend against possible misoptimization in recent
       gcc versions (Tom)
       This is known to be necessary when building PostgreSQL with gcc 4.3
       or later.
     * Correctly enforce statement_timeout values longer than INT_MAX
       microseconds (about 35 minutes) (Tom)
       This bug affects only builds with "--enable-integer-datetimes".
     * Fix "unexpected PARAM_SUBLINK ID" planner error when
       constant-folding simplifies a sub-select (Tom)
     * Fix logical errors in constraint-exclusion handling of IS NULL and
       NOT expressions (Tom)
       The planner would sometimes exclude partitions that should not have
       been excluded because of the possibility of NULL results.
     * Fix another cause of "failed to build any N-way joins" planner
       errors (Tom)
       This could happen in cases where a clauseless join needed to be
       forced before a join clause could be exploited.
     * Fix incorrect constant propagation in outer-join planning (Tom)
       The planner could sometimes incorrectly conclude that a variable
       could be constrained to be equal to a constant, leading to wrong
       query results.
     * Fix display of constant expressions in ORDER BY and GROUP BY (Tom)
       An explicitly casted constant would be shown incorrectly. This
       could for example lead to corruption of a view definition during
       dump and reload.
     * Fix libpq to handle NOTICE messages correctly during COPY OUT (Tom)
       This failure has only been observed to occur when a user-defined
       datatype's output routine issues a NOTICE, but there is no
       guarantee it couldn't happen due to other causes.
     __________________________________________________________________

                                Release 8.2.6

     Release Date: 2008-01-07

   This release contains a variety of fixes from 8.2.5, including fixes
   for significant security issues. For information about new features in
   the 8.2 major release, see the Section called Release 8.2.
     __________________________________________________________________

Migration to Version 8.2.6

   A dump/restore is not required for those running 8.2.X.
     __________________________________________________________________

Changes

     * Prevent functions in indexes from executing with the privileges of
       the user running "VACUUM", "ANALYZE", etc (Tom)
       Functions used in index expressions and partial-index predicates
       are evaluated whenever a new table entry is made. It has long been
       understood that this poses a risk of trojan-horse code execution if
       one modifies a table owned by an untrustworthy user. (Note that
       triggers, defaults, check constraints, etc. pose the same type of
       risk.) But functions in indexes pose extra danger because they will
       be executed by routine maintenance operations such as "VACUUM
       FULL", which are commonly performed automatically under a superuser
       account. For example, a nefarious user can execute code with
       superuser privileges by setting up a trojan-horse index definition
       and waiting for the next routine vacuum. The fix arranges for
       standard maintenance operations (including "VACUUM", "ANALYZE",
       "REINDEX", and "CLUSTER") to execute as the table owner rather than
       the calling user, using the same privilege-switching mechanism
       already used for SECURITY DEFINER functions. To prevent bypassing
       this security measure, execution of "SET SESSION AUTHORIZATION" and
       "SET ROLE" is now forbidden within a SECURITY DEFINER context.
       (CVE-2007-6600)
     * Repair assorted bugs in the regular-expression package (Tom, Will
       Drewry)
       Suitably crafted regular-expression patterns could cause crashes,
       infinite or near-infinite looping, and/or massive memory
       consumption, all of which pose denial-of-service hazards for
       applications that accept regex search patterns from untrustworthy
       sources. (CVE-2007-4769, CVE-2007-4772, CVE-2007-6067)
     * Require non-superusers who use "/contrib/dblink" to use only
       password authentication, as a security measure (Joe)
       The fix that appeared for this in 8.2.5 was incomplete, as it
       plugged the hole for only some "dblink" functions. (CVE-2007-6601,
       CVE-2007-3278)
     * Fix bugs in WAL replay for GIN indexes (Teodor)
     * Fix GIN index build to work properly when maintenance_work_mem is
       4GB or more (Tom)
     * Update time zone data files to tzdata release 2007k (in particular,
       recent Argentina changes) (Tom)
     * Improve planner's handling of LIKE/regex estimation in non-C
       locales (Tom)
     * Fix planning-speed problem for deep outer-join nests, as well as
       possible poor choice of join order (Tom)
     * Fix planner failure in some cases of WHERE false AND var IN (SELECT
       ...) (Tom)
     * Make "CREATE TABLE ... SERIAL" and "ALTER SEQUENCE ... OWNED BY"
       not change the currval() state of the sequence (Tom)
     * Preserve the tablespace and storage parameters of indexes that are
       rebuilt by "ALTER TABLE ... ALTER COLUMN TYPE" (Tom)
     * Make archive recovery always start a new WAL timeline, rather than
       only when a recovery stop time was used (Simon)
       This avoids a corner-case risk of trying to overwrite an existing
       archived copy of the last WAL segment, and seems simpler and
       cleaner than the original definition.
     * Make "VACUUM" not use all of maintenance_work_mem when the table is
       too small for it to be useful (Alvaro)
     * Fix potential crash in translate() when using a multibyte database
       encoding (Tom)
     * Make corr() return the correct result for negative correlation
       values (Neil)
     * Fix overflow in extract(epoch from interval) for intervals
       exceeding 68 years (Tom)
     * Fix PL/Perl to not fail when a UTF-8 regular expression is used in
       a trusted function (Andrew)
     * Fix PL/Perl to cope when platform's Perl defines type bool as int
       rather than char (Tom)
       While this could theoretically happen anywhere, no standard build
       of Perl did things this way ... until Mac OS X 10.5.
     * Fix PL/Python to work correctly with Python 2.5 on 64-bit machines
       (Marko Kreen)
     * Fix PL/Python to not crash on long exception messages (Alvaro)
     * Fix pg_dump to correctly handle inheritance child tables that have
       default expressions different from their parent's (Tom)
     * Fix libpq crash when PGPASSFILE refers to a file that is not a
       plain file (Martin Pitt)
     * ecpg parser fixes (Michael)
     * Make "contrib/pgcrypto" defend against OpenSSL libraries that fail
       on keys longer than 128 bits; which is the case at least on some
       Solaris versions (Marko Kreen)
     * Make "contrib/tablefunc"'s crosstab() handle NULL rowid as a
       category in its own right, rather than crashing (Joe)
     * Fix tsvector and tsquery output routines to escape backslashes
       correctly (Teodor, Bruce)
     * Fix crash of to_tsvector() on huge input strings (Teodor)
     * Require a specific version of Autoconf to be used when
       re-generating the "configure" script (Peter)
       This affects developers and packagers only. The change was made to
       prevent accidental use of untested combinations of Autoconf and
       PostgreSQL versions. You can remove the version check if you really
       want to use a different Autoconf version, but it's your
       responsibility whether the result works or not.
     * Update gettimeofday configuration check so that PostgreSQL can be
       built on newer versions of MinGW (Magnus)
     __________________________________________________________________

                                Release 8.2.5

     Release Date: 2007-09-17

   This release contains a variety of fixes from 8.2.4. For information
   about new features in the 8.2 major release, see the Section called
   Release 8.2.
     __________________________________________________________________

Migration to Version 8.2.5

   A dump/restore is not required for those running 8.2.X.
     __________________________________________________________________

Changes

     * Prevent index corruption when a transaction inserts rows and then
       aborts close to the end of a concurrent "VACUUM" on the same table
       (Tom)
     * Fix ALTER DOMAIN ADD CONSTRAINT for cases involving domains over
       domains (Tom)
     * Make "CREATE DOMAIN ... DEFAULT NULL" work properly (Tom)
     * Fix some planner problems with outer joins, notably poor size
       estimation for t1 LEFT JOIN t2 WHERE t2.col IS NULL (Tom)
     * Allow the interval data type to accept input consisting only of
       milliseconds or microseconds (Neil)
     * Allow timezone name to appear before the year in timestamp input
       (Tom)
     * Fixes for GIN indexes used by "/contrib/tsearch2" (Teodor)
     * Speed up rtree index insertion (Teodor)
     * Fix excessive logging of SSL error messages (Tom)
     * Fix logging so that log messages are never interleaved when using
       the syslogger process (Andrew)
     * Fix crash when log_min_error_statement logging runs out of memory
       (Tom)
     * Fix incorrect handling of some foreign-key corner cases (Tom)
     * Fix stddev_pop(numeric) and var_pop(numeric) (Tom)
     * Prevent "REINDEX" and "CLUSTER" from failing due to attempting to
       process temporary tables of other sessions (Alvaro)
     * Update the time zone database rules, particularly New Zealand's
       upcoming changes (Tom)
     * Windows socket and semaphore improvements (Magnus)
     * Make "pg_ctl -w" work properly in Windows service mode (Dave Page)
     * Fix memory allocation bug when using MIT Kerberos on Windows
       (Magnus)
     * Suppress timezone name (%Z) in log timestamps on Windows because of
       possible encoding mismatches (Tom)
     * Require non-superusers who use "/contrib/dblink" to use only
       password authentication, as a security measure (Joe)
     * Restrict "/contrib/pgstattuple" functions to superusers, for
       security reasons (Tom)
     * Do not let "/contrib/intarray" try to make its GIN opclass the
       default (this caused problems at dump/restore) (Tom)
     __________________________________________________________________

                                Release 8.2.4

     Release Date: 2007-04-23

   This release contains a variety of fixes from 8.2.3, including a
   security fix. For information about new features in the 8.2 major
   release, see the Section called Release 8.2.
     __________________________________________________________________

Migration to Version 8.2.4

   A dump/restore is not required for those running 8.2.X.
     __________________________________________________________________

Changes

     * Support explicit placement of the temporary-table schema within
       search_path, and disable searching it for functions and operators
       (Tom)
       This is needed to allow a security-definer function to set a truly
       secure value of search_path. Without it, an unprivileged SQL user
       can use temporary objects to execute code with the privileges of
       the security-definer function (CVE-2007-2138). See "CREATE
       FUNCTION" for more information.
     * Fix shared_preload_libraries for Windows by forcing reload in each
       backend (Korry Douglas)
     * Fix to_char() so it properly upper/lower cases localized day or
       month names (Pavel Stehule)
     * "/contrib/tsearch2" crash fixes (Teodor)
     * Require "COMMIT PREPARED" to be executed in the same database as
       the transaction was prepared in (Heikki)
     * Allow "pg_dump" to do binary backups larger than two gigabytes on
       Windows (Magnus)
     * New traditional (Taiwan) Chinese FAQ (Zhou Daojing)
     * Prevent the statistics collector from writing to disk too
       frequently (Tom)
     * Fix potential-data-corruption bug in how "VACUUM FULL" handles
       "UPDATE" chains (Tom, Pavan Deolasee)
     * Fix bug in domains that use array types (Tom)
     * Fix "pg_dump" so it can dump a serial column's sequence using "-t"
       when not also dumping the owning table (Tom)
     * Planner fixes, including improving outer join and bitmap scan
       selection logic (Tom)
     * Fix possible wrong answers or crash when a PL/pgSQL function tries
       to RETURN from within an EXCEPTION block (Tom)
     * Fix PANIC during enlargement of a hash index (Tom)
     * Fix POSIX-style timezone specs to follow new USA DST rules (Tom)
     __________________________________________________________________

                                Release 8.2.3

     Release Date: 2007-02-07

   This release contains two fixes from 8.2.2. For information about new
   features in the 8.2 major release, see the Section called Release 8.2.
     __________________________________________________________________

Migration to Version 8.2.3

   A dump/restore is not required for those running 8.2.X.
     __________________________________________________________________

Changes

     * Remove overly-restrictive check for type length in constraints and
       functional indexes(Tom)
     * Fix optimization so MIN/MAX in subqueries can again use indexes
       (Tom)
     __________________________________________________________________

                                Release 8.2.2

     Release Date: 2007-02-05

   This release contains a variety of fixes from 8.2.1, including a
   security fix. For information about new features in the 8.2 major
   release, see the Section called Release 8.2.
     __________________________________________________________________

Migration to Version 8.2.2

   A dump/restore is not required for those running 8.2.X.
     __________________________________________________________________

Changes

     * Remove security vulnerabilities that allowed connected users to
       read backend memory (Tom)
       The vulnerabilities involve suppressing the normal check that a SQL
       function returns the data type it's declared to, and changing the
       data type of a table column (CVE-2007-0555, CVE-2007-0556). These
       errors can easily be exploited to cause a backend crash, and in
       principle might be used to read database content that the user
       should not be able to access.
     * Fix not-so-rare-anymore bug wherein btree index page splits could
       fail due to choosing an infeasible split point (Heikki Linnakangas)
     * Fix Borland C compile scripts (L Bayuk)
     * Properly handle to_char('CC') for years ending in 00 (Tom)
       Year 2000 is in the twentieth century, not the twenty-first.
     * "/contrib/tsearch2" localization improvements (Tatsuo, Teodor)
     * Fix incorrect permission check in
       information_schema.key_column_usage view (Tom)
       The symptom is "relation with OID nnnnn does not exist" errors. To
       get this fix without using "initdb", use "CREATE OR REPLACE VIEW"
       to install the corrected definition found in
       "share/information_schema.sql". Note you will need to do this in
       each database.
     * Improve "VACUUM" performance for databases with many tables (Tom)
     * Fix for rare Assert() crash triggered by UNION (Tom)
     * Fix potentially incorrect results from index searches using ROW
       inequality conditions (Tom)
     * Tighten security of multi-byte character processing for UTF8
       sequences over three bytes long (Tom)
     * Fix bogus "permission denied" failures occurring on Windows due to
       attempts to fsync already-deleted files (Magnus, Tom)
     * Fix bug that could cause the statistics collector to hang on
       Windows (Magnus)
       This would in turn lead to autovacuum not working.
     * Fix possible crashes when an already-in-use PL/pgSQL function is
       updated (Tom)
     * Improve PL/pgSQL handling of domain types (Sergiy Vyshnevetskiy,
       Tom)
     * Fix possible errors in processing PL/pgSQL exception blocks (Tom)
     __________________________________________________________________

                                Release 8.2.1

     Release Date: 2007-01-08

   This release contains a variety of fixes from 8.2. For information
   about new features in the 8.2 major release, see the Section called
   Release 8.2.
     __________________________________________________________________

Migration to Version 8.2.1

   A dump/restore is not required for those running 8.2.
     __________________________________________________________________

Changes

     * Fix crash with SELECT ... LIMIT ALL (also LIMIT NULL) (Tom)
     * "Several /contrib/tsearch2" fixes (Teodor)
     * On Windows, make log messages coming from the operating system use
       ASCII encoding (Hiroshi Saito)
       This fixes a conversion problem when there is a mismatch between
       the encoding of the operating system and database server.
     * Fix Windows linking of pg_dump using "win32.mak" (Hiroshi Saito)
     * Fix planner mistakes for outer join queries (Tom)
     * Fix several problems in queries involving sub-SELECTs (Tom)
     * Fix potential crash in SPI during subtransaction abort (Tom)
       This affects all PL functions since they all use SPI.
     * Improve build speed of PDF documentation (Peter)
     * Re-add JST (Japan) timezone abbreviation (Tom)
     * Improve optimization decisions related to index scans (Tom)
     * Have psql print multi-byte combining characters as before, rather
       than output as \u (Tom)
     * Improve index usage of regular expressions that use parentheses
       (Tom)
       This improves psql \d performance also.
     * Make pg_dumpall assume that databases have public CONNECT
       privilege, when dumping from a pre-8.2 server (Tom)
       This preserves the previous behavior that anyone can connect to a
       database if allowed by "pg_hba.conf".
     __________________________________________________________________

                                 Release 8.2

     Release Date: 2006-12-05
     __________________________________________________________________

Overview

   This release adds many functionality and performance improvements that
   were requested by users, including:

     * Query language enhancements including "INSERT/UPDATE/DELETE
       RETURNING", multirow VALUES lists, and optional target-table alias
       in "UPDATE"/"DELETE"
     * Index creation without blocking concurrent
       "INSERT"/"UPDATE"/"DELETE" operations
     * Many query optimization improvements, including support for
       reordering outer joins
     * Improved sorting performance with lower memory usage
     * More efficient locking with better concurrency
     * More efficient vacuuming
     * Easier administration of warm standby servers
     * New FILLFACTOR support for tables and indexes
     * Monitoring, logging, and performance tuning additions
     * More control over creating and dropping objects
     * Table inheritance relationships can be defined for and removed from
       pre-existing tables
     * "COPY TO" can copy the output of an arbitrary "SELECT" statement
     * Array improvements, including nulls in arrays
     * Aggregate-function improvements, including multiple-input
       aggregates and SQL:2003 statistical functions
     * Many "contrib/" improvements
     __________________________________________________________________

Migration to Version 8.2

   A dump/restore using pg_dump is required for those wishing to migrate
   data from any previous release.

   Observe the following incompatibilities:

     * Set escape_string_warning to on by default (Bruce)
       This issues a warning if backslash escapes are used in non-escape
       (non-E'') strings.
     * Change the row constructor syntax (ROW(...)) so that list elements
       foo.* will be expanded to a list of their member fields, rather
       than creating a nested row type field as formerly (Tom)
       The new behavior is substantially more useful since it allows, for
       example, triggers to check for data changes with IF row(new.*) IS
       DISTINCT FROM row(old.*). The old behavior is still available by
       omitting .*.
     * Make row comparisons follow SQL standard semantics and allow them
       to be used in index scans (Tom)
       Previously, row = and <> comparisons followed the standard but < <=
       > >= did not. A row comparison can now be used as an index
       constraint for a multicolumn index matching the row value.
     * Make row IS [NOT] NULL tests follow SQL standard semantics (Tom)
       The former behavior conformed to the standard for simple cases with
       IS NULL, but IS NOT NULL would return true if any row field was
       non-null, whereas the standard says it should return true only when
       all fields are non-null.
     * Make "SET CONSTRAINT" affect only one constraint (Kris Jurka)
       In previous releases, "SET CONSTRAINT" modified all constraints
       with a matching name. In this release, the schema search path is
       used to modify only the first matching constraint. A schema
       specification is also supported. This more nearly conforms to the
       SQL standard.
     * Remove RULE permission for tables, for security reasons (Tom)
       As of this release, only a table's owner can create or modify rules
       for the table. For backwards compatibility, "GRANT"/"REVOKE RULE"
       is still accepted, but it does nothing.
     * Array comparison improvements (Tom)
       Now array dimensions are also compared.
     * Change array concatenation to match documented behavior (Tom)
       This changes the previous behavior where concatenation would modify
       the array lower bound.
     * Make command-line options of postmaster and postgres identical
       (Peter)
       This allows the postmaster to pass arguments to each backend
       without using -o. Note that some options are now only available as
       long-form options, because there were conflicting single-letter
       options.
     * Deprecate use of postmaster symbolic link (Peter)
       postmaster and postgres commands now act identically, with the
       behavior determined by command-line options. The postmaster
       symbolic link is kept for compatibility, but is not really needed.
     * Change log_duration to output even if the query is not output (Tom)
       In prior releases, log_duration only printed if the query appeared
       earlier in the log.
     * Make to_char(time) and to_char(interval) treat HH and HH12 as
       12-hour intervals
       Most applications should use HH24 unless they want a 12-hour
       display.
     * Zero unmasked bits in conversion from INET to CIDR (Tom)
       This ensures that the converted value is actually valid for CIDR.
     * Remove australian_timezones configuration variable (Joachim
       Wieland)
       This variable has been superseded by a more general facility for
       configuring timezone abbreviations.
     * Improve cost estimation for nested-loop index scans (Tom)
       This might eliminate the need to set unrealistically small values
       of random_page_cost. If you have been using a very small
       random_page_cost, please recheck your test cases.
     * Change behavior of "pg_dump" -n and -t options. (Greg Sabino
       Mullane)
       See the "pg_dump" manual page for details.
     * Change libpq PQdsplen() to return a useful value (Martijn van
       Oosterhout)
     * Declare libpq PQgetssl() as returning void *, rather than SSL *
       (Martijn van Oosterhout)
       This allows applications to use the function without including the
       OpenSSL headers.
     * C-language loadable modules must now include a PG_MODULE_MAGIC
       macro call for version compatibility checking (Martijn van
       Oosterhout)
     * For security's sake, modules used by a PL/PerlU function are no
       longer available to PL/Perl functions (Andrew)

     Note: This also implies that data can no longer be shared between a
     PL/Perl function and a PL/PerlU function. Some Perl installations
     have not been compiled with the correct flags to allow multiple
     interpreters to exist within a single process. In this situation
     PL/Perl and PL/PerlU cannot both be used in a single backend. The
     solution is to get a Perl installation which supports multiple
     interpreters.
     * In "contrib/xml2/", rename xml_valid() to xml_is_well_formed()
       (Tom)
       xml_valid() will remain for backward compatibility, but its
       behavior will change to do schema checking in a future release.
     * Remove "contrib/ora2pg/", now at http://www.samse.fr/GPL/ora2pg
     * Remove contrib modules that have been migrated to PgFoundry:
       "adddepend", "dbase", "dbmirror", "fulltextindex", "mac",
       "userlock"
     * Remove abandoned contrib modules: "mSQL-interface", "tips"
     * Remove QNX and BEOS ports (Bruce)
       These ports no longer had active maintainers.
     __________________________________________________________________

Changes

   Below you will find a detailed account of the changes between
   PostgreSQL 8.2 and the previous major release.
     __________________________________________________________________

Performance Improvements

     * Allow the planner to reorder outer joins in some circumstances
       (Tom)
       In previous releases, outer joins would always be evaluated in the
       order written in the query. This change allows the query optimizer
       to consider reordering outer joins, in cases where it can determine
       that the join order can be changed without altering the meaning of
       the query. This can make a considerable performance difference for
       queries involving multiple outer joins or mixed inner and outer
       joins.
     * Improve efficiency of IN (list-of-expressions) clauses (Tom)
     * Improve sorting speed and reduce memory usage (Simon, Tom)
     * Improve subtransaction performance (Alvaro, Itagaki Takahiro, Tom)
     * Add FILLFACTOR to table and index creation (ITAGAKI Takahiro)
       This leaves extra free space in each table or index page, allowing
       improved performance as the database grows. This is particularly
       valuable to maintain clustering.
     * Increase default values for shared_buffers and max_fsm_pages
       (Andrew)
     * Improve locking performance by breaking the lock manager tables
       into sections (Tom)
       This allows locking to be more fine-grained, reducing contention.
     * Reduce locking requirements of sequential scans (Qingqing Zhou)
     * Reduce locking required for database creation and destruction (Tom)
     * Improve the optimizer's selectivity estimates for LIKE, ILIKE, and
       regular expression operations (Tom)
     * Improve planning of joins to inherited tables and UNION ALL views
       (Tom)
     * Allow constraint exclusion to be applied to inherited "UPDATE" and
       "DELETE" queries (Tom)
       "SELECT" already honored constraint exclusion.
     * Improve planning of constant WHERE clauses, such as a condition
       that depends only on variables inherited from an outer query level
       (Tom)
     * Protocol-level unnamed prepared statements are re-planned for each
       set of BIND values (Tom)
       This improves performance because the exact parameter values can be
       used in the plan.
     * Speed up vacuuming of B-Tree indexes (Heikki Linnakangas, Tom)
     * Avoid extra scan of tables without indexes during "VACUUM" (Greg
       Stark)
     * Improve multicolumn GiST indexing (Oleg, Teodor)
     * Remove dead index entries before B-Tree page split (Junji Teramoto)
     __________________________________________________________________

Server Changes

     * Allow a forced switch to a new transaction log file (Simon, Tom)
       This is valuable for keeping warm standby slave servers in sync
       with the master. Transaction log file switching now also happens
       automatically during pg_stop_backup(). This ensures that all
       transaction log files needed for recovery can be archived
       immediately.
     * Add WAL informational functions (Simon)
       Add functions for interrogating the current transaction log
       insertion point and determining WAL filenames from the hex WAL
       locations displayed by pg_stop_backup() and related functions.
     * Improve recovery from a crash during WAL replay (Simon)
       The server now does periodic checkpoints during WAL recovery, so if
       there is a crash, future WAL recovery is shortened. This also
       eliminates the need for warm standby servers to replay the entire
       log since the base backup if they crash.
     * Improve reliability of long-term WAL replay (Heikki, Simon, Tom)
       Formerly, trying to roll forward through more than 2 billion
       transactions would not work due to XID wraparound. This meant warm
       standby servers had to be reloaded from fresh base backups
       periodically.
     * Add archive_timeout to force transaction log file switches at a
       given interval (Simon)
       This enforces a maximum replication delay for warm standby servers.
     * Add native LDAP authentication (Magnus Hagander)
       This is particularly useful for platforms that do not support PAM,
       such as Windows.
     * Add GRANT CONNECT ON DATABASE (Gevik Babakhani)
       This gives SQL-level control over database access. It works as an
       additional filter on top of the existing "pg_hba.conf" controls.
     * Add support for SSL Certificate Revocation List (CRL) files (Libor
       Hohos)
       The server and libpq both recognize CRL files now.
     * GiST indexes are now clusterable (Teodor)
     * Remove routine autovacuum server log entries (Bruce)
       pg_stat_activity now shows autovacuum activity.
     * Track maximum XID age within individual tables, instead of whole
       databases (Alvaro)
       This reduces the overhead involved in preventing transaction ID
       wraparound, by avoiding unnecessary VACUUMs.
     * Add last vacuum and analyze timestamp columns to the stats
       collector (Larry Rosenman)
       These values now appear in the pg_stat_*_tables system views.
     * Improve performance of statistics monitoring, especially
       stats_command_string (Tom, Bruce)
       This release enables stats_command_string by default, now that its
       overhead is minimal. This means pg_stat_activity will now show all
       active queries by default.
     * Add a waiting column to pg_stat_activity (Tom)
       This allows pg_stat_activity to show all the information included
       in the ps display.
     * Add configuration parameter update_process_title to control whether
       the ps display is updated for every command (Bruce)
       On platforms where it is expensive to update the ps display, it
       might be worthwhile to turn this off and rely solely on
       pg_stat_activity for status information.
     * Allow units to be specified in configuration settings (Peter)
       For example, you can now set shared_buffers to 32MB rather than
       mentally converting sizes.
     * Add support for include directives in "postgresql.conf" (Joachim
       Wieland)
     * Improve logging of protocol-level prepare/bind/execute messages
       (Bruce, Tom)
       Such logging now shows statement names, bind parameter values, and
       the text of the query being executed. Also, the query text is
       properly included in logged error messages when enabled by
       log_min_error_statement.
     * Prevent max_stack_depth from being set to unsafe values
       On platforms where we can determine the actual kernel stack depth
       limit (which is most), make sure that the initial default value of
       max_stack_depth is safe, and reject attempts to set it to unsafely
       large values.
     * Enable highlighting of error location in query in more cases (Tom)
       The server is now able to report a specific error location for some
       semantic errors (such as unrecognized column name), rather than
       just for basic syntax errors as before.
     * Fix "failed to re-find parent key" errors in "VACUUM" (Tom)
     * Clean out "pg_internal.init" cache files during server restart
       (Simon)
       This avoids a hazard that the cache files might contain stale data
       after PITR recovery.
     * Fix race condition for truncation of a large relation across a
       gigabyte boundary by "VACUUM" (Tom)
     * Fix bug causing needless deadlock errors on row-level locks (Tom)
     * Fix bugs affecting multi-gigabyte hash indexes (Tom)
     * Each backend process is now its own process group leader (Tom)
       This allows query cancel to abort subprocesses invoked from a
       backend or archive/recovery process.
     __________________________________________________________________

Query Changes

     * Add "INSERT"/"UPDATE"/"DELETE" RETURNING (Jonah Harris, Tom)
       This allows these commands to return values, such as the computed
       serial key for a new row. In the "UPDATE" case, values from the
       updated version of the row are returned.
     * Add support for multiple-row VALUES clauses, per SQL standard (Joe,
       Tom)
       This allows "INSERT" to insert multiple rows of constants, or
       queries to generate result sets using constants. For example,
       INSERT ... VALUES (...), (...), ...., and SELECT * FROM (VALUES
       (...), (...), ....) AS alias(f1, ...).
     * Allow "UPDATE" and "DELETE" to use an alias for the target table
       (Atsushi Ogawa)
       The SQL standard does not permit an alias in these commands, but
       many database systems allow one anyway for notational convenience.
     * Allow "UPDATE" to set multiple columns with a list of values
       (Susanne Ebrecht)
       This is basically a short-hand for assigning the columns and values
       in pairs. The syntax is UPDATE tab SET (column, ...) = (val, ...).
     * Make row comparisons work per standard (Tom)
       The forms <, <=, >, >= now compare rows lexicographically, that is,
       compare the first elements, if equal compare the second elements,
       and so on. Formerly they expanded to an AND condition across all
       the elements, which was neither standard nor very useful.
     * Add CASCADE option to "TRUNCATE" (Joachim Wieland)
       This causes "TRUNCATE" to automatically include all tables that
       reference the specified table(s) via foreign keys. While
       convenient, this is a dangerous tool -- use with caution!
     * Support FOR UPDATE and FOR SHARE in the same SELECT command (Tom)
     * Add IS NOT DISTINCT FROM (Pavel Stehule)
       This operator is similar to equality (=), but evaluates to true
       when both left and right operands are NULL, and to false when just
       one is, rather than yielding NULL in these cases.
     * Improve the length output used by UNION/INTERSECT/EXCEPT (Tom)
       When all corresponding columns are of the same defined length, that
       length is used for the result, rather than a generic length.
     * Allow ILIKE to work for multi-byte encodings (Tom)
       Internally, ILIKE now calls lower() and then uses LIKE.
       Locale-specific regular expression patterns still do not work in
       these encodings.
     * Enable standard_conforming_strings to be turned on (Kevin Grittner)
       This allows backslash escaping in strings to be disabled, making
       PostgreSQL more standards-compliant. The default is off for
       backwards compatibility, but future releases will default this to
       on.
     * Do not flatten subqueries that contain volatile functions in their
       target lists (Jaime Casanova)
       This prevents surprising behavior due to multiple evaluation of a
       volatile function (such as random() or nextval()). It might cause
       performance degradation in the presence of functions that are
       unnecessarily marked as volatile.
     * Add system views pg_prepared_statements and pg_cursors to show
       prepared statements and open cursors (Joachim Wieland, Neil)
       These are very useful in pooled connection setups.
     * Support portal parameters in "EXPLAIN" and "EXECUTE" (Tom)
       This allows, for example, JDBC ? parameters to work in these
       commands.
     * If SQL-level "PREPARE" parameters are unspecified, infer their
       types from the content of the query (Neil)
       Protocol-level "PREPARE" already did this.
     * Allow LIMIT and OFFSET to exceed two billion (Dhanaraj M)
     __________________________________________________________________

Object Manipulation Changes

     * Add TABLESPACE clause to "CREATE TABLE AS" (Neil)
       This allows a tablespace to be specified for the new table.
     * Add ON COMMIT clause to "CREATE TABLE AS" (Neil)
       This allows temporary tables to be truncated or dropped on
       transaction commit. The default behavior is for the table to remain
       until the session ends.
     * Add INCLUDING CONSTRAINTS to "CREATE TABLE LIKE" (Greg Stark)
       This allows easy copying of CHECK constraints to a new table.
     * Allow the creation of placeholder (shell) types (Martijn van
       Oosterhout)
       A shell type declaration creates a type name, without specifying
       any of the details of the type. Making a shell type is useful
       because it allows cleaner declaration of the type's input/output
       functions, which must exist before the type can be defined "for
       real". The syntax is "CREATE TYPE typename".
     * Aggregate functions now support multiple input parameters (Sergey
       Koposov, Tom)
     * Add new aggregate creation syntax (Tom)
       The new syntax is "CREATE AGGREGATE aggname (input_type)
       (parameter_list)". This more naturally supports the new
       multi-parameter aggregate functionality. The previous syntax is
       still supported.
     * Add "ALTER ROLE PASSWORD NULL" to remove a previously set role
       password (Peter)
     * Add "DROP" object IF EXISTS for many object types (Andrew)
       This allows "DROP" operations on non-existent objects without
       generating an error.
     * Add DROP OWNED to drop all objects owned by a role (Alvaro)
     * Add REASSIGN OWNED to reassign ownership of all objects owned by a
       role (Alvaro)
       This, and DROP OWNED above, facilitate dropping roles.
     * Add "GRANT ON SEQUENCE" syntax (Bruce)
       This was added for setting sequence-specific permissions. GRANT ON
       TABLE for sequences is still supported for backward compatibility.
     * Add USAGE permission for sequences that allows only currval() and
       nextval(), not setval() (Bruce)
       USAGE permission allows more fine-grained control over sequence
       access. Granting USAGE allows users to increment a sequence, but
       prevents them from setting the sequence to an arbitrary value using
       setval().
     * Add ALTER TABLE [ NO ] INHERIT (Greg Stark)
       This allows inheritance to be adjusted dynamically, rather than
       just at table creation and destruction. This is very valuable when
       using inheritance to implement table partitioning.
     * Allow comments on global objects to be stored globally (Kris Jurka)
       Previously, comments attached to databases were stored in
       individual databases, making them ineffective, and there was no
       provision at all for comments on roles or tablespaces. This change
       adds a new shared catalog pg_shdescription and stores comments on
       databases, roles, and tablespaces therein.
     __________________________________________________________________

Utility Command Changes

     * Add option to allow indexes to be created without blocking
       concurrent writes to the table (Greg Stark, Tom)
       The new syntax is "CREATE INDEX CONCURRENTLY". The default behavior
       is still to block table modification while a index is being
       created.
     * Provide advisory locking functionality (Abhijit Menon-Sen, Tom)
       This is a new locking API designed to replace what used to be in
       /contrib/userlock. The userlock code is now on pgfoundry.
     * Allow "COPY" to dump a "SELECT" query (Zoltan Boszormenyi, Karel
       Zak)
       This allows "COPY" to dump arbitrary SQL queries. The syntax is
       COPY (SELECT ...) TO.
     * Make the "COPY" command return a command tag that includes the
       number of rows copied (Volkan YAZICI)
     * Allow "VACUUM" to expire rows without being affected by other
       concurrent "VACUUM" operations (Hannu Krossing, Alvaro, Tom)
     * Make initdb detect the operating system locale and set the default
       DateStyle accordingly (Peter)
       This makes it more likely that the installed "postgresql.conf"
       DateStyle value will be as desired.
     * Reduce number of progress messages displayed by initdb (Tom)
     __________________________________________________________________

Date/Time Changes

     * Allow full timezone names in timestamp input values (Joachim
       Wieland)
       For example, '2006-05-24 21:11 America/New_York'::timestamptz.
     * Support configurable timezone abbreviations (Joachim Wieland)
       A desired set of timezone abbreviations can be chosen via the
       configuration parameter timezone_abbreviations.
     * Add pg_timezone_abbrevs and pg_timezone_names views to show
       supported timezones (Magnus Hagander)
     * Add clock_timestamp(), statement_timestamp(), and
       transaction_timestamp() (Bruce)
       clock_timestamp() is the current wall-clock time,
       statement_timestamp() is the time the current statement arrived at
       the server, and transaction_timestamp() is an alias for now().
     * Allow to_char() to print localized month and day names (Euler
       Taveira de Oliveira)
     * Allow to_char(time) and to_char(interval) to output AM/PM
       specifications (Bruce)
       Intervals and times are treated as 24-hour periods, e.g. 25 hours
       is considered AM.
     * Add new function justify_interval() to adjust interval units (Mark
       Dilger)
     * Allow timezone offsets up to 14:59 away from GMT
       Kiribati uses GMT+14, so we'd better accept that.
     * Interval computation improvements (Michael Glaesemann, Bruce)
     __________________________________________________________________

Other Data Type and Function Changes

     * Allow arrays to contain NULL elements (Tom)
     * Allow assignment to array elements not contiguous with the existing
       entries (Tom)
       The intervening array positions will be filled with nulls. This is
       per SQL standard.
     * New built-in operators for array-subset comparisons (@>, <@, &&)
       (Teodor, Tom)
       These operators can be indexed for many data types using GiST or
       GIN indexes.
     * Add convenient arithmetic operations on INET/CIDR values (Stephen
       R. van den Berg)
       The new operators are & (and), | (or), ~ (not), inet + int8, inet -
       int8, and inet - inet.
     * Add new aggregate functions from SQL:2003 (Neil)
       The new functions are var_pop(), var_samp(), stddev_pop(), and
       stddev_samp(). var_samp() and stddev_samp() are merely renamings of
       the existing aggregates variance() and stddev(). The latter names
       remain available for backward compatibility.
     * Add SQL:2003 statistical aggregates (Sergey Koposov)
       New functions: regr_intercept(), regr_slope(), regr_r2(), corr(),
       covar_samp(), covar_pop(), regr_avgx(), regr_avgy(), regr_sxy(),
       regr_sxx(), regr_syy(), regr_count().
     * Allow domains to be based on other domains (Tom)
     * Properly enforce domain CHECK constraints everywhere (Neil, Tom)
       For example, the result of a user-defined function that is declared
       to return a domain type is now checked against the domain's
       constraints. This closes a significant hole in the domain
       implementation.
     * Fix problems with dumping renamed SERIAL columns (Tom)
       The fix is to dump a SERIAL column by explicitly specifying its
       DEFAULT and sequence elements, and reconstructing the SERIAL column
       on reload using a new "ALTER SEQUENCE OWNED BY" command. This also
       allows dropping a SERIAL column specification.
     * Add a server-side sleep function pg_sleep() (Joachim Wieland)
     * Add all comparison operators for the tid (tuple id) data type (Mark
       Kirkwood, Greg Stark, Tom)
     __________________________________________________________________

PL/pgSQL Server-Side Language Changes

     * Add TG_table_name and TG_table_schema to trigger parameters
       (Andrew)
       TG_relname is now deprecated. Comparable changes have been made in
       the trigger parameters for the other PLs as well.
     * Allow FOR statements to return values to scalars as well as records
       and row types (Pavel Stehule)
     * Add a BY clause to the FOR loop, to control the iteration increment
       (Jaime Casanova)
     * Add STRICT to "SELECT INTO" (Matt Miller)
       STRICT mode throws an exception if more or less than one row is
       returned by the "SELECT", for Oracle PL/SQL compatibility.
     __________________________________________________________________

PL/Perl Server-Side Language Changes

     * Add table_name and table_schema to trigger parameters (Adam
       Sj?gren)
     * Add prepared queries (Dmitry Karasik)
     * Make $_TD trigger data a global variable (Andrew)
       Previously, it was lexical, which caused unexpected sharing
       violations.
     * Run PL/Perl and PL/PerlU in separate interpreters, for security
       reasons (Andrew)
       In consequence, they can no longer share data nor loaded modules.
       Also, if Perl has not been compiled with the requisite flags to
       allow multiple interpreters, only one of these languages can be
       used in any given backend process.
     __________________________________________________________________

PL/Python Server-Side Language Changes

     * Named parameters are passed as ordinary variables, as well as in
       the args[] array (Sven Suursoho)
     * Add table_name and table_schema to trigger parameters (Andrew)
     * Allow returning of composite types and result sets (Sven Suursoho)
     * Return result-set as list, iterator, or generator (Sven Suursoho)
     * Allow functions to return void (Neil)
     * Python 2.5 is now supported (Tom)
     __________________________________________________________________

psql Changes

     * Add new command \password for changing role password with
       client-side password encryption (Peter)
     * Allow \c to connect to a new host and port number (David, Volkan
       YAZICI)
     * Add tablespace display to \l+ (Philip Yarra)
     * Improve \df slash command to include the argument names and modes
       (OUT or INOUT) of the function (David Fetter)
     * Support binary "COPY" (Andreas Pflug)
     * Add option to run the entire session in a single transaction
       (Simon)
       Use option -1 or --single-transaction.
     * Support for automatically retrieving "SELECT" results in batches
       using a cursor (Chris Mair)
       This is enabled using "\set FETCH_COUNT n". This feature allows
       large result sets to be retrieved in psql without attempting to
       buffer the entire result set in memory.
     * Make multi-line values align in the proper column (Martijn van
       Oosterhout)
       Field values containing newlines are now displayed in a more
       readable fashion.
     * Save multi-line statements as a single entry, rather than one line
       at a time (Sergey E. Koposov)
       This makes up-arrow recall of queries easier. (This is not
       available on Windows, because that platform uses the native
       command-line editing present in the operating system.)
     * Make the line counter 64-bit so it can handle files with more than
       two billion lines (David Fetter)
     * Report both the returned data and the command status tag for
       "INSERT"/"UPDATE"/"DELETE RETURNING" (Tom)
     __________________________________________________________________

pg_dump Changes

     * Allow complex selection of objects to be included or excluded by
       pg_dump (Greg Sabino Mullane)
       pg_dump now supports multiple -n (schema) and -t (table) options,
       and adds -N and -T options to exclude objects. Also, the arguments
       of these switches can now be wild-card expressions rather than
       single object names, for example -t 'foo*', and a schema can be
       part of a -t or -T switch, for example -t schema1.table1.
     * Add pg_restore --no-data-for-failed-tables option to suppress
       loading data if table creation failed (i.e., the table already
       exists) (Martin Pitt)
     * Add pg_restore option to run the entire session in a single
       transaction (Simon)
       Use option -1 or --single-transaction.
     __________________________________________________________________

libpq Changes

     * Add PQencryptPassword() to encrypt passwords (Tom)
       This allows passwords to be sent pre-encrypted for commands like
       "ALTER ROLE ... PASSWORD".
     * Add function PQisthreadsafe() (Bruce)
       This allows applications to query the thread-safety status of the
       library.
     * Add PQdescribePrepared(), PQdescribePortal(), and related functions
       to return information about previously prepared statements and open
       cursors (Volkan YAZICI)
     * Allow LDAP lookups from "pg_service.conf" (Laurenz Albe)
     * Allow a hostname in "~/.pgpass" to match the default socket
       directory (Bruce)
       A blank hostname continues to match any Unix-socket connection, but
       this addition allows entries that are specific to one of several
       postmasters on the machine.
     __________________________________________________________________

ecpg Changes

     * Allow "SHOW" to put its result into a variable (Joachim Wieland)
     * Add "COPY TO STDOUT" (Joachim Wieland)
     * Add regression tests (Joachim Wieland, Michael)
     * Major source code cleanups (Joachim Wieland, Michael)
     __________________________________________________________________

Windows Port

     * Allow MSVC to compile the PostgreSQL server (Magnus, Hiroshi Saito)
     * Add MSVC support for utility commands and pg_dump (Hiroshi Saito)
     * Add support for Windows code pages 1253, 1254, 1255, and 1257 (Kris
       Jurka)
     * Drop privileges on startup, so that the server can be started from
       an administrative account (Magnus)
     * Stability fixes (Qingqing Zhou, Magnus)
     * Add native semaphore implementation (Qingqing Zhou)
       The previous code mimicked SysV semaphores.
     __________________________________________________________________

Source Code Changes

     * Add GIN (Generalized Inverted iNdex) index access method (Teodor,
       Oleg)
     * Remove R-tree indexing (Tom)
       Rtree has been re-implemented using GiST. Among other differences,
       this means that rtree indexes now have support for crash recovery
       via write-ahead logging (WAL).
     * Reduce libraries needlessly linked into the backend (Martijn van
       Oosterhout, Tom)
     * Add a configure flag to allow libedit to be preferred over GNU
       readline (Bruce)
       Use configure --with-libedit-preferred.
     * Allow installation into directories containing spaces (Peter)
     * Improve ability to relocate installation directories (Tom)
     * Add support for Solaris x86_64 using the Solaris compiler (Pierre
       Girard, Theo Schlossnagle, Bruce)
     * Add DTrace support (Robert Lor)
     * Add PG_VERSION_NUM for use by third-party applications wanting to
       test the backend version in C using > and < comparisons (Bruce)
     * Add XLOG_BLCKSZ as independent from BLCKSZ (Mark Wong)
     * Add LWLOCK_STATS define to report locking activity (Tom)
     * Emit warnings for unknown configure options (Martijn van
       Oosterhout)
     * Add server support for "plugin" libraries that can be used for
       add-on tasks such as debugging and performance measurement (Korry
       Douglas)
       This consists of two features: a table of "rendezvous variables"
       that allows separately-loaded shared libraries to communicate, and
       a new configuration parameter local_preload_libraries that allows
       libraries to be loaded into specific sessions without explicit
       cooperation from the client application. This allows external
       add-ons to implement features such as a PL/pgSQL debugger.
     * Rename existing configuration parameter preload_libraries to
       shared_preload_libraries (Tom)
       This was done for clarity in comparison to local_preload_libraries.
     * Add new configuration parameter server_version_num (Greg Sabino
       Mullane)
       This is like server_version, but is an integer, e.g. 80200. This
       allows applications to make version checks more easily.
     * Add a configuration parameter seq_page_cost (Tom)
     * Re-implement the regression test script as a C program (Magnus,
       Tom)
     * Allow loadable modules to allocate shared memory and lightweight
       locks (Marc Munro)
     * Add automatic initialization and finalization of dynamically loaded
       libraries (Ralf Engelschall, Tom)
       New functions _PG_init() and _PG_fini() are called if the library
       defines such symbols. Hence we no longer need to specify an
       initialization function in shared_preload_libraries; we can assume
       that the library used the _PG_init() convention instead.
     * Add PG_MODULE_MAGIC header block to all shared object files
       (Martijn van Oosterhout)
       The magic block prevents version mismatches between loadable object
       files and servers.
     * Add shared library support for AIX (Laurenz Albe)
     * New XML documentation section (Bruce)
     __________________________________________________________________

Contrib Changes

     * Major tsearch2 improvements (Oleg, Teodor)
          + multibyte encoding support, including UTF8
          + query rewriting support
          + improved ranking functions
          + thesaurus dictionary support
          + Ispell dictionaries now recognize MySpell format, used by
            OpenOffice
          + GIN support
     * Add adminpack module containing Pgadmin administration functions
       (Dave)
       These functions provide additional file system access routines not
       present in the default PostgreSQL server.
     * Add sslinfo module (Victor Wagner)
       Reports information about the current connection's SSL certificate.
     * Add pgrowlocks module (Tatsuo)
       This shows row locking information for a specified table.
     * Add hstore module (Oleg, Teodor)
     * Add isn module, replacing isbn_issn (Jeremy Kronuz)
       This new implementation supports EAN13, UPC, ISBN (books), ISMN
       (music), and ISSN (serials).
     * Add index information functions to pgstattuple (ITAGAKI Takahiro,
       Satoshi Nagayasu)
     * Add pg_freespacemap module to display free space map information
       (Mark Kirkwood)
     * pgcrypto now has all planned functionality (Marko Kreen)
          + Include iMath library in pgcrypto to have the public-key
            encryption functions always available.
          + Add SHA224 algorithm that was missing in OpenBSD code.
          + Activate builtin code for SHA224/256/384/512 hashes on older
            OpenSSL to have those algorithms always available.
          + New function gen_random_bytes() that returns cryptographically
            strong randomness. Useful for generating encryption keys.
          + Remove digest_exists(), hmac_exists() and cipher_exists()
            functions.
     * Improvements to cube module (Joshua Reich)
       New functions are cube(float[]), cube(float[], float[]), and
       cube_subset(cube, int4[]).
     * Add async query capability to dblink (Kai Londenberg, Joe Conway)
     * New operators for array-subset comparisons (@>, <@, &&) (Tom)
       Various contrib packages already had these operators for their
       datatypes, but the naming wasn't consistent. We have now added
       consistently named array-subset comparison operators to the core
       code and all the contrib packages that have such functionality.
       (The old names remain available, but are deprecated.)
     * Add uninstall scripts for all contrib packages that have install
       scripts (David, Josh Drake)
     __________________________________________________________________

                               Release 8.1.23

     Release Date: 2010-12-16

   This release contains a variety of fixes from 8.1.22. For information
   about new features in the 8.1 major release, see the Section called
   Release 8.1.

   This is expected to be the last PostgreSQL release in the 8.1.X series.
   Users are encouraged to update to a newer release branch soon.
     __________________________________________________________________

Migration to Version 8.1.23

   A dump/restore is not required for those running 8.1.X. However, if you
   are upgrading from a version earlier than 8.1.18, see the release notes
   for 8.1.18.
     __________________________________________________________________

Changes

     * Force the default wal_sync_method to be fdatasync on Linux (Tom
       Lane, Marti Raudsepp)
       The default on Linux has actually been fdatasync for many years,
       but recent kernel changes caused PostgreSQL to choose open_datasync
       instead. This choice did not result in any performance improvement,
       and caused outright failures on certain filesystems, notably ext4
       with the data=journal mount option.
     * Fix recovery from base backup when the starting checkpoint WAL
       record is not in the same WAL segment as its redo point (Jeff
       Davis)
     * Add support for detecting register-stack overrun on IA64 (Tom Lane)
       The IA64 architecture has two hardware stacks. Full prevention of
       stack-overrun failures requires checking both.
     * Add a check for stack overflow in copyObject() (Tom Lane)
       Certain code paths could crash due to stack overflow given a
       sufficiently complex query.
     * Fix detection of page splits in temporary GiST indexes (Heikki
       Linnakangas)
       It is possible to have a "concurrent" page split in a temporary
       index, if for example there is an open cursor scanning the index
       when an insertion is done. GiST failed to detect this case and
       hence could deliver wrong results when execution of the cursor
       continued.
     * Avoid memory leakage while "ANALYZE"'ing complex index expressions
       (Tom Lane)
     * Ensure an index that uses a whole-row Var still depends on its
       table (Tom Lane)
       An index declared like create index i on t (foo(t.*)) would not
       automatically get dropped when its table was dropped.
     * Do not "inline" a SQL function with multiple OUT parameters (Tom
       Lane)
       This avoids a possible crash due to loss of information about the
       expected result rowtype.
     * Fix constant-folding of COALESCE() expressions (Tom Lane)
       The planner would sometimes attempt to evaluate sub-expressions
       that in fact could never be reached, possibly leading to unexpected
       errors.
     * Add print functionality for InhRelation nodes (Tom Lane)
       This avoids a failure when debug_print_parse is enabled and certain
       types of query are executed.
     * Fix incorrect calculation of distance from a point to a horizontal
       line segment (Tom Lane)
       This bug affected several different geometric distance-measurement
       operators.
     * Fix PL/pgSQL's handling of "simple" expressions to not fail in
       recursion or error-recovery cases (Tom Lane)
     * Fix bug in "contrib/cube"'s GiST picksplit algorithm (Alexander
       Korotkov)
       This could result in considerable inefficiency, though not actually
       incorrect answers, in a GiST index on a cube column. If you have
       such an index, consider "REINDEX"ing it after installing this
       update.
     * Don't emit "identifier will be truncated" notices in
       "contrib/dblink" except when creating new connections (Itagaki
       Takahiro)
     * Fix potential coredump on missing public key in "contrib/pgcrypto"
       (Marti Raudsepp)
     * Fix memory leak in "contrib/xml2"'s XPath query functions (Tom
       Lane)
     * Update time zone data files to tzdata release 2010o for DST law
       changes in Fiji and Samoa; also historical corrections for Hong
       Kong.
     __________________________________________________________________

                               Release 8.1.22

     Release Date: 2010-10-04

   This release contains a variety of fixes from 8.1.21. For information
   about new features in the 8.1 major release, see the Section called
   Release 8.1.

   The PostgreSQL community will stop releasing updates for the 8.1.X
   release series in November 2010. Users are encouraged to update to a
   newer release branch soon.
     __________________________________________________________________

Migration to Version 8.1.22

   A dump/restore is not required for those running 8.1.X. However, if you
   are upgrading from a version earlier than 8.1.18, see the release notes
   for 8.1.18.
     __________________________________________________________________

Changes

     * Use a separate interpreter for each calling SQL userid in PL/Perl
       and PL/Tcl (Tom Lane)
       This change prevents security problems that can be caused by
       subverting Perl or Tcl code that will be executed later in the same
       session under another SQL user identity (for example, within a
       SECURITY DEFINER function). Most scripting languages offer numerous
       ways that that might be done, such as redefining standard functions
       or operators called by the target function. Without this change,
       any SQL user with Perl or Tcl language usage rights can do
       essentially anything with the SQL privileges of the target
       function's owner.
       The cost of this change is that intentional communication among
       Perl and Tcl functions becomes more difficult. To provide an escape
       hatch, PL/PerlU and PL/TclU functions continue to use only one
       interpreter per session. This is not considered a security issue
       since all such functions execute at the trust level of a database
       superuser already.
       It is likely that third-party procedural languages that claim to
       offer trusted execution have similar security issues. We advise
       contacting the authors of any PL you are depending on for
       security-critical purposes.
       Our thanks to Tim Bunce for pointing out this issue
       (CVE-2010-3433).
     * Prevent possible crashes in pg_get_expr() by disallowing it from
       being called with an argument that is not one of the system catalog
       columns it's intended to be used with (Heikki Linnakangas, Tom
       Lane)
     * Fix "cannot handle unplanned sub-select" error (Tom Lane)
       This occurred when a sub-select contains a join alias reference
       that expands into an expression containing another sub-select.
     * Prevent show_session_authorization() from crashing within
       autovacuum processes (Tom Lane)
     * Defend against functions returning setof record where not all the
       returned rows are actually of the same rowtype (Tom Lane)
     * Fix possible failure when hashing a pass-by-reference function
       result (Tao Ma, Tom Lane)
     * Take care to fsync the contents of lockfiles (both "postmaster.pid"
       and the socket lockfile) while writing them (Tom Lane)
       This omission could result in corrupted lockfile contents if the
       machine crashes shortly after postmaster start. That could in turn
       prevent subsequent attempts to start the postmaster from
       succeeding, until the lockfile is manually removed.
     * Avoid recursion while assigning XIDs to heavily-nested
       subtransactions (Andres Freund, Robert Haas)
       The original coding could result in a crash if there was limited
       stack space.
     * Fix log_line_prefix's %i escape, which could produce junk early in
       backend startup (Tom Lane)
     * Fix possible data corruption in "ALTER TABLE ... SET TABLESPACE"
       when archiving is enabled (Jeff Davis)
     * Allow "CREATE DATABASE" and "ALTER DATABASE ... SET TABLESPACE" to
       be interrupted by query-cancel (Guillaume Lelarge)
     * In PL/Python, defend against null pointer results from
       PyCObject_AsVoidPtr and PyCObject_FromVoidPtr (Peter Eisentraut)
     * Improve "contrib/dblink"'s handling of tables containing dropped
       columns (Tom Lane)
     * Fix connection leak after "duplicate connection name" errors in
       "contrib/dblink" (Itagaki Takahiro)
     * Fix "contrib/dblink" to handle connection names longer than 62
       bytes correctly (Itagaki Takahiro)
     * Update build infrastructure and documentation to reflect the source
       code repository's move from CVS to Git (Magnus Hagander and others)
     * Update time zone data files to tzdata release 2010l for DST law
       changes in Egypt and Palestine; also historical corrections for
       Finland.
       This change also adds new names for two Micronesian timezones:
       Pacific/Chuuk is now preferred over Pacific/Truk (and the preferred
       abbreviation is CHUT not TRUT) and Pacific/Pohnpei is preferred
       over Pacific/Ponape.
     __________________________________________________________________

                               Release 8.1.21

     Release Date: 2010-05-17

   This release contains a variety of fixes from 8.1.20. For information
   about new features in the 8.1 major release, see the Section called
   Release 8.1.
     __________________________________________________________________

Migration to Version 8.1.21

   A dump/restore is not required for those running 8.1.X. However, if you
   are upgrading from a version earlier than 8.1.18, see the release notes
   for 8.1.18.
     __________________________________________________________________

Changes

     * Enforce restrictions in plperl using an opmask applied to the whole
       interpreter, instead of using "Safe.pm" (Tim Bunce, Andrew Dunstan)
       Recent developments have convinced us that "Safe.pm" is too
       insecure to rely on for making plperl trustable. This change
       removes use of "Safe.pm" altogether, in favor of using a separate
       interpreter with an opcode mask that is always applied. Pleasant
       side effects of the change include that it is now possible to use
       Perl's strict pragma in a natural way in plperl, and that Perl's $a
       and $b variables work as expected in sort routines, and that
       function compilation is significantly faster. (CVE-2010-1169)
     * Prevent PL/Tcl from executing untrustworthy code from pltcl_modules
       (Tom)
       PL/Tcl's feature for autoloading Tcl code from a database table
       could be exploited for trojan-horse attacks, because there was no
       restriction on who could create or insert into that table. This
       change disables the feature unless pltcl_modules is owned by a
       superuser. (However, the permissions on the table are not checked,
       so installations that really need a less-than-secure modules table
       can still grant suitable privileges to trusted non-superusers.)
       Also, prevent loading code into the unrestricted "normal" Tcl
       interpreter unless we are really going to execute a pltclu
       function. (CVE-2010-1170)
     * Do not allow an unprivileged user to reset superuser-only parameter
       settings (Alvaro)
       Previously, if an unprivileged user ran ALTER USER ... RESET ALL
       for himself, or ALTER DATABASE ... RESET ALL for a database he
       owns, this would remove all special parameter settings for the user
       or database, even ones that are only supposed to be changeable by a
       superuser. Now, the "ALTER" will only remove the parameters that
       the user has permission to change.
     * Avoid possible crash during backend shutdown if shutdown occurs
       when a CONTEXT addition would be made to log entries (Tom)
       In some cases the context-printing function would fail because the
       current transaction had already been rolled back when it came time
       to print a log message.
     * Update pl/perl's "ppport.h" for modern Perl versions (Andrew)
     * Fix assorted memory leaks in pl/python (Andreas Freund, Tom)
     * Prevent infinite recursion in psql when expanding a variable that
       refers to itself (Tom)
     * Ensure that "contrib/pgstattuple" functions respond to cancel
       interrupts promptly (Tatsuhito Kasahara)
     * Make server startup deal properly with the case that shmget()
       returns EINVAL for an existing shared memory segment (Tom)
       This behavior has been observed on BSD-derived kernels including OS
       X. It resulted in an entirely-misleading startup failure
       complaining that the shared memory request size was too large.
     * Update time zone data files to tzdata release 2010j for DST law
       changes in Argentina, Australian Antarctic, Bangladesh, Mexico,
       Morocco, Pakistan, Palestine, Russia, Syria, Tunisia; also
       historical corrections for Taiwan.
     __________________________________________________________________

                               Release 8.1.20

     Release Date: 2010-03-15

   This release contains a variety of fixes from 8.1.19. For information
   about new features in the 8.1 major release, see the Section called
   Release 8.1.
     __________________________________________________________________

Migration to Version 8.1.20

   A dump/restore is not required for those running 8.1.X. However, if you
   are upgrading from a version earlier than 8.1.18, see the release notes
   for 8.1.18.
     __________________________________________________________________

Changes

     * Add new configuration parameter ssl_renegotiation_limit to control
       how often we do session key renegotiation for an SSL connection
       (Magnus)
       This can be set to zero to disable renegotiation completely, which
       may be required if a broken SSL library is used. In particular,
       some vendors are shipping stopgap patches for CVE-2009-3555 that
       cause renegotiation attempts to fail.
     * Fix possible crashes when trying to recover from a failure in
       subtransaction start (Tom)
     * Fix server memory leak associated with use of savepoints and a
       client encoding different from server's encoding (Tom)
     * Make substring() for bit types treat any negative length as meaning
       "all the rest of the string" (Tom)
       The previous coding treated only -1 that way, and would produce an
       invalid result value for other negative values, possibly leading to
       a crash (CVE-2010-0442).
     * Fix integer-to-bit-string conversions to handle the first
       fractional byte correctly when the output bit width is wider than
       the given integer by something other than a multiple of 8 bits
       (Tom)
     * Fix some cases of pathologically slow regular expression matching
       (Tom)
     * Fix the STOP WAL LOCATION entry in backup history files to report
       the next WAL segment's name when the end location is exactly at a
       segment boundary (Itagaki Takahiro)
     * Fix some more cases of temporary-file leakage (Heikki)
       This corrects a problem introduced in the previous minor release.
       One case that failed is when a plpgsql function returning set is
       called within another function's exception handler.
     * When reading "pg_hba.conf" and related files, do not treat
       @something as a file inclusion request if the @ appears inside
       quote marks; also, never treat @ by itself as a file inclusion
       request (Tom)
       This prevents erratic behavior if a role or database name starts
       with @. If you need to include a file whose path name contains
       spaces, you can still do so, but you must write @"/path to/file"
       rather than putting the quotes around the whole construct.
     * Prevent infinite loop on some platforms if a directory is named as
       an inclusion target in "pg_hba.conf" and related files (Tom)
     * Fix psql's numericlocale option to not format strings it shouldn't
       in latex and troff output formats (Heikki)
     * Fix plpgsql failure in one case where a composite column is set to
       NULL (Tom)
     * Add volatile markings in PL/Python to avoid possible
       compiler-specific misbehavior (Zdenek Kotala)
     * Ensure PL/Tcl initializes the Tcl interpreter fully (Tom)
       The only known symptom of this oversight is that the Tcl clock
       command misbehaves if using Tcl 8.5 or later.
     * Prevent crash in "contrib/dblink" when too many key columns are
       specified to a dblink_build_sql_* function (Rushabh Lathia, Joe
       Conway)
     * Fix assorted crashes in "contrib/xml2" caused by sloppy memory
       management (Tom)
     * Update time zone data files to tzdata release 2010e for DST law
       changes in Bangladesh, Chile, Fiji, Mexico, Paraguay, Samoa.
     __________________________________________________________________

                               Release 8.1.19

     Release Date: 2009-12-14

   This release contains a variety of fixes from 8.1.18. For information
   about new features in the 8.1 major release, see the Section called
   Release 8.1.
     __________________________________________________________________

Migration to Version 8.1.19

   A dump/restore is not required for those running 8.1.X. However, if you
   are upgrading from a version earlier than 8.1.18, see the release notes
   for 8.1.18.
     __________________________________________________________________

Changes

     * Protect against indirect security threats caused by index functions
       changing session-local state (Gurjeet Singh, Tom)
       This change prevents allegedly-immutable index functions from
       possibly subverting a superuser's session (CVE-2009-4136).
     * Reject SSL certificates containing an embedded null byte in the
       common name (CN) field (Magnus)
       This prevents unintended matching of a certificate to a server or
       client name during SSL validation (CVE-2009-4034).
     * Fix possible crash during backend-startup-time cache initialization
       (Tom)
     * Prevent signals from interrupting VACUUM at unsafe times (Alvaro)
       This fix prevents a PANIC if a VACUUM FULL is canceled after it's
       already committed its tuple movements, as well as transient errors
       if a plain VACUUM is interrupted after having truncated the table.
     * Fix possible crash due to integer overflow in hash table size
       calculation (Tom)
       This could occur with extremely large planner estimates for the
       size of a hashjoin's result.
     * Fix very rare crash in inet/cidr comparisons (Chris Mikkelson)
     * Ensure that shared tuple-level locks held by prepared transactions
       are not ignored (Heikki)
     * Fix premature drop of temporary files used for a cursor that is
       accessed within a subtransaction (Heikki)
     * Fix PAM password processing to be more robust (Tom)
       The previous code is known to fail with the combination of the
       Linux pam_krb5 PAM module with Microsoft Active Directory as the
       domain controller. It might have problems elsewhere too, since it
       was making unjustified assumptions about what arguments the PAM
       stack would pass to it.
     * Fix processing of ownership dependencies during CREATE OR REPLACE
       FUNCTION (Tom)
     * Ensure that Perl arrays are properly converted to PostgreSQL arrays
       when returned by a set-returning PL/Perl function (Andrew Dunstan,
       Abhijit Menon-Sen)
       This worked correctly already for non-set-returning functions.
     * Fix rare crash in exception processing in PL/Python (Peter)
     * Ensure psql's flex module is compiled with the correct system
       header definitions (Tom)
       This fixes build failures on platforms where --enable-largefile
       causes incompatible changes in the generated code.
     * Make the postmaster ignore any application_name parameter in
       connection request packets, to improve compatibility with future
       libpq versions (Tom)
     * Update time zone data files to tzdata release 2009s for DST law
       changes in Antarctica, Argentina, Bangladesh, Fiji, Novokuznetsk,
       Pakistan, Palestine, Samoa, Syria; also historical corrections for
       Hong Kong.
     __________________________________________________________________

                               Release 8.1.18

     Release Date: 2009-09-09

   This release contains a variety of fixes from 8.1.17. For information
   about new features in the 8.1 major release, see the Section called
   Release 8.1.
     __________________________________________________________________

Migration to Version 8.1.18

   A dump/restore is not required for those running 8.1.X. However, if you
   have any hash indexes on interval columns, you must "REINDEX" them
   after updating to 8.1.18. Also, if you are upgrading from a version
   earlier than 8.1.15, see the release notes for 8.1.15.
     __________________________________________________________________

Changes

     * Disallow "RESET ROLE" and "RESET SESSION AUTHORIZATION" inside
       security-definer functions (Tom, Heikki)
       This covers a case that was missed in the previous patch that
       disallowed "SET ROLE" and "SET SESSION AUTHORIZATION" inside
       security-definer functions. (See CVE-2007-6600)
     * Fix handling of sub-SELECTs appearing in the arguments of an
       outer-level aggregate function (Tom)
     * Fix hash calculation for data type interval (Tom)
       This corrects wrong results for hash joins on interval values. It
       also changes the contents of hash indexes on interval columns. If
       you have any such indexes, you must "REINDEX" them after updating.
     * Treat to_char(..., 'TH') as an uppercase ordinal suffix with
       'HH'/'HH12' (Heikki)
       It was previously handled as 'th' (lowercase).
     * Fix overflow for INTERVAL 'x ms' when "x" is more than 2 million
       and integer datetimes are in use (Alex Hunsaker)
     * Fix calculation of distance between a point and a line segment
       (Tom)
       This led to incorrect results from a number of geometric operators.
     * Fix money data type to work in locales where currency amounts have
       no fractional digits, e.g. Japan (Itagaki Takahiro)
     * Properly round datetime input like
       00:12:57.9999999999999999999999999999 (Tom)
     * Fix poor choice of page split point in GiST R-tree operator classes
       (Teodor)
     * Fix portability issues in plperl initialization (Andrew Dunstan)
     * Fix pg_ctl to not go into an infinite loop if "postgresql.conf" is
       empty (Jeff Davis)
     * Fix "contrib/xml2"'s xslt_process() to properly handle the maximum
       number of parameters (twenty) (Tom)
     * Improve robustness of libpq's code to recover from errors during
       "COPY FROM STDIN" (Tom)
     * Avoid including conflicting readline and editline header files when
       both libraries are installed (Zdenek Kotala)
     * Update time zone data files to tzdata release 2009l for DST law
       changes in Bangladesh, Egypt, Jordan, Pakistan, Argentina/San_Luis,
       Cuba, Jordan (historical correction only), Mauritius, Morocco,
       Palestine, Syria, Tunisia.
     __________________________________________________________________

                               Release 8.1.17

     Release Date: 2009-03-16

   This release contains a variety of fixes from 8.1.16. For information
   about new features in the 8.1 major release, see the Section called
   Release 8.1.
     __________________________________________________________________

Migration to Version 8.1.17

   A dump/restore is not required for those running 8.1.X. However, if you
   are upgrading from a version earlier than 8.1.15, see the release notes
   for 8.1.15.
     __________________________________________________________________

Changes

     * Prevent error recursion crashes when encoding conversion fails
       (Tom)
       This change extends fixes made in the last two minor releases for
       related failure scenarios. The previous fixes were narrowly
       tailored for the original problem reports, but we have now
       recognized that *any* error thrown by an encoding conversion
       function could potentially lead to infinite recursion while trying
       to report the error. The solution therefore is to disable
       translation and encoding conversion and report the plain-ASCII form
       of any error message, if we find we have gotten into a recursive
       error reporting situation. (CVE-2009-0922)
     * Disallow "CREATE CONVERSION" with the wrong encodings for the
       specified conversion function (Heikki)
       This prevents one possible scenario for encoding conversion
       failure. The previous change is a backstop to guard against other
       kinds of failures in the same area.
     * Fix core dump when to_char() is given format codes that are
       inappropriate for the type of the data argument (Tom)
     * Fix decompilation of CASE WHEN with an implicit coercion (Tom)
       This mistake could lead to Assert failures in an Assert-enabled
       build, or an "unexpected CASE WHEN clause" error message in other
       cases, when trying to examine or dump a view.
     * Fix possible misassignment of the owner of a TOAST table's rowtype
       (Tom)
       If "CLUSTER" or a rewriting variant of "ALTER TABLE" were executed
       by someone other than the table owner, the pg_type entry for the
       table's TOAST table would end up marked as owned by that someone.
       This caused no immediate problems, since the permissions on the
       TOAST rowtype aren't examined by any ordinary database operation.
       However, it could lead to unexpected failures if one later tried to
       drop the role that issued the command (in 8.1 or 8.2), or "owner of
       data type appears to be invalid" warnings from pg_dump after having
       done so (in 8.3).
     * Clean up PL/pgSQL error status variables fully at block exit
       (Ashesh Vashi and Dave Page)
       This is not a problem for PL/pgSQL itself, but the omission could
       cause the PL/pgSQL Debugger to crash while examining the state of a
       function.
     * Add MUST (Mauritius Island Summer Time) to the default list of
       known timezone abbreviations (Xavier Bugaud)
     __________________________________________________________________

                               Release 8.1.16

     Release Date: 2009-02-02

   This release contains a variety of fixes from 8.1.15. For information
   about new features in the 8.1 major release, see the Section called
   Release 8.1.
     __________________________________________________________________

Migration to Version 8.1.16

   A dump/restore is not required for those running 8.1.X. However, if you
   are upgrading from a version earlier than 8.1.15, see the release notes
   for 8.1.15.
     __________________________________________________________________

Changes

     * Fix crash in autovacuum (Alvaro)
       The crash occurs only after vacuuming a whole database for
       anti-transaction-wraparound purposes, which means that it occurs
       infrequently and is hard to track down.
     * Improve handling of URLs in headline() function (Teodor)
     * Improve handling of overlength headlines in headline() function
       (Teodor)
     * Prevent possible Assert failure or misconversion if an encoding
       conversion is created with the wrong conversion function for the
       specified pair of encodings (Tom, Heikki)
     * Avoid unnecessary locking of small tables in "VACUUM" (Heikki)
     * Ensure that the contents of a holdable cursor don't depend on the
       contents of TOAST tables (Tom)
       Previously, large field values in a cursor result might be
       represented as TOAST pointers, which would fail if the referenced
       table got dropped before the cursor is read, or if the large value
       is deleted and then vacuumed away. This cannot happen with an
       ordinary cursor, but it could with a cursor that is held past its
       creating transaction.
     * Fix uninitialized variables in "contrib/tsearch2"'s get_covers()
       function (Teodor)
     * Fix configure script to properly report failure when unable to
       obtain linkage information for PL/Perl (Andrew)
     * Make all documentation reference pgsql-bugs and/or pgsql-hackers as
       appropriate, instead of the now-decommissioned pgsql-ports and
       pgsql-patches mailing lists (Tom)
     * Update time zone data files to tzdata release 2009a (for Kathmandu
       and historical DST corrections in Switzerland, Cuba)
     __________________________________________________________________

                               Release 8.1.15

     Release Date: 2008-11-03

   This release contains a variety of fixes from 8.1.14. For information
   about new features in the 8.1 major release, see the Section called
   Release 8.1.
     __________________________________________________________________

Migration to Version 8.1.15

   A dump/restore is not required for those running 8.1.X. However, if you
   are upgrading from a version earlier than 8.1.2, see the release notes
   for 8.1.2. Also, if you were running a previous 8.1.X release, it is
   recommended to "REINDEX" all GiST indexes after the upgrade.
     __________________________________________________________________

Changes

     * Fix GiST index corruption due to marking the wrong index entry
       "dead" after a deletion (Teodor)
       This would result in index searches failing to find rows they
       should have found. Corrupted indexes can be fixed with "REINDEX".
     * Fix backend crash when the client encoding cannot represent a
       localized error message (Tom)
       We have addressed similar issues before, but it would still fail if
       the "character has no equivalent" message itself couldn't be
       converted. The fix is to disable localization and send the plain
       ASCII error message when we detect such a situation.
     * Fix possible crash when deeply nested functions are invoked from a
       trigger (Tom)
     * Fix mis-expansion of rule queries when a sub-SELECT appears in a
       function call in FROM, a multi-row VALUES list, or a RETURNING list
       (Tom)
       The usual symptom of this problem is an "unrecognized node type"
       error.
     * Ensure an error is reported when a newly-defined PL/pgSQL trigger
       function is invoked as a normal function (Tom)
     * Prevent possible collision of relfilenode numbers when moving a
       table to another tablespace with "ALTER SET TABLESPACE" (Heikki)
       The command tried to re-use the existing filename, instead of
       picking one that is known unused in the destination directory.
     * Fix incorrect tsearch2 headline generation when single query item
       matches first word of text (Sushant Sinha)
     * Fix improper display of fractional seconds in interval values when
       using a non-ISO datestyle in an "--enable-integer-datetimes" build
       (Ron Mayer)
     * Ensure SPI_getvalue and SPI_getbinval behave correctly when the
       passed tuple and tuple descriptor have different numbers of columns
       (Tom)
       This situation is normal when a table has had columns added or
       removed, but these two functions didn't handle it properly. The
       only likely consequence is an incorrect error indication.
     * Fix ecpg's parsing of "CREATE ROLE" (Michael)
     * Fix recent breakage of pg_ctl restart (Tom)
     * Update time zone data files to tzdata release 2008i (for DST law
       changes in Argentina, Brazil, Mauritius, Syria)
     __________________________________________________________________

                               Release 8.1.14

     Release Date: 2008-09-22

   This release contains a variety of fixes from 8.1.13. For information
   about new features in the 8.1 major release, see the Section called
   Release 8.1.
     __________________________________________________________________

Migration to Version 8.1.14

   A dump/restore is not required for those running 8.1.X. However, if you
   are upgrading from a version earlier than 8.1.2, see the release notes
   for 8.1.2.
     __________________________________________________________________

Changes

     * Widen local lock counters from 32 to 64 bits (Tom)
       This responds to reports that the counters could overflow in
       sufficiently long transactions, leading to unexpected "lock is
       already held" errors.
     * Fix possible duplicate output of tuples during a GiST index scan
       (Teodor)
     * Add checks in executor startup to ensure that the tuples produced
       by an "INSERT" or "UPDATE" will match the target table's current
       rowtype (Tom)
       "ALTER COLUMN TYPE", followed by re-use of a previously cached
       plan, could produce this type of situation. The check protects
       against data corruption and/or crashes that could ensue.
     * Fix AT TIME ZONE to first try to interpret its timezone argument as
       a timezone abbreviation, and only try it as a full timezone name if
       that fails, rather than the other way around as formerly (Tom)
       The timestamp input functions have always resolved ambiguous zone
       names in this order. Making AT TIME ZONE do so as well improves
       consistency, and fixes a compatibility bug introduced in 8.1: in
       ambiguous cases we now behave the same as 8.0 and before did, since
       in the older versions AT TIME ZONE accepted *only* abbreviations.
     * Fix datetime input functions to correctly detect integer overflow
       when running on a 64-bit platform (Tom)
     * Improve performance of writing very long log messages to syslog
       (Tom)
     * Fix bug in backwards scanning of a cursor on a SELECT DISTINCT ON
       query (Tom)
     * Fix planner bug with nested sub-select expressions (Tom)
       If the outer sub-select has no direct dependency on the parent
       query, but the inner one does, the outer value might not get
       recalculated for new parent query rows.
     * Fix planner to estimate that GROUP BY expressions yielding boolean
       results always result in two groups, regardless of the expressions'
       contents (Tom)
       This is very substantially more accurate than the regular GROUP BY
       estimate for certain boolean tests like "col" IS NULL.
     * Fix PL/pgSQL to not fail when a FOR loop's target variable is a
       record containing composite-type fields (Tom)
     * Fix PL/Tcl to behave correctly with Tcl 8.5, and to be more careful
       about the encoding of data sent to or from Tcl (Tom)
     * Fix PL/Python to work with Python 2.5
       This is a back-port of fixes made during the 8.2 development cycle.
     * Improve pg_dump and pg_restore's error reporting after failure to
       send a SQL command (Tom)
     * Fix pg_ctl to properly preserve postmaster command-line arguments
       across a restart (Bruce)
     * Update time zone data files to tzdata release 2008f (for DST law
       changes in Argentina, Bahamas, Brazil, Mauritius, Morocco,
       Pakistan, Palestine, and Paraguay)
     __________________________________________________________________

                               Release 8.1.13

     Release Date: 2008-06-12

   This release contains one serious and one minor bug fix over 8.1.12.
   For information about new features in the 8.1 major release, see the
   Section called Release 8.1.
     __________________________________________________________________

Migration to Version 8.1.13

   A dump/restore is not required for those running 8.1.X. However, if you
   are upgrading from a version earlier than 8.1.2, see the release notes
   for 8.1.2.
     __________________________________________________________________

Changes

     * Make pg_get_ruledef() parenthesize negative constants (Tom)
       Before this fix, a negative constant in a view or rule might be
       dumped as, say, -42::integer, which is subtly incorrect: it should
       be (-42)::integer due to operator precedence rules. Usually this
       would make little difference, but it could interact with another
       recent patch to cause PostgreSQL to reject what had been a valid
       "SELECT DISTINCT" view query. Since this could result in pg_dump
       output failing to reload, it is being treated as a high-priority
       fix. The only released versions in which dump output is actually
       incorrect are 8.3.1 and 8.2.7.
     * Make "ALTER AGGREGATE ... OWNER TO" update pg_shdepend (Tom)
       This oversight could lead to problems if the aggregate was later
       involved in a "DROP OWNED" or "REASSIGN OWNED" operation.
     __________________________________________________________________

                               Release 8.1.12

     Release Date: never released

   This release contains a variety of fixes from 8.1.11. For information
   about new features in the 8.1 major release, see the Section called
   Release 8.1.
     __________________________________________________________________

Migration to Version 8.1.12

   A dump/restore is not required for those running 8.1.X. However, if you
   are upgrading from a version earlier than 8.1.2, see the release notes
   for 8.1.2.
     __________________________________________________________________

Changes

     * Fix "ALTER TABLE ADD COLUMN ... PRIMARY KEY" so that the new column
       is correctly checked to see if it's been initialized to all
       non-nulls (Brendan Jurd)
       Previous versions neglected to check this requirement at all.
     * Fix possible "CREATE TABLE" failure when inheriting the "same"
       constraint from multiple parent relations that inherited that
       constraint from a common ancestor (Tom)
     * Fix conversions between ISO-8859-5 and other encodings to handle
       Cyrillic "Yo" characters (e and E with two dots) (Sergey Burladyan)
     * Fix a few datatype input functions that were allowing unused bytes
       in their results to contain uninitialized, unpredictable values
       (Tom)
       This could lead to failures in which two apparently identical
       literal values were not seen as equal, resulting in the parser
       complaining about unmatched ORDER BY and DISTINCT expressions.
     * Fix a corner case in regular-expression substring matching
       (substring(string from pattern)) (Tom)
       The problem occurs when there is a match to the pattern overall but
       the user has specified a parenthesized subexpression and that
       subexpression hasn't got a match. An example is substring('foo'
       from 'foo(bar)?'). This should return NULL, since (bar) isn't
       matched, but it was mistakenly returning the whole-pattern match
       instead (ie, foo).
     * Update time zone data files to tzdata release 2008c (for DST law
       changes in Morocco, Iraq, Choibalsan, Pakistan, Syria, Cuba,
       Argentina/San_Luis, and Chile)
     * Fix incorrect result from ecpg's PGTYPEStimestamp_sub() function
       (Michael)
     * Fix core dump in "contrib/xml2"'s xpath_table() function when the
       input query returns a NULL value (Tom)
     * Fix "contrib/xml2"'s makefile to not override CFLAGS (Tom)
     * Fix DatumGetBool macro to not fail with gcc 4.3 (Tom)
       This problem affects "old style" (V0) C functions that return
       boolean. The fix is already in 8.3, but the need to back-patch it
       was not realized at the time.
     * Fix longstanding "LISTEN"/"NOTIFY" race condition (Tom)
       In rare cases a session that had just executed a "LISTEN" might not
       get a notification, even though one would be expected because the
       concurrent transaction executing "NOTIFY" was observed to commit
       later.
       A side effect of the fix is that a transaction that has executed a
       not-yet-committed "LISTEN" command will not see any row in
       pg_listener for the "LISTEN", should it choose to look; formerly it
       would have. This behavior was never documented one way or the
       other, but it is possible that some applications depend on the old
       behavior.
     * Disallow "LISTEN" and "UNLISTEN" within a prepared transaction
       (Tom)
       This was formerly allowed but trying to do it had various
       unpleasant consequences, notably that the originating backend could
       not exit as long as an "UNLISTEN" remained uncommitted.
     * Fix rare crash when an error occurs during a query using a hash
       index (Heikki)
     * Fix input of datetime values for February 29 in years BC (Tom)
       The former coding was mistaken about which years were leap years.
     * Fix "unrecognized node type" error in some variants of "ALTER
       OWNER" (Tom)
     * Fix pg_ctl to correctly extract the postmaster's port number from
       command-line options (Itagaki Takahiro, Tom)
       Previously, pg_ctl start -w could try to contact the postmaster on
       the wrong port, leading to bogus reports of startup failure.
     * Use "-fwrapv" to defend against possible misoptimization in recent
       gcc versions (Tom)
       This is known to be necessary when building PostgreSQL with gcc 4.3
       or later.
     * Fix display of constant expressions in ORDER BY and GROUP BY (Tom)
       An explicitly casted constant would be shown incorrectly. This
       could for example lead to corruption of a view definition during
       dump and reload.
     * Fix libpq to handle NOTICE messages correctly during COPY OUT (Tom)
       This failure has only been observed to occur when a user-defined
       datatype's output routine issues a NOTICE, but there is no
       guarantee it couldn't happen due to other causes.
     __________________________________________________________________

                               Release 8.1.11

     Release Date: 2008-01-07

   This release contains a variety of fixes from 8.1.10, including fixes
   for significant security issues. For information about new features in
   the 8.1 major release, see the Section called Release 8.1.

   This is the last 8.1.X release for which the PostgreSQL community will
   produce binary packages for Windows. Windows users are encouraged to
   move to 8.2.X or later, since there are Windows-specific fixes in 8.2.X
   that are impractical to back-port. 8.1.X will continue to be supported
   on other platforms.
     __________________________________________________________________

Migration to Version 8.1.11

   A dump/restore is not required for those running 8.1.X. However, if you
   are upgrading from a version earlier than 8.1.2, see the release notes
   for 8.1.2.
     __________________________________________________________________

Changes

     * Prevent functions in indexes from executing with the privileges of
       the user running "VACUUM", "ANALYZE", etc (Tom)
       Functions used in index expressions and partial-index predicates
       are evaluated whenever a new table entry is made. It has long been
       understood that this poses a risk of trojan-horse code execution if
       one modifies a table owned by an untrustworthy user. (Note that
       triggers, defaults, check constraints, etc. pose the same type of
       risk.) But functions in indexes pose extra danger because they will
       be executed by routine maintenance operations such as "VACUUM
       FULL", which are commonly performed automatically under a superuser
       account. For example, a nefarious user can execute code with
       superuser privileges by setting up a trojan-horse index definition
       and waiting for the next routine vacuum. The fix arranges for
       standard maintenance operations (including "VACUUM", "ANALYZE",
       "REINDEX", and "CLUSTER") to execute as the table owner rather than
       the calling user, using the same privilege-switching mechanism
       already used for SECURITY DEFINER functions. To prevent bypassing
       this security measure, execution of "SET SESSION AUTHORIZATION" and
       "SET ROLE" is now forbidden within a SECURITY DEFINER context.
       (CVE-2007-6600)
     * Repair assorted bugs in the regular-expression package (Tom, Will
       Drewry)
       Suitably crafted regular-expression patterns could cause crashes,
       infinite or near-infinite looping, and/or massive memory
       consumption, all of which pose denial-of-service hazards for
       applications that accept regex search patterns from untrustworthy
       sources. (CVE-2007-4769, CVE-2007-4772, CVE-2007-6067)
     * Require non-superusers who use "/contrib/dblink" to use only
       password authentication, as a security measure (Joe)
       The fix that appeared for this in 8.1.10 was incomplete, as it
       plugged the hole for only some "dblink" functions. (CVE-2007-6601,
       CVE-2007-3278)
     * Update time zone data files to tzdata release 2007k (in particular,
       recent Argentina changes) (Tom)
     * Improve planner's handling of LIKE/regex estimation in non-C
       locales (Tom)
     * Fix planner failure in some cases of WHERE false AND var IN (SELECT
       ...) (Tom)
     * Preserve the tablespace of indexes that are rebuilt by "ALTER TABLE
       ... ALTER COLUMN TYPE" (Tom)
     * Make archive recovery always start a new WAL timeline, rather than
       only when a recovery stop time was used (Simon)
       This avoids a corner-case risk of trying to overwrite an existing
       archived copy of the last WAL segment, and seems simpler and
       cleaner than the original definition.
     * Make "VACUUM" not use all of maintenance_work_mem when the table is
       too small for it to be useful (Alvaro)
     * Fix potential crash in translate() when using a multibyte database
       encoding (Tom)
     * Fix overflow in extract(epoch from interval) for intervals
       exceeding 68 years (Tom)
     * Fix PL/Perl to not fail when a UTF-8 regular expression is used in
       a trusted function (Andrew)
     * Fix PL/Perl to cope when platform's Perl defines type bool as int
       rather than char (Tom)
       While this could theoretically happen anywhere, no standard build
       of Perl did things this way ... until Mac OS X 10.5.
     * Fix PL/Python to not crash on long exception messages (Alvaro)
     * Fix pg_dump to correctly handle inheritance child tables that have
       default expressions different from their parent's (Tom)
     * Fix libpq crash when PGPASSFILE refers to a file that is not a
       plain file (Martin Pitt)
     * ecpg parser fixes (Michael)
     * Make "contrib/pgcrypto" defend against OpenSSL libraries that fail
       on keys longer than 128 bits; which is the case at least on some
       Solaris versions (Marko Kreen)
     * Make "contrib/tablefunc"'s crosstab() handle NULL rowid as a
       category in its own right, rather than crashing (Joe)
     * Fix tsvector and tsquery output routines to escape backslashes
       correctly (Teodor, Bruce)
     * Fix crash of to_tsvector() on huge input strings (Teodor)
     * Require a specific version of Autoconf to be used when
       re-generating the "configure" script (Peter)
       This affects developers and packagers only. The change was made to
       prevent accidental use of untested combinations of Autoconf and
       PostgreSQL versions. You can remove the version check if you really
       want to use a different Autoconf version, but it's your
       responsibility whether the result works or not.
     __________________________________________________________________

                               Release 8.1.10

     Release Date: 2007-09-17

   This release contains a variety of fixes from 8.1.9. For information
   about new features in the 8.1 major release, see the Section called
   Release 8.1.
     __________________________________________________________________

Migration to Version 8.1.10

   A dump/restore is not required for those running 8.1.X. However, if you
   are upgrading from a version earlier than 8.1.2, see the release notes
   for 8.1.2.
     __________________________________________________________________

Changes

     * Prevent index corruption when a transaction inserts rows and then
       aborts close to the end of a concurrent "VACUUM" on the same table
       (Tom)
     * Make "CREATE DOMAIN ... DEFAULT NULL" work properly (Tom)
     * Allow the interval data type to accept input consisting only of
       milliseconds or microseconds (Neil)
     * Speed up rtree index insertion (Teodor)
     * Fix excessive logging of SSL error messages (Tom)
     * Fix logging so that log messages are never interleaved when using
       the syslogger process (Andrew)
     * Fix crash when log_min_error_statement logging runs out of memory
       (Tom)
     * Fix incorrect handling of some foreign-key corner cases (Tom)
     * Prevent "REINDEX" and "CLUSTER" from failing due to attempting to
       process temporary tables of other sessions (Alvaro)
     * Update the time zone database rules, particularly New Zealand's
       upcoming changes (Tom)
     * Windows socket improvements (Magnus)
     * Suppress timezone name (%Z) in log timestamps on Windows because of
       possible encoding mismatches (Tom)
     * Require non-superusers who use "/contrib/dblink" to use only
       password authentication, as a security measure (Joe)
     __________________________________________________________________

                                Release 8.1.9

     Release Date: 2007-04-23

   This release contains a variety of fixes from 8.1.8, including a
   security fix. For information about new features in the 8.1 major
   release, see the Section called Release 8.1.
     __________________________________________________________________

Migration to Version 8.1.9

   A dump/restore is not required for those running 8.1.X. However, if you
   are upgrading from a version earlier than 8.1.2, see the release notes
   for 8.1.2.
     __________________________________________________________________

Changes

     * Support explicit placement of the temporary-table schema within
       search_path, and disable searching it for functions and operators
       (Tom)
       This is needed to allow a security-definer function to set a truly
       secure value of search_path. Without it, an unprivileged SQL user
       can use temporary objects to execute code with the privileges of
       the security-definer function (CVE-2007-2138). See "CREATE
       FUNCTION" for more information.
     * "/contrib/tsearch2" crash fixes (Teodor)
     * Require "COMMIT PREPARED" to be executed in the same database as
       the transaction was prepared in (Heikki)
     * Fix potential-data-corruption bug in how "VACUUM FULL" handles
       "UPDATE" chains (Tom, Pavan Deolasee)
     * Planner fixes, including improving outer join and bitmap scan
       selection logic (Tom)
     * Fix PANIC during enlargement of a hash index (bug introduced in
       8.1.6) (Tom)
     * Fix POSIX-style timezone specs to follow new USA DST rules (Tom)
     __________________________________________________________________

                                Release 8.1.8

     Release Date: 2007-02-07

   This release contains one fix from 8.1.7. For information about new
   features in the 8.1 major release, see the Section called Release 8.1.
     __________________________________________________________________

Migration to Version 8.1.8

   A dump/restore is not required for those running 8.1.X. However, if you
   are upgrading from a version earlier than 8.1.2, see the release notes
   for 8.1.2.
     __________________________________________________________________

Changes

     * Remove overly-restrictive check for type length in constraints and
       functional indexes(Tom)
     __________________________________________________________________

                                Release 8.1.7

     Release Date: 2007-02-05

   This release contains a variety of fixes from 8.1.6, including a
   security fix. For information about new features in the 8.1 major
   release, see the Section called Release 8.1.
     __________________________________________________________________

Migration to Version 8.1.7

   A dump/restore is not required for those running 8.1.X. However, if you
   are upgrading from a version earlier than 8.1.2, see the release notes
   for 8.1.2.
     __________________________________________________________________

Changes

     * Remove security vulnerabilities that allowed connected users to
       read backend memory (Tom)
       The vulnerabilities involve suppressing the normal check that a SQL
       function returns the data type it's declared to, and changing the
       data type of a table column (CVE-2007-0555, CVE-2007-0556). These
       errors can easily be exploited to cause a backend crash, and in
       principle might be used to read database content that the user
       should not be able to access.
     * Fix rare bug wherein btree index page splits could fail due to
       choosing an infeasible split point (Heikki Linnakangas)
     * Improve "VACUUM" performance for databases with many tables (Tom)
     * Fix autovacuum to avoid leaving non-permanent transaction IDs in
       non-connectable databases (Alvaro)
       This bug affects the 8.1 branch only.
     * Fix for rare Assert() crash triggered by UNION (Tom)
     * Tighten security of multi-byte character processing for UTF8
       sequences over three bytes long (Tom)
     * Fix bogus "permission denied" failures occurring on Windows due to
       attempts to fsync already-deleted files (Magnus, Tom)
     * Fix possible crashes when an already-in-use PL/pgSQL function is
       updated (Tom)
     __________________________________________________________________

                                Release 8.1.6

     Release Date: 2007-01-08

   This release contains a variety of fixes from 8.1.5. For information
   about new features in the 8.1 major release, see the Section called
   Release 8.1.
     __________________________________________________________________

Migration to Version 8.1.6

   A dump/restore is not required for those running 8.1.X. However, if you
   are upgrading from a version earlier than 8.1.2, see the release notes
   for 8.1.2.
     __________________________________________________________________

Changes

     * Improve handling of getaddrinfo() on AIX (Tom)
       This fixes a problem with starting the statistics collector, among
       other things.
     * Fix pg_restore to handle a tar-format backup that contains large
       objects (blobs) with comments (Tom)
     * Fix "failed to re-find parent key" errors in "VACUUM" (Tom)
     * Clean out "pg_internal.init" cache files during server restart
       (Simon)
       This avoids a hazard that the cache files might contain stale data
       after PITR recovery.
     * Fix race condition for truncation of a large relation across a
       gigabyte boundary by "VACUUM" (Tom)
     * Fix bug causing needless deadlock errors on row-level locks (Tom)
     * Fix bugs affecting multi-gigabyte hash indexes (Tom)
     * Fix possible deadlock in Windows signal handling (Teodor)
     * Fix error when constructing an ARRAY[] made up of multiple empty
       elements (Tom)
     * Fix ecpg memory leak during connection (Michael)
     * Fix for Darwin (OS X) compilation (Tom)
     * to_number() and to_char(numeric) are now STABLE, not IMMUTABLE, for
       new initdb installs (Tom)
       This is because lc_numeric can potentially change the output of
       these functions.
     * Improve index usage of regular expressions that use parentheses
       (Tom)
       This improves psql \d performance also.
     * Update timezone database
       This affects Australian and Canadian daylight-savings rules in
       particular.
     __________________________________________________________________

                                Release 8.1.5

     Release Date: 2006-10-16

   This release contains a variety of fixes from 8.1.4. For information
   about new features in the 8.1 major release, see the Section called
   Release 8.1.
     __________________________________________________________________

Migration to Version 8.1.5

   A dump/restore is not required for those running 8.1.X. However, if you
   are upgrading from a version earlier than 8.1.2, see the release notes
   for 8.1.2.
     __________________________________________________________________

Changes

     * Disallow aggregate functions in "UPDATE" commands, except within
       sub-SELECTs (Tom)
       The behavior of such an aggregate was unpredictable, and in 8.1.X
       could cause a crash, so it has been disabled. The SQL standard does
       not allow this either.
     * Fix core dump when an untyped literal is taken as ANYARRAY
     * Fix core dump in duration logging for extended query protocol when
       a "COMMIT" or "ROLLBACK" is executed
     * Fix mishandling of AFTER triggers when query contains a SQL
       function returning multiple rows (Tom)
     * Fix "ALTER TABLE ... TYPE" to recheck NOT NULL for USING clause
       (Tom)
     * Fix string_to_array() to handle overlapping matches for the
       separator string
       For example, string_to_array('123xx456xxx789', 'xx').
     * Fix to_timestamp() for AM/PM formats (Bruce)
     * Fix autovacuum's calculation that decides whether "ANALYZE" is
       needed (Alvaro)
     * Fix corner cases in pattern matching for psql's \d commands
     * Fix index-corrupting bugs in /contrib/ltree (Teodor)
     * Numerous robustness fixes in ecpg (Joachim Wieland)
     * Fix backslash escaping in /contrib/dbmirror
     * Minor fixes in /contrib/dblink and /contrib/tsearch2
     * Efficiency improvements in hash tables and bitmap index scans (Tom)
     * Fix instability of statistics collection on Windows (Tom, Andrew)
     * Fix statement_timeout to use the proper units on Win32 (Bruce)
       In previous Win32 8.1.X versions, the delay was off by a factor of
       100.
     * Fixes for MSVC and Borland C++ compilers (Hiroshi Saito)
     * Fixes for AIX and Intel compilers (Tom)
     * Fix rare bug in continuous archiving (Tom)
     __________________________________________________________________

                                Release 8.1.4

     Release Date: 2006-05-23

   This release contains a variety of fixes from 8.1.3, including patches
   for extremely serious security issues. For information about new
   features in the 8.1 major release, see the Section called Release 8.1.
     __________________________________________________________________

Migration to Version 8.1.4

   A dump/restore is not required for those running 8.1.X. However, if you
   are upgrading from a version earlier than 8.1.2, see the release notes
   for 8.1.2.

   Full security against the SQL-injection attacks described in
   CVE-2006-2313 and CVE-2006-2314 might require changes in application
   code. If you have applications that embed untrustworthy strings into
   SQL commands, you should examine them as soon as possible to ensure
   that they are using recommended escaping techniques. In most cases,
   applications should be using subroutines provided by libraries or
   drivers (such as libpq's PQescapeStringConn()) to perform string
   escaping, rather than relying on ad hoc code to do it.
     __________________________________________________________________

Changes

     * Change the server to reject invalidly-encoded multibyte characters
       in all cases (Tatsuo, Tom)
       While PostgreSQL has been moving in this direction for some time,
       the checks are now applied uniformly to all encodings and all
       textual input, and are now always errors not merely warnings. This
       change defends against SQL-injection attacks of the type described
       in CVE-2006-2313.
     * Reject unsafe uses of \' in string literals
       As a server-side defense against SQL-injection attacks of the type
       described in CVE-2006-2314, the server now only accepts '' and not
       \' as a representation of ASCII single quote in SQL string
       literals. By default, \' is rejected only when client_encoding is
       set to a client-only encoding (SJIS, BIG5, GBK, GB18030, or UHC),
       which is the scenario in which SQL injection is possible. A new
       configuration parameter backslash_quote is available to adjust this
       behavior when needed. Note that full security against CVE-2006-2314
       might require client-side changes; the purpose of backslash_quote
       is in part to make it obvious that insecure clients are insecure.
     * Modify libpq's string-escaping routines to be aware of encoding
       considerations and standard_conforming_strings
       This fixes libpq-using applications for the security issues
       described in CVE-2006-2313 and CVE-2006-2314, and also
       future-proofs them against the planned changeover to SQL-standard
       string literal syntax. Applications that use multiple PostgreSQL
       connections concurrently should migrate to PQescapeStringConn() and
       PQescapeByteaConn() to ensure that escaping is done correctly for
       the settings in use in each database connection. Applications that
       do string escaping "by hand" should be modified to rely on library
       routines instead.
     * Fix weak key selection in pgcrypto (Marko Kreen)
       Errors in fortuna PRNG reseeding logic could cause a predictable
       session key to be selected by pgp_sym_encrypt() in some cases. This
       only affects non-OpenSSL-using builds.
     * Fix some incorrect encoding conversion functions
       win1251_to_iso, win866_to_iso, euc_tw_to_big5, euc_tw_to_mic,
       mic_to_euc_tw were all broken to varying extents.
     * Clean up stray remaining uses of \' in strings (Bruce, Jan)
     * Make autovacuum visible in pg_stat_activity (Alvaro)
     * Disable full_page_writes (Tom)
       In certain cases, having full_page_writes off would cause crash
       recovery to fail. A proper fix will appear in 8.2; for now it's
       just disabled.
     * Various planner fixes, particularly for bitmap index scans and
       MIN/MAX optimization (Tom)
     * Fix incorrect optimization in merge join (Tom)
       Outer joins could sometimes emit multiple copies of unmatched rows.
     * Fix crash from using and modifying a plpgsql function in the same
       transaction
     * Fix WAL replay for case where a B-Tree index has been truncated
     * Fix SIMILAR TO for patterns involving | (Tom)
     * Fix "SELECT INTO" and "CREATE TABLE AS" to create tables in the
       default tablespace, not the base directory (Kris Jurka)
     * Fix server to use custom DH SSL parameters correctly (Michael Fuhr)
     * Improve qsort performance (Dann Corbit)
       Currently this code is only used on Solaris.
     * Fix for OS/X Bonjour on x86 systems (Ashley Clark)
     * Fix various minor memory leaks
     * Fix problem with password prompting on some Win32 systems (Robert
       Kinberg)
     * Improve pg_dump's handling of default values for domains
     * Fix pg_dumpall to handle identically-named users and groups
       reasonably (only possible when dumping from a pre-8.1 server) (Tom)
       The user and group will be merged into a single role with LOGIN
       permission. Formerly the merged role wouldn't have LOGIN
       permission, making it unusable as a user.
     * Fix pg_restore -n to work as documented (Tom)
     __________________________________________________________________

                                Release 8.1.3

     Release Date: 2006-02-14

   This release contains a variety of fixes from 8.1.2, including one very
   serious security issue. For information about new features in the 8.1
   major release, see the Section called Release 8.1.
     __________________________________________________________________

Migration to Version 8.1.3

   A dump/restore is not required for those running 8.1.X. However, if you
   are upgrading from a version earlier than 8.1.2, see the release notes
   for 8.1.2.
     __________________________________________________________________

Changes

     * Fix bug that allowed any logged-in user to "SET ROLE" to any other
       database user id (CVE-2006-0553)
       Due to inadequate validity checking, a user could exploit the
       special case that "SET ROLE" normally uses to restore the previous
       role setting after an error. This allowed ordinary users to acquire
       superuser status, for example. The escalation-of-privilege risk
       exists only in 8.1.0-8.1.2. However, in all releases back to 7.3
       there is a related bug in "SET SESSION AUTHORIZATION" that allows
       unprivileged users to crash the server, if it has been compiled
       with Asserts enabled (which is not the default). Thanks to Akio
       Ishida for reporting this problem.
     * Fix bug with row visibility logic in self-inserted rows (Tom)
       Under rare circumstances a row inserted by the current command
       could be seen as already valid, when it should not be. Repairs bug
       created in 8.0.4, 7.4.9, and 7.3.11 releases.
     * Fix race condition that could lead to "file already exists" errors
       during pg_clog and pg_subtrans file creation (Tom)
     * Fix cases that could lead to crashes if a cache-invalidation
       message arrives at just the wrong time (Tom)
     * Properly check DOMAIN constraints for UNKNOWN parameters in
       prepared statements (Neil)
     * Ensure "ALTER COLUMN TYPE" will process FOREIGN KEY, UNIQUE, and
       PRIMARY KEY constraints in the proper order (Nakano Yoshihisa)
     * Fixes to allow restoring dumps that have cross-schema references to
       custom operators or operator classes (Tom)
     * Allow pg_restore to continue properly after a "COPY" failure;
       formerly it tried to treat the remaining "COPY" data as SQL
       commands (Stephen Frost)
     * Fix pg_ctl unregister crash when the data directory is not
       specified (Magnus)
     * Fix libpq PQprint HTML tags (Christoph Zwerschke)
     * Fix ecpg crash on AMD64 and PPC (Neil)
     * Allow SETOF and %TYPE to be used together in function result type
       declarations
     * Recover properly if error occurs during argument passing in
       PL/python (Neil)
     * Fix memory leak in plperl_return_next (Neil)
     * Fix PL/perl's handling of locales on Win32 to match the backend
       (Andrew)
     * Various optimizer fixes (Tom)
     * Fix crash when log_min_messages is set to DEBUG3 or above in
       "postgresql.conf" on Win32 (Bruce)
     * Fix pgxs -L library path specification for Win32, Cygwin, OS X, AIX
       (Bruce)
     * Check that SID is enabled while checking for Win32 admin privileges
       (Magnus)
     * Properly reject out-of-range date inputs (Kris Jurka)
     * Portability fix for testing presence of finite and isinf during
       configure (Tom)
     * Improve speed of "COPY IN" via libpq, by avoiding a kernel call per
       data line (Alon Goldshuv)
     * Improve speed of "/contrib/tsearch2" index creation (Tom)
     __________________________________________________________________

                                Release 8.1.2

     Release Date: 2006-01-09

   This release contains a variety of fixes from 8.1.1. For information
   about new features in the 8.1 major release, see the Section called
   Release 8.1.
     __________________________________________________________________

Migration to Version 8.1.2

   A dump/restore is not required for those running 8.1.X. However, you
   might need to "REINDEX" indexes on textual columns after updating, if
   you are affected by the locale or plperl issues described below.
     __________________________________________________________________

Changes

     * Fix Windows code so that postmaster will continue rather than exit
       if there is no more room in ShmemBackendArray (Magnus)
       The previous behavior could lead to a denial-of-service situation
       if too many connection requests arrive close together. This applies
       *only* to the Windows port.
     * Fix bug introduced in 8.0 that could allow ReadBuffer to return an
       already-used page as new, potentially causing loss of
       recently-committed data (Tom)
     * Fix for protocol-level Describe messages issued outside a
       transaction or in a failed transaction (Tom)
     * Fix character string comparison for locales that consider different
       character combinations as equal, such as Hungarian (Tom)
       This might require "REINDEX" to fix existing indexes on textual
       columns.
     * Set locale environment variables during postmaster startup to
       ensure that plperl won't change the locale later
       This fixes a problem that occurred if the postmaster was started
       with environment variables specifying a different locale than what
       initdb had been told. Under these conditions, any use of plperl was
       likely to lead to corrupt indexes. You might need "REINDEX" to fix
       existing indexes on textual columns if this has happened to you.
     * Allow more flexible relocation of installation directories (Tom)
       Previous releases supported relocation only if all installation
       directory paths were the same except for the last component.
     * Prevent crashes caused by the use of ISO-8859-5 and ISO-8859-9
       encodings (Tatsuo)
     * Fix longstanding bug in strpos() and regular expression handling in
       certain rarely used Asian multi-byte character sets (Tatsuo)
     * Fix bug where COPY CSV mode considered any \. to terminate the copy
       data
       The new code requires \. to appear alone on a line, as per
       documentation.
     * Make COPY CSV mode quote a literal data value of \. to ensure it
       cannot be interpreted as the end-of-data marker (Bruce)
     * Various fixes for functions returning RECORDs (Tom)
     * Fix processing of "postgresql.conf" so a final line with no newline
       is processed properly (Tom)
     * Fix bug in "/contrib/pgcrypto" gen_salt, which caused it not to use
       all available salt space for MD5 and XDES algorithms (Marko Kreen,
       Solar Designer)
       Salts for Blowfish and standard DES are unaffected.
     * Fix autovacuum crash when processing expression indexes
     * Fix "/contrib/dblink" to throw an error, rather than crashing, when
       the number of columns specified is different from what's actually
       returned by the query (Joe)
     __________________________________________________________________

                                Release 8.1.1

     Release Date: 2005-12-12

   This release contains a variety of fixes from 8.1.0. For information
   about new features in the 8.1 major release, see the Section called
   Release 8.1.
     __________________________________________________________________

Migration to Version 8.1.1

   A dump/restore is not required for those running 8.1.X.
     __________________________________________________________________

Changes

     * Fix incorrect optimizations of outer-join conditions (Tom)
     * Fix problems with wrong reported column names in cases involving
       sub-selects flattened by the optimizer (Tom)
     * Fix update failures in scenarios involving CHECK constraints,
       toasted columns, *and* indexes (Tom)
     * Fix bgwriter problems after recovering from errors (Tom)
       The background writer was found to leak buffer pins after write
       errors. While not fatal in itself, this might lead to mysterious
       blockages of later VACUUM commands.
     * Prevent failure if client sends Bind protocol message when current
       transaction is already aborted
     * "/contrib/tsearch2" and "/contrib/ltree" fixes (Teodor)
     * Fix problems with translated error messages in languages that
       require word reordering, such as Turkish; also problems with
       unexpected truncation of output strings and wrong display of the
       smallest possible bigint value (Andrew, Tom)
       These problems only appeared on platforms that were using our
       "port/snprintf.c" code, which includes BSD variants if --enable-nls
       was given, and perhaps others. In addition, a different form of the
       translated-error-message problem could appear on Windows depending
       on which version of "libintl" was used.
     * Re-allow AM/PM, HH, HH12, and D format specifiers for to_char(time)
       and to_char(interval). (to_char(interval) should probably use
       HH24.) (Bruce)
     * AIX, HPUX, and MSVC compile fixes (Tom, Hiroshi Saito)
     * Optimizer improvements (Tom)
     * Retry file reads and writes after Windows NO_SYSTEM_RESOURCES error
       (Qingqing Zhou)
     * Prevent autovacuum from crashing during ANALYZE of expression index
       (Alvaro)
     * Fix problems with ON COMMIT DELETE ROWS temp tables
     * Fix problems when a trigger alters the output of a SELECT DISTINCT
       query
     * Add 8.1.0 release note item on how to migrate invalid UTF-8 byte
       sequences (Paul Lindner)
     __________________________________________________________________

                                 Release 8.1

     Release Date: 2005-11-08
     __________________________________________________________________

Overview

   Major changes in this release:

   Improve concurrent access to the shared buffer cache (Tom)
          Access to the shared buffer cache was identified as a
          significant scalability problem, particularly on multi-CPU
          systems. In this release, the way that locking is done in the
          buffer manager has been overhauled to reduce lock contention and
          improve scalability. The buffer manager has also been changed to
          use a "clock sweep" replacement policy.

   Allow index scans to use an intermediate in-memory bitmap (Tom)
          In previous releases, only a single index could be used to do
          lookups on a table. With this feature, if a query has "WHERE
          tab.col1 = 4 and tab.col2 = 9", and there is no multicolumn
          index on col1 and col2, but there is an index on col1 and
          another on col2, it is possible to search both indexes and
          combine the results in memory, then do heap fetches for only the
          rows matching both the col1 and col2 restrictions. This is very
          useful in environments that have a lot of unstructured queries
          where it is impossible to create indexes that match all possible
          access conditions. Bitmap scans are useful even with a single
          index, as they reduce the amount of random access needed; a
          bitmap index scan is efficient for retrieving fairly large
          fractions of the complete table, whereas plain index scans are
          not.

   Add two-phase commit (Heikki Linnakangas, Alvaro, Tom)
          Two-phase commit allows transactions to be "prepared" on several
          computers, and once all computers have successfully prepared
          their transactions (none failed), all transactions can be
          committed. Even if a machine crashes after a prepare, the
          prepared transaction can be committed after the machine is
          restarted. New syntax includes "PREPARE TRANSACTION" and
          "COMMIT/ROLLBACK PREPARED". A new system view pg_prepared_xacts
          has also been added.

   Create a new role system that replaces users and groups (Stephen Frost)
          Roles are a combination of users and groups. Like users, they
          can have login capability, and like groups, a role can have
          other roles as members. Roles basically remove the distinction
          between users and groups. For example, a role can:

          + Have login capability (optionally)
          + Own objects
          + Hold access permissions for database objects
          + Inherit permissions from other roles it is a member of

          Once a user logs into a role, she obtains capabilities of the
          login role plus any inherited roles, and can use "SET ROLE" to
          switch to other roles she is a member of. This feature is a
          generalization of the SQL standard's concept of roles. This
          change also replaces pg_shadow and pg_group by new role-capable
          catalogs pg_authid and pg_auth_members. The old tables are
          redefined as read-only views on the new role tables.

   Automatically use indexes for MIN() and MAX() (Tom)
          In previous releases, the only way to use an index for MIN() or
          MAX() was to rewrite the query as "SELECT col FROM tab ORDER BY
          col LIMIT 1". Index usage now happens automatically.

   Move /contrib/pg_autovacuum into the main server (Alvaro)
          Integrating autovacuum into the server allows it to be
          automatically started and stopped in sync with the database
          server, and allows autovacuum to be configured from
          "postgresql.conf".

   Add shared row level locks using SELECT ... FOR SHARE (Alvaro)
          While PostgreSQL's MVCC locking allows "SELECT" to never be
          blocked by writers and therefore does not need shared row locks
          for typical operations, shared locks are useful for applications
          that require shared row locking. In particular this reduces the
          locking requirements imposed by referential integrity checks.

   Add dependencies on shared objects, specifically roles (Alvaro)
          This extension of the dependency mechanism prevents roles from
          being dropped while there are still database objects they own.
          Formerly it was possible to accidentally "orphan" objects by
          deleting their owner. While this could be recovered from, it was
          messy and unpleasant.

   Improve performance for partitioned tables (Simon)
          The new constraint_exclusion configuration parameter avoids
          lookups on child tables where constraints indicate that no
          matching rows exist in the child table.

          This allows for a basic type of table partitioning. If child
          tables store separate key ranges and this is enforced using
          appropriate "CHECK" constraints, the optimizer will skip child
          table accesses when the constraint guarantees no matching rows
          exist in the child table.
     __________________________________________________________________

Migration to Version 8.1

   A dump/restore using pg_dump is required for those wishing to migrate
   data from any previous release.

   The 8.0 release announced that the to_char() function for intervals
   would be removed in 8.1. However, since no better API has been
   suggested, to_char(interval) has been enhanced in 8.1 and will remain
   in the server.

   Observe the following incompatibilities:

     * add_missing_from is now false by default (Neil)
       By default, we now generate an error if a table is used in a query
       without a FROM reference. The old behavior is still available, but
       the parameter must be set to 'true' to obtain it.
       It might be necessary to set add_missing_from to true in order to
       load an existing dump file, if the dump contains any views or rules
       created using the implicit-FROM syntax. This should be a one-time
       annoyance, because PostgreSQL 8.1 will convert such views and rules
       to standard explicit-FROM syntax. Subsequent dumps will therefore
       not have the problem.
     * Cause input of a zero-length string ('') for float4/float8/oid to
       throw an error, rather than treating it as a zero (Neil)
       This change is consistent with the current handling of zero-length
       strings for integers. The schedule for this change was announced in
       8.0.
     * default_with_oids is now false by default (Neil)
       With this option set to false, user-created tables no longer have
       an OID column unless "WITH OIDS" is specified in "CREATE TABLE".
       Though OIDs have existed in all releases of PostgreSQL, their use
       is limited because they are only four bytes long and the counter is
       shared across all installed databases. The preferred way of
       uniquely identifying rows is via sequences and the SERIAL type,
       which have been supported since PostgreSQL 6.4.
     * Add E'' syntax so eventually ordinary strings can treat backslashes
       literally (Bruce)
       Currently PostgreSQL processes a backslash in a string literal as
       introducing a special escape sequence, e.g. \n or \010. While this
       allows easy entry of special values, it is nonstandard and makes
       porting of applications from other databases more difficult. For
       this reason, the PostgreSQL project is planning to remove the
       special meaning of backslashes in strings. For backward
       compatibility and for users who want special backslash processing,
       a new string syntax has been created. This new string syntax is
       formed by writing an E immediately preceding the single quote that
       starts the string, e.g. E'hi\n'. While this release does not change
       the handling of backslashes in strings, it does add new
       configuration parameters to help users migrate applications for
       future releases:
          + standard_conforming_strings -- does this release treat
            backslashes literally in ordinary strings?
          + escape_string_warning -- warn about backslashes in ordinary
            (non-E) strings
       The standard_conforming_strings value is read-only. Applications
       can retrieve the value to know how backslashes are processed.
       (Presence of the parameter can also be taken as an indication that
       E'' string syntax is supported.) In a future release,
       standard_conforming_strings will be true, meaning backslashes will
       be treated literally in non-E strings. To prepare for this change,
       use E'' strings in places that need special backslash processing,
       and turn on escape_string_warning to find additional strings that
       need to be converted to use E''. Also, use two single-quotes ('')
       to embed a literal single-quote in a string, rather than the
       PostgreSQL-supported syntax of backslash single-quote (\'). The
       former is standards-conforming and does not require the use of the
       E'' string syntax. You can also use the $$ string syntax, which
       does not treat backslashes specially.
     * Make "REINDEX DATABASE" reindex all indexes in the database (Tom)
       Formerly, "REINDEX DATABASE" reindexed only system tables. This new
       behavior seems more intuitive. A new command "REINDEX SYSTEM"
       provides the old functionality of reindexing just the system
       tables.
     * Read-only large object descriptors now obey MVCC snapshot semantics
       When a large object is opened with INV_READ (and not INV_WRITE),
       the data read from the descriptor will now reflect a "snapshot" of
       the large object's state at the time of the transaction snapshot in
       use by the query that called lo_open(). To obtain the old behavior
       of always returning the latest committed data, include INV_WRITE in
       the mode flags for lo_open().
     * Add proper dependencies for arguments of sequence functions (Tom)
       In previous releases, sequence names passed to nextval(),
       currval(), and setval() were stored as simple text strings, meaning
       that renaming or dropping a sequence used in a DEFAULT clause made
       the clause invalid. This release stores all newly-created sequence
       function arguments as internal OIDs, allowing them to track
       sequence renaming, and adding dependency information that prevents
       improper sequence removal. It also makes such DEFAULT clauses
       immune to schema renaming and search path changes.
       Some applications might rely on the old behavior of run-time lookup
       for sequence names. This can still be done by explicitly casting
       the argument to text, for example nextval('myseq'::text).
       Pre-8.1 database dumps loaded into 8.1 will use the old text-based
       representation and therefore will not have the features of
       OID-stored arguments. However, it is possible to update a database
       containing text-based DEFAULT clauses. First, save this query into
       a file, such as "fixseq.sql":
SELECT  'ALTER TABLE ' ||
   pg_catalog.quote_ident(n.nspname) || '.' ||
   pg_catalog.quote_ident(c.relname) ||
   ' ALTER COLUMN ' || pg_catalog.quote_ident(a.attname) ||
   ' SET DEFAULT ' ||
   regexp_replace(d.adsrc,
                  $$val\(\(('[^']*')::text\)::regclass$$,
                  $$val(\1$$,
                  'g') ||
   ';'
FROM    pg_namespace n, pg_class c, pg_attribute a, pg_attrdef d
WHERE   n.oid = c.relnamespace AND
   c.oid = a.attrelid AND
   a.attrelid = d.adrelid AND
   a.attnum = d.adnum AND
   d.adsrc ~ $$val\(\('[^']*'::text\)::regclass$$;
       Next, run the query against a database to find what adjustments are
       required, like this for database db1:
psql -t -f fixseq.sql db1
       This will show the "ALTER TABLE" commands needed to convert the
       database to the newer OID-based representation. If the commands
       look reasonable, run this to update the database:
psql -t -f fixseq.sql db1 | psql -e db1
       This process must be repeated in each database to be updated.
     * In psql, treat unquoted \{digit}+ sequences as octal (Bruce)
       In previous releases, \{digit}+ sequences were treated as decimal,
       and only \0{digit}+ were treated as octal. This change was made for
       consistency.
     * Remove grammar productions for prefix and postfix % and ^ operators
       (Tom)
       These have never been documented and complicated the use of the
       modulus operator (%) with negative numbers.
     * Make &< and &> for polygons consistent with the box "over"
       operators (Tom)
     * "CREATE LANGUAGE" can ignore the provided arguments in favor of
       information from pg_pltemplate (Tom)
       A new system catalog pg_pltemplate has been defined to carry
       information about the preferred definitions of procedural languages
       (such as whether they have validator functions). When an entry
       exists in this catalog for the language being created, "CREATE
       LANGUAGE" will ignore all its parameters except the language name
       and instead use the catalog information. This measure was taken
       because of increasing problems with obsolete language definitions
       being loaded by old dump files. As of 8.1, pg_dump will dump
       procedural language definitions as just "CREATE LANGUAGE name",
       relying on a template entry to exist at load time. We expect this
       will be a more future-proof representation.
     * Make pg_cancel_backend(int) return a boolean rather than an integer
       (Neil)
     * Some users are having problems loading UTF-8 data into 8.1.X. This
       is because previous versions allowed invalid UTF-8 byte sequences
       to be entered into the database, and this release properly accepts
       only valid UTF-8 sequences. One way to correct a dumpfile is to run
       the command "iconv -c -f UTF-8 -t UTF-8 -o cleanfile.sql
       dumpfile.sql". The -c option removes invalid character sequences. A
       diff of the two files will show the sequences that are invalid.
       "iconv" reads the entire input file into memory so it might be
       necessary to use split to break up the dump into multiple smaller
       files for processing.
     __________________________________________________________________

Additional Changes

   Below you will find a detailed account of the additional changes
   between PostgreSQL 8.1 and the previous major release.
     __________________________________________________________________

Performance Improvements

     * Improve GiST and R-tree index performance (Neil)
     * Improve the optimizer, including auto-resizing of hash joins (Tom)
     * Overhaul internal API in several areas
     * Change WAL record CRCs from 64-bit to 32-bit (Tom)
       We determined that the extra cost of computing 64-bit CRCs was
       significant, and the gain in reliability too marginal to justify
       it.
     * Prevent writing large empty gaps in WAL pages (Tom)
     * Improve spinlock behavior on SMP machines, particularly Opterons
       (Tom)
     * Allow nonconsecutive index columns to be used in a multicolumn
       index (Tom)
       For example, this allows an index on columns a,b,c to be used in a
       query with "WHERE a = 4 and c = 10".
     * Skip WAL logging for "CREATE TABLE AS" / "SELECT INTO" (Simon)
       Since a crash during "CREATE TABLE AS" would cause the table to be
       dropped during recovery, there is no reason to WAL log as the table
       is loaded. (Logging still happens if WAL archiving is enabled,
       however.)
     * Allow concurrent GiST index access (Teodor, Oleg)
     * Add configuration parameter full_page_writes to control writing
       full pages to WAL (Bruce)
       To prevent partial disk writes from corrupting the database,
       PostgreSQL writes a complete copy of each database disk page to WAL
       the first time it is modified after a checkpoint. This option turns
       off that functionality for more speed. This is safe to use with
       battery-backed disk caches where partial page writes cannot happen.
     * Use O_DIRECT if available when using O_SYNC for wal_sync_method
       (Itagaki Takahiro)
       O_DIRECT causes disk writes to bypass the kernel cache, and for WAL
       writes, this improves performance.
     * Improve "COPY FROM" performance (Alon Goldshuv)
       This was accomplished by reading "COPY" input in larger chunks,
       rather than character by character.
     * Improve the performance of COUNT(), SUM, AVG(), STDDEV(), and
       VARIANCE() (Neil, Tom)
     __________________________________________________________________

Server Changes

     * Prevent problems due to transaction ID (XID) wraparound (Tom)
       The server will now warn when the transaction counter approaches
       the wraparound point. If the counter becomes too close to
       wraparound, the server will stop accepting queries. This ensures
       that data is not lost before needed vacuuming is performed.
     * Fix problems with object IDs (OIDs) conflicting with existing
       system objects after the OID counter has wrapped around (Tom)
     * Add warning about the need to increase max_fsm_relations and
       max_fsm_pages during "VACUUM" (Ron Mayer)
     * Add temp_buffers configuration parameter to allow users to
       determine the size of the local buffer area for temporary table
       access (Tom)
     * Add session start time and client IP address to pg_stat_activity
       (Magnus)
     * Adjust pg_stat views for bitmap scans (Tom)
       The meanings of some of the fields have changed slightly.
     * Enhance pg_locks view (Tom)
     * Log queries for client-side "PREPARE" and "EXECUTE" (Simon)
     * Allow Kerberos name and user name case sensitivity to be specified
       in "postgresql.conf" (Magnus)
     * Add configuration parameter krb_server_hostname so that the server
       host name can be specified as part of service principal (Todd
       Kover)
       If not set, any service principal matching an entry in the keytab
       can be used. This is new Kerberos matching behavior in this
       release.
     * Add log_line_prefix options for millisecond timestamps (%m) and
       remote host (%h) (Ed L.)
     * Add WAL logging for GiST indexes (Teodor, Oleg)
       GiST indexes are now safe for crash and point-in-time recovery.
     * Remove old "*.backup" files when we do pg_stop_backup() (Bruce)
       This prevents a large number of "*.backup" files from existing in
       "pg_xlog/".
     * Add configuration parameters to control TCP/IP keep-alive times for
       idle, interval, and count (Oliver Jowett)
       These values can be changed to allow more rapid detection of lost
       client connections.
     * Add per-user and per-database connection limits (Petr Jelinek)
       Using "ALTER USER" and "ALTER DATABASE", limits can now be enforced
       on the maximum number of sessions that can concurrently connect as
       a specific user or to a specific database. Setting the limit to
       zero disables user or database connections.
     * Allow more than two gigabytes of shared memory and per-backend work
       memory on 64-bit machines (Koichi Suzuki)
     * New system catalog pg_pltemplate allows overriding obsolete
       procedural-language definitions in dump files (Tom)
     __________________________________________________________________

Query Changes

     * Add temporary views (Koju Iijima, Neil)
     * Fix "HAVING" without any aggregate functions or "GROUP BY" so that
       the query returns a single group (Tom)
       Previously, such a case would treat the "HAVING" clause the same as
       a "WHERE" clause. This was not per spec.
     * Add "USING" clause to allow additional tables to be specified to
       "DELETE" (Euler Taveira de Oliveira, Neil)
       In prior releases, there was no clear method for specifying
       additional tables to be used for joins in a "DELETE" statement.
       "UPDATE" already has a FROM clause for this purpose.
     * Add support for \x hex escapes in backend and ecpg strings (Bruce)
       This is just like the standard C \x escape syntax. Octal escapes
       were already supported.
     * Add "BETWEEN SYMMETRIC" query syntax (Pavel Stehule)
       This feature allows "BETWEEN" comparisons without requiring the
       first value to be less than the second. For example, "2 BETWEEN
       [ASYMMETRIC] 3 AND 1" returns false, while "2 BETWEEN SYMMETRIC 3
       AND 1" returns true. "BETWEEN ASYMMETRIC" was already supported.
     * Add "NOWAIT" option to "SELECT ... FOR UPDATE/SHARE" (Hans-Juergen
       Schoenig)
       While the statement_timeout configuration parameter allows a query
       taking more than a certain amount of time to be canceled, the
       "NOWAIT" option allows a query to be canceled as soon as a "SELECT
       ... FOR UPDATE/SHARE" command cannot immediately acquire a row
       lock.
     __________________________________________________________________

Object Manipulation Changes

     * Track dependencies of shared objects (Alvaro)
       PostgreSQL allows global tables (users, databases, tablespaces) to
       reference information in multiple databases. This addition adds
       dependency information for global tables, so, for example, user
       ownership can be tracked across databases, so a user who owns
       something in any database can no longer be removed. Dependency
       tracking already existed for database-local objects.
     * Allow limited "ALTER OWNER" commands to be performed by the object
       owner (Stephen Frost)
       Prior releases allowed only superusers to change object owners.
       Now, ownership can be transferred if the user executing the command
       owns the object and would be able to create it as the new owner
       (that is, the user is a member of the new owning role and that role
       has the CREATE permission that would be needed to create the object
       afresh).
     * Add "ALTER" object "SET SCHEMA" capability for some object types
       (tables, functions, types) (Bernd Helmle)
       This allows objects to be moved to different schemas.
     * Add "ALTER TABLE ENABLE/DISABLE TRIGGER" to disable triggers
       (Satoshi Nagayasu)
     __________________________________________________________________

Utility Command Changes

     * Allow "TRUNCATE" to truncate multiple tables in a single command
       (Alvaro)
       Because of referential integrity checks, it is not allowed to
       truncate a table that is part of a referential integrity
       constraint. Using this new functionality, "TRUNCATE" can be used to
       truncate such tables, if both tables involved in a referential
       integrity constraint are truncated in a single "TRUNCATE" command.
     * Properly process carriage returns and line feeds in "COPY CSV" mode
       (Andrew)
       In release 8.0, carriage returns and line feeds in "CSV COPY TO"
       were processed in an inconsistent manner. (This was documented on
       the TODO list.)
     * Add "COPY WITH CSV HEADER" to allow a header line as the first line
       in "COPY" (Andrew)
       This allows handling of the common "CSV" usage of placing the
       column names on the first line of the data file. For "COPY TO", the
       first line contains the column names, and for "COPY FROM", the
       first line is ignored.
     * On Windows, display better sub-second precision in "EXPLAIN
       ANALYZE" (Magnus)
     * Add trigger duration display to "EXPLAIN ANALYZE" (Tom)
       Prior releases included trigger execution time as part of the total
       execution time, but did not show it separately. It is now possible
       to see how much time is spent in each trigger.
     * Add support for \x hex escapes in "COPY" (Sergey Ten)
       Previous releases only supported octal escapes.
     * Make "SHOW ALL" include variable descriptions (Matthias Schmidt)
       "SHOW" varname still only displays the variable's value and does
       not include the description.
     * Make initdb create a new standard database called postgres, and
       convert utilities to use postgres rather than template1 for
       standard lookups (Dave)
       In prior releases, template1 was used both as a default connection
       for utilities like createuser, and as a template for new databases.
       This caused "CREATE DATABASE" to sometimes fail, because a new
       database cannot be created if anyone else is in the template
       database. With this change, the default connection database is now
       postgres, meaning it is much less likely someone will be using
       template1 during "CREATE DATABASE".
     * Create new reindexdb command-line utility by moving
       "/contrib/reindexdb" into the server (Euler Taveira de Oliveira)
     __________________________________________________________________

Data Type and Function Changes

     * Add MAX() and MIN() aggregates for array types (Koju Iijima)
     * Fix to_date() and to_timestamp() to behave reasonably when CC and
       YY fields are both used (Karel Zak)
       If the format specification contains CC and a year specification is
       YYY or longer, ignore the CC. If the year specification is YY or
       shorter, interpret CC as the previous century.
     * Add md5(bytea) (Abhijit Menon-Sen)
       md5(text) already existed.
     * Add support for "numeric ^ numeric" based on power(numeric,
       numeric)
       The function already existed, but there was no operator assigned to
       it.
     * Fix NUMERIC modulus by properly truncating the quotient during
       computation (Bruce)
       In previous releases, modulus for large values sometimes returned
       negative results due to rounding of the quotient.
     * Add a function lastval() (Dennis Bjorklund)
       lastval() is a simplified version of currval(). It automatically
       determines the proper sequence name based on the most recent
       nextval() or setval() call performed by the current session.
     * Add to_timestamp(DOUBLE PRECISION) (Michael Glaesemann)
       Converts Unix seconds since 1970 to a TIMESTAMP WITH TIMEZONE.
     * Add pg_postmaster_start_time() function (Euler Taveira de Oliveira,
       Matthias Schmidt)
     * Allow the full use of time zone names in "AT TIME ZONE", not just
       the short list previously available (Magnus)
       Previously, only a predefined list of time zone names were
       supported by "AT TIME ZONE". Now any supported time zone name can
       be used, e.g.:
SELECT CURRENT_TIMESTAMP AT TIME ZONE 'Europe/London';
       In the above query, the time zone used is adjusted based on the
       daylight saving time rules that were in effect on the supplied
       date.
     * Add GREATEST() and LEAST() variadic functions (Pavel Stehule)
       These functions take a variable number of arguments and return the
       greatest or least value among the arguments.
     * Add pg_column_size() (Mark Kirkwood)
       This returns storage size of a column, which might be compressed.
     * Add regexp_replace() (Atsushi Ogawa)
       This allows regular expression replacement, like sed. An optional
       flag argument allows selection of global (replace all) and
       case-insensitive modes.
     * Fix interval division and multiplication (Bruce)
       Previous versions sometimes returned unjustified results, like "'4
       months'::interval / 5" returning "'1 mon -6 days'".
     * Fix roundoff behavior in timestamp, time, and interval output (Tom)
       This fixes some cases in which the seconds field would be shown as
       60 instead of incrementing the higher-order fields.
     * Add a separate day field to type interval so a one day interval can
       be distinguished from a 24 hour interval (Michael Glaesemann)
       Days that contain a daylight saving time adjustment are not 24
       hours long, but typically 23 or 25 hours. This change creates a
       conceptual distinction between intervals of "so many days" and
       intervals of "so many hours". Adding 1 day to a timestamp now gives
       the same local time on the next day even if a daylight saving time
       adjustment occurs between, whereas adding 24 hours will give a
       different local time when this happens. For example, under US DST
       rules:
'2005-04-03 00:00:00-05' + '1 day' = '2005-04-04 00:00:00-04'
'2005-04-03 00:00:00-05' + '24 hours' = '2005-04-04 01:00:00-04'
     * Add justify_days() and justify_hours() (Michael Glaesemann)
       These functions, respectively, adjust days to an appropriate number
       of full months and days, and adjust hours to an appropriate number
       of full days and hours.
     * Move "/contrib/dbsize" into the backend, and rename some of the
       functions (Dave Page, Andreas Pflug)
          + pg_tablespace_size()
          + pg_database_size()
          + pg_relation_size()
          + pg_total_relation_size()
          + pg_size_pretty()
       pg_total_relation_size() includes indexes and TOAST tables.
     * Add functions for read-only file access to the cluster directory
       (Dave Page, Andreas Pflug)
          + pg_stat_file()
          + pg_read_file()
          + pg_ls_dir()
     * Add pg_reload_conf() to force reloading of the configuration files
       (Dave Page, Andreas Pflug)
     * Add pg_rotate_logfile() to force rotation of the server log file
       (Dave Page, Andreas Pflug)
     * Change pg_stat_* views to include TOAST tables (Tom)
     __________________________________________________________________

Encoding and Locale Changes

     * Rename some encodings to be more consistent and to follow
       international standards (Bruce)
          + UNICODE is now UTF8
          + ALT is now WIN866
          + WIN is now WIN1251
          + TCVN is now WIN1258
       The original names still work.
     * Add support for WIN1252 encoding (Roland Volkmann)
     * Add support for four-byte UTF8 characters (John Hansen)
       Previously only one, two, and three-byte UTF8 characters were
       supported. This is particularly important for support for some
       Chinese character sets.
     * Allow direct conversion between EUC_JP and SJIS to improve
       performance (Atsushi Ogawa)
     * Allow the UTF8 encoding to work on Windows (Magnus)
       This is done by mapping UTF8 to the Windows-native UTF16
       implementation.
     __________________________________________________________________

General Server-Side Language Changes

     * Fix "ALTER LANGUAGE RENAME" (Sergey Yatskevich)
     * Allow function characteristics, like strictness and volatility, to
       be modified via "ALTER FUNCTION" (Neil)
     * Increase the maximum number of function arguments to 100 (Tom)
     * Allow SQL and PL/pgSQL functions to use "OUT" and "INOUT"
       parameters (Tom)
       "OUT" is an alternate way for a function to return values. Instead
       of using "RETURN", values can be returned by assigning to
       parameters declared as "OUT" or "INOUT". This is notationally
       simpler in some cases, particularly so when multiple values need to
       be returned. While returning multiple values from a function was
       possible in previous releases, this greatly simplifies the process.
       (The feature will be extended to other server-side languages in
       future releases.)
     * Move language handler functions into the pg_catalog schema
       This makes it easier to drop the public schema if desired.
     * Add SPI_getnspname() to SPI (Neil)
     __________________________________________________________________

PL/pgSQL Server-Side Language Changes

     * Overhaul the memory management of PL/pgSQL functions (Neil)
       The parsetree of each function is now stored in a separate memory
       context. This allows this memory to be easily reclaimed when it is
       no longer needed.
     * Check function syntax at "CREATE FUNCTION" time, rather than at
       runtime (Neil)
       Previously, most syntax errors were reported only when the function
       was executed.
     * Allow "OPEN" to open non-"SELECT" queries like "EXPLAIN" and "SHOW"
       (Tom)
     * No longer require functions to issue a "RETURN" statement (Tom)
       This is a byproduct of the newly added "OUT" and "INOUT"
       functionality. "RETURN" can be omitted when it is not needed to
       provide the function's return value.
     * Add support for an optional "INTO" clause to PL/pgSQL's "EXECUTE"
       statement (Pavel Stehule, Neil)
     * Make "CREATE TABLE AS" set "ROW_COUNT" (Tom)
     * Define SQLSTATE and SQLERRM to return the SQLSTATE and error
       message of the current exception (Pavel Stehule, Neil)
       These variables are only defined inside exception blocks.
     * Allow the parameters to the "RAISE" statement to be expressions
       (Pavel Stehule, Neil)
     * Add a loop "CONTINUE" statement (Pavel Stehule, Neil)
     * Allow block and loop labels (Pavel Stehule)
     __________________________________________________________________

PL/Perl Server-Side Language Changes

     * Allow large result sets to be returned efficiently (Abhijit
       Menon-Sen)
       This allows functions to use return_next() to avoid building the
       entire result set in memory.
     * Allow one-row-at-a-time retrieval of query results (Abhijit
       Menon-Sen)
       This allows functions to use spi_query() and spi_fetchrow() to
       avoid accumulating the entire result set in memory.
     * Force PL/Perl to handle strings as UTF8 if the server encoding is
       UTF8 (David Kamholz)
     * Add a validator function for PL/Perl (Andrew)
       This allows syntax errors to be reported at definition time, rather
       than execution time.
     * Allow PL/Perl to return a Perl array when the function returns an
       array type (Andrew)
       This basically maps PostgreSQL arrays to Perl arrays.
     * Allow Perl nonfatal warnings to generate "NOTICE" messages (Andrew)
     * Allow Perl's strict mode to be enabled (Andrew)
     __________________________________________________________________

psql Changes

     * Add "\set ON_ERROR_ROLLBACK" to allow statements in a transaction
       to error without affecting the rest of the transaction (Greg Sabino
       Mullane)
       This is basically implemented by wrapping every statement in a
       sub-transaction.
     * Add support for \x hex strings in psql variables (Bruce)
       Octal escapes were already supported.
     * Add support for "troff -ms" output format (Roger Leigh)
     * Allow the history file location to be controlled by HISTFILE
       (Andreas Seltenreich)
       This allows configuration of per-database history storage.
     * Prevent "\x" (expanded mode) from affecting the output of "\d
       tablename" (Neil)
     * Add "-L" option to psql to log sessions (Lorne Sunley)
       This option was added because some operating systems do not have
       simple command-line activity logging functionality.
     * Make "\d" show the tablespaces of indexes (Qingqing Zhou)
     * Allow psql help ("\h") to make a best guess on the proper help
       information (Greg Sabino Mullane)
       This allows the user to just add "\h" to the front of the syntax
       error query and get help on the supported syntax. Previously any
       additional query text beyond the command name had to be removed to
       use "\h".
     * Add "\pset numericlocale" to allow numbers to be output in a
       locale-aware format (Eugen Nedelcu)
       For example, using C locale 100000 would be output as 100,000.0
       while a European locale might output this value as 100.000,0.
     * Make startup banner show both server version number and psql's
       version number, when they are different (Bruce)
       Also, a warning will be shown if the server and psql are from
       different major releases.
     __________________________________________________________________

pg_dump Changes

     * Add "-n" / "--schema" switch to pg_restore (Richard van den Berg)
       This allows just the objects in a specified schema to be restored.
     * Allow pg_dump to dump large objects even in text mode (Tom)
       With this change, large objects are now always dumped; the former
       "-b" switch is a no-op.
     * Allow pg_dump to dump a consistent snapshot of large objects (Tom)
     * Dump comments for large objects (Tom)
     * Add "--encoding" to pg_dump (Magnus Hagander)
       This allows a database to be dumped in an encoding that is
       different from the server's encoding. This is valuable when
       transferring the dump to a machine with a different encoding.
     * Rely on pg_pltemplate for procedural languages (Tom)
       If the call handler for a procedural language is in the pg_catalog
       schema, pg_dump does not dump the handler. Instead, it dumps the
       language using just "CREATE LANGUAGE name", relying on the
       pg_pltemplate catalog to provide the language's creation parameters
       at load time.
     __________________________________________________________________

libpq Changes

     * Add a PGPASSFILE environment variable to specify the password
       file's filename (Andrew)
     * Add lo_create(), that is similar to lo_creat() but allows the OID
       of the large object to be specified (Tom)
     * Make libpq consistently return an error to the client application
       on malloc() failure (Neil)
     __________________________________________________________________

Source Code Changes

     * Fix pgxs to support building against a relocated installation
     * Add spinlock support for the Itanium processor using Intel compiler
       (Vikram Kalsi)
     * Add Kerberos 5 support for Windows (Magnus)
     * Add Chinese FAQ (laser@pgsqldb.com)
     * Rename Rendezvous to Bonjour to match OS/X feature renaming (Bruce)
     * Add support for fsync_writethrough on Darwin (Chris Campbell)
     * Streamline the passing of information within the server, the
       optimizer, and the lock system (Tom)
     * Allow pg_config to be compiled using MSVC (Andrew)
       This is required to build DBD::Pg using MSVC.
     * Remove support for Kerberos V4 (Magnus)
       Kerberos 4 had security vulnerabilities and is no longer
       maintained.
     * Code cleanups (Coverity static analysis performed by EnterpriseDB)
     * Modify "postgresql.conf" to use documentation defaults on/off
       rather than true/false (Bruce)
     * Enhance pg_config to be able to report more build-time values (Tom)
     * Allow libpq to be built thread-safe on Windows (Dave Page)
     * Allow IPv6 connections to be used on Windows (Andrew)
     * Add Server Administration documentation about I/O subsystem
       reliability (Bruce)
     * Move private declarations from "gist.h" to "gist_private.h" (Neil)
       In previous releases, "gist.h" contained both the public GiST API
       (intended for use by authors of GiST index implementations) as well
       as some private declarations used by the implementation of GiST
       itself. The latter have been moved to a separate file,
       "gist_private.h". Most GiST index implementations should be
       unaffected.
     * Overhaul GiST memory management (Neil)
       GiST methods are now always invoked in a short-lived memory
       context. Therefore, memory allocated via palloc() will be reclaimed
       automatically, so GiST index implementations do not need to
       manually release allocated memory via pfree().
     __________________________________________________________________

Contrib Changes

     * Add "/contrib/pg_buffercache" contrib module (Mark Kirkwood)
       This displays the contents of the buffer cache, for debugging and
       performance tuning purposes.
     * Remove "/contrib/array" because it is obsolete (Tom)
     * Clean up the "/contrib/lo" module (Tom)
     * Move "/contrib/findoidjoins" to "/src/tools" (Tom)
     * Remove the <<, >>, &<, and &> operators from "/contrib/cube"
       These operators were not useful.
     * Improve "/contrib/btree_gist" (Janko Richter)
     * Improve "/contrib/pgbench" (Tomoaki Sato, Tatsuo)
       There is now a facility for testing with SQL command scripts given
       by the user, instead of only a hard-wired command sequence.
     * Improve "/contrib/pgcrypto" (Marko Kreen)
          + Implementation of OpenPGP symmetric-key and public-key
            encryption
            Both RSA and Elgamal public-key algorithms are supported.
          + Stand alone build: include SHA256/384/512 hashes, Fortuna PRNG
          + OpenSSL build: support 3DES, use internal AES with OpenSSL <
            0.9.7
          + Take build parameters (OpenSSL, zlib) from "configure" result
            There is no need to edit the "Makefile" anymore.
          + Remove support for "libmhash" and "libmcrypt"
     __________________________________________________________________

                               Release 8.0.26

     Release Date: 2010-10-04

   This release contains a variety of fixes from 8.0.25. For information
   about new features in the 8.0 major release, see the Section called
   Release 8.0.

   This is expected to be the last PostgreSQL release in the 8.0.X series.
   Users are encouraged to update to a newer release branch soon.
     __________________________________________________________________

Migration to Version 8.0.26

   A dump/restore is not required for those running 8.0.X. However, if you
   are upgrading from a version earlier than 8.0.22, see the release notes
   for 8.0.22.
     __________________________________________________________________

Changes

     * Use a separate interpreter for each calling SQL userid in PL/Perl
       and PL/Tcl (Tom Lane)
       This change prevents security problems that can be caused by
       subverting Perl or Tcl code that will be executed later in the same
       session under another SQL user identity (for example, within a
       SECURITY DEFINER function). Most scripting languages offer numerous
       ways that that might be done, such as redefining standard functions
       or operators called by the target function. Without this change,
       any SQL user with Perl or Tcl language usage rights can do
       essentially anything with the SQL privileges of the target
       function's owner.
       The cost of this change is that intentional communication among
       Perl and Tcl functions becomes more difficult. To provide an escape
       hatch, PL/PerlU and PL/TclU functions continue to use only one
       interpreter per session. This is not considered a security issue
       since all such functions execute at the trust level of a database
       superuser already.
       It is likely that third-party procedural languages that claim to
       offer trusted execution have similar security issues. We advise
       contacting the authors of any PL you are depending on for
       security-critical purposes.
       Our thanks to Tim Bunce for pointing out this issue
       (CVE-2010-3433).
     * Prevent possible crashes in pg_get_expr() by disallowing it from
       being called with an argument that is not one of the system catalog
       columns it's intended to be used with (Heikki Linnakangas, Tom
       Lane)
     * Fix "cannot handle unplanned sub-select" error (Tom Lane)
       This occurred when a sub-select contains a join alias reference
       that expands into an expression containing another sub-select.
     * Defend against functions returning setof record where not all the
       returned rows are actually of the same rowtype (Tom Lane)
     * Take care to fsync the contents of lockfiles (both "postmaster.pid"
       and the socket lockfile) while writing them (Tom Lane)
       This omission could result in corrupted lockfile contents if the
       machine crashes shortly after postmaster start. That could in turn
       prevent subsequent attempts to start the postmaster from
       succeeding, until the lockfile is manually removed.
     * Avoid recursion while assigning XIDs to heavily-nested
       subtransactions (Andres Freund, Robert Haas)
       The original coding could result in a crash if there was limited
       stack space.
     * Fix log_line_prefix's %i escape, which could produce junk early in
       backend startup (Tom Lane)
     * Fix possible data corruption in "ALTER TABLE ... SET TABLESPACE"
       when archiving is enabled (Jeff Davis)
     * Allow "CREATE DATABASE" and "ALTER DATABASE ... SET TABLESPACE" to
       be interrupted by query-cancel (Guillaume Lelarge)
     * In PL/Python, defend against null pointer results from
       PyCObject_AsVoidPtr and PyCObject_FromVoidPtr (Peter Eisentraut)
     * Improve "contrib/dblink"'s handling of tables containing dropped
       columns (Tom Lane)
     * Fix connection leak after "duplicate connection name" errors in
       "contrib/dblink" (Itagaki Takahiro)
     * Fix "contrib/dblink" to handle connection names longer than 62
       bytes correctly (Itagaki Takahiro)
     * Update build infrastructure and documentation to reflect the source
       code repository's move from CVS to Git (Magnus Hagander and others)
     * Update time zone data files to tzdata release 2010l for DST law
       changes in Egypt and Palestine; also historical corrections for
       Finland.
       This change also adds new names for two Micronesian timezones:
       Pacific/Chuuk is now preferred over Pacific/Truk (and the preferred
       abbreviation is CHUT not TRUT) and Pacific/Pohnpei is preferred
       over Pacific/Ponape.
     __________________________________________________________________

                               Release 8.0.25

     Release Date: 2010-05-17

   This release contains a variety of fixes from 8.0.24. For information
   about new features in the 8.0 major release, see the Section called
   Release 8.0.

   The PostgreSQL community will stop releasing updates for the 8.0.X
   release series in July 2010. Users are encouraged to update to a newer
   release branch soon.
     __________________________________________________________________

Migration to Version 8.0.25

   A dump/restore is not required for those running 8.0.X. However, if you
   are upgrading from a version earlier than 8.0.22, see the release notes
   for 8.0.22.
     __________________________________________________________________

Changes

     * Enforce restrictions in plperl using an opmask applied to the whole
       interpreter, instead of using "Safe.pm" (Tim Bunce, Andrew Dunstan)
       Recent developments have convinced us that "Safe.pm" is too
       insecure to rely on for making plperl trustable. This change
       removes use of "Safe.pm" altogether, in favor of using a separate
       interpreter with an opcode mask that is always applied. Pleasant
       side effects of the change include that it is now possible to use
       Perl's strict pragma in a natural way in plperl, and that Perl's $a
       and $b variables work as expected in sort routines, and that
       function compilation is significantly faster. (CVE-2010-1169)
     * Prevent PL/Tcl from executing untrustworthy code from pltcl_modules
       (Tom)
       PL/Tcl's feature for autoloading Tcl code from a database table
       could be exploited for trojan-horse attacks, because there was no
       restriction on who could create or insert into that table. This
       change disables the feature unless pltcl_modules is owned by a
       superuser. (However, the permissions on the table are not checked,
       so installations that really need a less-than-secure modules table
       can still grant suitable privileges to trusted non-superusers.)
       Also, prevent loading code into the unrestricted "normal" Tcl
       interpreter unless we are really going to execute a pltclu
       function. (CVE-2010-1170)
     * Do not allow an unprivileged user to reset superuser-only parameter
       settings (Alvaro)
       Previously, if an unprivileged user ran ALTER USER ... RESET ALL
       for himself, or ALTER DATABASE ... RESET ALL for a database he
       owns, this would remove all special parameter settings for the user
       or database, even ones that are only supposed to be changeable by a
       superuser. Now, the "ALTER" will only remove the parameters that
       the user has permission to change.
     * Avoid possible crash during backend shutdown if shutdown occurs
       when a CONTEXT addition would be made to log entries (Tom)
       In some cases the context-printing function would fail because the
       current transaction had already been rolled back when it came time
       to print a log message.
     * Update pl/perl's "ppport.h" for modern Perl versions (Andrew)
     * Fix assorted memory leaks in pl/python (Andreas Freund, Tom)
     * Prevent infinite recursion in psql when expanding a variable that
       refers to itself (Tom)
     * Ensure that "contrib/pgstattuple" functions respond to cancel
       interrupts promptly (Tatsuhito Kasahara)
     * Make server startup deal properly with the case that shmget()
       returns EINVAL for an existing shared memory segment (Tom)
       This behavior has been observed on BSD-derived kernels including OS
       X. It resulted in an entirely-misleading startup failure
       complaining that the shared memory request size was too large.
     * Update time zone data files to tzdata release 2010j for DST law
       changes in Argentina, Australian Antarctic, Bangladesh, Mexico,
       Morocco, Pakistan, Palestine, Russia, Syria, Tunisia; also
       historical corrections for Taiwan.
     __________________________________________________________________

                               Release 8.0.24

     Release Date: 2010-03-15

   This release contains a variety of fixes from 8.0.23. For information
   about new features in the 8.0 major release, see the Section called
   Release 8.0.

   The PostgreSQL community will stop releasing updates for the 8.0.X
   release series in July 2010. Users are encouraged to update to a newer
   release branch soon.
     __________________________________________________________________

Migration to Version 8.0.24

   A dump/restore is not required for those running 8.0.X. However, if you
   are upgrading from a version earlier than 8.0.22, see the release notes
   for 8.0.22.
     __________________________________________________________________

Changes

     * Add new configuration parameter ssl_renegotiation_limit to control
       how often we do session key renegotiation for an SSL connection
       (Magnus)
       This can be set to zero to disable renegotiation completely, which
       may be required if a broken SSL library is used. In particular,
       some vendors are shipping stopgap patches for CVE-2009-3555 that
       cause renegotiation attempts to fail.
     * Fix possible crashes when trying to recover from a failure in
       subtransaction start (Tom)
     * Fix server memory leak associated with use of savepoints and a
       client encoding different from server's encoding (Tom)
     * Make substring() for bit types treat any negative length as meaning
       "all the rest of the string" (Tom)
       The previous coding treated only -1 that way, and would produce an
       invalid result value for other negative values, possibly leading to
       a crash (CVE-2010-0442).
     * Fix integer-to-bit-string conversions to handle the first
       fractional byte correctly when the output bit width is wider than
       the given integer by something other than a multiple of 8 bits
       (Tom)
     * Fix some cases of pathologically slow regular expression matching
       (Tom)
     * Fix the STOP WAL LOCATION entry in backup history files to report
       the next WAL segment's name when the end location is exactly at a
       segment boundary (Itagaki Takahiro)
     * When reading "pg_hba.conf" and related files, do not treat
       @something as a file inclusion request if the @ appears inside
       quote marks; also, never treat @ by itself as a file inclusion
       request (Tom)
       This prevents erratic behavior if a role or database name starts
       with @. If you need to include a file whose path name contains
       spaces, you can still do so, but you must write @"/path to/file"
       rather than putting the quotes around the whole construct.
     * Prevent infinite loop on some platforms if a directory is named as
       an inclusion target in "pg_hba.conf" and related files (Tom)
     * Fix plpgsql failure in one case where a composite column is set to
       NULL (Tom)
     * Add volatile markings in PL/Python to avoid possible
       compiler-specific misbehavior (Zdenek Kotala)
     * Ensure PL/Tcl initializes the Tcl interpreter fully (Tom)
       The only known symptom of this oversight is that the Tcl clock
       command misbehaves if using Tcl 8.5 or later.
     * Prevent crash in "contrib/dblink" when too many key columns are
       specified to a dblink_build_sql_* function (Rushabh Lathia, Joe
       Conway)
     * Fix assorted crashes in "contrib/xml2" caused by sloppy memory
       management (Tom)
     * Update time zone data files to tzdata release 2010e for DST law
       changes in Bangladesh, Chile, Fiji, Mexico, Paraguay, Samoa.
     __________________________________________________________________

                               Release 8.0.23

     Release Date: 2009-12-14

   This release contains a variety of fixes from 8.0.22. For information
   about new features in the 8.0 major release, see the Section called
   Release 8.0.
     __________________________________________________________________

Migration to Version 8.0.23

   A dump/restore is not required for those running 8.0.X. However, if you
   are upgrading from a version earlier than 8.0.22, see the release notes
   for 8.0.22.
     __________________________________________________________________

Changes

     * Protect against indirect security threats caused by index functions
       changing session-local state (Gurjeet Singh, Tom)
       This change prevents allegedly-immutable index functions from
       possibly subverting a superuser's session (CVE-2009-4136).
     * Reject SSL certificates containing an embedded null byte in the
       common name (CN) field (Magnus)
       This prevents unintended matching of a certificate to a server or
       client name during SSL validation (CVE-2009-4034).
     * Fix possible crash during backend-startup-time cache initialization
       (Tom)
     * Prevent signals from interrupting VACUUM at unsafe times (Alvaro)
       This fix prevents a PANIC if a VACUUM FULL is canceled after it's
       already committed its tuple movements, as well as transient errors
       if a plain VACUUM is interrupted after having truncated the table.
     * Fix possible crash due to integer overflow in hash table size
       calculation (Tom)
       This could occur with extremely large planner estimates for the
       size of a hashjoin's result.
     * Fix very rare crash in inet/cidr comparisons (Chris Mikkelson)
     * Fix premature drop of temporary files used for a cursor that is
       accessed within a subtransaction (Heikki)
     * Fix PAM password processing to be more robust (Tom)
       The previous code is known to fail with the combination of the
       Linux pam_krb5 PAM module with Microsoft Active Directory as the
       domain controller. It might have problems elsewhere too, since it
       was making unjustified assumptions about what arguments the PAM
       stack would pass to it.
     * Fix rare crash in exception processing in PL/Python (Peter)
     * Ensure psql's flex module is compiled with the correct system
       header definitions (Tom)
       This fixes build failures on platforms where --enable-largefile
       causes incompatible changes in the generated code.
     * Make the postmaster ignore any application_name parameter in
       connection request packets, to improve compatibility with future
       libpq versions (Tom)
     * Update time zone data files to tzdata release 2009s for DST law
       changes in Antarctica, Argentina, Bangladesh, Fiji, Novokuznetsk,
       Pakistan, Palestine, Samoa, Syria; also historical corrections for
       Hong Kong.
     __________________________________________________________________

                               Release 8.0.22

     Release Date: 2009-09-09

   This release contains a variety of fixes from 8.0.21. For information
   about new features in the 8.0 major release, see the Section called
   Release 8.0.
     __________________________________________________________________

Migration to Version 8.0.22

   A dump/restore is not required for those running 8.0.X. However, if you
   have any hash indexes on interval columns, you must "REINDEX" them
   after updating to 8.0.22. Also, if you are upgrading from a version
   earlier than 8.0.6, see the release notes for 8.0.6.
     __________________________________________________________________

Changes

     * Disallow "RESET ROLE" and "RESET SESSION AUTHORIZATION" inside
       security-definer functions (Tom, Heikki)
       This covers a case that was missed in the previous patch that
       disallowed "SET ROLE" and "SET SESSION AUTHORIZATION" inside
       security-definer functions. (See CVE-2007-6600)
     * Fix handling of sub-SELECTs appearing in the arguments of an
       outer-level aggregate function (Tom)
     * Fix hash calculation for data type interval (Tom)
       This corrects wrong results for hash joins on interval values. It
       also changes the contents of hash indexes on interval columns. If
       you have any such indexes, you must "REINDEX" them after updating.
     * Treat to_char(..., 'TH') as an uppercase ordinal suffix with
       'HH'/'HH12' (Heikki)
       It was previously handled as 'th' (lowercase).
     * Fix overflow for INTERVAL 'x ms' when "x" is more than 2 million
       and integer datetimes are in use (Alex Hunsaker)
     * Fix calculation of distance between a point and a line segment
       (Tom)
       This led to incorrect results from a number of geometric operators.
     * Fix money data type to work in locales where currency amounts have
       no fractional digits, e.g. Japan (Itagaki Takahiro)
     * Properly round datetime input like
       00:12:57.9999999999999999999999999999 (Tom)
     * Fix poor choice of page split point in GiST R-tree operator classes
       (Teodor)
     * Fix portability issues in plperl initialization (Andrew Dunstan)
     * Fix pg_ctl to not go into an infinite loop if "postgresql.conf" is
       empty (Jeff Davis)
     * Fix "contrib/xml2"'s xslt_process() to properly handle the maximum
       number of parameters (twenty) (Tom)
     * Improve robustness of libpq's code to recover from errors during
       "COPY FROM STDIN" (Tom)
     * Avoid including conflicting readline and editline header files when
       both libraries are installed (Zdenek Kotala)
     * Update time zone data files to tzdata release 2009l for DST law
       changes in Bangladesh, Egypt, Jordan, Pakistan, Argentina/San_Luis,
       Cuba, Jordan (historical correction only), Mauritius, Morocco,
       Palestine, Syria, Tunisia.
     __________________________________________________________________

                               Release 8.0.21

     Release Date: 2009-03-16

   This release contains a variety of fixes from 8.0.20. For information
   about new features in the 8.0 major release, see the Section called
   Release 8.0.
     __________________________________________________________________

Migration to Version 8.0.21

   A dump/restore is not required for those running 8.0.X. However, if you
   are upgrading from a version earlier than 8.0.6, see the release notes
   for 8.0.6.
     __________________________________________________________________

Changes

     * Prevent error recursion crashes when encoding conversion fails
       (Tom)
       This change extends fixes made in the last two minor releases for
       related failure scenarios. The previous fixes were narrowly
       tailored for the original problem reports, but we have now
       recognized that *any* error thrown by an encoding conversion
       function could potentially lead to infinite recursion while trying
       to report the error. The solution therefore is to disable
       translation and encoding conversion and report the plain-ASCII form
       of any error message, if we find we have gotten into a recursive
       error reporting situation. (CVE-2009-0922)
     * Disallow "CREATE CONVERSION" with the wrong encodings for the
       specified conversion function (Heikki)
       This prevents one possible scenario for encoding conversion
       failure. The previous change is a backstop to guard against other
       kinds of failures in the same area.
     * Fix core dump when to_char() is given format codes that are
       inappropriate for the type of the data argument (Tom)
     * Add MUST (Mauritius Island Summer Time) to the default list of
       known timezone abbreviations (Xavier Bugaud)
     __________________________________________________________________

                               Release 8.0.20

     Release Date: 2009-02-02

   This release contains a variety of fixes from 8.0.19. For information
   about new features in the 8.0 major release, see the Section called
   Release 8.0.
     __________________________________________________________________

Migration to Version 8.0.20

   A dump/restore is not required for those running 8.0.X. However, if you
   are upgrading from a version earlier than 8.0.6, see the release notes
   for 8.0.6.
     __________________________________________________________________

Changes

     * Improve handling of URLs in headline() function (Teodor)
     * Improve handling of overlength headlines in headline() function
       (Teodor)
     * Prevent possible Assert failure or misconversion if an encoding
       conversion is created with the wrong conversion function for the
       specified pair of encodings (Tom, Heikki)
     * Avoid unnecessary locking of small tables in "VACUUM" (Heikki)
     * Fix uninitialized variables in "contrib/tsearch2"'s get_covers()
       function (Teodor)
     * Make all documentation reference pgsql-bugs and/or pgsql-hackers as
       appropriate, instead of the now-decommissioned pgsql-ports and
       pgsql-patches mailing lists (Tom)
     * Update time zone data files to tzdata release 2009a (for Kathmandu
       and historical DST corrections in Switzerland, Cuba)
     __________________________________________________________________

                               Release 8.0.19

     Release Date: 2008-11-03

   This release contains a variety of fixes from 8.0.18. For information
   about new features in the 8.0 major release, see the Section called
   Release 8.0.
     __________________________________________________________________

Migration to Version 8.0.19

   A dump/restore is not required for those running 8.0.X. However, if you
   are upgrading from a version earlier than 8.0.6, see the release notes
   for 8.0.6.
     __________________________________________________________________

Changes

     * Fix backend crash when the client encoding cannot represent a
       localized error message (Tom)
       We have addressed similar issues before, but it would still fail if
       the "character has no equivalent" message itself couldn't be
       converted. The fix is to disable localization and send the plain
       ASCII error message when we detect such a situation.
     * Fix possible crash when deeply nested functions are invoked from a
       trigger (Tom)
     * Ensure an error is reported when a newly-defined PL/pgSQL trigger
       function is invoked as a normal function (Tom)
     * Fix incorrect tsearch2 headline generation when single query item
       matches first word of text (Sushant Sinha)
     * Fix improper display of fractional seconds in interval values when
       using a non-ISO datestyle in an "--enable-integer-datetimes" build
       (Ron Mayer)
     * Ensure SPI_getvalue and SPI_getbinval behave correctly when the
       passed tuple and tuple descriptor have different numbers of columns
       (Tom)
       This situation is normal when a table has had columns added or
       removed, but these two functions didn't handle it properly. The
       only likely consequence is an incorrect error indication.
     * Fix ecpg's parsing of "CREATE USER" (Michael)
     * Fix recent breakage of pg_ctl restart (Tom)
     * Update time zone data files to tzdata release 2008i (for DST law
       changes in Argentina, Brazil, Mauritius, Syria)
     __________________________________________________________________

                               Release 8.0.18

     Release Date: 2008-09-22

   This release contains a variety of fixes from 8.0.17. For information
   about new features in the 8.0 major release, see the Section called
   Release 8.0.
     __________________________________________________________________

Migration to Version 8.0.18

   A dump/restore is not required for those running 8.0.X. However, if you
   are upgrading from a version earlier than 8.0.6, see the release notes
   for 8.0.6.
     __________________________________________________________________

Changes

     * Widen local lock counters from 32 to 64 bits (Tom)
       This responds to reports that the counters could overflow in
       sufficiently long transactions, leading to unexpected "lock is
       already held" errors.
     * Add checks in executor startup to ensure that the tuples produced
       by an "INSERT" or "UPDATE" will match the target table's current
       rowtype (Tom)
       "ALTER COLUMN TYPE", followed by re-use of a previously cached
       plan, could produce this type of situation. The check protects
       against data corruption and/or crashes that could ensue.
     * Fix datetime input functions to correctly detect integer overflow
       when running on a 64-bit platform (Tom)
     * Improve performance of writing very long log messages to syslog
       (Tom)
     * Fix bug in backwards scanning of a cursor on a SELECT DISTINCT ON
       query (Tom)
     * Fix planner to estimate that GROUP BY expressions yielding boolean
       results always result in two groups, regardless of the expressions'
       contents (Tom)
       This is very substantially more accurate than the regular GROUP BY
       estimate for certain boolean tests like "col" IS NULL.
     * Fix PL/Tcl to behave correctly with Tcl 8.5, and to be more careful
       about the encoding of data sent to or from Tcl (Tom)
     * Fix PL/Python to work with Python 2.5
       This is a back-port of fixes made during the 8.2 development cycle.
     * Improve pg_dump and pg_restore's error reporting after failure to
       send a SQL command (Tom)
     * Fix pg_ctl to properly preserve postmaster command-line arguments
       across a restart (Bruce)
     * Update time zone data files to tzdata release 2008f (for DST law
       changes in Argentina, Bahamas, Brazil, Mauritius, Morocco,
       Pakistan, Palestine, and Paraguay)
     __________________________________________________________________

                               Release 8.0.17

     Release Date: 2008-06-12

   This release contains one serious bug fix over 8.0.16. For information
   about new features in the 8.0 major release, see the Section called
   Release 8.0.
     __________________________________________________________________

Migration to Version 8.0.17

   A dump/restore is not required for those running 8.0.X. However, if you
   are upgrading from a version earlier than 8.0.6, see the release notes
   for 8.0.6.
     __________________________________________________________________

Changes

     * Make pg_get_ruledef() parenthesize negative constants (Tom)
       Before this fix, a negative constant in a view or rule might be
       dumped as, say, -42::integer, which is subtly incorrect: it should
       be (-42)::integer due to operator precedence rules. Usually this
       would make little difference, but it could interact with another
       recent patch to cause PostgreSQL to reject what had been a valid
       "SELECT DISTINCT" view query. Since this could result in pg_dump
       output failing to reload, it is being treated as a high-priority
       fix. The only released versions in which dump output is actually
       incorrect are 8.3.1 and 8.2.7.
     __________________________________________________________________

                               Release 8.0.16

     Release Date: never released

   This release contains a variety of fixes from 8.0.15. For information
   about new features in the 8.0 major release, see the Section called
   Release 8.0.
     __________________________________________________________________

Migration to Version 8.0.16

   A dump/restore is not required for those running 8.0.X. However, if you
   are upgrading from a version earlier than 8.0.6, see the release notes
   for 8.0.6.
     __________________________________________________________________

Changes

     * Fix "ALTER TABLE ADD COLUMN ... PRIMARY KEY" so that the new column
       is correctly checked to see if it's been initialized to all
       non-nulls (Brendan Jurd)
       Previous versions neglected to check this requirement at all.
     * Fix possible "CREATE TABLE" failure when inheriting the "same"
       constraint from multiple parent relations that inherited that
       constraint from a common ancestor (Tom)
     * Fix conversions between ISO-8859-5 and other encodings to handle
       Cyrillic "Yo" characters (e and E with two dots) (Sergey Burladyan)
     * Fix a few datatype input functions that were allowing unused bytes
       in their results to contain uninitialized, unpredictable values
       (Tom)
       This could lead to failures in which two apparently identical
       literal values were not seen as equal, resulting in the parser
       complaining about unmatched ORDER BY and DISTINCT expressions.
     * Fix a corner case in regular-expression substring matching
       (substring(string from pattern)) (Tom)
       The problem occurs when there is a match to the pattern overall but
       the user has specified a parenthesized subexpression and that
       subexpression hasn't got a match. An example is substring('foo'
       from 'foo(bar)?'). This should return NULL, since (bar) isn't
       matched, but it was mistakenly returning the whole-pattern match
       instead (ie, foo).
     * Update time zone data files to tzdata release 2008c (for DST law
       changes in Morocco, Iraq, Choibalsan, Pakistan, Syria, Cuba,
       Argentina/San_Luis, and Chile)
     * Fix incorrect result from ecpg's PGTYPEStimestamp_sub() function
       (Michael)
     * Fix core dump in "contrib/xml2"'s xpath_table() function when the
       input query returns a NULL value (Tom)
     * Fix "contrib/xml2"'s makefile to not override CFLAGS (Tom)
     * Fix DatumGetBool macro to not fail with gcc 4.3 (Tom)
       This problem affects "old style" (V0) C functions that return
       boolean. The fix is already in 8.3, but the need to back-patch it
       was not realized at the time.
     * Fix longstanding "LISTEN"/"NOTIFY" race condition (Tom)
       In rare cases a session that had just executed a "LISTEN" might not
       get a notification, even though one would be expected because the
       concurrent transaction executing "NOTIFY" was observed to commit
       later.
       A side effect of the fix is that a transaction that has executed a
       not-yet-committed "LISTEN" command will not see any row in
       pg_listener for the "LISTEN", should it choose to look; formerly it
       would have. This behavior was never documented one way or the
       other, but it is possible that some applications depend on the old
       behavior.
     * Fix rare crash when an error occurs during a query using a hash
       index (Heikki)
     * Fix input of datetime values for February 29 in years BC (Tom)
       The former coding was mistaken about which years were leap years.
     * Fix "unrecognized node type" error in some variants of "ALTER
       OWNER" (Tom)
     * Fix pg_ctl to correctly extract the postmaster's port number from
       command-line options (Itagaki Takahiro, Tom)
       Previously, pg_ctl start -w could try to contact the postmaster on
       the wrong port, leading to bogus reports of startup failure.
     * Use "-fwrapv" to defend against possible misoptimization in recent
       gcc versions (Tom)
       This is known to be necessary when building PostgreSQL with gcc 4.3
       or later.
     * Fix display of constant expressions in ORDER BY and GROUP BY (Tom)
       An explicitly casted constant would be shown incorrectly. This
       could for example lead to corruption of a view definition during
       dump and reload.
     * Fix libpq to handle NOTICE messages correctly during COPY OUT (Tom)
       This failure has only been observed to occur when a user-defined
       datatype's output routine issues a NOTICE, but there is no
       guarantee it couldn't happen due to other causes.
     __________________________________________________________________

                               Release 8.0.15

     Release Date: 2008-01-07

   This release contains a variety of fixes from 8.0.14, including fixes
   for significant security issues. For information about new features in
   the 8.0 major release, see the Section called Release 8.0.

   This is the last 8.0.X release for which the PostgreSQL community will
   produce binary packages for Windows. Windows users are encouraged to
   move to 8.2.X or later, since there are Windows-specific fixes in 8.2.X
   that are impractical to back-port. 8.0.X will continue to be supported
   on other platforms.
     __________________________________________________________________

Migration to Version 8.0.15

   A dump/restore is not required for those running 8.0.X. However, if you
   are upgrading from a version earlier than 8.0.6, see the release notes
   for 8.0.6.
     __________________________________________________________________

Changes

     * Prevent functions in indexes from executing with the privileges of
       the user running "VACUUM", "ANALYZE", etc (Tom)
       Functions used in index expressions and partial-index predicates
       are evaluated whenever a new table entry is made. It has long been
       understood that this poses a risk of trojan-horse code execution if
       one modifies a table owned by an untrustworthy user. (Note that
       triggers, defaults, check constraints, etc. pose the same type of
       risk.) But functions in indexes pose extra danger because they will
       be executed by routine maintenance operations such as "VACUUM
       FULL", which are commonly performed automatically under a superuser
       account. For example, a nefarious user can execute code with
       superuser privileges by setting up a trojan-horse index definition
       and waiting for the next routine vacuum. The fix arranges for
       standard maintenance operations (including "VACUUM", "ANALYZE",
       "REINDEX", and "CLUSTER") to execute as the table owner rather than
       the calling user, using the same privilege-switching mechanism
       already used for SECURITY DEFINER functions. To prevent bypassing
       this security measure, execution of "SET SESSION AUTHORIZATION" and
       "SET ROLE" is now forbidden within a SECURITY DEFINER context.
       (CVE-2007-6600)
     * Repair assorted bugs in the regular-expression package (Tom, Will
       Drewry)
       Suitably crafted regular-expression patterns could cause crashes,
       infinite or near-infinite looping, and/or massive memory
       consumption, all of which pose denial-of-service hazards for
       applications that accept regex search patterns from untrustworthy
       sources. (CVE-2007-4769, CVE-2007-4772, CVE-2007-6067)
     * Require non-superusers who use "/contrib/dblink" to use only
       password authentication, as a security measure (Joe)
       The fix that appeared for this in 8.0.14 was incomplete, as it
       plugged the hole for only some "dblink" functions. (CVE-2007-6601,
       CVE-2007-3278)
     * Update time zone data files to tzdata release 2007k (in particular,
       recent Argentina changes) (Tom)
     * Fix planner failure in some cases of WHERE false AND var IN (SELECT
       ...) (Tom)
     * Preserve the tablespace of indexes that are rebuilt by "ALTER TABLE
       ... ALTER COLUMN TYPE" (Tom)
     * Make archive recovery always start a new WAL timeline, rather than
       only when a recovery stop time was used (Simon)
       This avoids a corner-case risk of trying to overwrite an existing
       archived copy of the last WAL segment, and seems simpler and
       cleaner than the original definition.
     * Make "VACUUM" not use all of maintenance_work_mem when the table is
       too small for it to be useful (Alvaro)
     * Fix potential crash in translate() when using a multibyte database
       encoding (Tom)
     * Fix PL/Perl to cope when platform's Perl defines type bool as int
       rather than char (Tom)
       While this could theoretically happen anywhere, no standard build
       of Perl did things this way ... until Mac OS X 10.5.
     * Fix PL/Python to not crash on long exception messages (Alvaro)
     * Fix pg_dump to correctly handle inheritance child tables that have
       default expressions different from their parent's (Tom)
     * ecpg parser fixes (Michael)
     * Make "contrib/tablefunc"'s crosstab() handle NULL rowid as a
       category in its own right, rather than crashing (Joe)
     * Fix tsvector and tsquery output routines to escape backslashes
       correctly (Teodor, Bruce)
     * Fix crash of to_tsvector() on huge input strings (Teodor)
     * Require a specific version of Autoconf to be used when
       re-generating the "configure" script (Peter)
       This affects developers and packagers only. The change was made to
       prevent accidental use of untested combinations of Autoconf and
       PostgreSQL versions. You can remove the version check if you really
       want to use a different Autoconf version, but it's your
       responsibility whether the result works or not.
     __________________________________________________________________

                               Release 8.0.14

     Release Date: 2007-09-17

   This release contains a variety of fixes from 8.0.13. For information
   about new features in the 8.0 major release, see the Section called
   Release 8.0.
     __________________________________________________________________

Migration to Version 8.0.14

   A dump/restore is not required for those running 8.0.X. However, if you
   are upgrading from a version earlier than 8.0.6, see the release notes
   for 8.0.6.
     __________________________________________________________________

Changes

     * Prevent index corruption when a transaction inserts rows and then
       aborts close to the end of a concurrent "VACUUM" on the same table
       (Tom)
     * Make "CREATE DOMAIN ... DEFAULT NULL" work properly (Tom)
     * Fix excessive logging of SSL error messages (Tom)
     * Fix logging so that log messages are never interleaved when using
       the syslogger process (Andrew)
     * Fix crash when log_min_error_statement logging runs out of memory
       (Tom)
     * Fix incorrect handling of some foreign-key corner cases (Tom)
     * Prevent "CLUSTER" from failing due to attempting to process
       temporary tables of other sessions (Alvaro)
     * Update the time zone database rules, particularly New Zealand's
       upcoming changes (Tom)
     * Windows socket improvements (Magnus)
     * Suppress timezone name (%Z) in log timestamps on Windows because of
       possible encoding mismatches (Tom)
     * Require non-superusers who use "/contrib/dblink" to use only
       password authentication, as a security measure (Joe)
     __________________________________________________________________

                               Release 8.0.13

     Release Date: 2007-04-23

   This release contains a variety of fixes from 8.0.12, including a
   security fix. For information about new features in the 8.0 major
   release, see the Section called Release 8.0.
     __________________________________________________________________

Migration to Version 8.0.13

   A dump/restore is not required for those running 8.0.X. However, if you
   are upgrading from a version earlier than 8.0.6, see the release notes
   for 8.0.6.
     __________________________________________________________________

Changes

     * Support explicit placement of the temporary-table schema within
       search_path, and disable searching it for functions and operators
       (Tom)
       This is needed to allow a security-definer function to set a truly
       secure value of search_path. Without it, an unprivileged SQL user
       can use temporary objects to execute code with the privileges of
       the security-definer function (CVE-2007-2138). See "CREATE
       FUNCTION" for more information.
     * "/contrib/tsearch2" crash fixes (Teodor)
     * Fix potential-data-corruption bug in how "VACUUM FULL" handles
       "UPDATE" chains (Tom, Pavan Deolasee)
     * Fix PANIC during enlargement of a hash index (bug introduced in
       8.0.10) (Tom)
     * Fix POSIX-style timezone specs to follow new USA DST rules (Tom)
     __________________________________________________________________

                               Release 8.0.12

     Release Date: 2007-02-07

   This release contains one fix from 8.0.11. For information about new
   features in the 8.0 major release, see the Section called Release 8.0.
     __________________________________________________________________

Migration to Version 8.0.12

   A dump/restore is not required for those running 8.0.X. However, if you
   are upgrading from a version earlier than 8.0.6, see the release notes
   for 8.0.6.
     __________________________________________________________________

Changes

     * Remove overly-restrictive check for type length in constraints and
       functional indexes(Tom)
     __________________________________________________________________

                               Release 8.0.11

     Release Date: 2007-02-05

   This release contains a variety of fixes from 8.0.10, including a
   security fix. For information about new features in the 8.0 major
   release, see the Section called Release 8.0.
     __________________________________________________________________

Migration to Version 8.0.11

   A dump/restore is not required for those running 8.0.X. However, if you
   are upgrading from a version earlier than 8.0.6, see the release notes
   for 8.0.6.
     __________________________________________________________________

Changes

     * Remove security vulnerabilities that allowed connected users to
       read backend memory (Tom)
       The vulnerabilities involve suppressing the normal check that a SQL
       function returns the data type it's declared to, and changing the
       data type of a table column (CVE-2007-0555, CVE-2007-0556). These
       errors can easily be exploited to cause a backend crash, and in
       principle might be used to read database content that the user
       should not be able to access.
     * Fix rare bug wherein btree index page splits could fail due to
       choosing an infeasible split point (Heikki Linnakangas)
     * Fix for rare Assert() crash triggered by UNION (Tom)
     * Tighten security of multi-byte character processing for UTF8
       sequences over three bytes long (Tom)
     __________________________________________________________________

                               Release 8.0.10

     Release Date: 2007-01-08

   This release contains a variety of fixes from 8.0.9. For information
   about new features in the 8.0 major release, see the Section called
   Release 8.0.
     __________________________________________________________________

Migration to Version 8.0.10

   A dump/restore is not required for those running 8.0.X. However, if you
   are upgrading from a version earlier than 8.0.6, see the release notes
   for 8.0.6.
     __________________________________________________________________

Changes

     * Improve handling of getaddrinfo() on AIX (Tom)
       This fixes a problem with starting the statistics collector, among
       other things.
     * Fix "failed to re-find parent key" errors in "VACUUM" (Tom)
     * Fix race condition for truncation of a large relation across a
       gigabyte boundary by "VACUUM" (Tom)
     * Fix bugs affecting multi-gigabyte hash indexes (Tom)
     * Fix possible deadlock in Windows signal handling (Teodor)
     * Fix error when constructing an ARRAY[] made up of multiple empty
       elements (Tom)
     * Fix ecpg memory leak during connection (Michael)
     * to_number() and to_char(numeric) are now STABLE, not IMMUTABLE, for
       new initdb installs (Tom)
       This is because lc_numeric can potentially change the output of
       these functions.
     * Improve index usage of regular expressions that use parentheses
       (Tom)
       This improves psql \d performance also.
     * Update timezone database
       This affects Australian and Canadian daylight-savings rules in
       particular.
     __________________________________________________________________

                                Release 8.0.9

     Release Date: 2006-10-16

   This release contains a variety of fixes from 8.0.8. For information
   about new features in the 8.0 major release, see the Section called
   Release 8.0.
     __________________________________________________________________

Migration to Version 8.0.9

   A dump/restore is not required for those running 8.0.X. However, if you
   are upgrading from a version earlier than 8.0.6, see the release notes
   for 8.0.6.
     __________________________________________________________________

Changes

     * Fix crash when referencing NEW row values in rule WHERE expressions
       (Tom)
     * Fix core dump when an untyped literal is taken as ANYARRAY
     * Fix mishandling of AFTER triggers when query contains a SQL
       function returning multiple rows (Tom)
     * Fix "ALTER TABLE ... TYPE" to recheck NOT NULL for USING clause
       (Tom)
     * Fix string_to_array() to handle overlapping matches for the
       separator string
       For example, string_to_array('123xx456xxx789', 'xx').
     * Fix corner cases in pattern matching for psql's \d commands
     * Fix index-corrupting bugs in /contrib/ltree (Teodor)
     * Numerous robustness fixes in ecpg (Joachim Wieland)
     * Fix backslash escaping in /contrib/dbmirror
     * Fix instability of statistics collection on Win32 (Tom, Andrew)
     * Fixes for AIX and Intel compilers (Tom)
     __________________________________________________________________

                                Release 8.0.8

     Release Date: 2006-05-23

   This release contains a variety of fixes from 8.0.7, including patches
   for extremely serious security issues. For information about new
   features in the 8.0 major release, see the Section called Release 8.0.
     __________________________________________________________________

Migration to Version 8.0.8

   A dump/restore is not required for those running 8.0.X. However, if you
   are upgrading from a version earlier than 8.0.6, see the release notes
   for 8.0.6.

   Full security against the SQL-injection attacks described in
   CVE-2006-2313 and CVE-2006-2314 might require changes in application
   code. If you have applications that embed untrustworthy strings into
   SQL commands, you should examine them as soon as possible to ensure
   that they are using recommended escaping techniques. In most cases,
   applications should be using subroutines provided by libraries or
   drivers (such as libpq's PQescapeStringConn()) to perform string
   escaping, rather than relying on ad hoc code to do it.
     __________________________________________________________________

Changes

     * Change the server to reject invalidly-encoded multibyte characters
       in all cases (Tatsuo, Tom)
       While PostgreSQL has been moving in this direction for some time,
       the checks are now applied uniformly to all encodings and all
       textual input, and are now always errors not merely warnings. This
       change defends against SQL-injection attacks of the type described
       in CVE-2006-2313.
     * Reject unsafe uses of \' in string literals
       As a server-side defense against SQL-injection attacks of the type
       described in CVE-2006-2314, the server now only accepts '' and not
       \' as a representation of ASCII single quote in SQL string
       literals. By default, \' is rejected only when client_encoding is
       set to a client-only encoding (SJIS, BIG5, GBK, GB18030, or UHC),
       which is the scenario in which SQL injection is possible. A new
       configuration parameter backslash_quote is available to adjust this
       behavior when needed. Note that full security against CVE-2006-2314
       might require client-side changes; the purpose of backslash_quote
       is in part to make it obvious that insecure clients are insecure.
     * Modify libpq's string-escaping routines to be aware of encoding
       considerations and standard_conforming_strings
       This fixes libpq-using applications for the security issues
       described in CVE-2006-2313 and CVE-2006-2314, and also
       future-proofs them against the planned changeover to SQL-standard
       string literal syntax. Applications that use multiple PostgreSQL
       connections concurrently should migrate to PQescapeStringConn() and
       PQescapeByteaConn() to ensure that escaping is done correctly for
       the settings in use in each database connection. Applications that
       do string escaping "by hand" should be modified to rely on library
       routines instead.
     * Fix some incorrect encoding conversion functions
       win1251_to_iso, alt_to_iso, euc_tw_to_big5, euc_tw_to_mic,
       mic_to_euc_tw were all broken to varying extents.
     * Clean up stray remaining uses of \' in strings (Bruce, Jan)
     * Fix bug that sometimes caused OR'd index scans to miss rows they
       should have returned
     * Fix WAL replay for case where a btree index has been truncated
     * Fix SIMILAR TO for patterns involving | (Tom)
     * Fix "SELECT INTO" and "CREATE TABLE AS" to create tables in the
       default tablespace, not the base directory (Kris Jurka)
     * Fix server to use custom DH SSL parameters correctly (Michael Fuhr)
     * Fix for Bonjour on Intel Macs (Ashley Clark)
     * Fix various minor memory leaks
     * Fix problem with password prompting on some Win32 systems (Robert
       Kinberg)
     __________________________________________________________________

                                Release 8.0.7

     Release Date: 2006-02-14

   This release contains a variety of fixes from 8.0.6. For information
   about new features in the 8.0 major release, see the Section called
   Release 8.0.
     __________________________________________________________________

Migration to Version 8.0.7

   A dump/restore is not required for those running 8.0.X. However, if you
   are upgrading from a version earlier than 8.0.6, see the release notes
   for 8.0.6.
     __________________________________________________________________

Changes

     * Fix potential crash in "SET SESSION AUTHORIZATION" (CVE-2006-0553)
       An unprivileged user could crash the server process, resulting in
       momentary denial of service to other users, if the server has been
       compiled with Asserts enabled (which is not the default). Thanks to
       Akio Ishida for reporting this problem.
     * Fix bug with row visibility logic in self-inserted rows (Tom)
       Under rare circumstances a row inserted by the current command
       could be seen as already valid, when it should not be. Repairs bug
       created in 8.0.4, 7.4.9, and 7.3.11 releases.
     * Fix race condition that could lead to "file already exists" errors
       during pg_clog and pg_subtrans file creation (Tom)
     * Fix cases that could lead to crashes if a cache-invalidation
       message arrives at just the wrong time (Tom)
     * Properly check DOMAIN constraints for UNKNOWN parameters in
       prepared statements (Neil)
     * Ensure "ALTER COLUMN TYPE" will process FOREIGN KEY, UNIQUE, and
       PRIMARY KEY constraints in the proper order (Nakano Yoshihisa)
     * Fixes to allow restoring dumps that have cross-schema references to
       custom operators or operator classes (Tom)
     * Allow pg_restore to continue properly after a "COPY" failure;
       formerly it tried to treat the remaining "COPY" data as SQL
       commands (Stephen Frost)
     * Fix pg_ctl unregister crash when the data directory is not
       specified (Magnus)
     * Fix ecpg crash on AMD64 and PPC (Neil)
     * Recover properly if error occurs during argument passing in
       PL/python (Neil)
     * Fix PL/perl's handling of locales on Win32 to match the backend
       (Andrew)
     * Fix crash when log_min_messages is set to DEBUG3 or above in
       "postgresql.conf" on Win32 (Bruce)
     * Fix pgxs -L library path specification for Win32, Cygwin, OS X, AIX
       (Bruce)
     * Check that SID is enabled while checking for Win32 admin privileges
       (Magnus)
     * Properly reject out-of-range date inputs (Kris Jurka)
     * Portability fix for testing presence of finite and isinf during
       configure (Tom)
     __________________________________________________________________

                                Release 8.0.6

     Release Date: 2006-01-09

   This release contains a variety of fixes from 8.0.5. For information
   about new features in the 8.0 major release, see the Section called
   Release 8.0.
     __________________________________________________________________

Migration to Version 8.0.6

   A dump/restore is not required for those running 8.0.X. However, if you
   are upgrading from a version earlier than 8.0.3, see the release notes
   for 8.0.3. Also, you might need to "REINDEX" indexes on textual columns
   after updating, if you are affected by the locale or plperl issues
   described below.
     __________________________________________________________________

Changes

     * Fix Windows code so that postmaster will continue rather than exit
       if there is no more room in ShmemBackendArray (Magnus)
       The previous behavior could lead to a denial-of-service situation
       if too many connection requests arrive close together. This applies
       *only* to the Windows port.
     * Fix bug introduced in 8.0 that could allow ReadBuffer to return an
       already-used page as new, potentially causing loss of
       recently-committed data (Tom)
     * Fix for protocol-level Describe messages issued outside a
       transaction or in a failed transaction (Tom)
     * Fix character string comparison for locales that consider different
       character combinations as equal, such as Hungarian (Tom)
       This might require "REINDEX" to fix existing indexes on textual
       columns.
     * Set locale environment variables during postmaster startup to
       ensure that plperl won't change the locale later
       This fixes a problem that occurred if the postmaster was started
       with environment variables specifying a different locale than what
       initdb had been told. Under these conditions, any use of plperl was
       likely to lead to corrupt indexes. You might need "REINDEX" to fix
       existing indexes on textual columns if this has happened to you.
     * Allow more flexible relocation of installation directories (Tom)
       Previous releases supported relocation only if all installation
       directory paths were the same except for the last component.
     * Fix longstanding bug in strpos() and regular expression handling in
       certain rarely used Asian multi-byte character sets (Tatsuo)
     * Various fixes for functions returning RECORDs (Tom)
     * Fix bug in "/contrib/pgcrypto" gen_salt, which caused it not to use
       all available salt space for MD5 and XDES algorithms (Marko Kreen,
       Solar Designer)
       Salts for Blowfish and standard DES are unaffected.
     * Fix "/contrib/dblink" to throw an error, rather than crashing, when
       the number of columns specified is different from what's actually
       returned by the query (Joe)
     __________________________________________________________________

                                Release 8.0.5

     Release Date: 2005-12-12

   This release contains a variety of fixes from 8.0.4. For information
   about new features in the 8.0 major release, see the Section called
   Release 8.0.
     __________________________________________________________________

Migration to Version 8.0.5

   A dump/restore is not required for those running 8.0.X. However, if you
   are upgrading from a version earlier than 8.0.3, see the release notes
   for 8.0.3.
     __________________________________________________________________

Changes

     * Fix race condition in transaction log management
       There was a narrow window in which an I/O operation could be
       initiated for the wrong page, leading to an Assert failure or data
       corruption.
     * Fix bgwriter problems after recovering from errors (Tom)
       The background writer was found to leak buffer pins after write
       errors. While not fatal in itself, this might lead to mysterious
       blockages of later VACUUM commands.
     * Prevent failure if client sends Bind protocol message when current
       transaction is already aborted
     * "/contrib/ltree" fixes (Teodor)
     * AIX and HPUX compile fixes (Tom)
     * Retry file reads and writes after Windows NO_SYSTEM_RESOURCES error
       (Qingqing Zhou)
     * Fix intermittent failure when log_line_prefix includes %i
     * Fix psql performance issue with long scripts on Windows (Merlin
       Moncure)
     * Fix missing updates of "pg_group" flat file
     * Fix longstanding planning error for outer joins
       This bug sometimes caused a bogus error "RIGHT JOIN is only
       supported with merge-joinable join conditions".
     * Postpone timezone initialization until after "postmaster.pid" is
       created
       This avoids confusing startup scripts that expect the pid file to
       appear quickly.
     * Prevent core dump in pg_autovacuum when a table has been dropped
     * Fix problems with whole-row references (foo.*) to subquery results
     __________________________________________________________________

                                Release 8.0.4

     Release Date: 2005-10-04

   This release contains a variety of fixes from 8.0.3. For information
   about new features in the 8.0 major release, see the Section called
   Release 8.0.
     __________________________________________________________________

Migration to Version 8.0.4

   A dump/restore is not required for those running 8.0.X. However, if you
   are upgrading from a version earlier than 8.0.3, see the release notes
   for 8.0.3.
     __________________________________________________________________

Changes

     * Fix error that allowed "VACUUM" to remove ctid chains too soon, and
       add more checking in code that follows ctid links
       This fixes a long-standing problem that could cause crashes in very
       rare circumstances.
     * Fix CHAR() to properly pad spaces to the specified length when
       using a multiple-byte character set (Yoshiyuki Asaba)
       In prior releases, the padding of CHAR() was incorrect because it
       only padded to the specified number of bytes without considering
       how many characters were stored.
     * Force a checkpoint before committing "CREATE DATABASE"
       This should fix recent reports of "index is not a btree" failures
       when a crash occurs shortly after "CREATE DATABASE".
     * Fix the sense of the test for read-only transaction in "COPY"
       The code formerly prohibited "COPY TO", where it should prohibit
       "COPY FROM".
     * Handle consecutive embedded newlines in "COPY" CSV-mode input
     * Fix date_trunc(week) for dates near year end
     * Fix planning problem with outer-join ON clauses that reference only
       the inner-side relation
     * Further fixes for x FULL JOIN y ON true corner cases
     * Fix overenthusiastic optimization of x IN (SELECT DISTINCT ...) and
       related cases
     * Fix mis-planning of queries with small LIMIT values due to poorly
       thought out "fuzzy" cost comparison
     * Make array_in and array_recv more paranoid about validating their
       OID parameter
     * Fix missing rows in queries like UPDATE a=... WHERE a... with GiST
       index on column a
     * Improve robustness of datetime parsing
     * Improve checking for partially-written WAL pages
     * Improve robustness of signal handling when SSL is enabled
     * Improve MIPS and M68K spinlock code
     * Don't try to open more than max_files_per_process files during
       postmaster startup
     * Various memory leakage fixes
     * Various portability improvements
     * Update timezone data files
     * Improve handling of DLL load failures on Windows
     * Improve random-number generation on Windows
     * Make psql -f filename return a nonzero exit code when opening the
       file fails
     * Change pg_dump to handle inherited check constraints more reliably
     * Fix password prompting in pg_restore on Windows
     * Fix PL/pgSQL to handle var := var correctly when the variable is of
       pass-by-reference type
     * Fix PL/Perl %_SHARED so it's actually shared
     * Fix "contrib/pg_autovacuum" to allow sleep intervals over 2000 sec
     * Update "contrib/tsearch2" to use current Snowball code
     __________________________________________________________________

                                Release 8.0.3

     Release Date: 2005-05-09

   This release contains a variety of fixes from 8.0.2, including several
   security-related issues. For information about new features in the 8.0
   major release, see the Section called Release 8.0.
     __________________________________________________________________

Migration to Version 8.0.3

   A dump/restore is not required for those running 8.0.X. However, it is
   one possible way of handling two significant security problems that
   have been found in the initial contents of 8.0.X system catalogs. A
   dump/initdb/reload sequence using 8.0.3's initdb will automatically
   correct these problems.

   The larger security problem is that the built-in character set encoding
   conversion functions can be invoked from SQL commands by unprivileged
   users, but the functions were not designed for such use and are not
   secure against malicious choices of arguments. The fix involves
   changing the declared parameter list of these functions so that they
   can no longer be invoked from SQL commands. (This does not affect their
   normal use by the encoding conversion machinery.)

   The lesser problem is that the "contrib/tsearch2" module creates
   several functions that are improperly declared to return internal when
   they do not accept internal arguments. This breaks type safety for all
   functions using internal arguments.

   It is strongly recommended that all installations repair these errors,
   either by initdb or by following the manual repair procedure given
   below. The errors at least allow unprivileged database users to crash
   their server process, and might allow unprivileged users to gain the
   privileges of a database superuser.

   If you wish not to do an initdb, perform the same manual repair
   procedures shown in the 7.4.8 release notes.
     __________________________________________________________________

Changes

     * Change encoding function signature to prevent misuse
     * Change "contrib/tsearch2" to avoid unsafe use of INTERNAL function
       results
     * Guard against incorrect second parameter to record_out
     * Repair ancient race condition that allowed a transaction to be seen
       as committed for some purposes (eg SELECT FOR UPDATE) slightly
       sooner than for other purposes
       This is an extremely serious bug since it could lead to apparent
       data inconsistencies being briefly visible to applications.
     * Repair race condition between relation extension and VACUUM
       This could theoretically have caused loss of a page's worth of
       freshly-inserted data, although the scenario seems of very low
       probability. There are no known cases of it having caused more than
       an Assert failure.
     * Fix comparisons of TIME WITH TIME ZONE values
       The comparison code was wrong in the case where the
       --enable-integer-datetimes configuration switch had been used.
       NOTE: if you have an index on a TIME WITH TIME ZONE column, it will
       need to be "REINDEX"ed after installing this update, because the
       fix corrects the sort order of column values.
     * Fix EXTRACT(EPOCH) for TIME WITH TIME ZONE values
     * Fix mis-display of negative fractional seconds in INTERVAL values
       This error only occurred when the --enable-integer-datetimes
       configuration switch had been used.
     * Fix pg_dump to dump trigger names containing % correctly (Neil)
     * Still more 64-bit fixes for "contrib/intagg"
     * Prevent incorrect optimization of functions returning RECORD
     * Prevent crash on COALESCE(NULL,NULL)
     * Fix Borland makefile for libpq
     * Fix "contrib/btree_gist" for timetz type (Teodor)
     * Make "pg_ctl" check the PID found in "postmaster.pid" to see if it
       is still a live process
     * Fix "pg_dump"/"pg_restore" problems caused by addition of dump
       timestamps
     * Fix interaction between materializing holdable cursors and firing
       deferred triggers during transaction commit
     * Fix memory leak in SQL functions returning pass-by-reference data
       types
     __________________________________________________________________

                                Release 8.0.2

     Release Date: 2005-04-07

   This release contains a variety of fixes from 8.0.1. For information
   about new features in the 8.0 major release, see the Section called
   Release 8.0.
     __________________________________________________________________

Migration to Version 8.0.2

   A dump/restore is not required for those running 8.0.*. This release
   updates the major version number of the PostgreSQL libraries, so it
   might be necessary to re-link some user applications if they cannot
   find the properly-numbered shared library.
     __________________________________________________________________

Changes

     * Increment the major version number of all interface libraries
       (Bruce)
       This should have been done in 8.0.0. It is required so 7.4.X
       versions of PostgreSQL client applications, like psql, can be used
       on the same machine as 8.0.X applications. This might require
       re-linking user applications that use these libraries.
     * Add Windows-only wal_sync_method setting of "fsync_writethrough"
       (Magnus, Bruce)
       This setting causes PostgreSQL to write through any disk-drive
       write cache when writing to WAL. This behavior was formerly called
       "fsync", but was renamed because it acts quite differently from
       "fsync" on other platforms.
     * Enable the wal_sync_method setting of "open_datasync" on Windows,
       and make it the default for that platform (Magnus, Bruce)
       Because the default is no longer "fsync_writethrough", data loss is
       possible during a power failure if the disk drive has write caching
       enabled. To turn off the write cache on Windows, from the Device
       Manager, choose the drive properties, then Policies.
     * New cache management algorithm 2Q replaces ARC (Tom)
       This was done to avoid a pending US patent on ARC. The 2Q code
       might be a few percentage points slower than ARC for some work
       loads. A better cache management algorithm will appear in 8.1.
     * Planner adjustments to improve behavior on freshly-created tables
       (Tom)
     * Allow plpgsql to assign to an element of an array that is initially
       NULL (Tom)
       Formerly the array would remain NULL, but now it becomes a
       single-element array. The main SQL engine was changed to handle
       "UPDATE" of a null array value this way in 8.0, but the similar
       case in plpgsql was overlooked.
     * Convert \r\n and \r to \n in plpython function bodies (Michael
       Fuhr)
       This prevents syntax errors when plpython code is written on a
       Windows or Mac client.
     * Allow SPI cursors to handle utility commands that return rows, such
       as "EXPLAIN" (Tom)
     * Fix "CLUSTER" failure after "ALTER TABLE SET WITHOUT OIDS" (Tom)
     * Reduce memory usage of "ALTER TABLE ADD COLUMN" (Neil)
     * Fix "ALTER LANGUAGE RENAME" (Tom)
     * Document the Windows-only register and unregister options of pg_ctl
       (Magnus)
     * Ensure operations done during backend shutdown are counted by
       statistics collector
       This is expected to resolve reports of pg_autovacuum not vacuuming
       the system catalogs often enough -- it was not being told about
       catalog deletions caused by temporary table removal during backend
       exit.
     * Change the Windows default for configuration parameter
       log_destination to "eventlog" (Magnus)
       By default, a server running on Windows will now send log output to
       the Windows event logger rather than standard error.
     * Make Kerberos authentication work on Windows (Magnus)
     * Allow "ALTER DATABASE RENAME" by superusers who aren't flagged as
       having CREATEDB privilege (Tom)
     * Modify WAL log entries for "CREATE" and "DROP DATABASE" to not
       specify absolute paths (Tom)
       This allows point-in-time recovery on a different machine with
       possibly different database location. Note that "CREATE TABLESPACE"
       still poses a hazard in such situations.
     * Fix crash from a backend exiting with an open transaction that
       created a table and opened a cursor on it (Tom)
     * Fix array_map() so it can call PL functions (Tom)
     * Several "contrib/tsearch2" and "contrib/btree_gist" fixes (Teodor)
     * Fix crash of some "contrib/pgcrypto" functions on some platforms
       (Marko Kreen)
     * Fix "contrib/intagg" for 64-bit platforms (Tom)
     * Fix ecpg bugs in parsing of "CREATE" statement (Michael)
     * Work around gcc bug on powerpc and amd64 causing problems in ecpg
       (Christof Petig)
     * Do not use locale-aware versions of upper(), lower(), and initcap()
       when the locale is C (Bruce)
       This allows these functions to work on platforms that generate
       errors for non-7-bit data when the locale is C.
     * Fix quote_ident() to quote names that match keywords (Tom)
     * Fix to_date() to behave reasonably when CC and YY fields are both
       used (Karel)
     * Prevent to_char(interval) from failing when given a zero-month
       interval (Tom)
     * Fix wrong week returned by date_trunc('week') (Bruce)
       date_trunc('week') returned the wrong year for the first few days
       of January in some years.
     * Use the correct default mask length for class D addresses in INET
       data types (Tom)
     __________________________________________________________________

                                Release 8.0.1

     Release Date: 2005-01-31

   This release contains a variety of fixes from 8.0.0, including several
   security-related issues. For information about new features in the 8.0
   major release, see the Section called Release 8.0.
     __________________________________________________________________

Migration to Version 8.0.1

   A dump/restore is not required for those running 8.0.0.
     __________________________________________________________________

Changes

     * Disallow "LOAD" to non-superusers
       On platforms that will automatically execute initialization
       functions of a shared library (this includes at least Windows and
       ELF-based Unixen), "LOAD" can be used to make the server execute
       arbitrary code. Thanks to NGS Software for reporting this.
     * Check that creator of an aggregate function has the right to
       execute the specified transition functions
       This oversight made it possible to bypass denial of EXECUTE
       permission on a function.
     * Fix security and 64-bit issues in contrib/intagg
     * Add needed STRICT marking to some contrib functions (Kris Jurka)
     * Avoid buffer overrun when plpgsql cursor declaration has too many
       parameters (Neil)
     * Make "ALTER TABLE ADD COLUMN" enforce domain constraints in all
       cases
     * Fix planning error for FULL and RIGHT outer joins
       The result of the join was mistakenly supposed to be sorted the
       same as the left input. This could not only deliver mis-sorted
       output to the user, but in case of nested merge joins could give
       outright wrong answers.
     * Improve planning of grouped aggregate queries
     * "ROLLBACK TO savepoint" closes cursors created since the savepoint
     * Fix inadequate backend stack size on Windows
     * Avoid SHGetSpecialFolderPath() on Windows (Magnus)
     * Fix some problems in running pg_autovacuum as a Windows service
       (Dave Page)
     * Multiple minor bug fixes in pg_dump/pg_restore
     * Fix ecpg segfault with named structs used in typedefs (Michael)
     __________________________________________________________________

                                 Release 8.0

     Release Date: 2005-01-19
     __________________________________________________________________

Overview

   Major changes in this release:

   Microsoft Windows Native Server
          This is the first PostgreSQL release to run natively on
          Microsoft Windows(R) as a server. It can run as a Windows service.
          This release supports NT-based Windows releases like Windows
          2000 SP4, Windows XP, and Windows 2003. Older releases like
          Windows 95, Windows 98, and Windows ME are not supported because
          these operating systems do not have the infrastructure to
          support PostgreSQL. A separate installer project has been
          created to ease installation on Windows -- see
          http://www.postgresql.org/ftp/win32/.

          Although tested throughout our release cycle, the Windows port
          does not have the benefit of years of use in production
          environments that PostgreSQL has on Unix platforms. Therefore it
          should be treated with the same level of caution as you would a
          new product.

          Previous releases required the Unix emulation toolkit Cygwin in
          order to run the server on Windows operating systems. PostgreSQL
          has supported native clients on Windows for many years.

   Savepoints
          Savepoints allow specific parts of a transaction to be aborted
          without affecting the remainder of the transaction. Prior
          releases had no such capability; there was no way to recover
          from a statement failure within a transaction except by aborting
          the whole transaction. This feature is valuable for application
          writers who require error recovery within a complex transaction.

   Point-In-Time Recovery
          In previous releases there was no way to recover from disk drive
          failure except to restore from a previous backup or use a
          standby replication server. Point-in-time recovery allows
          continuous backup of the server. You can recover either to the
          point of failure or to some transaction in the past.

   Tablespaces
          Tablespaces allow administrators to select different file
          systems for storage of individual tables, indexes, and
          databases. This improves performance and control over disk space
          usage. Prior releases used initlocation and manual symlink
          management for such tasks.

   Improved Buffer Management, CHECKPOINT, VACUUM
          This release has a more intelligent buffer replacement strategy,
          which will make better use of available shared buffers and
          improve performance. The performance impact of vacuum and
          checkpoints is also lessened.

   Change Column Types
          A column's data type can now be changed with "ALTER TABLE".

   New Perl Server-Side Language
          A new version of the plperl server-side language now supports a
          persistent shared storage area, triggers, returning records and
          arrays of records, and SPI calls to access the database.

   Comma-separated-value (CSV) support in COPY
          "COPY" can now read and write comma-separated-value files. It
          has the flexibility to interpret nonstandard quoting and
          separation characters too.
     __________________________________________________________________

Migration to Version 8.0

   A dump/restore using pg_dump is required for those wishing to migrate
   data from any previous release.

   Observe the following incompatibilities:

     * In "READ COMMITTED" serialization mode, volatile functions now see
       the results of concurrent transactions committed up to the
       beginning of each statement within the function, rather than up to
       the beginning of the interactive command that called the function.
     * Functions declared "STABLE" or "IMMUTABLE" always use the snapshot
       of the calling query, and therefore do not see the effects of
       actions taken after the calling query starts, whether in their own
       transaction or other transactions. Such a function must be
       read-only, too, meaning that it cannot use any SQL commands other
       than "SELECT".
     * Nondeferred "AFTER" triggers are now fired immediately after
       completion of the triggering query, rather than upon finishing the
       current interactive command. This makes a difference when the
       triggering query occurred within a function: the trigger is invoked
       before the function proceeds to its next operation.
     * Server configuration parameters virtual_host and tcpip_socket have
       been replaced with a more general parameter listen_addresses. Also,
       the server now listens on localhost by default, which eliminates
       the need for the -i postmaster switch in many scenarios.
     * Server configuration parameters SortMem and VacuumMem have been
       renamed to work_mem and maintenance_work_mem to better reflect
       their use. The original names are still supported in "SET" and
       "SHOW".
     * Server configuration parameters log_pid, log_timestamp, and
       log_source_port have been replaced with a more general parameter
       log_line_prefix.
     * Server configuration parameter syslog has been replaced with a more
       logical log_destination variable to control the log output
       destination.
     * Server configuration parameter log_statement has been changed so it
       can selectively log just database modification or data definition
       statements. Server configuration parameter log_duration now prints
       only when log_statement prints the query.
     * Server configuration parameter max_expr_depth parameter has been
       replaced with max_stack_depth which measures the physical stack
       size rather than the expression nesting depth. This helps prevent
       session termination due to stack overflow caused by recursive
       functions.
     * The length() function no longer counts trailing spaces in CHAR(n)
       values.
     * Casting an integer to BIT(N) selects the rightmost N bits of the
       integer, not the leftmost N bits as before.
     * Updating an element or slice of a NULL array value now produces a
       nonnull array result, namely an array containing just the
       assigned-to positions.
     * Syntax checking of array input values has been tightened up
       considerably. Junk that was previously allowed in odd places with
       odd results now causes an error. Empty-string element values must
       now be written as "", rather than writing nothing. Also changed
       behavior with respect to whitespace surrounding array elements:
       trailing whitespace is now ignored, for symmetry with leading
       whitespace (which has always been ignored).
     * Overflow in integer arithmetic operations is now detected and
       reported as an error.
     * The arithmetic operators associated with the single-byte "char"
       data type have been removed.
     * The extract() function (also called date_part) now returns the
       proper year for BC dates. It previously returned one less than the
       correct year. The function now also returns the proper values for
       millennium and century.
     * CIDR values now must have their nonmasked bits be zero. For
       example, we no longer allow 204.248.199.1/31 as a CIDR value. Such
       values should never have been accepted by PostgreSQL and will now
       be rejected.
     * "EXECUTE" now returns a completion tag that matches the executed
       statement.
     * psql's "\copy" command now reads or writes to the query's
       stdin/stdout, rather than psql's stdin/stdout. The previous
       behavior can be accessed via new "pstdin"/"pstdout" parameters.
     * The JDBC client interface has been removed from the core
       distribution, and is now hosted at http://jdbc.postgresql.org.
     * The Tcl client interface has also been removed. There are several
       Tcl interfaces now hosted at http://gborg.postgresql.org.
     * The server now uses its own time zone database, rather than the one
       supplied by the operating system. This will provide consistent
       behavior across all platforms. In most cases, there should be
       little noticeable difference in time zone behavior, except that the
       time zone names used by "SET"/"SHOW" TimeZone might be different
       from what your platform provides.
     * Configure's threading option no longer requires users to run tests
       or edit configuration files; threading options are now detected
       automatically.
     * Now that tablespaces have been implemented, initlocation has been
       removed.
     * The API for user-defined GiST indexes has been changed. The Union
       and PickSplit methods are now passed a pointer to a special
       GistEntryVector structure, rather than a bytea.
     __________________________________________________________________

Deprecated Features

   Some aspects of PostgreSQL's behavior have been determined to be
   suboptimal. For the sake of backward compatibility these have not been
   removed in 8.0, but they are considered deprecated and will be removed
   in the next major release.

     * The 8.1 release will remove the to_char() function for intervals.
     * The server now warns of empty strings passed to oid/float4/float8
       data types, but continues to interpret them as zeroes as before. In
       the next major release, empty strings will be considered invalid
       input for these data types.
     * By default, tables in PostgreSQL 8.0 and earlier are created with
       OIDs. In the next release, this will *not* be the case: to create a
       table that contains OIDs, the "WITH OIDS" clause must be specified
       or the default_with_oids configuration parameter must be set. Users
       are encouraged to explicitly specify "WITH OIDS" if their tables
       require OIDs for compatibility with future releases of PostgreSQL.
     __________________________________________________________________

Changes

   Below you will find a detailed account of the changes between release
   8.0 and the previous major release.
     __________________________________________________________________

Performance Improvements

     * Support cross-data-type index usage (Tom)
       Before this change, many queries would not use an index if the data
       types did not match exactly. This improvement makes index usage
       more intuitive and consistent.
     * New buffer replacement strategy that improves caching (Jan)
       Prior releases used a least-recently-used (LRU) cache to keep
       recently referenced pages in memory. The LRU algorithm did not
       consider the number of times a specific cache entry was accessed,
       so large table scans could force out useful cache pages. The new
       cache algorithm uses four separate lists to track most recently
       used and most frequently used cache pages and dynamically optimize
       their replacement based on the work load. This should lead to much
       more efficient use of the shared buffer cache. Administrators who
       have tested shared buffer sizes in the past should retest with this
       new cache replacement policy.
     * Add subprocess to write dirty buffers periodically to reduce
       checkpoint writes (Jan)
       In previous releases, the checkpoint process, which runs every few
       minutes, would write all dirty buffers to the operating system's
       buffer cache then flush all dirty operating system buffers to disk.
       This resulted in a periodic spike in disk usage that often hurt
       performance. The new code uses a background writer to trickle disk
       writes at a steady pace so checkpoints have far fewer dirty pages
       to write to disk. Also, the new code does not issue a global sync()
       call, but instead fsync()s just the files written since the last
       checkpoint. This should improve performance and minimize
       degradation during checkpoints.
     * Add ability to prolong vacuum to reduce performance impact (Jan)
       On busy systems, "VACUUM" performs many I/O requests which can hurt
       performance for other users. This release allows you to slow down
       "VACUUM" to reduce its impact on other users, though this increases
       the total duration of "VACUUM".
     * Improve B-tree index performance for duplicate keys (Dmitry Tkach,
       Tom)
       This improves the way indexes are scanned when many duplicate
       values exist in the index.
     * Use dynamically-generated table size estimates while planning (Tom)
       Formerly the planner estimated table sizes using the values seen by
       the last "VACUUM" or "ANALYZE", both as to physical table size
       (number of pages) and number of rows. Now, the current physical
       table size is obtained from the kernel, and the number of rows is
       estimated by multiplying the table size by the row density (rows
       per page) seen by the last "VACUUM" or "ANALYZE". This should
       produce more reliable estimates in cases where the table size has
       changed significantly since the last housekeeping command.
     * Improved index usage with OR clauses (Tom)
       This allows the optimizer to use indexes in statements with many OR
       clauses that would not have been indexed in the past. It can also
       use multi-column indexes where the first column is specified and
       the second column is part of an OR clause.
     * Improve matching of partial index clauses (Tom)
       The server is now smarter about using partial indexes in queries
       involving complex "WHERE" clauses.
     * Improve performance of the GEQO optimizer (Tom)
       The GEQO optimizer is used to plan queries involving many tables
       (by default, twelve or more). This release speeds up the way
       queries are analyzed to decrease time spent in optimization.
     * Miscellaneous optimizer improvements
       There is not room here to list all the minor improvements made, but
       numerous special cases work better than in prior releases.
     * Improve lookup speed for C functions (Tom)
       This release uses a hash table to lookup information for
       dynamically loaded C functions. This improves their speed so they
       perform nearly as quickly as functions that are built into the
       server executable.
     * Add type-specific "ANALYZE" statistics capability (Mark
       Cave-Ayland)
       This feature allows more flexibility in generating statistics for
       nonstandard data types.
     * "ANALYZE" now collects statistics for expression indexes (Tom)
       Expression indexes (also called functional indexes) allow users to
       index not just columns but the results of expressions and function
       calls. With this release, the optimizer can gather and use
       statistics about the contents of expression indexes. This will
       greatly improve the quality of planning for queries in which an
       expression index is relevant.
     * New two-stage sampling method for "ANALYZE" (Manfred Koizar)
       This gives better statistics when the density of valid rows is very
       different in different regions of a table.
     * Speed up "TRUNCATE" (Tom)
       This buys back some of the performance loss observed in 7.4, while
       still keeping "TRUNCATE" transaction-safe.
     __________________________________________________________________

Server Changes

     * Add WAL file archiving and point-in-time recovery (Simon Riggs)
     * Add tablespaces so admins can control disk layout (Gavin)
     * Add a built-in log rotation program (Andreas Pflug)
       It is now possible to log server messages conveniently without
       relying on either syslog or an external log rotation program.
     * Add new read-only server configuration parameters to show server
       compile-time settings: block_size, integer_datetimes,
       max_function_args, max_identifier_length, max_index_keys (Joe)
     * Make quoting of sameuser, samegroup, and all remove special meaning
       of these terms in "pg_hba.conf" (Andrew)
     * Use clearer IPv6 name ::1/128 for localhost in default
       "pg_hba.conf" (Andrew)
     * Use CIDR format in "pg_hba.conf" examples (Andrew)
     * Rename server configuration parameters SortMem and VacuumMem to
       work_mem and maintenance_work_mem (Old names still supported) (Tom)
       This change was made to clarify that bulk operations such as index
       and foreign key creation use maintenance_work_mem, while work_mem
       is for workspaces used during query execution.
     * Allow logging of session disconnections using server configuration
       log_disconnections (Andrew)
     * Add new server configuration parameter log_line_prefix to allow
       control of information emitted in each log line (Andrew)
       Available information includes user name, database name, remote IP
       address, and session start time.
     * Remove server configuration parameters log_pid, log_timestamp,
       log_source_port; functionality superseded by log_line_prefix
       (Andrew)
     * Replace the virtual_host and tcpip_socket parameters with a unified
       listen_addresses parameter (Andrew, Tom)
       virtual_host could only specify a single IP address to listen on.
       listen_addresses allows multiple addresses to be specified.
     * Listen on localhost by default, which eliminates the need for the
       "-i" postmaster switch in many scenarios (Andrew)
       Listening on localhost (127.0.0.1) opens no new security holes but
       allows configurations like Windows and JDBC, which do not support
       local sockets, to work without special adjustments.
     * Remove syslog server configuration parameter, and add more logical
       log_destination variable to control log output location (Magnus)
     * Change server configuration parameter log_statement to take values
       all, mod, ddl, or none to select which queries are logged (Bruce)
       This allows administrators to log only data definition changes or
       only data modification statements.
     * Some logging-related configuration parameters could formerly be
       adjusted by ordinary users, but only in the "more verbose"
       direction. They are now treated more strictly: only superusers can
       set them. However, a superuser can use "ALTER USER" to provide
       per-user settings of these values for non-superusers. Also, it is
       now possible for superusers to set values of superuser-only
       configuration parameters via PGOPTIONS.
     * Allow configuration files to be placed outside the data directory
       (mlw)
       By default, configuration files are kept in the cluster's top
       directory. With this addition, configuration files can be placed
       outside the data directory, easing administration.
     * Plan prepared queries only when first executed so constants can be
       used for statistics (Oliver Jowett)
       Prepared statements plan queries once and execute them many times.
       While prepared queries avoid the overhead of re-planning on each
       use, the quality of the plan suffers from not knowing the exact
       parameters to be used in the query. In this release, planning of
       unnamed prepared statements is delayed until the first execution,
       and the actual parameter values of that execution are used as
       optimization hints. This allows use of out-of-line parameter
       passing without incurring a performance penalty.
     * Allow "DECLARE CURSOR" to take parameters (Oliver Jowett)
       It is now useful to issue "DECLARE CURSOR" in a Parse message with
       parameters. The parameter values sent at Bind time will be
       substituted into the execution of the cursor's query.
     * Fix hash joins and aggregates of inet and cidr data types (Tom)
       Release 7.4 handled hashing of mixed inet and cidr values
       incorrectly. (This bug did not exist in prior releases because they
       wouldn't try to hash either data type.)
     * Make log_duration print only when log_statement prints the query
       (Ed L.)
     __________________________________________________________________

Query Changes

     * Add savepoints (nested transactions) (Alvaro)
     * Unsupported isolation levels are now accepted and promoted to the
       nearest supported level (Peter)
       The SQL specification states that if a database doesn't support a
       specific isolation level, it should use the next more restrictive
       level. This change complies with that recommendation.
     * Allow "BEGIN WORK" to specify transaction isolation levels like
       "START TRANSACTION" does (Bruce)
     * Fix table permission checking for cases in which rules generate a
       query type different from the originally submitted query (Tom)
     * Implement dollar quoting to simplify single-quote usage (Andrew,
       Tom, David Fetter)
       In previous releases, because single quotes had to be used to quote
       a function's body, the use of single quotes inside the function
       text required use of two single quotes or other error-prone
       notations. With this release we add the ability to use "dollar
       quoting" to quote a block of text. The ability to use different
       quoting delimiters at different nesting levels greatly simplifies
       the task of quoting correctly, especially in complex functions.
       Dollar quoting can be used anywhere quoted text is needed.
     * Make CASE val WHEN compval1 THEN ... evaluate val only once (Tom)
       "CASE" no longer evaluates the tested expression multiple times.
       This has benefits when the expression is complex or is volatile.
     * Test "HAVING" before computing target list of an aggregate query
       (Tom)
       Fixes improper failure of cases such as SELECT SUM(win)/SUM(lose)
       ... GROUP BY ... HAVING SUM(lose) > 0. This should work but
       formerly could fail with divide-by-zero.
     * Replace max_expr_depth parameter with max_stack_depth parameter,
       measured in kilobytes of stack size (Tom)
       This gives us a fairly bulletproof defense against crashing due to
       runaway recursive functions. Instead of measuring the depth of
       expression nesting, we now directly measure the size of the
       execution stack.
     * Allow arbitrary row expressions (Tom)
       This release allows SQL expressions to contain arbitrary composite
       types, that is, row values. It also allows functions to more easily
       take rows as arguments and return row values.
     * Allow "LIKE"/"ILIKE" to be used as the operator in row and
       subselect comparisons (Fabien Coelho)
     * Avoid locale-specific case conversion of basic ASCII letters in
       identifiers and keywords (Tom)
       This solves the "Turkish problem" with mangling of words containing
       I and i. Folding of characters outside the 7-bit-ASCII set is still
       locale-aware.
     * Improve syntax error reporting (Fabien, Tom)
       Syntax error reports are more useful than before.
     * Change "EXECUTE" to return a completion tag matching the executed
       statement (Kris Jurka)
       Previous releases return an "EXECUTE" tag for any "EXECUTE" call.
       In this release, the tag returned will reflect the command
       executed.
     * Avoid emitting "NATURAL CROSS JOIN" in rule listings (Tom)
       Such a clause makes no logical sense, but in some cases the rule
       decompiler formerly produced this syntax.
     __________________________________________________________________

Object Manipulation Changes

     * Add "COMMENT ON" for casts, conversions, languages, operator
       classes, and large objects (Christopher)
     * Add new server configuration parameter default_with_oids to control
       whether tables are created with OIDs by default (Neil)
       This allows administrators to control whether "CREATE TABLE"
       commands create tables with or without OID columns by default.
       (Note: the current factory default setting for default_with_oids is
       TRUE, but the default will become FALSE in future releases.)
     * Add "WITH" / "WITHOUT OIDS" clause to "CREATE TABLE AS" (Neil)
     * Allow "ALTER TABLE DROP COLUMN" to drop an OID column ("ALTER TABLE
       SET WITHOUT OIDS" still works) (Tom)
     * Allow composite types as table columns (Tom)
     * Allow "ALTER ... ADD COLUMN" with defaults and "NOT NULL"
       constraints; works per SQL spec (Rod)
       It is now possible for "ADD COLUMN" to create a column that is not
       initially filled with NULLs, but with a specified default value.
     * Add "ALTER COLUMN TYPE" to change column's type (Rod)
       It is now possible to alter a column's data type without dropping
       and re-adding the column.
     * Allow multiple "ALTER" actions in a single "ALTER TABLE" command
       (Rod)
       This is particularly useful for "ALTER" commands that rewrite the
       table (which include "ALTER COLUMN TYPE" and "ADD COLUMN" with a
       default). By grouping "ALTER" commands together, the table need be
       rewritten only once.
     * Allow "ALTER TABLE" to add SERIAL columns (Tom)
       This falls out from the new capability of specifying defaults for
       new columns.
     * Allow changing the owners of aggregates, conversions, databases,
       functions, operators, operator classes, schemas, types, and
       tablespaces (Christopher, Euler Taveira de Oliveira)
       Previously this required modifying the system tables directly.
     * Allow temporary object creation to be limited to "SECURITY DEFINER"
       functions (Sean Chittenden)
     * Add "ALTER TABLE ... SET WITHOUT CLUSTER" (Christopher)
       Prior to this release, there was no way to clear an auto-cluster
       specification except to modify the system tables.
     * Constraint/Index/SERIAL names are now "table_column_type" with
       numbers appended to guarantee uniqueness within the schema (Tom)
       The SQL specification states that such names should be unique
       within a schema.
     * Add pg_get_serial_sequence() to return a SERIAL column's sequence
       name (Christopher)
       This allows automated scripts to reliably find the SERIAL sequence
       name.
     * Warn when primary/foreign key data type mismatch requires costly
       lookup
     * New "ALTER INDEX" command to allow moving of indexes between
       tablespaces (Gavin)
     * Make "ALTER TABLE OWNER" change dependent sequence ownership too
       (Alvaro)
     __________________________________________________________________

Utility Command Changes

     * Allow "CREATE SCHEMA" to create triggers, indexes, and sequences
       (Neil)
     * Add "ALSO" keyword to "CREATE RULE" (Fabien Coelho)
       This allows "ALSO" to be added to rule creation to contrast it with
       "INSTEAD" rules.
     * Add "NOWAIT" option to "LOCK" (Tatsuo)
       This allows the "LOCK" command to fail if it would have to wait for
       the requested lock.
     * Allow "COPY" to read and write comma-separated-value (CSV) files
       (Andrew, Bruce)
     * Generate error if the "COPY" delimiter and NULL string conflict
       (Bruce)
     * "GRANT"/"REVOKE" behavior follows the SQL spec more closely
     * Avoid locking conflict between "CREATE INDEX" and "CHECKPOINT"
       (Tom)
       In 7.3 and 7.4, a long-running B-tree index build could block
       concurrent "CHECKPOINT"s from completing, thereby causing WAL bloat
       because the WAL log could not be recycled.
     * Database-wide "ANALYZE" does not hold locks across tables (Tom)
       This reduces the potential for deadlocks against other backends
       that want exclusive locks on tables. To get the benefit of this
       change, do not execute database-wide "ANALYZE" inside a transaction
       block ("BEGIN" block); it must be able to commit and start a new
       transaction for each table.
     * "REINDEX" does not exclusively lock the index's parent table
       anymore
       The index itself is still exclusively locked, but readers of the
       table can continue if they are not using the particular index being
       rebuilt.
     * Erase MD5 user passwords when a user is renamed (Bruce)
       PostgreSQL uses the user name as salt when encrypting passwords via
       MD5. When a user's name is changed, the salt will no longer match
       the stored MD5 password, so the stored password becomes useless. In
       this release a notice is generated and the password is cleared. A
       new password must then be assigned if the user is to be able to log
       in with a password.
     * New pg_ctl "kill" option for Windows (Andrew)
       Windows does not have a kill command to send signals to backends so
       this capability was added to pg_ctl.
     * Information schema improvements
     * Add "--pwfile" option to initdb so the initial password can be set
       by GUI tools (Magnus)
     * Detect locale/encoding mismatch in initdb (Peter)
     * Add "register" command to pg_ctl to register Windows operating
       system service (Dave Page)
     __________________________________________________________________

Data Type and Function Changes

     * More complete support for composite types (row types) (Tom)
       Composite values can be used in many places where only scalar
       values worked before.
     * Reject nonrectangular array values as erroneous (Joe)
       Formerly, array_in would silently build a surprising result.
     * Overflow in integer arithmetic operations is now detected (Tom)
     * The arithmetic operators associated with the single-byte "char"
       data type have been removed.
       Formerly, the parser would select these operators in many
       situations where an "unable to select an operator" error would be
       more appropriate, such as null * null. If you actually want to do
       arithmetic on a "char" column, you can cast it to integer
       explicitly.
     * Syntax checking of array input values considerably tightened up
       (Joe)
       Junk that was previously allowed in odd places with odd results now
       causes an ERROR, for example, non-whitespace after the closing
       right brace.
     * Empty-string array element values must now be written as "", rather
       than writing nothing (Joe)
       Formerly, both ways of writing an empty-string element value were
       allowed, but now a quoted empty string is required. The case where
       nothing at all appears will probably be considered to be a NULL
       element value in some future release.
     * Array element trailing whitespace is now ignored (Joe)
       Formerly leading whitespace was ignored, but trailing whitespace
       between an element value and the delimiter or right brace was
       significant. Now trailing whitespace is also ignored.
     * Emit array values with explicit array bounds when lower bound is
       not one (Joe)
     * Accept YYYY-monthname-DD as a date string (Tom)
     * Make netmask and hostmask functions return maximum-length mask
       length (Tom)
     * Change factorial function to return numeric (Gavin)
       Returning numeric allows the factorial function to work for a wider
       range of input values.
     * to_char/to_date() date conversion improvements (Kurt Roeckx, Fabien
       Coelho)
     * Make length() disregard trailing spaces in CHAR(n) (Gavin)
       This change was made to improve consistency: trailing spaces are
       semantically insignificant in CHAR(n) data, so they should not be
       counted by length().
     * Warn about empty string being passed to OID/float4/float8 data
       types (Neil)
       8.1 will throw an error instead.
     * Allow leading or trailing whitespace in
       int2/int4/int8/float4/float8 input routines (Neil)
     * Better support for IEEE Infinity and NaN values in float4/float8
       (Neil)
       These should now work on all platforms that support IEEE-compliant
       floating point arithmetic.
     * Add "week" option to date_trunc() (Robert Creager)
     * Fix to_char for 1 BC (previously it returned 1 AD) (Bruce)
     * Fix date_part(year) for BC dates (previously it returned one less
       than the correct year) (Bruce)
     * Fix date_part() to return the proper millennium and century (Fabien
       Coelho)
       In previous versions, the century and millennium results had a
       wrong number and started in the wrong year, as compared to standard
       reckoning of such things.
     * Add ceiling() as an alias for ceil(), and power() as an alias for
       pow() for standards compliance (Neil)
     * Change ln(), log(), power(), and sqrt() to emit the correct
       SQLSTATE error codes for certain error conditions, as specified by
       SQL:2003 (Neil)
     * Add width_bucket() function as defined by SQL:2003 (Neil)
     * Add generate_series() functions to simplify working with numeric
       sets (Joe)
     * Fix upper/lower/initcap() functions to work with multibyte
       encodings (Tom)
     * Add boolean and bitwise integer "AND"/"OR" aggregates (Fabien
       Coelho)
     * New session information functions to return network addresses for
       client and server (Sean Chittenden)
     * Add function to determine the area of a closed path (Sean
       Chittenden)
     * Add function to send cancel request to other backends (Magnus)
     * Add interval plus datetime operators (Tom)
       The reverse ordering, datetime plus interval, was already
       supported, but both are required by the SQL standard.
     * Casting an integer to BIT(N) selects the rightmost N bits of the
       integer (Tom)
       In prior releases, the leftmost N bits were selected, but this was
       deemed unhelpful, not to mention inconsistent with casting from bit
       to int.
     * Require CIDR values to have all nonmasked bits be zero (Kevin
       Brintnall)
     __________________________________________________________________

Server-Side Language Changes

     * In READ COMMITTED serialization mode, volatile functions now see
       the results of concurrent transactions committed up to the
       beginning of each statement within the function, rather than up to
       the beginning of the interactive command that called the function.
     * Functions declared STABLE or IMMUTABLE always use the snapshot of
       the calling query, and therefore do not see the effects of actions
       taken after the calling query starts, whether in their own
       transaction or other transactions. Such a function must be
       read-only, too, meaning that it cannot use any SQL commands other
       than "SELECT". There is a considerable performance gain from
       declaring a function STABLE or IMMUTABLE rather than VOLATILE.
     * Nondeferred "AFTER" triggers are now fired immediately after
       completion of the triggering query, rather than upon finishing the
       current interactive command. This makes a difference when the
       triggering query occurred within a function: the trigger is invoked
       before the function proceeds to its next operation. For example, if
       a function inserts a new row into a table, any nondeferred foreign
       key checks occur before proceeding with the function.
     * Allow function parameters to be declared with names (Dennis
       Bjorklund)
       This allows better documentation of functions. Whether the names
       actually do anything depends on the specific function language
       being used.
     * Allow PL/pgSQL parameter names to be referenced in the function
       (Dennis Bjorklund)
       This basically creates an automatic alias for each named parameter.
     * Do minimal syntax checking of PL/pgSQL functions at creation time
       (Tom)
       This allows us to catch simple syntax errors sooner.
     * More support for composite types (row and record variables) in
       PL/pgSQL
       For example, it now works to pass a rowtype variable to another
       function as a single variable.
     * Default values for PL/pgSQL variables can now reference previously
       declared variables
     * Improve parsing of PL/pgSQL FOR loops (Tom)
       Parsing is now driven by presence of ".." rather than data type of
       "FOR" variable. This makes no difference for correct functions, but
       should result in more understandable error messages when a mistake
       is made.
     * Major overhaul of PL/Perl server-side language (Command Prompt,
       Andrew Dunstan)
     * In PL/Tcl, SPI commands are now run in subtransactions. If an error
       occurs, the subtransaction is cleaned up and the error is reported
       as an ordinary Tcl error, which can be trapped with catch.
       Formerly, it was not possible to catch such errors.
     * Accept "ELSEIF" in PL/pgSQL (Neil)
       Previously PL/pgSQL only allowed "ELSIF", but many people are
       accustomed to spelling this keyword "ELSEIF".
     __________________________________________________________________

psql Changes

     * Improve psql information display about database objects
       (Christopher)
     * Allow psql to display group membership in "\du" and "\dg" (Markus
       Bertheau)
     * Prevent psql "\dn" from showing temporary schemas (Bruce)
     * Allow psql to handle tilde user expansion for file names (Zach
       Irmen)
     * Allow psql to display fancy prompts, including color, via readline
       (Reece Hart, Chet Ramey)
     * Make psql "\copy" match "COPY" command syntax fully (Tom)
     * Show the location of syntax errors (Fabien Coelho, Tom)
     * Add "CLUSTER" information to psql "\d" display (Bruce)
     * Change psql "\copy stdin/stdout" to read from command input/output
       (Bruce)
     * Add "pstdin"/"pstdout" to read from psql's stdin/stdout (Mark Feit)
     * Add global psql configuration file, "psqlrc.sample" (Bruce)
       This allows a central file where global psql startup commands can
       be stored.
     * Have psql "\d+" indicate if the table has an OID column (Neil)
     * On Windows, use binary mode in psql when reading files so control-Z
       is not seen as end-of-file
     * Have "\dn+" show permissions and description for schemas (Dennis
       Bjorklund)
     * Improve tab completion support (Stefan Kaltenbrunn, Greg Sabino
       Mullane)
     * Allow boolean settings to be set using upper or lower case (Michael
       Paesold)
     __________________________________________________________________

pg_dump Changes

     * Use dependency information to improve the reliability of pg_dump
       (Tom)
       This should solve the longstanding problems with related objects
       sometimes being dumped in the wrong order.
     * Have pg_dump output objects in alphabetical order if possible (Tom)
       This should make it easier to identify changes between dump files.
     * Allow pg_restore to ignore some SQL errors (Fabien Coelho)
       This makes pg_restore's behavior similar to the results of feeding
       a pg_dump output script to psql. In most cases, ignoring errors and
       plowing ahead is the most useful thing to do. Also added was a
       pg_restore option to give the old behavior of exiting on an error.
     * pg_restore "-l" display now includes objects' schema names
     * New begin/end markers in pg_dump text output (Bruce)
     * Add start/stop times for pg_dump/pg_dumpall in verbose mode (Bruce)
     * Allow most pg_dump options in pg_dumpall (Christopher)
     * Have pg_dump use "ALTER OWNER" rather than "SET SESSION
       AUTHORIZATION" by default (Christopher)
     __________________________________________________________________

libpq Changes

     * Make libpq's "SIGPIPE" handling thread-safe (Bruce)
     * Add PQmbdsplen() which returns the display length of a character
       (Tatsuo)
     * Add thread locking to SSL and Kerberos connections (Manfred Spraul)
     * Allow PQoidValue(), PQcmdTuples(), and PQoidStatus() to work on
       "EXECUTE" commands (Neil)
     * Add PQserverVersion() to provide more convenient access to the
       server version number (Greg Sabino Mullane)
     * Add PQprepare/PQsendPrepared() functions to support preparing
       statements without necessarily specifying the data types of their
       parameters (Abhijit Menon-Sen)
     * Many ECPG improvements, including "SET DESCRIPTOR" (Michael)
     __________________________________________________________________

Source Code Changes

     * Allow the database server to run natively on Windows (Claudio,
       Magnus, Andrew)
     * Shell script commands converted to C versions for Windows support
       (Andrew)
     * Create an extension makefile framework (Fabien Coelho, Peter)
       This simplifies the task of building extensions outside the
       original source tree.
     * Support relocatable installations (Bruce)
       Directory paths for installed files (such as the "/share"
       directory) are now computed relative to the actual location of the
       executables, so that an installation tree can be moved to another
       place without reconfiguring and rebuilding.
     * Use "--with-docdir" to choose installation location of
       documentation; also allow "--infodir" (Peter)
     * Add "--without-docdir" to prevent installation of documentation
       (Peter)
     * Upgrade to DocBook V4.2 SGML (Peter)
     * New PostgreSQL CVS tag (Marc)
       This was done to make it easier for organizations to manage their
       own copies of the PostgreSQL CVS repository. File version stamps
       from the master repository will not get munged by checking into or
       out of a copied repository.
     * Clarify locking code (Manfred Koizar)
     * Buffer manager cleanup (Neil)
     * Decouple platform tests from CPU spinlock code (Bruce, Tom)
     * Add inlined test-and-set code on PA-RISC for gcc (ViSolve, Tom)
     * Improve i386 spinlock code (Manfred Spraul)
     * Clean up spinlock assembly code to avoid warnings from newer gcc
       releases (Tom)
     * Remove JDBC from source tree; now a separate project
     * Remove the libpgtcl client interface; now a separate project
     * More accurately estimate memory and file descriptor usage (Tom)
     * Improvements to the Mac OS X startup scripts (Ray A.)
     * New fsync() test program (Bruce)
     * Major documentation improvements (Neil, Peter)
     * Remove pg_encoding; not needed anymore
     * Remove pg_id; not needed anymore
     * Remove initlocation; not needed anymore
     * Auto-detect thread flags (no more manual testing) (Bruce)
     * Use Olson's public domain timezone library (Magnus)
     * With threading enabled, use thread flags on Unixware for backend
       executables too (Bruce)
       Unixware cannot mix threaded and nonthreaded object files in the
       same executable, so everything must be compiled as threaded.
     * psql now uses a flex-generated lexical analyzer to process command
       strings
     * Reimplement the linked list data structure used throughout the
       backend (Neil)
       This improves performance by allowing list append and length
       operations to be more efficient.
     * Allow dynamically loaded modules to create their own server
       configuration parameters (Thomas Hallgren)
     * New Brazilian version of FAQ (Euler Taveira de Oliveira)
     * Add French FAQ (Guillaume Lelarge)
     * New pgevent for Windows logging
     * Make libpq and ECPG build as proper shared libraries on OS X (Tom)
     __________________________________________________________________

Contrib Changes

     * Overhaul of "contrib/dblink" (Joe)
     * "contrib/dbmirror" improvements (Steven Singer)
     * New "contrib/xml2" (John Gray, Torchbox)
     * Updated "contrib/mysql"
     * New version of "contrib/btree_gist" (Teodor)
     * New "contrib/trgm", trigram matching for PostgreSQL (Teodor)
     * Many "contrib/tsearch2" improvements (Teodor)
     * Add double metaphone to "contrib/fuzzystrmatch" (Andrew)
     * Allow "contrib/pg_autovacuum" to run as a Windows service (Dave
       Page)
     * Add functions to "contrib/dbsize" (Andreas Pflug)
     * Removed "contrib/pg_logger": obsoleted by integrated logging
       subprocess
     * Removed "contrib/rserv": obsoleted by various separate projects
     __________________________________________________________________

                               Release 7.4.30

     Release Date: 2010-10-04

   This release contains a variety of fixes from 7.4.29. For information
   about new features in the 7.4 major release, see the Section called
   Release 7.4.

   This is expected to be the last PostgreSQL release in the 7.4.X series.
   Users are encouraged to update to a newer release branch soon.
     __________________________________________________________________

Migration to Version 7.4.30

   A dump/restore is not required for those running 7.4.X. However, if you
   are upgrading from a version earlier than 7.4.26, see the release notes
   for 7.4.26.
     __________________________________________________________________

Changes

     * Use a separate interpreter for each calling SQL userid in PL/Perl
       and PL/Tcl (Tom Lane)
       This change prevents security problems that can be caused by
       subverting Perl or Tcl code that will be executed later in the same
       session under another SQL user identity (for example, within a
       SECURITY DEFINER function). Most scripting languages offer numerous
       ways that that might be done, such as redefining standard functions
       or operators called by the target function. Without this change,
       any SQL user with Perl or Tcl language usage rights can do
       essentially anything with the SQL privileges of the target
       function's owner.
       The cost of this change is that intentional communication among
       Perl and Tcl functions becomes more difficult. To provide an escape
       hatch, PL/PerlU and PL/TclU functions continue to use only one
       interpreter per session. This is not considered a security issue
       since all such functions execute at the trust level of a database
       superuser already.
       It is likely that third-party procedural languages that claim to
       offer trusted execution have similar security issues. We advise
       contacting the authors of any PL you are depending on for
       security-critical purposes.
       Our thanks to Tim Bunce for pointing out this issue
       (CVE-2010-3433).
     * Prevent possible crashes in pg_get_expr() by disallowing it from
       being called with an argument that is not one of the system catalog
       columns it's intended to be used with (Heikki Linnakangas, Tom
       Lane)
     * Fix "cannot handle unplanned sub-select" error (Tom Lane)
       This occurred when a sub-select contains a join alias reference
       that expands into an expression containing another sub-select.
     * Take care to fsync the contents of lockfiles (both "postmaster.pid"
       and the socket lockfile) while writing them (Tom Lane)
       This omission could result in corrupted lockfile contents if the
       machine crashes shortly after postmaster start. That could in turn
       prevent subsequent attempts to start the postmaster from
       succeeding, until the lockfile is manually removed.
     * Improve "contrib/dblink"'s handling of tables containing dropped
       columns (Tom Lane)
     * Fix connection leak after "duplicate connection name" errors in
       "contrib/dblink" (Itagaki Takahiro)
     * Update build infrastructure and documentation to reflect the source
       code repository's move from CVS to Git (Magnus Hagander and others)
     __________________________________________________________________

                               Release 7.4.29

     Release Date: 2010-05-17

   This release contains a variety of fixes from 7.4.28. For information
   about new features in the 7.4 major release, see the Section called
   Release 7.4.

   The PostgreSQL community will stop releasing updates for the 7.4.X
   release series in July 2010. Users are encouraged to update to a newer
   release branch soon.
     __________________________________________________________________

Migration to Version 7.4.29

   A dump/restore is not required for those running 7.4.X. However, if you
   are upgrading from a version earlier than 7.4.26, see the release notes
   for 7.4.26.
     __________________________________________________________________

Changes

     * Enforce restrictions in plperl using an opmask applied to the whole
       interpreter, instead of using "Safe.pm" (Tim Bunce, Andrew Dunstan)
       Recent developments have convinced us that "Safe.pm" is too
       insecure to rely on for making plperl trustable. This change
       removes use of "Safe.pm" altogether, in favor of using a separate
       interpreter with an opcode mask that is always applied. Pleasant
       side effects of the change include that it is now possible to use
       Perl's strict pragma in a natural way in plperl, and that Perl's $a
       and $b variables work as expected in sort routines, and that
       function compilation is significantly faster. (CVE-2010-1169)
     * Prevent PL/Tcl from executing untrustworthy code from pltcl_modules
       (Tom)
       PL/Tcl's feature for autoloading Tcl code from a database table
       could be exploited for trojan-horse attacks, because there was no
       restriction on who could create or insert into that table. This
       change disables the feature unless pltcl_modules is owned by a
       superuser. (However, the permissions on the table are not checked,
       so installations that really need a less-than-secure modules table
       can still grant suitable privileges to trusted non-superusers.)
       Also, prevent loading code into the unrestricted "normal" Tcl
       interpreter unless we are really going to execute a pltclu
       function. (CVE-2010-1170)
     * Do not allow an unprivileged user to reset superuser-only parameter
       settings (Alvaro)
       Previously, if an unprivileged user ran ALTER USER ... RESET ALL
       for himself, or ALTER DATABASE ... RESET ALL for a database he
       owns, this would remove all special parameter settings for the user
       or database, even ones that are only supposed to be changeable by a
       superuser. Now, the "ALTER" will only remove the parameters that
       the user has permission to change.
     * Avoid possible crash during backend shutdown if shutdown occurs
       when a CONTEXT addition would be made to log entries (Tom)
       In some cases the context-printing function would fail because the
       current transaction had already been rolled back when it came time
       to print a log message.
     * Update pl/perl's "ppport.h" for modern Perl versions (Andrew)
     * Fix assorted memory leaks in pl/python (Andreas Freund, Tom)
     * Ensure that "contrib/pgstattuple" functions respond to cancel
       interrupts promptly (Tatsuhito Kasahara)
     * Make server startup deal properly with the case that shmget()
       returns EINVAL for an existing shared memory segment (Tom)
       This behavior has been observed on BSD-derived kernels including OS
       X. It resulted in an entirely-misleading startup failure
       complaining that the shared memory request size was too large.
     __________________________________________________________________

                               Release 7.4.28

     Release Date: 2010-03-15

   This release contains a variety of fixes from 7.4.27. For information
   about new features in the 7.4 major release, see the Section called
   Release 7.4.

   The PostgreSQL community will stop releasing updates for the 7.4.X
   release series in July 2010. Users are encouraged to update to a newer
   release branch soon.
     __________________________________________________________________

Migration to Version 7.4.28

   A dump/restore is not required for those running 7.4.X. However, if you
   are upgrading from a version earlier than 7.4.26, see the release notes
   for 7.4.26.
     __________________________________________________________________

Changes

     * Add new configuration parameter ssl_renegotiation_limit to control
       how often we do session key renegotiation for an SSL connection
       (Magnus)
       This can be set to zero to disable renegotiation completely, which
       may be required if a broken SSL library is used. In particular,
       some vendors are shipping stopgap patches for CVE-2009-3555 that
       cause renegotiation attempts to fail.
     * Make substring() for bit types treat any negative length as meaning
       "all the rest of the string" (Tom)
       The previous coding treated only -1 that way, and would produce an
       invalid result value for other negative values, possibly leading to
       a crash (CVE-2010-0442).
     * Fix some cases of pathologically slow regular expression matching
       (Tom)
     * When reading "pg_hba.conf" and related files, do not treat
       @something as a file inclusion request if the @ appears inside
       quote marks; also, never treat @ by itself as a file inclusion
       request (Tom)
       This prevents erratic behavior if a role or database name starts
       with @. If you need to include a file whose path name contains
       spaces, you can still do so, but you must write @"/path to/file"
       rather than putting the quotes around the whole construct.
     * Prevent infinite loop on some platforms if a directory is named as
       an inclusion target in "pg_hba.conf" and related files (Tom)
     * Ensure PL/Tcl initializes the Tcl interpreter fully (Tom)
       The only known symptom of this oversight is that the Tcl clock
       command misbehaves if using Tcl 8.5 or later.
     * Prevent crash in "contrib/dblink" when too many key columns are
       specified to a dblink_build_sql_* function (Rushabh Lathia, Joe
       Conway)
     __________________________________________________________________

                               Release 7.4.27

     Release Date: 2009-12-14

   This release contains a variety of fixes from 7.4.26. For information
   about new features in the 7.4 major release, see the Section called
   Release 7.4.
     __________________________________________________________________

Migration to Version 7.4.27

   A dump/restore is not required for those running 7.4.X. However, if you
   are upgrading from a version earlier than 7.4.26, see the release notes
   for 7.4.26.
     __________________________________________________________________

Changes

     * Protect against indirect security threats caused by index functions
       changing session-local state (Gurjeet Singh, Tom)
       This change prevents allegedly-immutable index functions from
       possibly subverting a superuser's session (CVE-2009-4136).
     * Reject SSL certificates containing an embedded null byte in the
       common name (CN) field (Magnus)
       This prevents unintended matching of a certificate to a server or
       client name during SSL validation (CVE-2009-4034).
     * Fix possible crash during backend-startup-time cache initialization
       (Tom)
     * Prevent signals from interrupting VACUUM at unsafe times (Alvaro)
       This fix prevents a PANIC if a VACUUM FULL is canceled after it's
       already committed its tuple movements, as well as transient errors
       if a plain VACUUM is interrupted after having truncated the table.
     * Fix possible crash due to integer overflow in hash table size
       calculation (Tom)
       This could occur with extremely large planner estimates for the
       size of a hashjoin's result.
     * Fix very rare crash in inet/cidr comparisons (Chris Mikkelson)
     * Fix PAM password processing to be more robust (Tom)
       The previous code is known to fail with the combination of the
       Linux pam_krb5 PAM module with Microsoft Active Directory as the
       domain controller. It might have problems elsewhere too, since it
       was making unjustified assumptions about what arguments the PAM
       stack would pass to it.
     * Make the postmaster ignore any application_name parameter in
       connection request packets, to improve compatibility with future
       libpq versions (Tom)
     __________________________________________________________________

                               Release 7.4.26

     Release Date: 2009-09-09

   This release contains a variety of fixes from 7.4.25. For information
   about new features in the 7.4 major release, see the Section called
   Release 7.4.
     __________________________________________________________________

Migration to Version 7.4.26

   A dump/restore is not required for those running 7.4.X. However, if you
   have any hash indexes on interval columns, you must "REINDEX" them
   after updating to 7.4.26. Also, if you are upgrading from a version
   earlier than 7.4.11, see the release notes for 7.4.11.
     __________________________________________________________________

Changes

     * Disallow "RESET ROLE" and "RESET SESSION AUTHORIZATION" inside
       security-definer functions (Tom, Heikki)
       This covers a case that was missed in the previous patch that
       disallowed "SET ROLE" and "SET SESSION AUTHORIZATION" inside
       security-definer functions. (See CVE-2007-6600)
     * Fix handling of sub-SELECTs appearing in the arguments of an
       outer-level aggregate function (Tom)
     * Fix hash calculation for data type interval (Tom)
       This corrects wrong results for hash joins on interval values. It
       also changes the contents of hash indexes on interval columns. If
       you have any such indexes, you must "REINDEX" them after updating.
     * Fix overflow for INTERVAL 'x ms' when "x" is more than 2 million
       and integer datetimes are in use (Alex Hunsaker)
     * Fix calculation of distance between a point and a line segment
       (Tom)
       This led to incorrect results from a number of geometric operators.
     * Fix money data type to work in locales where currency amounts have
       no fractional digits, e.g. Japan (Itagaki Takahiro)
     * Properly round datetime input like
       00:12:57.9999999999999999999999999999 (Tom)
     * Fix poor choice of page split point in GiST R-tree operator classes
       (Teodor)
     * Fix portability issues in plperl initialization (Andrew Dunstan)
     * Improve robustness of libpq's code to recover from errors during
       "COPY FROM STDIN" (Tom)
     * Avoid including conflicting readline and editline header files when
       both libraries are installed (Zdenek Kotala)
     __________________________________________________________________

                               Release 7.4.25

     Release Date: 2009-03-16

   This release contains a variety of fixes from 7.4.24. For information
   about new features in the 7.4 major release, see the Section called
   Release 7.4.
     __________________________________________________________________

Migration to Version 7.4.25

   A dump/restore is not required for those running 7.4.X. However, if you
   are upgrading from a version earlier than 7.4.11, see the release notes
   for 7.4.11.
     __________________________________________________________________

Changes

     * Prevent error recursion crashes when encoding conversion fails
       (Tom)
       This change extends fixes made in the last two minor releases for
       related failure scenarios. The previous fixes were narrowly
       tailored for the original problem reports, but we have now
       recognized that *any* error thrown by an encoding conversion
       function could potentially lead to infinite recursion while trying
       to report the error. The solution therefore is to disable
       translation and encoding conversion and report the plain-ASCII form
       of any error message, if we find we have gotten into a recursive
       error reporting situation. (CVE-2009-0922)
     * Disallow "CREATE CONVERSION" with the wrong encodings for the
       specified conversion function (Heikki)
       This prevents one possible scenario for encoding conversion
       failure. The previous change is a backstop to guard against other
       kinds of failures in the same area.
     * Fix core dump when to_char() is given format codes that are
       inappropriate for the type of the data argument (Tom)
     * Add MUST (Mauritius Island Summer Time) to the default list of
       known timezone abbreviations (Xavier Bugaud)
     __________________________________________________________________

                               Release 7.4.24

     Release Date: 2009-02-02

   This release contains a variety of fixes from 7.4.23. For information
   about new features in the 7.4 major release, see the Section called
   Release 7.4.
     __________________________________________________________________

Migration to Version 7.4.24

   A dump/restore is not required for those running 7.4.X. However, if you
   are upgrading from a version earlier than 7.4.11, see the release notes
   for 7.4.11.
     __________________________________________________________________

Changes

     * Improve handling of URLs in headline() function (Teodor)
     * Improve handling of overlength headlines in headline() function
       (Teodor)
     * Prevent possible Assert failure or misconversion if an encoding
       conversion is created with the wrong conversion function for the
       specified pair of encodings (Tom, Heikki)
     * Avoid unnecessary locking of small tables in "VACUUM" (Heikki)
     * Fix uninitialized variables in "contrib/tsearch2"'s get_covers()
       function (Teodor)
     * Fix bug in to_char()'s handling of TH format codes (Andreas
       Scherbaum)
     * Make all documentation reference pgsql-bugs and/or pgsql-hackers as
       appropriate, instead of the now-decommissioned pgsql-ports and
       pgsql-patches mailing lists (Tom)
     __________________________________________________________________

                               Release 7.4.23

     Release Date: 2008-11-03

   This release contains a variety of fixes from 7.4.22. For information
   about new features in the 7.4 major release, see the Section called
   Release 7.4.
     __________________________________________________________________

Migration to Version 7.4.23

   A dump/restore is not required for those running 7.4.X. However, if you
   are upgrading from a version earlier than 7.4.11, see the release notes
   for 7.4.11.
     __________________________________________________________________

Changes

     * Fix backend crash when the client encoding cannot represent a
       localized error message (Tom)
       We have addressed similar issues before, but it would still fail if
       the "character has no equivalent" message itself couldn't be
       converted. The fix is to disable localization and send the plain
       ASCII error message when we detect such a situation.
     * Fix incorrect tsearch2 headline generation when single query item
       matches first word of text (Sushant Sinha)
     * Fix improper display of fractional seconds in interval values when
       using a non-ISO datestyle in an "--enable-integer-datetimes" build
       (Ron Mayer)
     * Ensure SPI_getvalue and SPI_getbinval behave correctly when the
       passed tuple and tuple descriptor have different numbers of columns
       (Tom)
       This situation is normal when a table has had columns added or
       removed, but these two functions didn't handle it properly. The
       only likely consequence is an incorrect error indication.
     * Fix ecpg's parsing of "CREATE USER" (Michael)
     __________________________________________________________________

                               Release 7.4.22

     Release Date: 2008-09-22

   This release contains a variety of fixes from 7.4.21. For information
   about new features in the 7.4 major release, see the Section called
   Release 7.4.
     __________________________________________________________________

Migration to Version 7.4.22

   A dump/restore is not required for those running 7.4.X. However, if you
   are upgrading from a version earlier than 7.4.11, see the release notes
   for 7.4.11.
     __________________________________________________________________

Changes

     * Fix datetime input functions to correctly detect integer overflow
       when running on a 64-bit platform (Tom)
     * Improve performance of writing very long log messages to syslog
       (Tom)
     * Fix bug in backwards scanning of a cursor on a SELECT DISTINCT ON
       query (Tom)
     * Fix planner to estimate that GROUP BY expressions yielding boolean
       results always result in two groups, regardless of the expressions'
       contents (Tom)
       This is very substantially more accurate than the regular GROUP BY
       estimate for certain boolean tests like "col" IS NULL.
     * Improve pg_dump and pg_restore's error reporting after failure to
       send a SQL command (Tom)
     __________________________________________________________________

                               Release 7.4.21

     Release Date: 2008-06-12

   This release contains one serious bug fix over 7.4.20. For information
   about new features in the 7.4 major release, see the Section called
   Release 7.4.
     __________________________________________________________________

Migration to Version 7.4.21

   A dump/restore is not required for those running 7.4.X. However, if you
   are upgrading from a version earlier than 7.4.11, see the release notes
   for 7.4.11.
     __________________________________________________________________

Changes

     * Make pg_get_ruledef() parenthesize negative constants (Tom)
       Before this fix, a negative constant in a view or rule might be
       dumped as, say, -42::integer, which is subtly incorrect: it should
       be (-42)::integer due to operator precedence rules. Usually this
       would make little difference, but it could interact with another
       recent patch to cause PostgreSQL to reject what had been a valid
       "SELECT DISTINCT" view query. Since this could result in pg_dump
       output failing to reload, it is being treated as a high-priority
       fix. The only released versions in which dump output is actually
       incorrect are 8.3.1 and 8.2.7.
     __________________________________________________________________

                               Release 7.4.20

     Release Date: never released

   This release contains a variety of fixes from 7.4.19. For information
   about new features in the 7.4 major release, see the Section called
   Release 7.4.
     __________________________________________________________________

Migration to Version 7.4.20

   A dump/restore is not required for those running 7.4.X. However, if you
   are upgrading from a version earlier than 7.4.11, see the release notes
   for 7.4.11.
     __________________________________________________________________

Changes

     * Fix conversions between ISO-8859-5 and other encodings to handle
       Cyrillic "Yo" characters (e and E with two dots) (Sergey Burladyan)
     * Fix a few datatype input functions that were allowing unused bytes
       in their results to contain uninitialized, unpredictable values
       (Tom)
       This could lead to failures in which two apparently identical
       literal values were not seen as equal, resulting in the parser
       complaining about unmatched ORDER BY and DISTINCT expressions.
     * Fix a corner case in regular-expression substring matching
       (substring(string from pattern)) (Tom)
       The problem occurs when there is a match to the pattern overall but
       the user has specified a parenthesized subexpression and that
       subexpression hasn't got a match. An example is substring('foo'
       from 'foo(bar)?'). This should return NULL, since (bar) isn't
       matched, but it was mistakenly returning the whole-pattern match
       instead (ie, foo).
     * Fix incorrect result from ecpg's PGTYPEStimestamp_sub() function
       (Michael)
     * Fix DatumGetBool macro to not fail with gcc 4.3 (Tom)
       This problem affects "old style" (V0) C functions that return
       boolean. The fix is already in 8.3, but the need to back-patch it
       was not realized at the time.
     * Fix longstanding "LISTEN"/"NOTIFY" race condition (Tom)
       In rare cases a session that had just executed a "LISTEN" might not
       get a notification, even though one would be expected because the
       concurrent transaction executing "NOTIFY" was observed to commit
       later.
       A side effect of the fix is that a transaction that has executed a
       not-yet-committed "LISTEN" command will not see any row in
       pg_listener for the "LISTEN", should it choose to look; formerly it
       would have. This behavior was never documented one way or the
       other, but it is possible that some applications depend on the old
       behavior.
     * Fix display of constant expressions in ORDER BY and GROUP BY (Tom)
       An explicitly casted constant would be shown incorrectly. This
       could for example lead to corruption of a view definition during
       dump and reload.
     * Fix libpq to handle NOTICE messages correctly during COPY OUT (Tom)
       This failure has only been observed to occur when a user-defined
       datatype's output routine issues a NOTICE, but there is no
       guarantee it couldn't happen due to other causes.
     __________________________________________________________________

                               Release 7.4.19

     Release Date: 2008-01-07

   This release contains a variety of fixes from 7.4.18, including fixes
   for significant security issues. For information about new features in
   the 7.4 major release, see the Section called Release 7.4.
     __________________________________________________________________

Migration to Version 7.4.19

   A dump/restore is not required for those running 7.4.X. However, if you
   are upgrading from a version earlier than 7.4.11, see the release notes
   for 7.4.11.
     __________________________________________________________________

Changes

     * Prevent functions in indexes from executing with the privileges of
       the user running "VACUUM", "ANALYZE", etc (Tom)
       Functions used in index expressions and partial-index predicates
       are evaluated whenever a new table entry is made. It has long been
       understood that this poses a risk of trojan-horse code execution if
       one modifies a table owned by an untrustworthy user. (Note that
       triggers, defaults, check constraints, etc. pose the same type of
       risk.) But functions in indexes pose extra danger because they will
       be executed by routine maintenance operations such as "VACUUM
       FULL", which are commonly performed automatically under a superuser
       account. For example, a nefarious user can execute code with
       superuser privileges by setting up a trojan-horse index definition
       and waiting for the next routine vacuum. The fix arranges for
       standard maintenance operations (including "VACUUM", "ANALYZE",
       "REINDEX", and "CLUSTER") to execute as the table owner rather than
       the calling user, using the same privilege-switching mechanism
       already used for SECURITY DEFINER functions. To prevent bypassing
       this security measure, execution of "SET SESSION AUTHORIZATION" and
       "SET ROLE" is now forbidden within a SECURITY DEFINER context.
       (CVE-2007-6600)
     * Repair assorted bugs in the regular-expression package (Tom, Will
       Drewry)
       Suitably crafted regular-expression patterns could cause crashes,
       infinite or near-infinite looping, and/or massive memory
       consumption, all of which pose denial-of-service hazards for
       applications that accept regex search patterns from untrustworthy
       sources. (CVE-2007-4769, CVE-2007-4772, CVE-2007-6067)
     * Require non-superusers who use "/contrib/dblink" to use only
       password authentication, as a security measure (Joe)
       The fix that appeared for this in 7.4.18 was incomplete, as it
       plugged the hole for only some "dblink" functions. (CVE-2007-6601,
       CVE-2007-3278)
     * Fix planner failure in some cases of WHERE false AND var IN (SELECT
       ...) (Tom)
     * Fix potential crash in translate() when using a multibyte database
       encoding (Tom)
     * Fix PL/Python to not crash on long exception messages (Alvaro)
     * ecpg parser fixes (Michael)
     * Make "contrib/tablefunc"'s crosstab() handle NULL rowid as a
       category in its own right, rather than crashing (Joe)
     * Fix tsvector and tsquery output routines to escape backslashes
       correctly (Teodor, Bruce)
     * Fix crash of to_tsvector() on huge input strings (Teodor)
     * Require a specific version of Autoconf to be used when
       re-generating the "configure" script (Peter)
       This affects developers and packagers only. The change was made to
       prevent accidental use of untested combinations of Autoconf and
       PostgreSQL versions. You can remove the version check if you really
       want to use a different Autoconf version, but it's your
       responsibility whether the result works or not.
     __________________________________________________________________

                               Release 7.4.18

     Release Date: 2007-09-17

   This release contains fixes from 7.4.17. For information about new
   features in the 7.4 major release, see the Section called Release 7.4.
     __________________________________________________________________

Migration to Version 7.4.18

   A dump/restore is not required for those running 7.4.X. However, if you
   are upgrading from a version earlier than 7.4.11, see the release notes
   for 7.4.11.
     __________________________________________________________________

Changes

     * Prevent index corruption when a transaction inserts rows and then
       aborts close to the end of a concurrent "VACUUM" on the same table
       (Tom)
     * Make "CREATE DOMAIN ... DEFAULT NULL" work properly (Tom)
     * Fix excessive logging of SSL error messages (Tom)
     * Fix crash when log_min_error_statement logging runs out of memory
       (Tom)
     * Prevent "CLUSTER" from failing due to attempting to process
       temporary tables of other sessions (Alvaro)
     * Require non-superusers who use "/contrib/dblink" to use only
       password authentication, as a security measure (Joe)
     __________________________________________________________________

                               Release 7.4.17

     Release Date: 2007-04-23

   This release contains fixes from 7.4.16, including a security fix. For
   information about new features in the 7.4 major release, see the
   Section called Release 7.4.
     __________________________________________________________________

Migration to Version 7.4.17

   A dump/restore is not required for those running 7.4.X. However, if you
   are upgrading from a version earlier than 7.4.11, see the release notes
   for 7.4.11.
     __________________________________________________________________

Changes

     * Support explicit placement of the temporary-table schema within
       search_path, and disable searching it for functions and operators
       (Tom)
       This is needed to allow a security-definer function to set a truly
       secure value of search_path. Without it, an unprivileged SQL user
       can use temporary objects to execute code with the privileges of
       the security-definer function (CVE-2007-2138). See "CREATE
       FUNCTION" for more information.
     * "/contrib/tsearch2" crash fixes (Teodor)
     * Fix potential-data-corruption bug in how "VACUUM FULL" handles
       "UPDATE" chains (Tom, Pavan Deolasee)
     * Fix PANIC during enlargement of a hash index (bug introduced in
       7.4.15) (Tom)
     __________________________________________________________________

                               Release 7.4.16

     Release Date: 2007-02-05

   This release contains a variety of fixes from 7.4.15, including a
   security fix. For information about new features in the 7.4 major
   release, see the Section called Release 7.4.
     __________________________________________________________________

Migration to Version 7.4.16

   A dump/restore is not required for those running 7.4.X. However, if you
   are upgrading from a version earlier than 7.4.11, see the release notes
   for 7.4.11.
     __________________________________________________________________

Changes

     * Remove security vulnerability that allowed connected users to read
       backend memory (Tom)
       The vulnerability involves suppressing the normal check that a SQL
       function returns the data type it's declared to, or changing the
       data type of a table column used in a SQL function (CVE-2007-0555).
       This error can easily be exploited to cause a backend crash, and in
       principle might be used to read database content that the user
       should not be able to access.
     * Fix rare bug wherein btree index page splits could fail due to
       choosing an infeasible split point (Heikki Linnakangas)
     * Fix for rare Assert() crash triggered by UNION (Tom)
     * Tighten security of multi-byte character processing for UTF8
       sequences over three bytes long (Tom)
     __________________________________________________________________

                               Release 7.4.15

     Release Date: 2007-01-08

   This release contains a variety of fixes from 7.4.14. For information
   about new features in the 7.4 major release, see the Section called
   Release 7.4.
     __________________________________________________________________

Migration to Version 7.4.15

   A dump/restore is not required for those running 7.4.X. However, if you
   are upgrading from a version earlier than 7.4.11, see the release notes
   for 7.4.11.
     __________________________________________________________________

Changes

     * Improve handling of getaddrinfo() on AIX (Tom)
       This fixes a problem with starting the statistics collector, among
       other things.
     * Fix "failed to re-find parent key" errors in "VACUUM" (Tom)
     * Fix bugs affecting multi-gigabyte hash indexes (Tom)
     * Fix error when constructing an ARRAY[] made up of multiple empty
       elements (Tom)
     * to_number() and to_char(numeric) are now STABLE, not IMMUTABLE, for
       new initdb installs (Tom)
       This is because lc_numeric can potentially change the output of
       these functions.
     * Improve index usage of regular expressions that use parentheses
       (Tom)
       This improves psql \d performance also.
     __________________________________________________________________

                               Release 7.4.14

     Release Date: 2006-10-16

   This release contains a variety of fixes from 7.4.13. For information
   about new features in the 7.4 major release, see the Section called
   Release 7.4.
     __________________________________________________________________

Migration to Version 7.4.14

   A dump/restore is not required for those running 7.4.X. However, if you
   are upgrading from a version earlier than 7.4.11, see the release notes
   for 7.4.11.
     __________________________________________________________________

Changes

     * Fix core dump when an untyped literal is taken as ANYARRAY
     * Fix string_to_array() to handle overlapping matches for the
       separator string
       For example, string_to_array('123xx456xxx789', 'xx').
     * Fix corner cases in pattern matching for psql's \d commands
     * Fix index-corrupting bugs in /contrib/ltree (Teodor)
     * Fix backslash escaping in /contrib/dbmirror
     * Adjust regression tests for recent changes in US DST laws
     __________________________________________________________________

                               Release 7.4.13

     Release Date: 2006-05-23

   This release contains a variety of fixes from 7.4.12, including patches
   for extremely serious security issues. For information about new
   features in the 7.4 major release, see the Section called Release 7.4.
     __________________________________________________________________

Migration to Version 7.4.13

   A dump/restore is not required for those running 7.4.X. However, if you
   are upgrading from a version earlier than 7.4.11, see the release notes
   for 7.4.11.

   Full security against the SQL-injection attacks described in
   CVE-2006-2313 and CVE-2006-2314 might require changes in application
   code. If you have applications that embed untrustworthy strings into
   SQL commands, you should examine them as soon as possible to ensure
   that they are using recommended escaping techniques. In most cases,
   applications should be using subroutines provided by libraries or
   drivers (such as libpq's PQescapeStringConn()) to perform string
   escaping, rather than relying on ad hoc code to do it.
     __________________________________________________________________

Changes

     * Change the server to reject invalidly-encoded multibyte characters
       in all cases (Tatsuo, Tom)
       While PostgreSQL has been moving in this direction for some time,
       the checks are now applied uniformly to all encodings and all
       textual input, and are now always errors not merely warnings. This
       change defends against SQL-injection attacks of the type described
       in CVE-2006-2313.
     * Reject unsafe uses of \' in string literals
       As a server-side defense against SQL-injection attacks of the type
       described in CVE-2006-2314, the server now only accepts '' and not
       \' as a representation of ASCII single quote in SQL string
       literals. By default, \' is rejected only when client_encoding is
       set to a client-only encoding (SJIS, BIG5, GBK, GB18030, or UHC),
       which is the scenario in which SQL injection is possible. A new
       configuration parameter backslash_quote is available to adjust this
       behavior when needed. Note that full security against CVE-2006-2314
       might require client-side changes; the purpose of backslash_quote
       is in part to make it obvious that insecure clients are insecure.
     * Modify libpq's string-escaping routines to be aware of encoding
       considerations and standard_conforming_strings
       This fixes libpq-using applications for the security issues
       described in CVE-2006-2313 and CVE-2006-2314, and also
       future-proofs them against the planned changeover to SQL-standard
       string literal syntax. Applications that use multiple PostgreSQL
       connections concurrently should migrate to PQescapeStringConn() and
       PQescapeByteaConn() to ensure that escaping is done correctly for
       the settings in use in each database connection. Applications that
       do string escaping "by hand" should be modified to rely on library
       routines instead.
     * Fix some incorrect encoding conversion functions
       win1251_to_iso, alt_to_iso, euc_tw_to_big5, euc_tw_to_mic,
       mic_to_euc_tw were all broken to varying extents.
     * Clean up stray remaining uses of \' in strings (Bruce, Jan)
     * Fix bug that sometimes caused OR'd index scans to miss rows they
       should have returned
     * Fix WAL replay for case where a btree index has been truncated
     * Fix SIMILAR TO for patterns involving | (Tom)
     * Fix server to use custom DH SSL parameters correctly (Michael Fuhr)
     * Fix for Bonjour on Intel Macs (Ashley Clark)
     * Fix various minor memory leaks
     __________________________________________________________________

                               Release 7.4.12

     Release Date: 2006-02-14

   This release contains a variety of fixes from 7.4.11. For information
   about new features in the 7.4 major release, see the Section called
   Release 7.4.
     __________________________________________________________________

Migration to Version 7.4.12

   A dump/restore is not required for those running 7.4.X. However, if you
   are upgrading from a version earlier than 7.4.11, see the release notes
   for 7.4.11.
     __________________________________________________________________

Changes

     * Fix potential crash in "SET SESSION AUTHORIZATION" (CVE-2006-0553)
       An unprivileged user could crash the server process, resulting in
       momentary denial of service to other users, if the server has been
       compiled with Asserts enabled (which is not the default). Thanks to
       Akio Ishida for reporting this problem.
     * Fix bug with row visibility logic in self-inserted rows (Tom)
       Under rare circumstances a row inserted by the current command
       could be seen as already valid, when it should not be. Repairs bug
       created in 7.4.9 and 7.3.11 releases.
     * Fix race condition that could lead to "file already exists" errors
       during pg_clog file creation (Tom)
     * Properly check DOMAIN constraints for UNKNOWN parameters in
       prepared statements (Neil)
     * Fix to allow restoring dumps that have cross-schema references to
       custom operators (Tom)
     * Portability fix for testing presence of finite and isinf during
       configure (Tom)
     __________________________________________________________________

                               Release 7.4.11

     Release Date: 2006-01-09

   This release contains a variety of fixes from 7.4.10. For information
   about new features in the 7.4 major release, see the Section called
   Release 7.4.
     __________________________________________________________________

Migration to Version 7.4.11

   A dump/restore is not required for those running 7.4.X. However, if you
   are upgrading from a version earlier than 7.4.8, see the release notes
   for 7.4.8. Also, you might need to "REINDEX" indexes on textual columns
   after updating, if you are affected by the locale or plperl issues
   described below.
     __________________________________________________________________

Changes

     * Fix for protocol-level Describe messages issued outside a
       transaction or in a failed transaction (Tom)
     * Fix character string comparison for locales that consider different
       character combinations as equal, such as Hungarian (Tom)
       This might require "REINDEX" to fix existing indexes on textual
       columns.
     * Set locale environment variables during postmaster startup to
       ensure that plperl won't change the locale later
       This fixes a problem that occurred if the postmaster was started
       with environment variables specifying a different locale than what
       initdb had been told. Under these conditions, any use of plperl was
       likely to lead to corrupt indexes. You might need "REINDEX" to fix
       existing indexes on textual columns if this has happened to you.
     * Fix longstanding bug in strpos() and regular expression handling in
       certain rarely used Asian multi-byte character sets (Tatsuo)
     * Fix bug in "/contrib/pgcrypto" gen_salt, which caused it not to use
       all available salt space for MD5 and XDES algorithms (Marko Kreen,
       Solar Designer)
       Salts for Blowfish and standard DES are unaffected.
     * Fix "/contrib/dblink" to throw an error, rather than crashing, when
       the number of columns specified is different from what's actually
       returned by the query (Joe)
     __________________________________________________________________

                               Release 7.4.10

     Release Date: 2005-12-12

   This release contains a variety of fixes from 7.4.9. For information
   about new features in the 7.4 major release, see the Section called
   Release 7.4.
     __________________________________________________________________

Migration to Version 7.4.10

   A dump/restore is not required for those running 7.4.X. However, if you
   are upgrading from a version earlier than 7.4.8, see the release notes
   for 7.4.8.
     __________________________________________________________________

Changes

     * Fix race condition in transaction log management
       There was a narrow window in which an I/O operation could be
       initiated for the wrong page, leading to an Assert failure or data
       corruption.
     * Prevent failure if client sends Bind protocol message when current
       transaction is already aborted
     * "/contrib/ltree" fixes (Teodor)
     * AIX and HPUX compile fixes (Tom)
     * Fix longstanding planning error for outer joins
       This bug sometimes caused a bogus error "RIGHT JOIN is only
       supported with merge-joinable join conditions".
     * Prevent core dump in pg_autovacuum when a table has been dropped
     __________________________________________________________________

                                Release 7.4.9

     Release Date: 2005-10-04

   This release contains a variety of fixes from 7.4.8. For information
   about new features in the 7.4 major release, see the Section called
   Release 7.4.
     __________________________________________________________________

Migration to Version 7.4.9

   A dump/restore is not required for those running 7.4.X. However, if you
   are upgrading from a version earlier than 7.4.8, see the release notes
   for 7.4.8.
     __________________________________________________________________

Changes

     * Fix error that allowed "VACUUM" to remove ctid chains too soon, and
       add more checking in code that follows ctid links
       This fixes a long-standing problem that could cause crashes in very
       rare circumstances.
     * Fix CHAR() to properly pad spaces to the specified length when
       using a multiple-byte character set (Yoshiyuki Asaba)
       In prior releases, the padding of CHAR() was incorrect because it
       only padded to the specified number of bytes without considering
       how many characters were stored.
     * Fix the sense of the test for read-only transaction in "COPY"
       The code formerly prohibited "COPY TO", where it should prohibit
       "COPY FROM".
     * Fix planning problem with outer-join ON clauses that reference only
       the inner-side relation
     * Further fixes for x FULL JOIN y ON true corner cases
     * Make array_in and array_recv more paranoid about validating their
       OID parameter
     * Fix missing rows in queries like UPDATE a=... WHERE a... with GiST
       index on column a
     * Improve robustness of datetime parsing
     * Improve checking for partially-written WAL pages
     * Improve robustness of signal handling when SSL is enabled
     * Don't try to open more than max_files_per_process files during
       postmaster startup
     * Various memory leakage fixes
     * Various portability improvements
     * Fix PL/pgSQL to handle var := var correctly when the variable is of
       pass-by-reference type
     * Update "contrib/tsearch2" to use current Snowball code
     __________________________________________________________________

                                Release 7.4.8

     Release Date: 2005-05-09

   This release contains a variety of fixes from 7.4.7, including several
   security-related issues. For information about new features in the 7.4
   major release, see the Section called Release 7.4.
     __________________________________________________________________

Migration to Version 7.4.8

   A dump/restore is not required for those running 7.4.X. However, it is
   one possible way of handling two significant security problems that
   have been found in the initial contents of 7.4.X system catalogs. A
   dump/initdb/reload sequence using 7.4.8's initdb will automatically
   correct these problems.

   The larger security problem is that the built-in character set encoding
   conversion functions can be invoked from SQL commands by unprivileged
   users, but the functions were not designed for such use and are not
   secure against malicious choices of arguments. The fix involves
   changing the declared parameter list of these functions so that they
   can no longer be invoked from SQL commands. (This does not affect their
   normal use by the encoding conversion machinery.)

   The lesser problem is that the "contrib/tsearch2" module creates
   several functions that are misdeclared to return internal when they do
   not accept internal arguments. This breaks type safety for all
   functions using internal arguments.

   It is strongly recommended that all installations repair these errors,
   either by initdb or by following the manual repair procedures given
   below. The errors at least allow unprivileged database users to crash
   their server process, and might allow unprivileged users to gain the
   privileges of a database superuser.

   If you wish not to do an initdb, perform the following procedures
   instead. As the database superuser, do:
BEGIN;
UPDATE pg_proc SET proargtypes[3] = 'internal'::regtype
WHERE pronamespace = 11 AND pronargs = 5
     AND proargtypes[2] = 'cstring'::regtype;
-- The command should report having updated 90 rows;
-- if not, rollback and investigate instead of committing!
COMMIT;

   Next, if you have installed "contrib/tsearch2", do:
BEGIN;
UPDATE pg_proc SET proargtypes[0] = 'internal'::regtype
WHERE oid IN (
   'dex_init(text)'::regprocedure,
   'snb_en_init(text)'::regprocedure,
   'snb_ru_init(text)'::regprocedure,
   'spell_init(text)'::regprocedure,
   'syn_init(text)'::regprocedure
);
-- The command should report having updated 5 rows;
-- if not, rollback and investigate instead of committing!
COMMIT;

   If this command fails with a message like "function "dex_init(text)"
   does not exist", then either "tsearch2" is not installed in this
   database, or you already did the update.

   The above procedures must be carried out in *each* database of an
   installation, including template1, and ideally including template0 as
   well. If you do not fix the template databases then any subsequently
   created databases will contain the same errors. template1 can be fixed
   in the same way as any other database, but fixing template0 requires
   additional steps. First, from any database issue:
UPDATE pg_database SET datallowconn = true WHERE datname = 'template0';

   Next connect to template0 and perform the above repair procedures.
   Finally, do:
-- re-freeze template0:
VACUUM FREEZE;
-- and protect it against future alterations:
UPDATE pg_database SET datallowconn = false WHERE datname = 'template0';
     __________________________________________________________________

Changes

     * Change encoding function signature to prevent misuse
     * Change "contrib/tsearch2" to avoid unsafe use of INTERNAL function
       results
     * Repair ancient race condition that allowed a transaction to be seen
       as committed for some purposes (eg SELECT FOR UPDATE) slightly
       sooner than for other purposes
       This is an extremely serious bug since it could lead to apparent
       data inconsistencies being briefly visible to applications.
     * Repair race condition between relation extension and VACUUM
       This could theoretically have caused loss of a page's worth of
       freshly-inserted data, although the scenario seems of very low
       probability. There are no known cases of it having caused more than
       an Assert failure.
     * Fix comparisons of TIME WITH TIME ZONE values
       The comparison code was wrong in the case where the
       --enable-integer-datetimes configuration switch had been used.
       NOTE: if you have an index on a TIME WITH TIME ZONE column, it will
       need to be "REINDEX"ed after installing this update, because the
       fix corrects the sort order of column values.
     * Fix EXTRACT(EPOCH) for TIME WITH TIME ZONE values
     * Fix mis-display of negative fractional seconds in INTERVAL values
       This error only occurred when the --enable-integer-datetimes
       configuration switch had been used.
     * Ensure operations done during backend shutdown are counted by
       statistics collector
       This is expected to resolve reports of pg_autovacuum not vacuuming
       the system catalogs often enough -- it was not being told about
       catalog deletions caused by temporary table removal during backend
       exit.
     * Additional buffer overrun checks in plpgsql (Neil)
     * Fix pg_dump to dump trigger names containing % correctly (Neil)
     * Fix "contrib/pgcrypto" for newer OpenSSL builds (Marko Kreen)
     * Still more 64-bit fixes for "contrib/intagg"
     * Prevent incorrect optimization of functions returning RECORD
     * Prevent to_char(interval) from dumping core for month-related
       formats
     * Prevent crash on COALESCE(NULL,NULL)
     * Fix array_map to call PL functions correctly
     * Fix permission checking in "ALTER DATABASE RENAME"
     * Fix "ALTER LANGUAGE RENAME"
     * Make RemoveFromWaitQueue clean up after itself
       This fixes a lock management error that would only be visible if a
       transaction was kicked out of a wait for a lock (typically by query
       cancel) and then the holder of the lock released it within a very
       narrow window.
     * Fix problem with untyped parameter appearing in "INSERT ... SELECT"
     * Fix "CLUSTER" failure after "ALTER TABLE SET WITHOUT OIDS"
     __________________________________________________________________

                                Release 7.4.7

     Release Date: 2005-01-31

   This release contains a variety of fixes from 7.4.6, including several
   security-related issues. For information about new features in the 7.4
   major release, see the Section called Release 7.4.
     __________________________________________________________________

Migration to Version 7.4.7

   A dump/restore is not required for those running 7.4.X.
     __________________________________________________________________

Changes

     * Disallow "LOAD" to non-superusers
       On platforms that will automatically execute initialization
       functions of a shared library (this includes at least Windows and
       ELF-based Unixen), "LOAD" can be used to make the server execute
       arbitrary code. Thanks to NGS Software for reporting this.
     * Check that creator of an aggregate function has the right to
       execute the specified transition functions
       This oversight made it possible to bypass denial of EXECUTE
       permission on a function.
     * Fix security and 64-bit issues in contrib/intagg
     * Add needed STRICT marking to some contrib functions (Kris Jurka)
     * Avoid buffer overrun when plpgsql cursor declaration has too many
       parameters (Neil)
     * Fix planning error for FULL and RIGHT outer joins
       The result of the join was mistakenly supposed to be sorted the
       same as the left input. This could not only deliver mis-sorted
       output to the user, but in case of nested merge joins could give
       outright wrong answers.
     * Fix plperl for quote marks in tuple fields
     * Fix display of negative intervals in SQL and GERMAN datestyles
     * Make age(timestamptz) do calculation in local timezone not GMT
     __________________________________________________________________

                                Release 7.4.6

     Release Date: 2004-10-22

   This release contains a variety of fixes from 7.4.5. For information
   about new features in the 7.4 major release, see the Section called
   Release 7.4.
     __________________________________________________________________

Migration to Version 7.4.6

   A dump/restore is not required for those running 7.4.X.
     __________________________________________________________________

Changes

     * Repair possible failure to update hint bits on disk
       Under rare circumstances this oversight could lead to "could not
       access transaction status" failures, which qualifies it as a
       potential-data-loss bug.
     * Ensure that hashed outer join does not miss tuples
       Very large left joins using a hash join plan could fail to output
       unmatched left-side rows given just the right data distribution.
     * Disallow running pg_ctl as root
       This is to guard against any possible security issues.
     * Avoid using temp files in "/tmp" in "make_oidjoins_check"
       This has been reported as a security issue, though it's hardly
       worthy of concern since there is no reason for non-developers to
       use this script anyway.
     * Prevent forced backend shutdown from re-emitting prior command
       result
       In rare cases, a client might think that its last command had
       succeeded when it really had been aborted by forced database
       shutdown.
     * Repair bug in pg_stat_get_backend_idset
       This could lead to misbehavior in some of the system-statistics
       views.
     * Fix small memory leak in postmaster
     * Fix "expected both swapped tables to have TOAST tables" bug
       This could arise in cases such as CLUSTER after ALTER TABLE DROP
       COLUMN.
     * Prevent pg_ctl restart from adding -D multiple times
     * Fix problem with NULL values in GiST indexes
     * :: is no longer interpreted as a variable in an ECPG prepare
       statement
     __________________________________________________________________

                                Release 7.4.5

     Release Date: 2004-08-18

   This release contains one serious bug fix over 7.4.4. For information
   about new features in the 7.4 major release, see the Section called
   Release 7.4.
     __________________________________________________________________

Migration to Version 7.4.5

   A dump/restore is not required for those running 7.4.X.
     __________________________________________________________________

Changes

     * Repair possible crash during concurrent B-tree index insertions
       This patch fixes a rare case in which concurrent insertions into a
       B-tree index could result in a server panic. No permanent damage
       would result, but it's still worth a re-release. The bug does not
       exist in pre-7.4 releases.
     __________________________________________________________________

                                Release 7.4.4

     Release Date: 2004-08-16

   This release contains a variety of fixes from 7.4.3. For information
   about new features in the 7.4 major release, see the Section called
   Release 7.4.
     __________________________________________________________________

Migration to Version 7.4.4

   A dump/restore is not required for those running 7.4.X.
     __________________________________________________________________

Changes

     * Prevent possible loss of committed transactions during crash
       Due to insufficient interlocking between transaction commit and
       checkpointing, it was possible for transactions committed just
       before the most recent checkpoint to be lost, in whole or in part,
       following a database crash and restart. This is a serious bug that
       has existed since PostgreSQL 7.1.
     * Check HAVING restriction before evaluating result list of an
       aggregate plan
     * Avoid crash when session's current user ID is deleted
     * Fix hashed crosstab for zero-rows case (Joe)
     * Force cache update after renaming a column in a foreign key
     * Pretty-print UNION queries correctly
     * Make psql handle \r\n newlines properly in COPY IN
     * pg_dump handled ACLs with grant options incorrectly
     * Fix thread support for OS X and Solaris
     * Updated JDBC driver (build 215) with various fixes
     * ECPG fixes
     * Translation updates (various contributors)
     __________________________________________________________________

                                Release 7.4.3

     Release Date: 2004-06-14

   This release contains a variety of fixes from 7.4.2. For information
   about new features in the 7.4 major release, see the Section called
   Release 7.4.
     __________________________________________________________________

Migration to Version 7.4.3

   A dump/restore is not required for those running 7.4.X.
     __________________________________________________________________

Changes

     * Fix temporary memory leak when using non-hashed aggregates (Tom)
     * ECPG fixes, including some for Informix compatibility (Michael)
     * Fixes for compiling with thread-safety, particularly Solaris
       (Bruce)
     * Fix error in COPY IN termination when using the old network
       protocol (ljb)
     * Several important fixes in pg_autovacuum, including fixes for large
       tables, unsigned oids, stability, temp tables, and debug mode
       (Matthew T. O'Connor)
     * Fix problem with reading tar-format dumps on NetBSD and BSD/OS
       (Bruce)
     * Several JDBC fixes
     * Fix ALTER SEQUENCE RESTART where last_value equals the restart
       value (Tom)
     * Repair failure to recalculate nested sub-selects (Tom)
     * Fix problems with non-constant expressions in LIMIT/OFFSET
     * Support FULL JOIN with no join clause, such as X FULL JOIN Y ON
       TRUE (Tom)
     * Fix another zero-column table bug (Tom)
     * Improve handling of non-qualified identifiers in GROUP BY clauses
       in sub-selects (Tom)
       Select-list aliases within the sub-select will now take precedence
       over names from outer query levels.
     * Do not generate "NATURAL CROSS JOIN" when decompiling rules (Tom)
     * Add checks for invalid field length in binary COPY (Tom)
       This fixes a difficult-to-exploit security hole.
     * Avoid locking conflict between "ANALYZE" and "LISTEN"/"NOTIFY"
     * Numerous translation updates (various contributors)
     __________________________________________________________________

                                Release 7.4.2

     Release Date: 2004-03-08

   This release contains a variety of fixes from 7.4.1. For information
   about new features in the 7.4 major release, see the Section called
   Release 7.4.
     __________________________________________________________________

Migration to Version 7.4.2

   A dump/restore is not required for those running 7.4.X. However, it
   might be advisable as the easiest method of incorporating fixes for two
   errors that have been found in the initial contents of 7.4.X system
   catalogs. A dump/initdb/reload sequence using 7.4.2's initdb will
   automatically correct these problems.

   The more severe of the two errors is that data type anyarray has the
   wrong alignment label; this is a problem because the pg_statistic
   system catalog uses anyarray columns. The mislabeling can cause planner
   misestimations and even crashes when planning queries that involve
   WHERE clauses on double-aligned columns (such as float8 and timestamp).
   It is strongly recommended that all installations repair this error,
   either by initdb or by following the manual repair procedure given
   below.

   The lesser error is that the system view pg_settings ought to be marked
   as having public update access, to allow UPDATE pg_settings to be used
   as a substitute for "SET". This can also be fixed either by initdb or
   manually, but it is not necessary to fix unless you want to use UPDATE
   pg_settings.

   If you wish not to do an initdb, the following procedure will work for
   fixing pg_statistic. As the database superuser, do:
-- clear out old data in pg_statistic:
DELETE FROM pg_statistic;
VACUUM pg_statistic;
-- this should update 1 row:
UPDATE pg_type SET typalign = 'd' WHERE oid = 2277;
-- this should update 6 rows:
UPDATE pg_attribute SET attalign = 'd' WHERE atttypid = 2277;
--
-- At this point you MUST start a fresh backend to avoid a crash!
--
-- repopulate pg_statistic:
ANALYZE;

   This can be done in a live database, but beware that all backends
   running in the altered database must be restarted before it is safe to
   repopulate pg_statistic.

   To repair the pg_settings error, simply do:
GRANT SELECT, UPDATE ON pg_settings TO PUBLIC;

   The above procedures must be carried out in *each* database of an
   installation, including template1, and ideally including template0 as
   well. If you do not fix the template databases then any subsequently
   created databases will contain the same errors. template1 can be fixed
   in the same way as any other database, but fixing template0 requires
   additional steps. First, from any database issue:
UPDATE pg_database SET datallowconn = true WHERE datname = 'template0';

   Next connect to template0 and perform the above repair procedures.
   Finally, do:
-- re-freeze template0:
VACUUM FREEZE;
-- and protect it against future alterations:
UPDATE pg_database SET datallowconn = false WHERE datname = 'template0';
     __________________________________________________________________

Changes

   Release 7.4.2 incorporates all the fixes included in release 7.3.6,
   plus the following fixes:

     * Fix pg_statistics alignment bug that could crash optimizer
       See above for details about this problem.
     * Allow non-super users to update pg_settings
     * Fix several optimizer bugs, most of which led to "variable not
       found in subplan target lists" errors
     * Avoid out-of-memory failure during startup of large multiple index
       scan
     * Fix multibyte problem that could lead to "out of memory" error
       during "COPY IN"
     * Fix problems with "SELECT INTO" / "CREATE TABLE AS" from tables
       without OIDs
     * Fix problems with "alter_table" regression test during parallel
       testing
     * Fix problems with hitting open file limit, especially on OS X (Tom)
     * Partial fix for Turkish-locale issues
       initdb will succeed now in Turkish locale, but there are still some
       inconveniences associated with the i/I problem.
     * Make pg_dump set client encoding on restore
     * Other minor pg_dump fixes
     * Allow ecpg to again use C keywords as column names (Michael)
     * Added ecpg WHENEVER NOT_FOUND to SELECT/INSERT/UPDATE/DELETE
       (Michael)
     * Fix ecpg crash for queries calling set-returning functions
       (Michael)
     * Various other ecpg fixes (Michael)
     * Fixes for Borland compiler
     * Thread build improvements (Bruce)
     * Various other build fixes
     * Various JDBC fixes
     __________________________________________________________________

                                Release 7.4.1

     Release Date: 2003-12-22

   This release contains a variety of fixes from 7.4. For information
   about new features in the 7.4 major release, see the Section called
   Release 7.4.
     __________________________________________________________________

Migration to Version 7.4.1

   A dump/restore is *not* required for those running 7.4.

   If you want to install the fixes in the information schema you need to
   reload it into the database. This is either accomplished by
   initializing a new cluster by running "initdb", or by running the
   following sequence of SQL commands in each database (ideally including
   template1) as a superuser in psql, after installing the new release:
DROP SCHEMA information_schema CASCADE;
\i /usr/local/pgsql/share/information_schema.sql

   Substitute your installation path in the second command.
     __________________________________________________________________

Changes

     * Fixed bug in "CREATE SCHEMA" parsing in ECPG (Michael)
     * Fix compile error when "--enable-thread-safety" and "--with-perl"
       are used together (Peter)
     * Fix for subqueries that used hash joins (Tom)
       Certain subqueries that used hash joins would crash because of
       improperly shared structures.
     * Fix free space map compaction bug (Tom)
       This fixes a bug where compaction of the free space map could lead
       to a database server shutdown.
     * Fix for Borland compiler build of libpq (Bruce)
     * Fix netmask() and hostmask() to return the maximum-length masklen
       (Tom)
       Fix these functions to return values consistent with pre-7.4
       releases.
     * Several "contrib/pg_autovacuum" fixes
       Fixes include improper variable initialization, missing vacuum
       after "TRUNCATE", and duration computation overflow for long
       vacuums.
     * Allow compile of "contrib/cube" under Cygwin (Jason Tishler)
     * Fix Solaris use of password file when no passwords are defined
       (Tom)
       Fix crash on Solaris caused by use of any type of password
       authentication when no passwords were defined.
     * JDBC fix for thread problems, other fixes
     * Fix for bytea index lookups (Joe)
     * Fix information schema for bit data types (Peter)
     * Force zero_damaged_pages to be on during recovery from WAL
     * Prevent some obscure cases of "variable not in subplan target
       lists"
     * Make PQescapeBytea and byteaout consistent with each other (Joe)
     * Escape bytea output for bytes > 0x7e(Joe)
       If different client encodings are used for bytea output and input,
       it is possible for bytea values to be corrupted by the differing
       encodings. This fix escapes all bytes that might be affected.
     * Added missing SPI_finish() calls to dblink's
       get_tuple_of_interest() (Joe)
     * New Czech FAQ
     * Fix information schema view constraint_column_usage for foreign
       keys (Peter)
     * ECPG fixes (Michael)
     * Fix bug with multiple IN subqueries and joins in the subqueries
       (Tom)
     * Allow COUNT('x') to work (Tom)
     * Install ECPG include files for Informix compatibility into separate
       directory (Peter)
       Some names of ECPG include files for Informix compatibility
       conflicted with operating system include files. By installing them
       in their own directory, name conflicts have been reduced.
     * Fix SSL memory leak (Neil)
       This release fixes a bug in 7.4 where SSL didn't free all memory it
       allocated.
     * Prevent "pg_service.conf" from using service name as default dbname
       (Bruce)
     * Fix local ident authentication on FreeBSD (Tom)
     __________________________________________________________________

                                 Release 7.4

     Release Date: 2003-11-17
     __________________________________________________________________

Overview

   Major changes in this release:

   IN / NOT IN subqueries are now much more efficient
          In previous releases, IN/NOT IN subqueries were joined to the
          upper query by sequentially scanning the subquery looking for a
          match. The 7.4 code uses the same sophisticated techniques used
          by ordinary joins and so is much faster. An IN will now usually
          be as fast as or faster than an equivalent EXISTS subquery; this
          reverses the conventional wisdom that applied to previous
          releases.

   Improved GROUP BY processing by using hash buckets
          In previous releases, rows to be grouped had to be sorted first.
          The 7.4 code can do GROUP BY without sorting, by accumulating
          results into a hash table with one entry per group. It will
          still use the sort technique, however, if the hash table is
          estimated to be too large to fit in sort_mem.

   New multikey hash join capability
          In previous releases, hash joins could only occur on single
          keys. This release allows multicolumn hash joins.

   Queries using the explicit JOIN syntax are now better optimized
          Prior releases evaluated queries using the explicit JOIN syntax
          only in the order implied by the syntax. 7.4 allows full
          optimization of these queries, meaning the optimizer considers
          all possible join orderings and chooses the most efficient.
          Outer joins, however, must still follow the declared ordering.

   Faster and more powerful regular expression code
          The entire regular expression module has been replaced with a
          new version by Henry Spencer, originally written for Tcl. The
          code greatly improves performance and supports several flavors
          of regular expressions.

   Function-inlining for simple SQL functions
          Simple SQL functions can now be inlined by including their SQL
          in the main query. This improves performance by eliminating
          per-call overhead. That means simple SQL functions now behave
          like macros.

   Full support for IPv6 connections and IPv6 address data types
          Previous releases allowed only IPv4 connections, and the IP data
          types only supported IPv4 addresses. This release adds full IPv6
          support in both of these areas.

   Major improvements in SSL performance and reliability
          Several people very familiar with the SSL API have overhauled
          our SSL code to improve SSL key negotiation and error recovery.

   Make free space map efficiently reuse empty index pages, and other free
          space management improvements
          In previous releases, B-tree index pages that were left empty
          because of deleted rows could only be reused by rows with index
          values similar to the rows originally indexed on that page. In
          7.4, "VACUUM" records empty index pages and allows them to be
          reused for any future index rows.

   SQL-standard information schema
          The information schema provides a standardized and stable way to
          access information about the schema objects defined in a
          database.

   Cursors conform more closely to the SQL standard
          The commands "FETCH" and "MOVE" have been overhauled to conform
          more closely to the SQL standard.

   Cursors can exist outside transactions
          These cursors are also called holdable cursors.

   New client-to-server protocol
          The new protocol adds error codes, more status information,
          faster startup, better support for binary data transmission,
          parameter values separated from SQL commands, prepared
          statements available at the protocol level, and cleaner recovery
          from "COPY" failures. The older protocol is still supported by
          both server and clients.

   libpq and ECPG applications are now fully thread-safe
          While previous libpq releases already supported threads, this
          release improves thread safety by fixing some non-thread-safe
          code that was used during database connection startup. The
          "configure" option "--enable-thread-safety" must be used to
          enable this feature.

   New version of full-text indexing
          A new full-text indexing suite is available in
          "contrib/tsearch2".

   New autovacuum tool
          The new autovacuum tool in "contrib/autovacuum" monitors the
          database statistics tables for "INSERT"/"UPDATE"/"DELETE"
          activity and automatically vacuums tables when needed.

   Array handling has been improved and moved into the server core
          Many array limitations have been removed, and arrays behave more
          like fully-supported data types.
     __________________________________________________________________

Migration to Version 7.4

   A dump/restore using pg_dump is required for those wishing to migrate
   data from any previous release.

   Observe the following incompatibilities:

     * The server-side autocommit setting was removed and reimplemented in
       client applications and languages. Server-side autocommit was
       causing too many problems with languages and applications that
       wanted to control their own autocommit behavior, so autocommit was
       removed from the server and added to individual client APIs as
       appropriate.
     * Error message wording has changed substantially in this release.
       Significant effort was invested to make the messages more
       consistent and user-oriented. If your applications try to detect
       different error conditions by parsing the error message, you are
       strongly encouraged to use the new error code facility instead.
     * Inner joins using the explicit JOIN syntax might behave differently
       because they are now better optimized.
     * A number of server configuration parameters have been renamed for
       clarity, primarily those related to logging.
     * FETCH 0 or MOVE 0 now does nothing. In prior releases, FETCH 0
       would fetch all remaining rows, and MOVE 0 would move to the end of
       the cursor.
     * "FETCH" and "MOVE" now return the actual number of rows
       fetched/moved, or zero if at the beginning/end of the cursor. Prior
       releases would return the row count passed to the command, not the
       number of rows actually fetched or moved.
     * "COPY" now can process files that use carriage-return or
       carriage-return/line-feed end-of-line sequences. Literal
       carriage-returns and line-feeds are no longer accepted in data
       values; use \r and \n instead.
     * Trailing spaces are now trimmed when converting from type char(n)
       to varchar(n) or text. This is what most people always expected to
       happen anyway.
     * The data type float(p) now measures "p" in binary digits, not
       decimal digits. The new behavior follows the SQL standard.
     * Ambiguous date values now must match the ordering specified by the
       datestyle setting. In prior releases, a date specification of
       10/20/03 was interpreted as a date in October even if datestyle
       specified that the day should be first. 7.4 will throw an error if
       a date specification is invalid for the current setting of
       datestyle.
     * The functions oidrand, oidsrand, and userfntest have been removed.
       These functions were determined to be no longer useful.
     * String literals specifying time-varying date/time values, such as
       'now' or 'today' will no longer work as expected in column default
       expressions; they now cause the time of the table creation to be
       the default, not the time of the insertion. Functions such as
       now(), current_timestamp, or current_date should be used instead.
       In previous releases, there was special code so that strings such
       as 'now' were interpreted at "INSERT" time and not at table
       creation time, but this work around didn't cover all cases. Release
       7.4 now requires that defaults be defined properly using functions
       such as now() or current_timestamp. These will work in all
       situations.
     * The dollar sign ($) is no longer allowed in operator names. It can
       instead be a non-first character in identifiers. This was done to
       improve compatibility with other database systems, and to avoid
       syntax problems when parameter placeholders ($n) are written
       adjacent to operators.
     __________________________________________________________________

Changes

   Below you will find a detailed account of the changes between release
   7.4 and the previous major release.
     __________________________________________________________________

Server Operation Changes

     * Allow IPv6 server connections (Nigel Kukard, Johan Jordaan, Bruce,
       Tom, Kurt Roeckx, Andrew Dunstan)
     * Fix SSL to handle errors cleanly (Nathan Mueller)
       In prior releases, certain SSL API error reports were not handled
       correctly. This release fixes those problems.
     * SSL protocol security and performance improvements (Sean
       Chittenden)
       SSL key renegotiation was happening too frequently, causing poor
       SSL performance. Also, initial key handling was improved.
     * Print lock information when a deadlock is detected (Tom)
       This allows easier debugging of deadlock situations.
     * Update "/tmp" socket modification times regularly to avoid their
       removal (Tom)
       This should help prevent "/tmp" directory cleaner administration
       scripts from removing server socket files.
     * Enable PAM for Mac OS X (Aaron Hillegass)
     * Make B-tree indexes fully WAL-safe (Tom)
       In prior releases, under certain rare cases, a server crash could
       cause B-tree indexes to become corrupt. This release removes those
       last few rare cases.
     * Allow B-tree index compaction and empty page reuse (Tom)
     * Fix inconsistent index lookups during split of first root page
       (Tom)
       In prior releases, when a single-page index split into two pages,
       there was a brief period when another database session could miss
       seeing an index entry. This release fixes that rare failure case.
     * Improve free space map allocation logic (Tom)
     * Preserve free space information between server restarts (Tom)
       In prior releases, the free space map was not saved when the
       postmaster was stopped, so newly started servers had no free space
       information. This release saves the free space map, and reloads it
       when the server is restarted.
     * Add start time to pg_stat_activity (Neil)
     * New code to detect corrupt disk pages; erase with
       zero_damaged_pages (Tom)
     * New client/server protocol: faster, no username length limit, allow
       clean exit from "COPY" (Tom)
     * Add transaction status, table ID, column ID to client/server
       protocol (Tom)
     * Add binary I/O to client/server protocol (Tom)
     * Remove autocommit server setting; move to client applications (Tom)
     * New error message wording, error codes, and three levels of error
       detail (Tom, Joe, Peter)
     __________________________________________________________________

Performance Improvements

     * Add hashing for GROUP BY aggregates (Tom)
     * Make nested-loop joins be smarter about multicolumn indexes (Tom)
     * Allow multikey hash joins (Tom)
     * Improve constant folding (Tom)
     * Add ability to inline simple SQL functions (Tom)
     * Reduce memory usage for queries using complex functions (Tom)
       In prior releases, functions returning allocated memory would not
       free it until the query completed. This release allows the freeing
       of function-allocated memory when the function call completes,
       reducing the total memory used by functions.
     * Improve GEQO optimizer performance (Tom)
       This release fixes several inefficiencies in the way the GEQO
       optimizer manages potential query paths.
     * Allow IN/NOT IN to be handled via hash tables (Tom)
     * Improve NOT IN (subquery) performance (Tom)
     * Allow most IN subqueries to be processed as joins (Tom)
     * Pattern matching operations can use indexes regardless of locale
       (Peter)
       There is no way for non-ASCII locales to use the standard indexes
       for LIKE comparisons. This release adds a way to create a special
       index for LIKE.
     * Allow the postmaster to preload libraries using preload_libraries
       (Joe)
       For shared libraries that require a long time to load, this option
       is available so the library can be preloaded in the postmaster and
       inherited by all database sessions.
     * Improve optimizer cost computations, particularly for subqueries
       (Tom)
     * Avoid sort when subquery ORDER BY matches upper query (Tom)
     * Deduce that WHERE a.x = b.y AND b.y = 42 also means a.x = 42 (Tom)
     * Allow hash/merge joins on complex joins (Tom)
     * Allow hash joins for more data types (Tom)
     * Allow join optimization of explicit inner joins, disable with
       join_collapse_limit (Tom)
     * Add parameter from_collapse_limit to control conversion of
       subqueries to joins (Tom)
     * Use faster and more powerful regular expression code from Tcl
       (Henry Spencer, Tom)
     * Use bit-mapped relation sets in the optimizer (Tom)
     * Improve connection startup time (Tom)
       The new client/server protocol requires fewer network packets to
       start a database session.
     * Improve trigger/constraint performance (Stephan)
     * Improve speed of col IN (const, const, const, ...) (Tom)
     * Fix hash indexes which were broken in rare cases (Tom)
     * Improve hash index concurrency and speed (Tom)
       Prior releases suffered from poor hash index performance,
       particularly for high concurrency situations. This release fixes
       that, and the development group is interested in reports comparing
       B-tree and hash index performance.
     * Align shared buffers on 32-byte boundary for copy speed improvement
       (Manfred Spraul)
       Certain CPU's perform faster data copies when addresses are 32-byte
       aligned.
     * Data type numeric reimplemented for better performance (Tom)
       numeric used to be stored in base 100. The new code uses base
       10000, for significantly better performance.
     __________________________________________________________________

Server Configuration Changes

     * Rename server parameter server_min_messages to log_min_messages
       (Bruce)
       This was done so most parameters that control the server logs begin
       with log_.
     * Rename show_*_stats to log_*_stats (Bruce)
     * Rename show_source_port to log_source_port (Bruce)
     * Rename hostname_lookup to log_hostname (Bruce)
     * Add checkpoint_warning to warn of excessive checkpointing (Bruce)
       In prior releases, it was difficult to determine if checkpoint was
       happening too frequently. This feature adds a warning to the server
       logs when excessive checkpointing happens.
     * New read-only server parameters for localization (Tom)
     * Change debug server log messages to output as DEBUG rather than LOG
       (Bruce)
     * Prevent server log variables from being turned off by
       non-superusers (Bruce)
       This is a security feature so non-superusers cannot disable logging
       that was enabled by the administrator.
     * log_min_messages/client_min_messages now controls debug_* output
       (Bruce)
       This centralizes client debug information so all debug output can
       be sent to either the client or server logs.
     * Add Mac OS X Rendezvous server support (Chris Campbell)
       This allows Mac OS X hosts to query the network for available
       PostgreSQL servers.
     * Add ability to print only slow statements using
       log_min_duration_statement (Christopher)
       This is an often requested debugging feature that allows
       administrators to see only slow queries in their server logs.
     * Allow "pg_hba.conf" to accept netmasks in CIDR format (Andrew
       Dunstan)
       This allows administrators to merge the host IP address and netmask
       fields into a single CIDR field in "pg_hba.conf".
     * New read-only parameter is_superuser (Tom)
     * New parameter log_error_verbosity to control error detail (Tom)
       This works with the new error reporting feature to supply
       additional error information like hints, file names and line
       numbers.
     * postgres --describe-config now dumps server config variables (Aizaz
       Ahmed, Peter)
       This option is useful for administration tools that need to know
       the configuration variable names and their minimums, maximums,
       defaults, and descriptions.
     * Add new columns in pg_settings: context, type, source, min_val,
       max_val (Joe)
     * Make default shared_buffers 1000 and max_connections 100, if
       possible (Tom)
       Prior versions defaulted to 64 shared buffers so PostgreSQL would
       start on even very old systems. This release tests the amount of
       shared memory allowed by the platform and selects more reasonable
       default values if possible. Of course, users are still encouraged
       to evaluate their resource load and size shared_buffers
       accordingly.
     * New "pg_hba.conf" record type hostnossl to prevent SSL connections
       (Jon Jensen)
       In prior releases, there was no way to prevent SSL connections if
       both the client and server supported SSL. This option allows that
       capability.
     * Remove parameter geqo_random_seed (Tom)
     * Add server parameter regex_flavor to control regular expression
       processing (Tom)
     * Make "pg_ctl" better handle nonstandard ports (Greg)
     __________________________________________________________________

Query Changes

     * New SQL-standard information schema (Peter)
     * Add read-only transactions (Peter)
     * Print key name and value in foreign-key violation messages (Dmitry
       Tkach)
     * Allow users to see their own queries in pg_stat_activity (Kevin
       Brown)
       In prior releases, only the superuser could see query strings using
       pg_stat_activity. Now ordinary users can see their own query
       strings.
     * Fix aggregates in subqueries to match SQL standard (Tom)
       The SQL standard says that an aggregate function appearing within a
       nested subquery belongs to the outer query if its argument contains
       only outer-query variables. Prior PostgreSQL releases did not
       handle this fine point correctly.
     * Add option to prevent auto-addition of tables referenced in query
       (Nigel J. Andrews)
       By default, tables mentioned in the query are automatically added
       to the FROM clause if they are not already there. This is
       compatible with historic POSTGRES behavior but is contrary to the
       SQL standard. This option allows selecting standard-compatible
       behavior.
     * Allow UPDATE ... SET col = DEFAULT (Rod)
       This allows "UPDATE" to set a column to its declared default value.
     * Allow expressions to be used in LIMIT/OFFSET (Tom)
       In prior releases, LIMIT/OFFSET could only use constants, not
       expressions.
     * Implement CREATE TABLE AS EXECUTE (Neil, Peter)
     __________________________________________________________________

Object Manipulation Changes

     * Make "CREATE SEQUENCE" grammar more conforming to SQL:2003 (Neil)
     * Add statement-level triggers (Neil)
       While this allows a trigger to fire at the end of a statement, it
       does not allow the trigger to access all rows modified by the
       statement. This capability is planned for a future release.
     * Add check constraints for domains (Rod)
       This greatly increases the usefulness of domains by allowing them
       to use check constraints.
     * Add "ALTER DOMAIN" (Rod)
       This allows manipulation of existing domains.
     * Fix several zero-column table bugs (Tom)
       PostgreSQL supports zero-column tables. This fixes various bugs
       that occur when using such tables.
     * Have ALTER TABLE ... ADD PRIMARY KEY add not-null constraint (Rod)
       In prior releases, ALTER TABLE ... ADD PRIMARY would add a unique
       index, but not a not-null constraint. That is fixed in this
       release.
     * Add ALTER TABLE ... WITHOUT OIDS (Rod)
       This allows control over whether new and updated rows will have an
       OID column. This is most useful for saving storage space.
     * Add ALTER SEQUENCE to modify minimum, maximum, increment, cache,
       cycle values (Rod)
     * Add ALTER TABLE ... CLUSTER ON (Alvaro Herrera)
       This command is used by "pg_dump" to record the cluster column for
       each table previously clustered. This information is used by
       database-wide cluster to cluster all previously clustered tables.
     * Improve automatic type casting for domains (Rod, Tom)
     * Allow dollar signs in identifiers, except as first character (Tom)
     * Disallow dollar signs in operator names, so x=$1 works (Tom)
     * Allow copying table schema using LIKE subtable, also SQL:2003
       feature INCLUDING DEFAULTS (Rod)
     * Add WITH GRANT OPTION clause to "GRANT" (Peter)
       This enabled "GRANT" to give other users the ability to grant
       privileges on a object.
     __________________________________________________________________

Utility Command Changes

     * Add ON COMMIT clause to "CREATE TABLE" for temporary tables (Gavin)
       This adds the ability for a table to be dropped or all rows deleted
       on transaction commit.
     * Allow cursors outside transactions using WITH HOLD (Neil)
       In previous releases, cursors were removed at the end of the
       transaction that created them. Cursors can now be created with the
       WITH HOLD option, which allows them to continue to be accessed
       after the creating transaction has committed.
     * FETCH 0 and MOVE 0 now do nothing (Bruce)
       In previous releases, FETCH 0 fetched all remaining rows, and MOVE
       0 moved to the end of the cursor.
     * Cause "FETCH" and "MOVE" to return the number of rows
       fetched/moved, or zero if at the beginning/end of cursor, per SQL
       standard (Bruce)
       In prior releases, the row count returned by "FETCH" and "MOVE" did
       not accurately reflect the number of rows processed.
     * Properly handle SCROLL with cursors, or report an error (Neil)
       Allowing random access (both forward and backward scrolling) to
       some kinds of queries cannot be done without some additional work.
       If SCROLL is specified when the cursor is created, this additional
       work will be performed. Furthermore, if the cursor has been created
       with NO SCROLL, no random access is allowed.
     * Implement SQL-compatible options FIRST, LAST, ABSOLUTE n, RELATIVE
       n for "FETCH" and "MOVE" (Tom)
     * Allow "EXPLAIN" on "DECLARE CURSOR" (Tom)
     * Allow "CLUSTER" to use index marked as pre-clustered by default
       (Alvaro Herrera)
     * Allow "CLUSTER" to cluster all tables (Alvaro Herrera)
       This allows all previously clustered tables in a database to be
       reclustered with a single command.
     * Prevent "CLUSTER" on partial indexes (Tom)
     * Allow DOS and Mac line-endings in "COPY" files (Bruce)
     * Disallow literal carriage return as a data value,
       backslash-carriage-return and \r are still allowed (Bruce)
     * "COPY" changes (binary, \.) (Tom)
     * Recover from "COPY" failure cleanly (Tom)
     * Prevent possible memory leaks in "COPY" (Tom)
     * Make "TRUNCATE" transaction-safe (Rod)
       "TRUNCATE" can now be used inside a transaction. If the transaction
       aborts, the changes made by the "TRUNCATE" are automatically rolled
       back.
     * Allow prepare/bind of utility commands like "FETCH" and "EXPLAIN"
       (Tom)
     * Add "EXPLAIN EXECUTE" (Neil)
     * Improve "VACUUM" performance on indexes by reducing WAL traffic
       (Tom)
     * Functional indexes have been generalized into indexes on
       expressions (Tom)
       In prior releases, functional indexes only supported a simple
       function applied to one or more column names. This release allows
       any type of scalar expression.
     * Have "SHOW TRANSACTION ISOLATION" match input to "SET TRANSACTION
       ISOLATION" (Tom)
     * Have "COMMENT ON DATABASE" on nonlocal database generate a warning,
       rather than an error (Rod)
       Database comments are stored in database-local tables so comments
       on a database have to be stored in each database.
     * Improve reliability of "LISTEN"/"NOTIFY" (Tom)
     * Allow "REINDEX" to reliably reindex nonshared system catalog
       indexes (Tom)
       This allows system tables to be reindexed without the requirement
       of a standalone session, which was necessary in previous releases.
       The only tables that now require a standalone session for
       reindexing are the global system tables pg_database, pg_shadow, and
       pg_group.
     __________________________________________________________________

Data Type and Function Changes

     * New server parameter extra_float_digits to control precision
       display of floating-point numbers (Pedro Ferreira, Tom)
       This controls output precision which was causing regression testing
       problems.
     * Allow +1300 as a numeric time-zone specifier, for FJST (Tom)
     * Remove rarely used functions oidrand, oidsrand, and userfntest
       functions (Neil)
     * Add md5() function to main server, already in "contrib/pgcrypto"
       (Joe)
       An MD5 function was frequently requested. For more complex
       encryption capabilities, use "contrib/pgcrypto".
     * Increase date range of timestamp (John Cochran)
     * Change EXTRACT(EPOCH FROM timestamp) so timestamp without time zone
       is assumed to be in local time, not GMT (Tom)
     * Trap division by zero in case the operating system doesn't prevent
       it (Tom)
     * Change the numeric data type internally to base 10000 (Tom)
     * New hostmask() function (Greg Wickham)
     * Fixes for to_char() and to_timestamp() (Karel)
     * Allow functions that can take any argument data type and return any
       data type, using anyelement and anyarray (Joe)
       This allows the creation of functions that can work with any data
       type.
     * Arrays can now be specified as ARRAY[1,2,3],
       ARRAY[['a','b'],['c','d']], or ARRAY[ARRAY[ARRAY[2]]] (Joe)
     * Allow proper comparisons for arrays, including ORDER BY and
       DISTINCT support (Joe)
     * Allow indexes on array columns (Joe)
     * Allow array concatenation with || (Joe)
     * Allow WHERE qualification expr op ANY/SOME/ALL (array_expr) (Joe)
       This allows arrays to behave like a list of values, for purposes
       like SELECT * FROM tab WHERE col IN (array_val).
     * New array functions array_append, array_cat, array_lower,
       array_prepend, array_to_string, array_upper, string_to_array (Joe)
     * Allow user defined aggregates to use polymorphic functions (Joe)
     * Allow assignments to empty arrays (Joe)
     * Allow 60 in seconds fields of time, timestamp, and interval input
       values (Tom)
       Sixty-second values are needed for leap seconds.
     * Allow cidr data type to be cast to text (Tom)
     * Disallow invalid time zone names in SET TIMEZONE
     * Trim trailing spaces when char is cast to varchar or text (Tom)
     * Make float(p) measure the precision "p" in binary digits, not
       decimal digits (Tom)
     * Add IPv6 support to the inet and cidr data types (Michael Graff)
     * Add family() function to report whether address is IPv4 or IPv6
       (Michael Graff)
     * Have SHOW datestyle generate output similar to that used by SET
       datestyle (Tom)
     * Make EXTRACT(TIMEZONE) and SET/SHOW TIME ZONE follow the SQL
       convention for the sign of time zone offsets, i.e., positive is
       east from UTC (Tom)
     * Fix date_trunc('quarter', ...) (Bojthe Zoltan)
       Prior releases returned an incorrect value for this function call.
     * Make initcap() more compatible with Oracle (Mike Nolan)
       initcap() now uppercases a letter appearing after any
       non-alphanumeric character, rather than only after whitespace.
     * Allow only datestyle field order for date values not in ISO-8601
       format (Greg)
     * Add new datestyle values MDY, DMY, and YMD to set input field
       order; honor US and European for backward compatibility (Tom)
     * String literals like 'now' or 'today' will no longer work as a
       column default. Use functions such as now(), current_timestamp
       instead. (change required for prepared statements) (Tom)
     * Treat NaN as larger than any other value in min()/max() (Tom)
       NaN was already sorted after ordinary numeric values for most
       purposes, but min() and max() didn't get this right.
     * Prevent interval from suppressing :00 seconds display
     * New functions pg_get_triggerdef(prettyprint) and
       pg_conversion_is_visible() (Christopher)
     * Allow time to be specified as 040506 or 0405 (Tom)
     * Input date order must now be YYYY-MM-DD (with 4-digit year) or
       match datestyle
     * Make pg_get_constraintdef support unique, primary-key, and check
       constraints (Christopher)
     __________________________________________________________________

Server-Side Language Changes

     * Prevent PL/pgSQL crash when RETURN NEXT is used on a zero-row
       record variable (Tom)
     * Make PL/Python's spi_execute interface handle null values properly
       (Andrew Bosma)
     * Allow PL/pgSQL to declare variables of composite types without
       %ROWTYPE (Tom)
     * Fix PL/Python's _quote() function to handle big integers
     * Make PL/Python an untrusted language, now called plpythonu (Kevin
       Jacobs, Tom)
       The Python language no longer supports a restricted execution
       environment, so the trusted version of PL/Python was removed. If
       this situation changes, a version of PL/Python that can be used by
       non-superusers will be readded.
     * Allow polymorphic PL/pgSQL functions (Joe, Tom)
     * Allow polymorphic SQL functions (Joe)
     * Improved compiled function caching mechanism in PL/pgSQL with full
       support for polymorphism (Joe)
     * Add new parameter $0 in PL/pgSQL representing the function's actual
       return type (Joe)
     * Allow PL/Tcl and PL/Python to use the same trigger on multiple
       tables (Tom)
     * Fixed PL/Tcl's spi_prepare to accept fully qualified type names in
       the parameter type list (Jan)
     __________________________________________________________________

psql Changes

     * Add \pset pager always to always use pager (Greg)
       This forces the pager to be used even if the number of rows is less
       than the screen height. This is valuable for rows that wrap across
       several screen rows.
     * Improve tab completion (Rod, Ross Reedstrom, Ian Barwick)
     * Reorder \? help into groupings (Harald Armin Massa, Bruce)
     * Add backslash commands for listing schemas, casts, and conversions
       (Christopher)
     * "\encoding" now changes based on the server parameter
       client_encoding (Tom)
       In previous versions, "\encoding" was not aware of encoding changes
       made using SET client_encoding.
     * Save editor buffer into readline history (Ross)
       When "\e" is used to edit a query, the result is saved in the
       readline history for retrieval using the up arrow.
     * Improve "\d" display (Christopher)
     * Enhance HTML mode to be more standards-conforming (Greg)
     * New "\set AUTOCOMMIT off" capability (Tom)
       This takes the place of the removed server parameter autocommit.
     * New "\set VERBOSITY" to control error detail (Tom)
       This controls the new error reporting details.
     * New prompt escape sequence %x to show transaction status (Tom)
     * Long options for psql are now available on all platforms
     __________________________________________________________________

pg_dump Changes

     * Multiple pg_dump fixes, including tar format and large objects
     * Allow pg_dump to dump specific schemas (Neil)
     * Make pg_dump preserve column storage characteristics (Christopher)
       This preserves ALTER TABLE ... SET STORAGE information.
     * Make pg_dump preserve "CLUSTER" characteristics (Christopher)
     * Have pg_dumpall use "GRANT"/"REVOKE" to dump database-level
       privileges (Tom)
     * Allow pg_dumpall to support the options "-a", "-s", "-x" of pg_dump
       (Tom)
     * Prevent pg_dump from lowercasing identifiers specified on the
       command line (Tom)
     * pg_dump options "--use-set-session-authorization" and
       "--no-reconnect" now do nothing, all dumps use "SET SESSION
       AUTHORIZATION"
       pg_dump no longer reconnects to switch users, but instead always
       uses "SET SESSION AUTHORIZATION". This will reduce password
       prompting during restores.
     * Long options for pg_dump are now available on all platforms
       PostgreSQL now includes its own long-option processing routines.
     __________________________________________________________________

libpq Changes

     * Add function PQfreemem for freeing memory on Windows, suggested for
       "NOTIFY" (Bruce)
       Windows requires that memory allocated in a library be freed by a
       function in the same library, hence free() doesn't work for freeing
       memory allocated by libpq. PQfreemem is the proper way to free
       libpq memory, especially on Windows, and is recommended for other
       platforms as well.
     * Document service capability, and add sample file (Bruce)
       This allows clients to look up connection information in a central
       file on the client machine.
     * Make PQsetdbLogin have the same defaults as PQconnectdb (Tom)
     * Allow libpq to cleanly fail when result sets are too large (Tom)
     * Improve performance of function PQunescapeBytea (Ben Lamb)
     * Allow thread-safe libpq with "configure" option
       "--enable-thread-safety" (Lee Kindness, Philip Yarra)
     * Allow function pqInternalNotice to accept a format string and
       arguments instead of just a preformatted message (Tom, Sean
       Chittenden)
     * Control SSL negotiation with sslmode values disable, allow, prefer,
       and require (Jon Jensen)
     * Allow new error codes and levels of text (Tom)
     * Allow access to the underlying table and column of a query result
       (Tom)
       This is helpful for query-builder applications that want to know
       the underlying table and column names associated with a specific
       result set.
     * Allow access to the current transaction status (Tom)
     * Add ability to pass binary data directly to the server (Tom)
     * Add function PQexecPrepared and PQsendQueryPrepared functions which
       perform bind/execute of previously prepared statements (Tom)
     __________________________________________________________________

JDBC Changes

     * Allow setNull on updateable result sets
     * Allow executeBatch on a prepared statement (Barry)
     * Support SSL connections (Barry)
     * Handle schema names in result sets (Paul Sorenson)
     * Add refcursor support (Nic Ferrier)
     __________________________________________________________________

Miscellaneous Interface Changes

     * Prevent possible memory leak or core dump during libpgtcl shutdown
       (Tom)
     * Add Informix compatibility to ECPG (Michael)
       This allows ECPG to process embedded C programs that were written
       using certain Informix extensions.
     * Add type decimal to ECPG that is fixed length, for Informix
       (Michael)
     * Allow thread-safe embedded SQL programs with "configure" option
       "--enable-thread-safety" (Lee Kindness, Bruce)
       This allows multiple threads to access the database at the same
       time.
     * Moved Python client PyGreSQL to http://www.pygresql.org (Marc)
     __________________________________________________________________

Source Code Changes

     * Prevent need for separate platform geometry regression result files
       (Tom)
     * Improved PPC locking primitive (Reinhard Max)
     * New function palloc0 to allocate and clear memory (Bruce)
     * Fix locking code for s390x CPU (64-bit) (Tom)
     * Allow OpenBSD to use local ident credentials (William Ahern)
     * Make query plan trees read-only to executor (Tom)
     * Add Darwin startup scripts (David Wheeler)
     * Allow libpq to compile with Borland C++ compiler (Lester Godwin,
       Karl Waclawek)
     * Use our own version of getopt_long() if needed (Peter)
     * Convert administration scripts to C (Peter)
     * Bison >= 1.85 is now required to build the PostgreSQL grammar, if
       building from CVS
     * Merge documentation into one book (Peter)
     * Add Windows compatibility functions (Bruce)
     * Allow client interfaces to compile under MinGW (Bruce)
     * New ereport() function for error reporting (Tom)
     * Support Intel compiler on Linux (Peter)
     * Improve Linux startup scripts (Slawomir Sudnik, Darko Prenosil)
     * Add support for AMD Opteron and Itanium (Jeffrey W. Baker, Bruce)
     * Remove "--enable-recode" option from "configure"
       This was no longer needed now that we have "CREATE CONVERSION".
     * Generate a compile error if spinlock code is not found (Bruce)
       Platforms without spinlock code will now fail to compile, rather
       than silently using semaphores. This failure can be disabled with a
       new "configure" option.
     __________________________________________________________________

Contrib Changes

     * Change dbmirror license to BSD
     * Improve earthdistance (Bruno Wolff III)
     * Portability improvements to pgcrypto (Marko Kreen)
     * Prevent crash in xml (John Gray, Michael Richards)
     * Update oracle
     * Update mysql
     * Update cube (Bruno Wolff III)
     * Update earthdistance to use cube (Bruno Wolff III)
     * Update btree_gist (Oleg)
     * New tsearch2 full-text search module (Oleg, Teodor)
     * Add hash-based crosstab function to tablefuncs (Joe)
     * Add serial column to order connectby() siblings in tablefuncs
       (Nabil Sayegh,Joe)
     * Add named persistent connections to dblink (Shridhar Daithanka)
     * New pg_autovacuum allows automatic "VACUUM" (Matthew T. O'Connor)
     * Make pgbench honor environment variables PGHOST, PGPORT, PGUSER
       (Tatsuo)
     * Improve intarray (Teodor Sigaev)
     * Improve pgstattuple (Rod)
     * Fix bug in metaphone() in fuzzystrmatch
     * Improve adddepend (Rod)
     * Update spi/timetravel (Bojthe Zoltan)
     * Fix dbase "-s" option and improve non-ASCII handling (Thomas Behr,
       Marcio Smiderle)
     * Remove array module because features now included by default (Joe)
     __________________________________________________________________

                               Release 7.3.21

     Release Date: 2008-01-07

   This release contains a variety of fixes from 7.3.20, including fixes
   for significant security issues.

   This is expected to be the last PostgreSQL release in the 7.3.X series.
   Users are encouraged to update to a newer release branch soon.
     __________________________________________________________________

Migration to Version 7.3.21

   A dump/restore is not required for those running 7.3.X. However, if you
   are upgrading from a version earlier than 7.3.13, see the release notes
   for 7.3.13.
     __________________________________________________________________

Changes

     * Prevent functions in indexes from executing with the privileges of
       the user running "VACUUM", "ANALYZE", etc (Tom)
       Functions used in index expressions and partial-index predicates
       are evaluated whenever a new table entry is made. It has long been
       understood that this poses a risk of trojan-horse code execution if
       one modifies a table owned by an untrustworthy user. (Note that
       triggers, defaults, check constraints, etc. pose the same type of
       risk.) But functions in indexes pose extra danger because they will
       be executed by routine maintenance operations such as "VACUUM
       FULL", which are commonly performed automatically under a superuser
       account. For example, a nefarious user can execute code with
       superuser privileges by setting up a trojan-horse index definition
       and waiting for the next routine vacuum. The fix arranges for
       standard maintenance operations (including "VACUUM", "ANALYZE",
       "REINDEX", and "CLUSTER") to execute as the table owner rather than
       the calling user, using the same privilege-switching mechanism
       already used for SECURITY DEFINER functions. To prevent bypassing
       this security measure, execution of "SET SESSION AUTHORIZATION" and
       "SET ROLE" is now forbidden within a SECURITY DEFINER context.
       (CVE-2007-6600)
     * Require non-superusers who use "/contrib/dblink" to use only
       password authentication, as a security measure (Joe)
       The fix that appeared for this in 7.3.20 was incomplete, as it
       plugged the hole for only some "dblink" functions. (CVE-2007-6601,
       CVE-2007-3278)
     * Fix potential crash in translate() when using a multibyte database
       encoding (Tom)
     * Make "contrib/tablefunc"'s crosstab() handle NULL rowid as a
       category in its own right, rather than crashing (Joe)
     * Require a specific version of Autoconf to be used when
       re-generating the "configure" script (Peter)
       This affects developers and packagers only. The change was made to
       prevent accidental use of untested combinations of Autoconf and
       PostgreSQL versions. You can remove the version check if you really
       want to use a different Autoconf version, but it's your
       responsibility whether the result works or not.
     __________________________________________________________________

                               Release 7.3.20

     Release Date: 2007-09-17

   This release contains fixes from 7.3.19.
     __________________________________________________________________

Migration to Version 7.3.20

   A dump/restore is not required for those running 7.3.X. However, if you
   are upgrading from a version earlier than 7.3.13, see the release notes
   for 7.3.13.
     __________________________________________________________________

Changes

     * Prevent index corruption when a transaction inserts rows and then
       aborts close to the end of a concurrent "VACUUM" on the same table
       (Tom)
     * Make "CREATE DOMAIN ... DEFAULT NULL" work properly (Tom)
     * Fix crash when log_min_error_statement logging runs out of memory
       (Tom)
     * Require non-superusers who use "/contrib/dblink" to use only
       password authentication, as a security measure (Joe)
     __________________________________________________________________

                               Release 7.3.19

     Release Date: 2007-04-23

   This release contains fixes from 7.3.18, including a security fix.
     __________________________________________________________________

Migration to Version 7.3.19

   A dump/restore is not required for those running 7.3.X. However, if you
   are upgrading from a version earlier than 7.3.13, see the release notes
   for 7.3.13.
     __________________________________________________________________

Changes

     * Support explicit placement of the temporary-table schema within
       search_path, and disable searching it for functions and operators
       (Tom)
       This is needed to allow a security-definer function to set a truly
       secure value of search_path. Without it, an unprivileged SQL user
       can use temporary objects to execute code with the privileges of
       the security-definer function (CVE-2007-2138). See "CREATE
       FUNCTION" for more information.
     * Fix potential-data-corruption bug in how "VACUUM FULL" handles
       "UPDATE" chains (Tom, Pavan Deolasee)
     __________________________________________________________________

                               Release 7.3.18

     Release Date: 2007-02-05

   This release contains a variety of fixes from 7.3.17, including a
   security fix.
     __________________________________________________________________

Migration to Version 7.3.18

   A dump/restore is not required for those running 7.3.X. However, if you
   are upgrading from a version earlier than 7.3.13, see the release notes
   for 7.3.13.
     __________________________________________________________________

Changes

     * Remove security vulnerability that allowed connected users to read
       backend memory (Tom)
       The vulnerability involves changing the data type of a table column
       used in a SQL function (CVE-2007-0555). This error can easily be
       exploited to cause a backend crash, and in principle might be used
       to read database content that the user should not be able to
       access.
     * Fix rare bug wherein btree index page splits could fail due to
       choosing an infeasible split point (Heikki Linnakangas)
     * Tighten security of multi-byte character processing for UTF8
       sequences over three bytes long (Tom)
     __________________________________________________________________

                               Release 7.3.17

     Release Date: 2007-01-08

   This release contains a variety of fixes from 7.3.16.
     __________________________________________________________________

Migration to Version 7.3.17

   A dump/restore is not required for those running 7.3.X. However, if you
   are upgrading from a version earlier than 7.3.13, see the release notes
   for 7.3.13.
     __________________________________________________________________

Changes

     * to_number() and to_char(numeric) are now STABLE, not IMMUTABLE, for
       new initdb installs (Tom)
       This is because lc_numeric can potentially change the output of
       these functions.
     * Improve index usage of regular expressions that use parentheses
       (Tom)
       This improves psql \d performance also.
     __________________________________________________________________

                               Release 7.3.16

     Release Date: 2006-10-16

   This release contains a variety of fixes from 7.3.15.
     __________________________________________________________________

Migration to Version 7.3.16

   A dump/restore is not required for those running 7.3.X. However, if you
   are upgrading from a version earlier than 7.3.13, see the release notes
   for 7.3.13.
     __________________________________________________________________

Changes

     * Fix corner cases in pattern matching for psql's \d commands
     * Fix index-corrupting bugs in /contrib/ltree (Teodor)
     * Back-port 7.4 spinlock code to improve performance and support
       64-bit architectures better
     * Fix SSL-related memory leak in libpq
     * Fix backslash escaping in /contrib/dbmirror
     * Adjust regression tests for recent changes in US DST laws
     __________________________________________________________________

                               Release 7.3.15

     Release Date: 2006-05-23

   This release contains a variety of fixes from 7.3.14, including patches
   for extremely serious security issues.
     __________________________________________________________________

Migration to Version 7.3.15

   A dump/restore is not required for those running 7.3.X. However, if you
   are upgrading from a version earlier than 7.3.13, see the release notes
   for 7.3.13.

   Full security against the SQL-injection attacks described in
   CVE-2006-2313 and CVE-2006-2314 might require changes in application
   code. If you have applications that embed untrustworthy strings into
   SQL commands, you should examine them as soon as possible to ensure
   that they are using recommended escaping techniques. In most cases,
   applications should be using subroutines provided by libraries or
   drivers (such as libpq's PQescapeStringConn()) to perform string
   escaping, rather than relying on ad hoc code to do it.
     __________________________________________________________________

Changes

     * Change the server to reject invalidly-encoded multibyte characters
       in all cases (Tatsuo, Tom)
       While PostgreSQL has been moving in this direction for some time,
       the checks are now applied uniformly to all encodings and all
       textual input, and are now always errors not merely warnings. This
       change defends against SQL-injection attacks of the type described
       in CVE-2006-2313.
     * Reject unsafe uses of \' in string literals
       As a server-side defense against SQL-injection attacks of the type
       described in CVE-2006-2314, the server now only accepts '' and not
       \' as a representation of ASCII single quote in SQL string
       literals. By default, \' is rejected only when client_encoding is
       set to a client-only encoding (SJIS, BIG5, GBK, GB18030, or UHC),
       which is the scenario in which SQL injection is possible. A new
       configuration parameter backslash_quote is available to adjust this
       behavior when needed. Note that full security against CVE-2006-2314
       might require client-side changes; the purpose of backslash_quote
       is in part to make it obvious that insecure clients are insecure.
     * Modify libpq's string-escaping routines to be aware of encoding
       considerations
       This fixes libpq-using applications for the security issues
       described in CVE-2006-2313 and CVE-2006-2314. Applications that use
       multiple PostgreSQL connections concurrently should migrate to
       PQescapeStringConn() and PQescapeByteaConn() to ensure that
       escaping is done correctly for the settings in use in each database
       connection. Applications that do string escaping "by hand" should
       be modified to rely on library routines instead.
     * Fix some incorrect encoding conversion functions
       win1251_to_iso, alt_to_iso, euc_tw_to_big5, euc_tw_to_mic,
       mic_to_euc_tw were all broken to varying extents.
     * Clean up stray remaining uses of \' in strings (Bruce, Jan)
     * Fix server to use custom DH SSL parameters correctly (Michael Fuhr)
     * Fix various minor memory leaks
     __________________________________________________________________

                               Release 7.3.14

     Release Date: 2006-02-14

   This release contains a variety of fixes from 7.3.13.
     __________________________________________________________________

Migration to Version 7.3.14

   A dump/restore is not required for those running 7.3.X. However, if you
   are upgrading from a version earlier than 7.3.13, see the release notes
   for 7.3.13.
     __________________________________________________________________

Changes

     * Fix potential crash in "SET SESSION AUTHORIZATION" (CVE-2006-0553)
       An unprivileged user could crash the server process, resulting in
       momentary denial of service to other users, if the server has been
       compiled with Asserts enabled (which is not the default). Thanks to
       Akio Ishida for reporting this problem.
     * Fix bug with row visibility logic in self-inserted rows (Tom)
       Under rare circumstances a row inserted by the current command
       could be seen as already valid, when it should not be. Repairs bug
       created in 7.3.11 release.
     * Fix race condition that could lead to "file already exists" errors
       during pg_clog file creation (Tom)
     * Fix to allow restoring dumps that have cross-schema references to
       custom operators (Tom)
     * Portability fix for testing presence of finite and isinf during
       configure (Tom)
     __________________________________________________________________

                               Release 7.3.13

     Release Date: 2006-01-09

   This release contains a variety of fixes from 7.3.12.
     __________________________________________________________________

Migration to Version 7.3.13

   A dump/restore is not required for those running 7.3.X. However, if you
   are upgrading from a version earlier than 7.3.10, see the release notes
   for 7.3.10. Also, you might need to "REINDEX" indexes on textual
   columns after updating, if you are affected by the locale or plperl
   issues described below.
     __________________________________________________________________

Changes

     * Fix character string comparison for locales that consider different
       character combinations as equal, such as Hungarian (Tom)
       This might require "REINDEX" to fix existing indexes on textual
       columns.
     * Set locale environment variables during postmaster startup to
       ensure that plperl won't change the locale later
       This fixes a problem that occurred if the postmaster was started
       with environment variables specifying a different locale than what
       initdb had been told. Under these conditions, any use of plperl was
       likely to lead to corrupt indexes. You might need "REINDEX" to fix
       existing indexes on textual columns if this has happened to you.
     * Fix longstanding bug in strpos() and regular expression handling in
       certain rarely used Asian multi-byte character sets (Tatsuo)
     * Fix bug in "/contrib/pgcrypto" gen_salt, which caused it not to use
       all available salt space for MD5 and XDES algorithms (Marko Kreen,
       Solar Designer)
       Salts for Blowfish and standard DES are unaffected.
     * Fix "/contrib/dblink" to throw an error, rather than crashing, when
       the number of columns specified is different from what's actually
       returned by the query (Joe)
     __________________________________________________________________

                               Release 7.3.12

     Release Date: 2005-12-12

   This release contains a variety of fixes from 7.3.11.
     __________________________________________________________________

Migration to Version 7.3.12

   A dump/restore is not required for those running 7.3.X. However, if you
   are upgrading from a version earlier than 7.3.10, see the release notes
   for 7.3.10.
     __________________________________________________________________

Changes

     * Fix race condition in transaction log management
       There was a narrow window in which an I/O operation could be
       initiated for the wrong page, leading to an Assert failure or data
       corruption.
     * "/contrib/ltree" fixes (Teodor)
     * Fix longstanding planning error for outer joins
       This bug sometimes caused a bogus error "RIGHT JOIN is only
       supported with merge-joinable join conditions".
     * Prevent core dump in pg_autovacuum when a table has been dropped
     __________________________________________________________________

                               Release 7.3.11

     Release Date: 2005-10-04

   This release contains a variety of fixes from 7.3.10.
     __________________________________________________________________

Migration to Version 7.3.11

   A dump/restore is not required for those running 7.3.X. However, if you
   are upgrading from a version earlier than 7.3.10, see the release notes
   for 7.3.10.
     __________________________________________________________________

Changes

     * Fix error that allowed "VACUUM" to remove ctid chains too soon, and
       add more checking in code that follows ctid links
       This fixes a long-standing problem that could cause crashes in very
       rare circumstances.
     * Fix CHAR() to properly pad spaces to the specified length when
       using a multiple-byte character set (Yoshiyuki Asaba)
       In prior releases, the padding of CHAR() was incorrect because it
       only padded to the specified number of bytes without considering
       how many characters were stored.
     * Fix missing rows in queries like UPDATE a=... WHERE a... with GiST
       index on column a
     * Improve checking for partially-written WAL pages
     * Improve robustness of signal handling when SSL is enabled
     * Various memory leakage fixes
     * Various portability improvements
     * Fix PL/pgSQL to handle var := var correctly when the variable is of
       pass-by-reference type
     __________________________________________________________________

                               Release 7.3.10

     Release Date: 2005-05-09

   This release contains a variety of fixes from 7.3.9, including several
   security-related issues.
     __________________________________________________________________

Migration to Version 7.3.10

   A dump/restore is not required for those running 7.3.X. However, it is
   one possible way of handling a significant security problem that has
   been found in the initial contents of 7.3.X system catalogs. A
   dump/initdb/reload sequence using 7.3.10's initdb will automatically
   correct this problem.

   The security problem is that the built-in character set encoding
   conversion functions can be invoked from SQL commands by unprivileged
   users, but the functions were not designed for such use and are not
   secure against malicious choices of arguments. The fix involves
   changing the declared parameter list of these functions so that they
   can no longer be invoked from SQL commands. (This does not affect their
   normal use by the encoding conversion machinery.) It is strongly
   recommended that all installations repair this error, either by initdb
   or by following the manual repair procedure given below. The error at
   least allows unprivileged database users to crash their server process,
   and might allow unprivileged users to gain the privileges of a database
   superuser.

   If you wish not to do an initdb, perform the following procedure
   instead. As the database superuser, do:
BEGIN;
UPDATE pg_proc SET proargtypes[3] = 'internal'::regtype
WHERE pronamespace = 11 AND pronargs = 5
     AND proargtypes[2] = 'cstring'::regtype;
-- The command should report having updated 90 rows;
-- if not, rollback and investigate instead of committing!
COMMIT;

   The above procedure must be carried out in *each* database of an
   installation, including template1, and ideally including template0 as
   well. If you do not fix the template databases then any subsequently
   created databases will contain the same error. template1 can be fixed
   in the same way as any other database, but fixing template0 requires
   additional steps. First, from any database issue:
UPDATE pg_database SET datallowconn = true WHERE datname = 'template0';

   Next connect to template0 and perform the above repair procedure.
   Finally, do:
-- re-freeze template0:
VACUUM FREEZE;
-- and protect it against future alterations:
UPDATE pg_database SET datallowconn = false WHERE datname = 'template0';
     __________________________________________________________________

Changes

     * Change encoding function signature to prevent misuse
     * Repair ancient race condition that allowed a transaction to be seen
       as committed for some purposes (eg SELECT FOR UPDATE) slightly
       sooner than for other purposes
       This is an extremely serious bug since it could lead to apparent
       data inconsistencies being briefly visible to applications.
     * Repair race condition between relation extension and VACUUM
       This could theoretically have caused loss of a page's worth of
       freshly-inserted data, although the scenario seems of very low
       probability. There are no known cases of it having caused more than
       an Assert failure.
     * Fix comparisons of TIME WITH TIME ZONE values
       The comparison code was wrong in the case where the
       --enable-integer-datetimes configuration switch had been used.
       NOTE: if you have an index on a TIME WITH TIME ZONE column, it will
       need to be "REINDEX"ed after installing this update, because the
       fix corrects the sort order of column values.
     * Fix EXTRACT(EPOCH) for TIME WITH TIME ZONE values
     * Fix mis-display of negative fractional seconds in INTERVAL values
       This error only occurred when the --enable-integer-datetimes
       configuration switch had been used.
     * Additional buffer overrun checks in plpgsql (Neil)
     * Fix pg_dump to dump trigger names containing % correctly (Neil)
     * Prevent to_char(interval) from dumping core for month-related
       formats
     * Fix "contrib/pgcrypto" for newer OpenSSL builds (Marko Kreen)
     * Still more 64-bit fixes for "contrib/intagg"
     * Prevent incorrect optimization of functions returning RECORD
     __________________________________________________________________

                                Release 7.3.9

     Release Date: 2005-01-31

   This release contains a variety of fixes from 7.3.8, including several
   security-related issues.
     __________________________________________________________________

Migration to Version 7.3.9

   A dump/restore is not required for those running 7.3.X.
     __________________________________________________________________

Changes

     * Disallow "LOAD" to non-superusers
       On platforms that will automatically execute initialization
       functions of a shared library (this includes at least Windows and
       ELF-based Unixen), "LOAD" can be used to make the server execute
       arbitrary code. Thanks to NGS Software for reporting this.
     * Check that creator of an aggregate function has the right to
       execute the specified transition functions
       This oversight made it possible to bypass denial of EXECUTE
       permission on a function.
     * Fix security and 64-bit issues in contrib/intagg
     * Add needed STRICT marking to some contrib functions (Kris Jurka)
     * Avoid buffer overrun when plpgsql cursor declaration has too many
       parameters (Neil)
     * Fix planning error for FULL and RIGHT outer joins
       The result of the join was mistakenly supposed to be sorted the
       same as the left input. This could not only deliver mis-sorted
       output to the user, but in case of nested merge joins could give
       outright wrong answers.
     * Fix plperl for quote marks in tuple fields
     * Fix display of negative intervals in SQL and GERMAN datestyles
     __________________________________________________________________

                                Release 7.3.8

     Release Date: 2004-10-22

   This release contains a variety of fixes from 7.3.7.
     __________________________________________________________________

Migration to Version 7.3.8

   A dump/restore is not required for those running 7.3.X.
     __________________________________________________________________

Changes

     * Repair possible failure to update hint bits on disk
       Under rare circumstances this oversight could lead to "could not
       access transaction status" failures, which qualifies it as a
       potential-data-loss bug.
     * Ensure that hashed outer join does not miss tuples
       Very large left joins using a hash join plan could fail to output
       unmatched left-side rows given just the right data distribution.
     * Disallow running pg_ctl as root
       This is to guard against any possible security issues.
     * Avoid using temp files in /tmp in make_oidjoins_check
       This has been reported as a security issue, though it's hardly
       worthy of concern since there is no reason for non-developers to
       use this script anyway.
     __________________________________________________________________

                                Release 7.3.7

     Release Date: 2004-08-16

   This release contains one critical fix over 7.3.6, and some minor
   items.
     __________________________________________________________________

Migration to Version 7.3.7

   A dump/restore is not required for those running 7.3.X.
     __________________________________________________________________

Changes

     * Prevent possible loss of committed transactions during crash
       Due to insufficient interlocking between transaction commit and
       checkpointing, it was possible for transactions committed just
       before the most recent checkpoint to be lost, in whole or in part,
       following a database crash and restart. This is a serious bug that
       has existed since PostgreSQL 7.1.
     * Remove asymmetrical word processing in tsearch (Teodor)
     * Properly schema-qualify function names when pg_dump'ing a CAST
     __________________________________________________________________

                                Release 7.3.6

     Release Date: 2004-03-02

   This release contains a variety of fixes from 7.3.5.
     __________________________________________________________________

Migration to Version 7.3.6

   A dump/restore is *not* required for those running 7.3.*.
     __________________________________________________________________

Changes

     * Revert erroneous changes in rule permissions checking
       A patch applied in 7.3.3 to fix a corner case in rule permissions
       checks turns out to have disabled rule-related permissions checks
       in many not-so-corner cases. This would for example allow users to
       insert into views they weren't supposed to have permission to
       insert into. We have therefore reverted the 7.3.3 patch. The
       original bug will be fixed in 8.0.
     * Repair incorrect order of operations in GetNewTransactionId()
       This bug could result in failure under out-of-disk-space
       conditions, including inability to restart even after disk space is
       freed.
     * Ensure configure selects -fno-strict-aliasing even when an external
       value for CFLAGS is supplied
       On some platforms, building with -fstrict-aliasing causes bugs.
     * Make pg_restore handle 64-bit off_t correctly
       This bug prevented proper restoration from archive files exceeding
       4 GB.
     * Make contrib/dblink not assume that local and remote type OIDs
       match (Joe)
     * Quote connectby()'s start_with argument properly (Joe)
     * Don't crash when a rowtype argument to a plpgsql function is NULL
     * Avoid generating invalid character encoding sequences in corner
       cases when planning LIKE operations
     * Ensure text_position() cannot scan past end of source string in
       multibyte cases (Korea PostgreSQL Users' Group)
     * Fix index optimization and selectivity estimates for LIKE
       operations on bytea columns (Joe)
     __________________________________________________________________

                                Release 7.3.5

     Release Date: 2003-12-03

   This has a variety of fixes from 7.3.4.
     __________________________________________________________________

Migration to Version 7.3.5

   A dump/restore is *not* required for those running 7.3.*.
     __________________________________________________________________

Changes

     * Force zero_damaged_pages to be on during recovery from WAL
     * Prevent some obscure cases of "variable not in subplan target
       lists"
     * Force stats processes to detach from shared memory, ensuring
       cleaner shutdown
     * Make PQescapeBytea and byteaout consistent with each other (Joe)
     * Added missing SPI_finish() calls to dblink's
       get_tuple_of_interest() (Joe)
     * Fix for possible foreign key violation when rule rewrites INSERT
       (Jan)
     * Support qualified type names in PL/Tcl's spi_prepare command (Jan)
     * Make pg_dump handle a procedural language handler located in
       pg_catalog
     * Make pg_dump handle cases where a custom opclass is in another
       schema
     * Make pg_dump dump binary-compatible casts correctly (Jan)
     * Fix insertion of expressions containing subqueries into rule bodies
     * Fix incorrect argument processing in clusterdb script (Anand
       Ranganathan)
     * Fix problems with dropped columns in plpython triggers
     * Repair problems with to_char() reading past end of its input string
       (Karel)
     * Fix GB18030 mapping errors (Tatsuo)
     * Fix several problems with SSL error handling and asynchronous SSL
       I/O
     * Remove ability to bind a list of values to a single parameter in
       JDBC (prevents possible SQL-injection attacks)
     * Fix some errors in HAVE_INT64_TIMESTAMP code paths
     * Fix corner case for btree search in parallel with first root page
       split
     __________________________________________________________________

                                Release 7.3.4

     Release Date: 2003-07-24

   This has a variety of fixes from 7.3.3.
     __________________________________________________________________

Migration to Version 7.3.4

   A dump/restore is *not* required for those running 7.3.*.
     __________________________________________________________________

Changes

     * Repair breakage in timestamp-to-date conversion for dates before
       2000
     * Prevent rare possibility of server startup failure (Tom)
     * Fix bugs in interval-to-time conversion (Tom)
     * Add constraint names in a few places in pg_dump (Rod)
     * Improve performance of functions with many parameters (Tom)
     * Fix to_ascii() buffer overruns (Tom)
     * Prevent restore of database comments from throwing an error (Tom)
     * Work around buggy strxfrm() present in some Solaris releases (Tom)
     * Properly escape jdbc setObject() strings to improve security
       (Barry)
     __________________________________________________________________

                                Release 7.3.3

     Release Date: 2003-05-22

   This release contains a variety of fixes for version 7.3.2.
     __________________________________________________________________

Migration to Version 7.3.3

   A dump/restore is *not* required for those running version 7.3.*.
     __________________________________________________________________

Changes

     * Repair sometimes-incorrect computation of StartUpID after a crash
     * Avoid slowness with lots of deferred triggers in one transaction
       (Stephan)
     * Don't lock referenced row when "UPDATE" doesn't change foreign
       key's value (Jan)
     * Use "-fPIC" not "-fpic" on Sparc (Tom Callaway)
     * Repair lack of schema-awareness in contrib/reindexdb
     * Fix contrib/intarray error for zero-element result array (Teodor)
     * Ensure createuser script will exit on control-C (Oliver)
     * Fix errors when the type of a dropped column has itself been
       dropped
     * "CHECKPOINT" does not cause database panic on failure in
       noncritical steps
     * Accept 60 in seconds fields of timestamp, time, interval input
       values
     * Issue notice, not error, if TIMESTAMP, TIME, or INTERVAL precision
       too large
     * Fix abstime-to-time cast function (fix is not applied unless you
       initdb)
     * Fix pg_proc entry for timestampt_izone (fix is not applied unless
       you initdb)
     * Make EXTRACT(EPOCH FROM timestamp without time zone) treat input as
       local time
     * "'now'::timestamptz" gave wrong answer if timezone changed earlier
       in transaction
     * HAVE_INT64_TIMESTAMP code for time with timezone overwrote its
       input
     * Accept "GLOBAL TEMP/TEMPORARY" as a synonym for "TEMPORARY"
     * Avoid improper schema-privilege-check failure in foreign-key
       triggers
     * Fix bugs in foreign-key triggers for "SET DEFAULT" action
     * Fix incorrect time-qual check in row fetch for "UPDATE" and
       "DELETE" triggers
     * Foreign-key clauses were parsed but ignored in "ALTER TABLE ADD
       COLUMN"
     * Fix createlang script breakage for case where handler function
       already exists
     * Fix misbehavior on zero-column tables in pg_dump, COPY, ANALYZE,
       other places
     * Fix misbehavior of func_error() on type names containing '%'
     * Fix misbehavior of replace() on strings containing '%'
     * Regular-expression patterns containing certain multibyte characters
       failed
     * Account correctly for "NULL"s in more cases in join size estimation
     * Avoid conflict with system definition of isblank() function or
       macro
     * Fix failure to convert large code point values in EUC_TW
       conversions (Tatsuo)
     * Fix error recovery for SSL_read/SSL_write calls
     * Don't do early constant-folding of type coercion expressions
     * Validate page header fields immediately after reading in any page
     * Repair incorrect check for ungrouped variables in unnamed joins
     * Fix buffer overrun in to_ascii (Guido Notari)
     * contrib/ltree fixes (Teodor)
     * Fix core dump in deadlock detection on machines where char is
       unsigned
     * Avoid running out of buffers in many-way indexscan (bug introduced
       in 7.3)
     * Fix planner's selectivity estimation functions to handle domains
       properly
     * Fix dbmirror memory-allocation bug (Steven Singer)
     * Prevent infinite loop in ln(numeric) due to roundoff error
     * "GROUP BY" got confused if there were multiple equal GROUP BY items
     * Fix bad plan when inherited "UPDATE"/"DELETE" references another
       inherited table
     * Prevent clustering on incomplete (partial or non-NULL-storing)
       indexes
     * Service shutdown request at proper time if it arrives while still
       starting up
     * Fix left-links in temporary indexes (could make backwards scans
       miss entries)
     * Fix incorrect handling of client_encoding setting in
       postgresql.conf (Tatsuo)
     * Fix failure to respond to "pg_ctl stop -m fast" after
       Async_NotifyHandler runs
     * Fix SPI for case where rule contains multiple statements of the
       same type
     * Fix problem with checking for wrong type of access privilege in
       rule query
     * Fix problem with "EXCEPT" in "CREATE RULE"
     * Prevent problem with dropping temp tables having serial columns
     * Fix replace_vars_with_subplan_refs failure in complex views
     * Fix regexp slowness in single-byte encodings (Tatsuo)
     * Allow qualified type names in "CREATE CAST" and " DROP CAST"
     * Accept SETOF type[], which formerly had to be written SETOF _type
     * Fix pg_dump core dump in some cases with procedural languages
     * Force ISO datestyle in pg_dump output, for portability (Oliver)
     * pg_dump failed to handle error return from lo_read (Oleg Drokin)
     * pg_dumpall failed with groups having no members (Nick Eskelinen)
     * pg_dumpall failed to recognize --globals-only switch
     * pg_restore failed to restore blobs if -X disable-triggers is
       specified
     * Repair intrafunction memory leak in plpgsql
     * pltcl's "elog" command dumped core if given wrong parameters (Ian
       Harding)
     * plpython used wrong value of atttypmod (Brad McLean)
     * Fix improper quoting of boolean values in Python interface (D'Arcy)
     * Added addDataType() method to PGConnection interface for JDBC
     * Fixed various problems with updateable ResultSets for JDBC (Shawn
       Green)
     * Fixed various problems with DatabaseMetaData for JDBC (Kris Jurka,
       Peter Royal)
     * Fixed problem with parsing table ACLs in JDBC
     * Better error message for character set conversion problems in JDBC
     __________________________________________________________________

                                Release 7.3.2

     Release Date: 2003-02-04

   This release contains a variety of fixes for version 7.3.1.
     __________________________________________________________________

Migration to Version 7.3.2

   A dump/restore is *not* required for those running version 7.3.*.
     __________________________________________________________________

Changes

     * Restore creation of OID column in CREATE TABLE AS / SELECT INTO
     * Fix pg_dump core dump when dumping views having comments
     * Dump DEFERRABLE/INITIALLY DEFERRED constraints properly
     * Fix UPDATE when child table's column numbering differs from parent
     * Increase default value of max_fsm_relations
     * Fix problem when fetching backwards in a cursor for a single-row
       query
     * Make backward fetch work properly with cursor on SELECT DISTINCT
       query
     * Fix problems with loading pg_dump files containing contrib/lo usage
     * Fix problem with all-numeric user names
     * Fix possible memory leak and core dump during disconnect in
       libpgtcl
     * Make plpython's spi_execute command handle nulls properly (Andrew
       Bosma)
     * Adjust plpython error reporting so that its regression test passes
       again
     * Work with bison 1.875
     * Handle mixed-case names properly in plpgsql's %type (Neil)
     * Fix core dump in pltcl when executing a query rewritten by a rule
     * Repair array subscript overruns (per report from Yichen Xie)
     * Reduce MAX_TIME_PRECISION from 13 to 10 in floating-point case
     * Correctly case-fold variable names in per-database and per-user
       settings
     * Fix coredump in plpgsql's RETURN NEXT when SELECT into record
       returns no rows
     * Fix outdated use of pg_type.typprtlen in python client interface
     * Correctly handle fractional seconds in timestamps in JDBC driver
     * Improve performance of getImportedKeys() in JDBC
     * Make shared-library symlinks work standardly on HPUX (Giles)
     * Repair inconsistent rounding behavior for timestamp, time, interval
     * SSL negotiation fixes (Nathan Mueller)
     * Make libpq's ~/.pgpass feature work when connecting with
       PQconnectDB
     * Update my2pg, ora2pg
     * Translation updates
     * Add casts between types lo and oid in contrib/lo
     * fastpath code now checks for privilege to call function
     __________________________________________________________________

                                Release 7.3.1

     Release Date: 2002-12-18

   This release contains a variety of fixes for version 7.3.
     __________________________________________________________________

Migration to Version 7.3.1

   A dump/restore is *not* required for those running version 7.3.
   However, it should be noted that the main PostgreSQL interface library,
   libpq, has a new major version number for this release, which might
   require recompilation of client code in certain cases.
     __________________________________________________________________

Changes

     * Fix a core dump of COPY TO when client/server encodings don't match
       (Tom)
     * Allow pg_dump to work with pre-7.2 servers (Philip)
     * contrib/adddepend fixes (Tom)
     * Fix problem with deletion of per-user/per-database config settings
       (Tom)
     * contrib/vacuumlo fix (Tom)
     * Allow 'password' encryption even when pg_shadow contains MD5
       passwords (Bruce)
     * contrib/dbmirror fix (Steven Singer)
     * Optimizer fixes (Tom)
     * contrib/tsearch fixes (Teodor Sigaev, Magnus)
     * Allow locale names to be mixed case (Nicolai Tufar)
     * Increment libpq library's major version number (Bruce)
     * pg_hba.conf error reporting fixes (Bruce, Neil)
     * Add SCO Openserver 5.0.4 as a supported platform (Bruce)
     * Prevent EXPLAIN from crashing server (Tom)
     * SSL fixes (Nathan Mueller)
     * Prevent composite column creation via ALTER TABLE (Tom)
     __________________________________________________________________

                                 Release 7.3

     Release Date: 2002-11-27
     __________________________________________________________________

Overview

   Major changes in this release:

   Schemas
          Schemas allow users to create objects in separate namespaces, so
          two people or applications can have tables with the same name.
          There is also a public schema for shared tables. Table/index
          creation can be restricted by removing privileges on the public
          schema.

   Drop Column
          PostgreSQL now supports the ALTER TABLE ... DROP COLUMN
          functionality.

   Table Functions
          Functions returning multiple rows and/or multiple columns are
          now much easier to use than before. You can call such a "table
          function" in the SELECT FROM clause, treating its output like a
          table. Also, PL/pgSQL functions can now return sets.

   Prepared Queries
          PostgreSQL now supports prepared queries, for improved
          performance.

   Dependency Tracking
          PostgreSQL now records object dependencies, which allows
          improvements in many areas. "DROP" statements now take either
          CASCADE or RESTRICT to control whether dependent objects are
          also dropped.

   Privileges
          Functions and procedural languages now have privileges, and
          functions can be defined to run with the privileges of their
          creator.

   Internationalization
          Both multibyte and locale support are now always enabled.

   Logging
          A variety of logging options have been enhanced.

   Interfaces
          A large number of interfaces have been moved to
          http://gborg.postgresql.org where they can be developed and
          released independently.

   Functions/Identifiers
          By default, functions can now take up to 32 parameters, and
          identifiers can be up to 63 bytes long. Also, OPAQUE is now
          deprecated: there are specific "pseudo-datatypes" to represent
          each of the former meanings of OPAQUE in function argument and
          result types.
     __________________________________________________________________

Migration to Version 7.3

   A dump/restore using pg_dump is required for those wishing to migrate
   data from any previous release. If your application examines the system
   catalogs, additional changes will be required due to the introduction
   of schemas in 7.3; for more information, see:
   http://developer.postgresql.org/~momjian/upgrade_tips_7.3.

   Observe the following incompatibilities:

     * Pre-6.3 clients are no longer supported.
     * "pg_hba.conf" now has a column for the user name and additional
       features. Existing files need to be adjusted.
     * Several "postgresql.conf" logging parameters have been renamed.
     * LIMIT #,# has been disabled; use LIMIT # OFFSET #.
     * "INSERT" statements with column lists must specify a value for each
       specified column. For example, INSERT INTO tab (col1, col2) VALUES
       ('val1') is now invalid. It's still allowed to supply fewer columns
       than expected if the "INSERT" does not have a column list.
     * serial columns are no longer automatically UNIQUE; thus, an index
       will not automatically be created.
     * A "SET" command inside an aborted transaction is now rolled back.
     * "COPY" no longer considers missing trailing columns to be null. All
       columns need to be specified. (However, one can achieve a similar
       effect by specifying a column list in the "COPY" command.)
     * The data type timestamp is now equivalent to timestamp without time
       zone, instead of timestamp with time zone.
     * Pre-7.3 databases loaded into 7.3 will not have the new object
       dependencies for serial columns, unique constraints, and foreign
       keys. See the directory "contrib/adddepend/" for a detailed
       description and a script that will add such dependencies.
     * An empty string ('') is no longer allowed as the input into an
       integer field. Formerly, it was silently interpreted as 0.
     __________________________________________________________________

Changes

Server Operation

     * Add pg_locks view to show locks (Neil)
     * Security fixes for password negotiation memory allocation (Neil)
     * Remove support for version 0 FE/BE protocol (PostgreSQL 6.2 and
       earlier) (Tom)
     * Reserve the last few backend slots for superusers, add parameter
       superuser_reserved_connections to control this (Nigel J. Andrews)
     __________________________________________________________________

Performance

     * Improve startup by calling localtime() only once (Tom)
     * Cache system catalog information in flat files for faster startup
       (Tom)
     * Improve caching of index information (Tom)
     * Optimizer improvements (Tom, Fernando Nasser)
     * Catalog caches now store failed lookups (Tom)
     * Hash function improvements (Neil)
     * Improve performance of query tokenization and network handling
       (Peter)
     * Speed improvement for large object restore (Mario Weilguni)
     * Mark expired index entries on first lookup, saving later heap
       fetches (Tom)
     * Avoid excessive NULL bitmap padding (Manfred Koizar)
     * Add BSD-licensed qsort() for Solaris, for performance (Bruce)
     * Reduce per-row overhead by four bytes (Manfred Koizar)
     * Fix GEQO optimizer bug (Neil Conway)
     * Make WITHOUT OID actually save four bytes per row (Manfred Koizar)
     * Add default_statistics_target variable to specify ANALYZE buckets
       (Neil)
     * Use local buffer cache for temporary tables so no WAL overhead
       (Tom)
     * Improve free space map performance on large tables (Stephen
       Marshall, Tom)
     * Improved WAL write concurrency (Tom)
     __________________________________________________________________

Privileges

     * Add privileges on functions and procedural languages (Peter)
     * Add OWNER to CREATE DATABASE so superusers can create databases on
       behalf of unprivileged users (Gavin Sherry, Tom)
     * Add new object privilege bits EXECUTE and USAGE (Tom)
     * Add SET SESSION AUTHORIZATION DEFAULT and RESET SESSION
       AUTHORIZATION (Tom)
     * Allow functions to be executed with the privilege of the function
       owner (Peter)
     __________________________________________________________________

Server Configuration

     * Server log messages now tagged with LOG, not DEBUG (Bruce)
     * Add user column to pg_hba.conf (Bruce)
     * Have log_connections output two lines in log file (Tom)
     * Remove debug_level from postgresql.conf, now server_min_messages
       (Bruce)
     * New ALTER DATABASE/USER ... SET command for per-user/database
       initialization (Peter)
     * New parameters server_min_messages and client_min_messages to
       control which messages are sent to the server logs or client
       applications (Bruce)
     * Allow pg_hba.conf to specify lists of users/databases separated by
       commas, group names prepended with +, and file names prepended with
       @ (Bruce)
     * Remove secondary password file capability and pg_password utility
       (Bruce)
     * Add variable db_user_namespace for database-local user names
       (Bruce)
     * SSL improvements (Bear Giles)
     * Make encryption of stored passwords the default (Bruce)
     * Allow pg_statistics to be reset by calling pg_stat_reset()
       (Christopher)
     * Add log_duration parameter (Bruce)
     * Rename debug_print_query to log_statement (Bruce)
     * Rename show_query_stats to show_statement_stats (Bruce)
     * Add param log_min_error_statement to print commands to logs on
       error (Gavin)
     __________________________________________________________________

Queries

     * Make cursors insensitive, meaning their contents do not change
       (Tom)
     * Disable LIMIT #,# syntax; now only LIMIT # OFFSET # supported
       (Bruce)
     * Increase identifier length to 63 (Neil, Bruce)
     * UNION fixes for merging >= 3 columns of different lengths (Tom)
     * Add DEFAULT key word to INSERT, e.g., INSERT ... (..., DEFAULT,
       ...) (Rod)
     * Allow views to have default values using ALTER COLUMN ... SET
       DEFAULT (Neil)
     * Fail on INSERTs with column lists that don't supply all column
       values, e.g., INSERT INTO tab (col1, col2) VALUES ('val1'); (Rod)
     * Fix for join aliases (Tom)
     * Fix for FULL OUTER JOINs (Tom)
     * Improve reporting of invalid identifier and location (Tom, Gavin)
     * Fix OPEN cursor(args) (Tom)
     * Allow 'ctid' to be used in a view and currtid(viewname) (Hiroshi)
     * Fix for CREATE TABLE AS with UNION (Tom)
     * SQL99 syntax improvements (Thomas)
     * Add statement_timeout variable to cancel queries (Bruce)
     * Allow prepared queries with PREPARE/EXECUTE (Neil)
     * Allow FOR UPDATE to appear after LIMIT/OFFSET (Bruce)
     * Add variable autocommit (Tom, David Van Wie)
     __________________________________________________________________

Object Manipulation

     * Make equals signs optional in CREATE DATABASE (Gavin Sherry)
     * Make ALTER TABLE OWNER change index ownership too (Neil)
     * New ALTER TABLE tabname ALTER COLUMN colname SET STORAGE controls
       TOAST storage, compression (John Gray)
     * Add schema support, CREATE/DROP SCHEMA (Tom)
     * Create schema for temporary tables (Tom)
     * Add variable search_path for schema search (Tom)
     * Add ALTER TABLE SET/DROP NOT NULL (Christopher)
     * New CREATE FUNCTION volatility levels (Tom)
     * Make rule names unique only per table (Tom)
     * Add 'ON tablename' clause to DROP RULE and COMMENT ON RULE (Tom)
     * Add ALTER TRIGGER RENAME (Joe)
     * New current_schema() and current_schemas() inquiry functions (Tom)
     * Allow functions to return multiple rows (table functions) (Joe)
     * Make WITH optional in CREATE DATABASE, for consistency (Bruce)
     * Add object dependency tracking (Rod, Tom)
     * Add RESTRICT/CASCADE to DROP commands (Rod)
     * Add ALTER TABLE DROP for non-CHECK CONSTRAINT (Rod)
     * Autodestroy sequence on DROP of table with SERIAL (Rod)
     * Prevent column dropping if column is used by foreign key (Rod)
     * Automatically drop constraints/functions when object is dropped
       (Rod)
     * Add CREATE/DROP OPERATOR CLASS (Bill Studenmund, Tom)
     * Add ALTER TABLE DROP COLUMN (Christopher, Tom, Hiroshi)
     * Prevent inherited columns from being removed or renamed (Alvaro
       Herrera)
     * Fix foreign key constraints to not error on intermediate database
       states (Stephan)
     * Propagate column or table renaming to foreign key constraints
     * Add CREATE OR REPLACE VIEW (Gavin, Neil, Tom)
     * Add CREATE OR REPLACE RULE (Gavin, Neil, Tom)
     * Have rules execute alphabetically, returning more predictable
       values (Tom)
     * Triggers are now fired in alphabetical order (Tom)
     * Add /contrib/adddepend to handle pre-7.3 object dependencies (Rod)
     * Allow better casting when inserting/updating values (Tom)
     __________________________________________________________________

Utility Commands

     * Have COPY TO output embedded carriage returns and newlines as \r
       and \n (Tom)
     * Allow DELIMITER in COPY FROM to be 8-bit clean (Tatsuo)
     * Make pg_dump use ALTER TABLE ADD PRIMARY KEY, for performance
       (Neil)
     * Disable brackets in multistatement rules (Bruce)
     * Disable VACUUM from being called inside a function (Bruce)
     * Allow dropdb and other scripts to use identifiers with spaces
       (Bruce)
     * Restrict database comment changes to the current database
     * Allow comments on operators, independent of the underlying function
       (Rod)
     * Rollback SET commands in aborted transactions (Tom)
     * EXPLAIN now outputs as a query (Tom)
     * Display condition expressions and sort keys in EXPLAIN (Tom)
     * Add 'SET LOCAL var = value' to set configuration variables for a
       single transaction (Tom)
     * Allow ANALYZE to run in a transaction (Bruce)
     * Improve COPY syntax using new WITH clauses, keep backward
       compatibility (Bruce)
     * Fix pg_dump to consistently output tags in non-ASCII dumps (Bruce)
     * Make foreign key constraints clearer in dump file (Rod)
     * Add COMMENT ON CONSTRAINT (Rod)
     * Allow COPY TO/FROM to specify column names (Brent Verner)
     * Dump UNIQUE and PRIMARY KEY constraints as ALTER TABLE (Rod)
     * Have SHOW output a query result (Joe)
     * Generate failure on short COPY lines rather than pad NULLs (Neil)
     * Fix CLUSTER to preserve all table attributes (Alvaro Herrera)
     * New pg_settings table to view/modify GUC settings (Joe)
     * Add smart quoting, portability improvements to pg_dump output
       (Peter)
     * Dump serial columns out as SERIAL (Tom)
     * Enable large file support, >2G for pg_dump (Peter, Philip Warner,
       Bruce)
     * Disallow TRUNCATE on tables that are involved in referential
       constraints (Rod)
     * Have TRUNCATE also auto-truncate the toast table of the relation
       (Tom)
     * Add clusterdb utility that will auto-cluster an entire database
       based on previous CLUSTER operations (Alvaro Herrera)
     * Overhaul pg_dumpall (Peter)
     * Allow REINDEX of TOAST tables (Tom)
     * Implemented START TRANSACTION, per SQL99 (Neil)
     * Fix rare index corruption when a page split affects bulk delete
       (Tom)
     * Fix ALTER TABLE ... ADD COLUMN for inheritance (Alvaro Herrera)
     __________________________________________________________________

Data Types and Functions

     * Fix factorial(0) to return 1 (Bruce)
     * Date/time/timezone improvements (Thomas)
     * Fix for array slice extraction (Tom)
     * Fix extract/date_part to report proper microseconds for timestamp
       (Tatsuo)
     * Allow text_substr() and bytea_substr() to read TOAST values more
       efficiently (John Gray)
     * Add domain support (Rod)
     * Make WITHOUT TIME ZONE the default for TIMESTAMP and TIME data
       types (Thomas)
     * Allow alternate storage scheme of 64-bit integers for date/time
       types using --enable-integer-datetimes in configure (Thomas)
     * Make timezone(timestamptz) return timestamp rather than a string
       (Thomas)
     * Allow fractional seconds in date/time types for dates prior to 1BC
       (Thomas)
     * Limit timestamp data types to 6 decimal places of precision
       (Thomas)
     * Change timezone conversion functions from timetz() to timezone()
       (Thomas)
     * Add configuration variables datestyle and timezone (Tom)
     * Add OVERLAY(), which allows substitution of a substring in a string
       (Thomas)
     * Add SIMILAR TO (Thomas, Tom)
     * Add regular expression SUBSTRING(string FROM pat FOR escape)
       (Thomas)
     * Add LOCALTIME and LOCALTIMESTAMP functions (Thomas)
     * Add named composite types using CREATE TYPE typename AS (column)
       (Joe)
     * Allow composite type definition in the table alias clause (Joe)
     * Add new API to simplify creation of C language table functions
       (Joe)
     * Remove ODBC-compatible empty parentheses from calls to SQL99
       functions for which these parentheses do not match the standard
       (Thomas)
     * Allow macaddr data type to accept 12 hex digits with no separators
       (Mike Wyer)
     * Add CREATE/DROP CAST (Peter)
     * Add IS DISTINCT FROM operator (Thomas)
     * Add SQL99 TREAT() function, synonym for CAST() (Thomas)
     * Add pg_backend_pid() to output backend pid (Bruce)
     * Add IS OF / IS NOT OF type predicate (Thomas)
     * Allow bit string constants without fully-specified length (Thomas)
     * Allow conversion between 8-byte integers and bit strings (Thomas)
     * Implement hex literal conversion to bit string literal (Thomas)
     * Allow table functions to appear in the FROM clause (Joe)
     * Increase maximum number of function parameters to 32 (Bruce)
     * No longer automatically create index for SERIAL column (Tom)
     * Add current_database() (Rod)
     * Fix cash_words() to not overflow buffer (Tom)
     * Add functions replace(), split_part(), to_hex() (Joe)
     * Fix LIKE for bytea as a right-hand argument (Joe)
     * Prevent crashes caused by SELECT cash_out(2) (Tom)
     * Fix to_char(1,'FM999.99') to return a period (Karel)
     * Fix trigger/type/language functions returning OPAQUE to return
       proper type (Tom)
     __________________________________________________________________

Internationalization

     * Add additional encodings: Korean (JOHAB), Thai (WIN874), Vietnamese
       (TCVN), Arabic (WIN1256), Simplified Chinese (GBK), Korean (UHC)
       (Eiji Tokuya)
     * Enable locale support by default (Peter)
     * Add locale variables (Peter)
     * Escape byes >= 0x7f for multibyte in PQescapeBytea/PQunescapeBytea
       (Tatsuo)
     * Add locale awareness to regular expression character classes
     * Enable multibyte support by default (Tatsuo)
     * Add GB18030 multibyte support (Bill Huang)
     * Add CREATE/DROP CONVERSION, allowing loadable encodings (Tatsuo,
       Kaori)
     * Add pg_conversion table (Tatsuo)
     * Add SQL99 CONVERT() function (Tatsuo)
     * pg_dumpall, pg_controldata, and pg_resetxlog now national-language
       aware (Peter)
     * New and updated translations
     __________________________________________________________________

Server-side Languages

     * Allow recursive SQL function (Peter)
     * Change PL/Tcl build to use configured compiler and Makefile.shlib
       (Peter)
     * Overhaul the PL/pgSQL FOUND variable to be more Oracle-compatible
       (Neil, Tom)
     * Allow PL/pgSQL to handle quoted identifiers (Tom)
     * Allow set-returning PL/pgSQL functions (Neil)
     * Make PL/pgSQL schema-aware (Joe)
     * Remove some memory leaks (Nigel J. Andrews, Tom)
     __________________________________________________________________

psql

     * Don't lowercase psql \connect database name for 7.2.0 compatibility
       (Tom)
     * Add psql \timing to time user queries (Greg Sabino Mullane)
     * Have psql \d show index information (Greg Sabino Mullane)
     * New psql \dD shows domains (Jonathan Eisler)
     * Allow psql to show rules on views (Paul ?)
     * Fix for psql variable substitution (Tom)
     * Allow psql \d to show temporary table structure (Tom)
     * Allow psql \d to show foreign keys (Rod)
     * Fix \? to honor \pset pager (Bruce)
     * Have psql reports its version number on startup (Tom)
     * Allow \copy to specify column names (Tom)
     __________________________________________________________________

libpq

     * Add ~/.pgpass to store host/user password combinations (Alvaro
       Herrera)
     * Add PQunescapeBytea() function to libpq (Patrick Welche)
     * Fix for sending large queries over non-blocking connections
       (Bernhard Herzog)
     * Fix for libpq using timers on Win9X (David Ford)
     * Allow libpq notify to handle servers with different-length
       identifiers (Tom)
     * Add libpq PQescapeString() and PQescapeBytea() to Windows (Bruce)
     * Fix for SSL with non-blocking connections (Jack Bates)
     * Add libpq connection timeout parameter (Denis A Ustimenko)
     __________________________________________________________________

JDBC

     * Allow JDBC to compile with JDK 1.4 (Dave)
     * Add JDBC 3 support (Barry)
     * Allows JDBC to set loglevel by adding ?loglevel=X to the connection
       URL (Barry)
     * Add Driver.info() message that prints out the version number
       (Barry)
     * Add updateable result sets (Raghu Nidagal, Dave)
     * Add support for callable statements (Paul Bethe)
     * Add query cancel capability
     * Add refresh row (Dave)
     * Fix MD5 encryption handling for multibyte servers (Jun Kawai)
     * Add support for prepared statements (Barry)
     __________________________________________________________________

Miscellaneous Interfaces

     * Fixed ECPG bug concerning octal numbers in single quotes (Michael)
     * Move src/interfaces/libpgeasy to http://gborg.postgresql.org (Marc,
       Bruce)
     * Improve Python interface (Elliot Lee, Andrew Johnson, Greg
       Copeland)
     * Add libpgtcl connection close event (Gerhard Hintermayer)
     * Move src/interfaces/libpq++ to http://gborg.postgresql.org (Marc,
       Bruce)
     * Move src/interfaces/odbc to http://gborg.postgresql.org (Marc)
     * Move src/interfaces/libpgeasy to http://gborg.postgresql.org (Marc,
       Bruce)
     * Move src/interfaces/perl5 to http://gborg.postgresql.org (Marc,
       Bruce)
     * Remove src/bin/pgaccess from main tree, now at
       http://www.pgaccess.org (Bruce)
     * Add pg_on_connection_loss command to libpgtcl (Gerhard Hintermayer,
       Tom)
     __________________________________________________________________

Source Code

     * Fix for parallel make (Peter)
     * AIX fixes for linking Tcl (Andreas Zeugswetter)
     * Allow PL/Perl to build under Cygwin (Jason Tishler)
     * Improve MIPS compiles (Peter, Oliver Elphick)
     * Require Autoconf version 2.53 (Peter)
     * Require readline and zlib by default in configure (Peter)
     * Allow Solaris to use Intimate Shared Memory (ISM), for performance
       (Scott Brunza, P.J. Josh Rovero)
     * Always enable syslog in compile, remove --enable-syslog option
       (Tatsuo)
     * Always enable multibyte in compile, remove --enable-multibyte
       option (Tatsuo)
     * Always enable locale in compile, remove --enable-locale option
       (Peter)
     * Fix for Win9x DLL creation (Magnus Naeslund)
     * Fix for link() usage by WAL code on Windows, BeOS (Jason Tishler)
     * Add sys/types.h to c.h, remove from main files (Peter, Bruce)
     * Fix AIX hang on SMP machines (Tomoyuki Niijima)
     * AIX SMP hang fix (Tomoyuki Niijima)
     * Fix pre-1970 date handling on newer glibc libraries (Tom)
     * Fix PowerPC SMP locking (Tom)
     * Prevent gcc -ffast-math from being used (Peter, Tom)
     * Bison >= 1.50 now required for developer builds
     * Kerberos 5 support now builds with Heimdal (Peter)
     * Add appendix in the User's Guide which lists SQL features (Thomas)
     * Improve loadable module linking to use RTLD_NOW (Tom)
     * New error levels WARNING, INFO, LOG, DEBUG[1-5] (Bruce)
     * New src/port directory holds replaced libc functions (Peter, Bruce)
     * New pg_namespace system catalog for schemas (Tom)
     * Add pg_class.relnamespace for schemas (Tom)
     * Add pg_type.typnamespace for schemas (Tom)
     * Add pg_proc.pronamespace for schemas (Tom)
     * Restructure aggregates to have pg_proc entries (Tom)
     * System relations now have their own namespace, pg_* test not
       required (Fernando Nasser)
     * Rename TOAST index names to be *_index rather than *_idx (Neil)
     * Add namespaces for operators, opclasses (Tom)
     * Add additional checks to server control file (Thomas)
     * New Polish FAQ (Marcin Mazurek)
     * Add Posix semaphore support (Tom)
     * Document need for reindex (Bruce)
     * Rename some internal identifiers to simplify Windows compile (Jan,
       Katherine Ward)
     * Add documentation on computing disk space (Bruce)
     * Remove KSQO from GUC (Bruce)
     * Fix memory leak in rtree (Kenneth Been)
     * Modify a few error messages for consistency (Bruce)
     * Remove unused system table columns (Peter)
     * Make system columns NOT NULL where appropriate (Tom)
     * Clean up use of sprintf in favor of snprintf() (Neil, Jukka
       Holappa)
     * Remove OPAQUE and create specific subtypes (Tom)
     * Cleanups in array internal handling (Joe, Tom)
     * Disallow pg_atoi('') (Bruce)
     * Remove parameter wal_files because WAL files are now recycled
       (Bruce)
     * Add version numbers to heap pages (Tom)
     __________________________________________________________________

Contrib

     * Allow inet arrays in /contrib/array (Neil)
     * GiST fixes (Teodor Sigaev, Neil)
     * Upgrade /contrib/mysql
     * Add /contrib/dbsize which shows table sizes without vacuum (Peter)
     * Add /contrib/intagg, integer aggregator routines (mlw)
     * Improve /contrib/oid2name (Neil, Bruce)
     * Improve /contrib/tsearch (Oleg, Teodor Sigaev)
     * Cleanups of /contrib/rserver (Alexey V. Borzov)
     * Update /contrib/oracle conversion utility (Gilles Darold)
     * Update /contrib/dblink (Joe)
     * Improve options supported by /contrib/vacuumlo (Mario Weilguni)
     * Improvements to /contrib/intarray (Oleg, Teodor Sigaev, Andrey
       Oktyabrski)
     * Add /contrib/reindexdb utility (Shaun Thomas)
     * Add indexing to /contrib/isbn_issn (Dan Weston)
     * Add /contrib/dbmirror (Steven Singer)
     * Improve /contrib/pgbench (Neil)
     * Add /contrib/tablefunc table function examples (Joe)
     * Add /contrib/ltree data type for tree structures (Teodor Sigaev,
       Oleg Bartunov)
     * Move /contrib/pg_controldata, pg_resetxlog into main tree (Bruce)
     * Fixes to /contrib/cube (Bruno Wolff)
     * Improve /contrib/fulltextindex (Christopher)
     __________________________________________________________________

                                Release 7.2.8

     Release Date: 2005-05-09

   This release contains a variety of fixes from 7.2.7, including one
   security-related issue.
     __________________________________________________________________

Migration to Version 7.2.8

   A dump/restore is not required for those running 7.2.X.
     __________________________________________________________________

Changes

     * Repair ancient race condition that allowed a transaction to be seen
       as committed for some purposes (eg SELECT FOR UPDATE) slightly
       sooner than for other purposes
       This is an extremely serious bug since it could lead to apparent
       data inconsistencies being briefly visible to applications.
     * Repair race condition between relation extension and VACUUM
       This could theoretically have caused loss of a page's worth of
       freshly-inserted data, although the scenario seems of very low
       probability. There are no known cases of it having caused more than
       an Assert failure.
     * Fix EXTRACT(EPOCH) for TIME WITH TIME ZONE values
     * Additional buffer overrun checks in plpgsql (Neil)
     * Fix pg_dump to dump index names and trigger names containing %
       correctly (Neil)
     * Prevent to_char(interval) from dumping core for month-related
       formats
     * Fix "contrib/pgcrypto" for newer OpenSSL builds (Marko Kreen)
     __________________________________________________________________

                                Release 7.2.7

     Release Date: 2005-01-31

   This release contains a variety of fixes from 7.2.6, including several
   security-related issues.
     __________________________________________________________________

Migration to Version 7.2.7

   A dump/restore is not required for those running 7.2.X.
     __________________________________________________________________

Changes

     * Disallow "LOAD" to non-superusers
       On platforms that will automatically execute initialization
       functions of a shared library (this includes at least Windows and
       ELF-based Unixen), "LOAD" can be used to make the server execute
       arbitrary code. Thanks to NGS Software for reporting this.
     * Add needed STRICT marking to some contrib functions (Kris Jurka)
     * Avoid buffer overrun when plpgsql cursor declaration has too many
       parameters (Neil)
     * Fix planning error for FULL and RIGHT outer joins
       The result of the join was mistakenly supposed to be sorted the
       same as the left input. This could not only deliver mis-sorted
       output to the user, but in case of nested merge joins could give
       outright wrong answers.
     * Fix display of negative intervals in SQL and GERMAN datestyles
     __________________________________________________________________

                                Release 7.2.6

     Release Date: 2004-10-22

   This release contains a variety of fixes from 7.2.5.
     __________________________________________________________________

Migration to Version 7.2.6

   A dump/restore is not required for those running 7.2.X.
     __________________________________________________________________

Changes

     * Repair possible failure to update hint bits on disk
       Under rare circumstances this oversight could lead to "could not
       access transaction status" failures, which qualifies it as a
       potential-data-loss bug.
     * Ensure that hashed outer join does not miss tuples
       Very large left joins using a hash join plan could fail to output
       unmatched left-side rows given just the right data distribution.
     * Disallow running pg_ctl as root
       This is to guard against any possible security issues.
     * Avoid using temp files in /tmp in make_oidjoins_check
       This has been reported as a security issue, though it's hardly
       worthy of concern since there is no reason for non-developers to
       use this script anyway.
     * Update to newer versions of Bison
     __________________________________________________________________

                                Release 7.2.5

     Release Date: 2004-08-16

   This release contains a variety of fixes from 7.2.4.
     __________________________________________________________________

Migration to Version 7.2.5

   A dump/restore is not required for those running 7.2.X.
     __________________________________________________________________

Changes

     * Prevent possible loss of committed transactions during crash
       Due to insufficient interlocking between transaction commit and
       checkpointing, it was possible for transactions committed just
       before the most recent checkpoint to be lost, in whole or in part,
       following a database crash and restart. This is a serious bug that
       has existed since PostgreSQL 7.1.
     * Fix corner case for btree search in parallel with first root page
       split
     * Fix buffer overrun in to_ascii (Guido Notari)
     * Fix core dump in deadlock detection on machines where char is
       unsigned
     * Fix failure to respond to "pg_ctl stop -m fast" after
       Async_NotifyHandler runs
     * Repair memory leaks in pg_dump
     * Avoid conflict with system definition of isblank() function or
       macro
     __________________________________________________________________

                                Release 7.2.4

     Release Date: 2003-01-30

   This release contains a variety of fixes for version 7.2.3, including
   fixes to prevent possible data loss.
     __________________________________________________________________

Migration to Version 7.2.4

   A dump/restore is *not* required for those running version 7.2.*.
     __________________________________________________________________

Changes

     * Fix some additional cases of VACUUM "No one parent tuple was found"
       error
     * Prevent VACUUM from being called inside a function (Bruce)
     * Ensure pg_clog updates are sync'd to disk before marking checkpoint
       complete
     * Avoid integer overflow during large hash joins
     * Make GROUP commands work when pg_group.grolist is large enough to
       be toasted
     * Fix errors in datetime tables; some timezone names weren't being
       recognized
     * Fix integer overflows in circle_poly(), path_encode(), path_add()
       (Neil)
     * Repair long-standing logic errors in lseg_eq(), lseg_ne(),
       lseg_center()
     __________________________________________________________________

                                Release 7.2.3

     Release Date: 2002-10-01

   This release contains a variety of fixes for version 7.2.2, including
   fixes to prevent possible data loss.
     __________________________________________________________________

Migration to Version 7.2.3

   A dump/restore is *not* required for those running version 7.2.*.
     __________________________________________________________________

Changes

     * Prevent possible compressed transaction log loss (Tom)
     * Prevent non-superuser from increasing most recent vacuum info (Tom)
     * Handle pre-1970 date values in newer versions of glibc (Tom)
     * Fix possible hang during server shutdown
     * Prevent spinlock hangs on SMP PPC machines (Tomoyuki Niijima)
     * Fix pg_dump to properly dump FULL JOIN USING (Tom)
     __________________________________________________________________

                                Release 7.2.2

     Release Date: 2002-08-23

   This release contains a variety of fixes for version 7.2.1.
     __________________________________________________________________

Migration to Version 7.2.2

   A dump/restore is *not* required for those running version 7.2.*.
     __________________________________________________________________

Changes

     * Allow EXECUTE of "CREATE TABLE AS ... SELECT" in PL/pgSQL (Tom)
     * Fix for compressed transaction log id wraparound (Tom)
     * Fix PQescapeBytea/PQunescapeBytea so that they handle bytes > 0x7f
       (Tatsuo)
     * Fix for psql and pg_dump crashing when invoked with non-existent
       long options (Tatsuo)
     * Fix crash when invoking geometric operators (Tom)
     * Allow OPEN cursor(args) (Tom)
     * Fix for rtree_gist index build (Teodor)
     * Fix for dumping user-defined aggregates (Tom)
     * contrib/intarray fixes (Oleg)
     * Fix for complex UNION/EXCEPT/INTERSECT queries using parens (Tom)
     * Fix to pg_convert (Tatsuo)
     * Fix for crash with long DATA strings (Thomas, Neil)
     * Fix for repeat(), lpad(), rpad() and long strings (Neil)
     __________________________________________________________________

                                Release 7.2.1

     Release Date: 2002-03-21

   This release contains a variety of fixes for version 7.2.
     __________________________________________________________________

Migration to Version 7.2.1

   A dump/restore is *not* required for those running version 7.2.
     __________________________________________________________________

Changes

     * Ensure that sequence counters do not go backwards after a crash
       (Tom)
     * Fix pgaccess kanji-conversion key binding (Tatsuo)
     * Optimizer improvements (Tom)
     * Cash I/O improvements (Tom)
     * New Russian FAQ
     * Compile fix for missing AuthBlockSig (Heiko)
     * Additional time zones and time zone fixes (Thomas)
     * Allow psql \connect to handle mixed case database and user names
       (Tom)
     * Return proper OID on command completion even with ON INSERT rules
       (Tom)
     * Allow COPY FROM to use 8-bit DELIMITERS (Tatsuo)
     * Fix bug in extract/date_part for milliseconds/microseconds (Tatsuo)
     * Improve handling of multiple UNIONs with different lengths (Tom)
     * contrib/btree_gist improvements (Teodor Sigaev)
     * contrib/tsearch dictionary improvements, see README.tsearch for an
       additional installation step (Thomas T. Thai, Teodor Sigaev)
     * Fix for array subscripts handling (Tom)
     * Allow EXECUTE of "CREATE TABLE AS ... SELECT" in PL/pgSQL (Tom)
     __________________________________________________________________

                                 Release 7.2

     Release Date: 2002-02-04
     __________________________________________________________________

Overview

   This release improves PostgreSQL for use in high-volume applications.

   Major changes in this release:

   VACUUM
          Vacuuming no longer locks tables, thus allowing normal user
          access during the vacuum. A new "VACUUM FULL" command does
          old-style vacuum by locking the table and shrinking the on-disk
          copy of the table.

   Transactions
          There is no longer a problem with installations that exceed four
          billion transactions.

   OIDs
          OIDs are now optional. Users can now create tables without OIDs
          for cases where OID usage is excessive.

   Optimizer
          The system now computes histogram column statistics during
          "ANALYZE", allowing much better optimizer choices.

   Security
          A new MD5 encryption option allows more secure storage and
          transfer of passwords. A new Unix-domain socket authentication
          option is available on Linux and BSD systems.

   Statistics
          Administrators can use the new table access statistics module to
          get fine-grained information about table and index usage.

   Internationalization
          Program and library messages can now be displayed in several
          languages.
     __________________________________________________________________

Migration to Version 7.2

   A dump/restore using "pg_dump" is required for those wishing to migrate
   data from any previous release.

   Observe the following incompatibilities:

     * The semantics of the "VACUUM" command have changed in this release.
       You might wish to update your maintenance procedures accordingly.
     * In this release, comparisons using = NULL will always return false
       (or NULL, more precisely). Previous releases automatically
       transformed this syntax to IS NULL. The old behavior can be
       re-enabled using a "postgresql.conf" parameter.
     * The "pg_hba.conf" and "pg_ident.conf" configuration is now only
       reloaded after receiving a SIGHUP signal, not with each connection.
     * The function "octet_length()" now returns the uncompressed data
       length.
     * The date/time value 'current' is no longer available. You will need
       to rewrite your applications.
     * The timestamp(), time(), and interval() functions are no longer
       available. Instead of timestamp(), use timestamp 'string' or CAST.

   The SELECT ... LIMIT #,# syntax will be removed in the next release.
   You should change your queries to use separate LIMIT and OFFSET
   clauses, e.g. LIMIT 10 OFFSET 20.
     __________________________________________________________________

Changes

Server Operation

     * Create temporary files in a separate directory (Bruce)
     * Delete orphaned temporary files on postmaster startup (Bruce)
     * Added unique indexes to some system tables (Tom)
     * System table operator reorganization (Oleg Bartunov, Teodor Sigaev,
       Tom)
     * Renamed pg_log to pg_clog (Tom)
     * Enable SIGTERM, SIGQUIT to kill backends (Jan)
     * Removed compile-time limit on number of backends (Tom)
     * Better cleanup for semaphore resource failure (Tatsuo, Tom)
     * Allow safe transaction ID wraparound (Tom)
     * Removed OIDs from some system tables (Tom)
     * Removed "triggered data change violation" error check (Tom)
     * SPI portal creation of prepared/saved plans (Jan)
     * Allow SPI column functions to work for system columns (Tom)
     * Long value compression improvement (Tom)
     * Statistics collector for table, index access (Jan)
     * Truncate extra-long sequence names to a reasonable value (Tom)
     * Measure transaction times in milliseconds (Thomas)
     * Fix TID sequential scans (Hiroshi)
     * Superuser ID now fixed at 1 (Peter E)
     * New pg_ctl "reload" option (Tom)
     __________________________________________________________________

Performance

     * Optimizer improvements (Tom)
     * New histogram column statistics for optimizer (Tom)
     * Reuse write-ahead log files rather than discarding them (Tom)
     * Cache improvements (Tom)
     * IS NULL, IS NOT NULL optimizer improvement (Tom)
     * Improve lock manager to reduce lock contention (Tom)
     * Keep relcache entries for index access support functions (Tom)
     * Allow better selectivity with NaN and infinities in NUMERIC (Tom)
     * R-tree performance improvements (Kenneth Been)
     * B-tree splits more efficient (Tom)
     __________________________________________________________________

Privileges

     * Change UPDATE, DELETE privileges to be distinct (Peter E)
     * New REFERENCES, TRIGGER privileges (Peter E)
     * Allow GRANT/REVOKE to/from more than one user at a time (Peter E)
     * New has_table_privilege() function (Joe Conway)
     * Allow non-superuser to vacuum database (Tom)
     * New SET SESSION AUTHORIZATION command (Peter E)
     * Fix bug in privilege modifications on newly created tables (Tom)
     * Disallow access to pg_statistic for non-superuser, add
       user-accessible views (Tom)
     __________________________________________________________________

Client Authentication

     * Fork postmaster before doing authentication to prevent hangs (Peter
       E)
     * Add ident authentication over Unix domain sockets on Linux, *BSD
       (Helge Bahmann, Oliver Elphick, Teodor Sigaev, Bruce)
     * Add a password authentication method that uses MD5 encryption
       (Bruce)
     * Allow encryption of stored passwords using MD5 (Bruce)
     * PAM authentication (Dominic J. Eidson)
     * Load pg_hba.conf and pg_ident.conf only on startup and SIGHUP
       (Bruce)
     __________________________________________________________________

Server Configuration

     * Interpretation of some time zone abbreviations as Australian rather
       than North American now settable at run time (Bruce)
     * New parameter to set default transaction isolation level (Peter E)
     * New parameter to enable conversion of "expr = NULL" into "expr IS
       NULL", off by default (Peter E)
     * New parameter to control memory usage by VACUUM (Tom)
     * New parameter to set client authentication timeout (Tom)
     * New parameter to set maximum number of open files (Tom)
     __________________________________________________________________

Queries

     * Statements added by INSERT rules now execute after the INSERT (Jan)
     * Prevent unadorned relation names in target list (Bruce)
     * NULLs now sort after all normal values in ORDER BY (Tom)
     * New IS UNKNOWN, IS NOT UNKNOWN Boolean tests (Tom)
     * New SHARE UPDATE EXCLUSIVE lock mode (Tom)
     * New EXPLAIN ANALYZE command that shows run times and row counts
       (Martijn van Oosterhout)
     * Fix problem with LIMIT and subqueries (Tom)
     * Fix for LIMIT, DISTINCT ON pushed into subqueries (Tom)
     * Fix nested EXCEPT/INTERSECT (Tom)
     __________________________________________________________________

Schema Manipulation

     * Fix SERIAL in temporary tables (Bruce)
     * Allow temporary sequences (Bruce)
     * Sequences now use int8 internally (Tom)
     * New SERIAL8 creates int8 columns with sequences, default still
       SERIAL4 (Tom)
     * Make OIDs optional using WITHOUT OIDS (Tom)
     * Add %TYPE syntax to CREATE TYPE (Ian Lance Taylor)
     * Add ALTER TABLE / DROP CONSTRAINT for CHECK constraints
       (Christopher Kings-Lynne)
     * New CREATE OR REPLACE FUNCTION to alter existing function
       (preserving the function OID) (Gavin Sherry)
     * Add ALTER TABLE / ADD [ UNIQUE | PRIMARY ] (Christopher
       Kings-Lynne)
     * Allow column renaming in views
     * Make ALTER TABLE / RENAME COLUMN update column names of indexes
       (Brent Verner)
     * Fix for ALTER TABLE / ADD CONSTRAINT ... CHECK with inherited
       tables (Stephan Szabo)
     * ALTER TABLE RENAME update foreign-key trigger arguments correctly
       (Brent Verner)
     * DROP AGGREGATE and COMMENT ON AGGREGATE now accept an aggtype (Tom)
     * Add automatic return type data casting for SQL functions (Tom)
     * Allow GiST indexes to handle NULLs and multikey indexes (Oleg
       Bartunov, Teodor Sigaev, Tom)
     * Enable partial indexes (Martijn van Oosterhout)
     __________________________________________________________________

Utility Commands

     * Add RESET ALL, SHOW ALL (Marko Kreen)
     * CREATE/ALTER USER/GROUP now allow options in any order (Vince)
     * Add LOCK A, B, C functionality (Neil Padgett)
     * New ENCRYPTED/UNENCRYPTED option to CREATE/ALTER USER (Bruce)
     * New light-weight VACUUM does not lock table; old semantics are
       available as VACUUM FULL (Tom)
     * Disable COPY TO/FROM on views (Bruce)
     * COPY DELIMITERS string must be exactly one character (Tom)
     * VACUUM warning about index tuples fewer than heap now only appears
       when appropriate (Martijn van Oosterhout)
     * Fix privilege checks for CREATE INDEX (Tom)
     * Disallow inappropriate use of CREATE/DROP INDEX/TRIGGER/VIEW (Tom)
     __________________________________________________________________

Data Types and Functions

     * SUM(), AVG(), COUNT() now uses int8 internally for speed (Tom)
     * Add convert(), convert2() (Tatsuo)
     * New function bit_length() (Peter E)
     * Make the "n" in CHAR(n)/VARCHAR(n) represents letters, not bytes
       (Tatsuo)
     * CHAR(), VARCHAR() now reject strings that are too long (Peter E)
     * BIT VARYING now rejects bit strings that are too long (Peter E)
     * BIT now rejects bit strings that do not match declared size (Peter
       E)
     * INET, CIDR text conversion functions (Alex Pilosov)
     * INET, CIDR operators << and <<= indexable (Alex Pilosov)
     * Bytea \### now requires valid three digit octal number
     * Bytea comparison improvements, now supports =, <>, >, >=, <, and <=
     * Bytea now supports B-tree indexes
     * Bytea now supports LIKE, LIKE...ESCAPE, NOT LIKE, NOT LIKE...ESCAPE
     * Bytea now supports concatenation
     * New bytea functions: position, substring, trim, btrim, and length
     * New encode() function mode, "escaped", converts minimally escaped
       bytea to/from text
     * Add pg_database_encoding_max_length() (Tatsuo)
     * Add pg_client_encoding() function (Tatsuo)
     * now() returns time with millisecond precision (Thomas)
     * New TIMESTAMP WITHOUT TIMEZONE data type (Thomas)
     * Add ISO date/time specification with "T", yyyy-mm-ddThh:mm:ss
       (Thomas)
     * New xid/int comparison functions (Hiroshi)
     * Add precision to TIME, TIMESTAMP, and INTERVAL data types (Thomas)
     * Modify type coercion logic to attempt binary-compatible functions
       first (Tom)
     * New encode() function installed by default (Marko Kreen)
     * Improved to_*() conversion functions (Karel Zak)
     * Optimize LIKE/ILIKE when using single-byte encodings (Tatsuo)
     * New functions in contrib/pgcrypto: crypt(), hmac(), encrypt(),
       gen_salt() (Marko Kreen)
     * Correct description of translate() function (Bruce)
     * Add INTERVAL argument for SET TIME ZONE (Thomas)
     * Add INTERVAL YEAR TO MONTH (etc.) syntax (Thomas)
     * Optimize length functions when using single-byte encodings (Tatsuo)
     * Fix path_inter, path_distance, path_length, dist_ppath to handle
       closed paths (Curtis Barrett, Tom)
     * octet_length(text) now returns non-compressed length (Tatsuo,
       Bruce)
     * Handle "July" full name in date/time literals (Greg Sabino Mullane)
     * Some datatype() function calls now evaluated differently
     * Add support for Julian and ISO time specifications (Thomas)
     __________________________________________________________________

Internationalization

     * National language support in psql, pg_dump, libpq, and server
       (Peter E)
     * Message translations in Chinese (simplified, traditional), Czech,
       French, German, Hungarian, Russian, Swedish (Peter E, Serguei A.
       Mokhov, Karel Zak, Weiping He, Zhenbang Wei, Kovacs Zoltan)
     * Make trim, ltrim, rtrim, btrim, lpad, rpad, translate multibyte
       aware (Tatsuo)
     * Add LATIN5,6,7,8,9,10 support (Tatsuo)
     * Add ISO 8859-5,6,7,8 support (Tatsuo)
     * Correct LATIN5 to mean ISO-8859-9, not ISO-8859-5 (Tatsuo)
     * Make mic2ascii() non-ASCII aware (Tatsuo)
     * Reject invalid multibyte character sequences (Tatsuo)
     __________________________________________________________________

PL/pgSQL

     * Now uses portals for SELECT loops, allowing huge result sets (Jan)
     * CURSOR and REFCURSOR support (Jan)
     * Can now return open cursors (Jan)
     * Add ELSEIF (Klaus Reger)
     * Improve PL/pgSQL error reporting, including location of error (Tom)
     * Allow IS or FOR key words in cursor declaration, for compatibility
       (Bruce)
     * Fix for SELECT ... FOR UPDATE (Tom)
     * Fix for PERFORM returning multiple rows (Tom)
     * Make PL/pgSQL use the server's type coercion code (Tom)
     * Memory leak fix (Jan, Tom)
     * Make trailing semicolon optional (Tom)
     __________________________________________________________________

PL/Perl

     * New untrusted PL/Perl (Alex Pilosov)
     * PL/Perl is now built on some platforms even if libperl is not
       shared (Peter E)
     __________________________________________________________________

PL/Tcl

     * Now reports errorInfo (Vsevolod Lobko)
     * Add spi_lastoid function (bob@redivi.com)
     __________________________________________________________________

PL/Python

     * ...is new (Andrew Bosma)
     __________________________________________________________________

psql

     * \d displays indexes in unique, primary groupings (Christopher
       Kings-Lynne)
     * Allow trailing semicolons in backslash commands (Greg Sabino
       Mullane)
     * Read password from /dev/tty if possible
     * Force new password prompt when changing user and database (Tatsuo,
       Tom)
     * Format the correct number of columns for Unicode (Patrice)
     __________________________________________________________________

libpq

     * New function PQescapeString() to escape quotes in command strings
       (Florian Weimer)
     * New function PQescapeBytea() escapes binary strings for use as SQL
       string literals
     __________________________________________________________________

JDBC

     * Return OID of INSERT (Ken K)
     * Handle more data types (Ken K)
     * Handle single quotes and newlines in strings (Ken K)
     * Handle NULL variables (Ken K)
     * Fix for time zone handling (Barry Lind)
     * Improved Druid support
     * Allow eight-bit characters with non-multibyte server (Barry Lind)
     * Support BIT, BINARY types (Ned Wolpert)
     * Reduce memory usage (Michael Stephens, Dave Cramer)
     * Update DatabaseMetaData (Peter E)
     * Add DatabaseMetaData.getCatalogs() (Peter E)
     * Encoding fixes (Anders Bengtsson)
     * Get/setCatalog methods (Jason Davies)
     * DatabaseMetaData.getColumns() now returns column defaults (Jason
       Davies)
     * DatabaseMetaData.getColumns() performance improvement (Jeroen van
       Vianen)
     * Some JDBC1 and JDBC2 merging (Anders Bengtsson)
     * Transaction performance improvements (Barry Lind)
     * Array fixes (Greg Zoller)
     * Serialize addition
     * Fix batch processing (Rene Pijlman)
     * ExecSQL method reorganization (Anders Bengtsson)
     * GetColumn() fixes (Jeroen van Vianen)
     * Fix isWriteable() function (Rene Pijlman)
     * Improved passage of JDBC2 conformance tests (Rene Pijlman)
     * Add bytea type capability (Barry Lind)
     * Add isNullable() (Rene Pijlman)
     * JDBC date/time test suite fixes (Liam Stewart)
     * Fix for SELECT 'id' AS xxx FROM table (Dave Cramer)
     * Fix DatabaseMetaData to show precision properly (Mark Lillywhite)
     * New getImported/getExported keys (Jason Davies)
     * MD5 password encryption support (Jeremy Wohl)
     * Fix to actually use type cache (Ned Wolpert)
     __________________________________________________________________

ODBC

     * Remove query size limit (Hiroshi)
     * Remove text field size limit (Hiroshi)
     * Fix for SQLPrimaryKeys in multibyte mode (Hiroshi)
     * Allow ODBC procedure calls (Hiroshi)
     * Improve boolean handing (Aidan Mountford)
     * Most configuration options now settable via DSN (Hiroshi)
     * Multibyte, performance fixes (Hiroshi)
     * Allow driver to be used with iODBC or unixODBC (Peter E)
     * MD5 password encryption support (Bruce)
     * Add more compatibility functions to odbc.sql (Peter E)
     __________________________________________________________________

ECPG

     * EXECUTE ... INTO implemented (Christof Petig)
     * Multiple row descriptor support (e.g. CARDINALITY) (Christof Petig)
     * Fix for GRANT parameters (Lee Kindness)
     * Fix INITIALLY DEFERRED bug
     * Various bug fixes (Michael, Christof Petig)
     * Auto allocation for indicator variable arrays (int *ind_p=NULL)
     * Auto allocation for string arrays (char **foo_pp=NULL)
     * ECPGfree_auto_mem fixed
     * All function names with external linkage are now prefixed by ECPG
     * Fixes for arrays of structures (Michael)
     __________________________________________________________________

Misc. Interfaces

     * Python fix fetchone() (Gerhard Haring)
     * Use UTF, Unicode in Tcl where appropriate (Vsevolod Lobko, Reinhard
       Max)
     * Add Tcl COPY TO/FROM (ljb)
     * Prevent output of default index op class in pg_dump (Tom)
     * Fix libpgeasy memory leak (Bruce)
     __________________________________________________________________

Build and Install

     * Configure, dynamic loader, and shared library fixes (Peter E)
     * Fixes in QNX 4 port (Bernd Tegge)
     * Fixes in Cygwin and Windows ports (Jason Tishler, Gerhard Haring,
       Dmitry Yurtaev, Darko Prenosil, Mikhail Terekhov)
     * Fix for Windows socket communication failures (Magnus, Mikhail
       Terekhov)
     * Hurd compile fix (Oliver Elphick)
     * BeOS fixes (Cyril Velter)
     * Remove configure --enable-unicode-conversion, now enabled by
       multibyte (Tatsuo)
     * AIX fixes (Tatsuo, Andreas)
     * Fix parallel make (Peter E)
     * Install SQL language manual pages into OS-specific directories
       (Peter E)
     * Rename config.h to pg_config.h (Peter E)
     * Reorganize installation layout of header files (Peter E)
     __________________________________________________________________

Source Code

     * Remove SEP_CHAR (Bruce)
     * New GUC hooks (Tom)
     * Merge GUC and command line handling (Marko Kreen)
     * Remove EXTEND INDEX (Martijn van Oosterhout, Tom)
     * New pgjindent utility to indent java code (Bruce)
     * Remove define of true/false when compiling under C++ (Leandro
       Fanzone, Tom)
     * pgindent fixes (Bruce, Tom)
     * Replace strcasecmp() with strcmp() where appropriate (Peter E)
     * Dynahash portability improvements (Tom)
     * Add 'volatile' usage in spinlock structures
     * Improve signal handling logic (Tom)
     __________________________________________________________________

Contrib

     * New contrib/rtree_gist (Oleg Bartunov, Teodor Sigaev)
     * New contrib/tsearch full-text indexing (Oleg, Teodor Sigaev)
     * Add contrib/dblink for remote database access (Joe Conway)
     * contrib/ora2pg Oracle conversion utility (Gilles Darold)
     * contrib/xml XML conversion utility (John Gray)
     * contrib/fulltextindex fixes (Christopher Kings-Lynne)
     * New contrib/fuzzystrmatch with levenshtein and metaphone, soundex
       merged (Joe Conway)
     * Add contrib/intarray boolean queries, binary search, fixes (Oleg
       Bartunov)
     * New pg_upgrade utility (Bruce)
     * Add new pg_resetxlog options (Bruce, Tom)
     __________________________________________________________________

                                Release 7.1.3

     Release Date: 2001-08-15
     __________________________________________________________________

Migration to Version 7.1.3

   A dump/restore is *not* required for those running 7.1.X.
     __________________________________________________________________

Changes

Remove unused WAL segments of large transactions (Tom)
Multiaction rule fix (Tom)
PL/pgSQL memory allocation fix (Jan)
VACUUM buffer fix (Tom)
Regression test fixes (Tom)
pg_dump fixes for GRANT/REVOKE/comments on views, user-defined types (Tom)
Fix subselects with DISTINCT ON or LIMIT (Tom)
BeOS fix
Disable COPY TO/FROM a view (Tom)
Cygwin build (Jason Tishler)
     __________________________________________________________________

                                Release 7.1.2

     Release Date: 2001-05-11

   This has one fix from 7.1.1.
     __________________________________________________________________

Migration to Version 7.1.2

   A dump/restore is *not* required for those running 7.1.X.
     __________________________________________________________________

Changes

Fix PL/pgSQL SELECTs when returning no rows
Fix for psql backslash core dump
Referential integrity privilege fix
Optimizer fixes
pg_dump cleanups
     __________________________________________________________________

                                Release 7.1.1

     Release Date: 2001-05-05

   This has a variety of fixes from 7.1.
     __________________________________________________________________

Migration to Version 7.1.1

   A dump/restore is *not* required for those running 7.1.
     __________________________________________________________________

Changes

Fix for numeric MODULO operator (Tom)
pg_dump fixes (Philip)
pg_dump can dump 7.0 databases (Philip)
readline 4.2 fixes (Peter E)
JOIN fixes (Tom)
AIX, MSWIN, VAX, N32K fixes (Tom)
Multibytes fixes (Tom)
Unicode fixes (Tatsuo)
Optimizer improvements (Tom)
Fix for whole rows in functions (Tom)
Fix for pg_ctl and option strings with spaces (Peter E)
ODBC fixes (Hiroshi)
EXTRACT can now take string argument (Thomas)
Python fixes (Darcy)
     __________________________________________________________________

                                 Release 7.1

     Release Date: 2001-04-13

   This release focuses on removing limitations that have existed in the
   PostgreSQL code for many years.

   Major changes in this release:

   Write-ahead Log (WAL)
          To maintain database consistency in case of an operating system
          crash, previous releases of PostgreSQL have forced all data
          modifications to disk before each transaction commit. With WAL,
          only one log file must be flushed to disk, greatly improving
          performance. If you have been using -F in previous releases to
          disable disk flushes, you might want to consider discontinuing
          its use.

   TOAST
          TOAST - Previous releases had a compiled-in row length limit,
          typically 8k - 32k. This limit made storage of long text fields
          difficult. With TOAST, long rows of any length can be stored
          with good performance.

   Outer Joins
          We now support outer joins. The UNION/NOT IN workaround for
          outer joins is no longer required. We use the SQL92 outer join
          syntax.

   Function Manager
          The previous C function manager did not handle null values
          properly, nor did it support 64-bit CPU's (Alpha). The new
          function manager does. You can continue using your old custom
          functions, but you might want to rewrite them in the future to
          use the new function manager call interface.

   Complex Queries
          A large number of complex queries that were unsupported in
          previous releases now work. Many combinations of views,
          aggregates, UNION, LIMIT, cursors, subqueries, and inherited
          tables now work properly. Inherited tables are now accessed by
          default. Subqueries in FROM are now supported.
     __________________________________________________________________

Migration to Version 7.1

   A dump/restore using pg_dump is required for those wishing to migrate
   data from any previous release.
     __________________________________________________________________

Changes

Bug Fixes
---------
Many multibyte/Unicode/locale fixes (Tatsuo and others)
More reliable ALTER TABLE RENAME (Tom)
Kerberos V fixes (David Wragg)
Fix for INSERT INTO...SELECT where targetlist has subqueries (Tom)
Prompt username/password on standard error (Bruce)
Large objects inv_read/inv_write fixes (Tom)
Fixes for to_char(), to_date(), to_ascii(), and to_timestamp() (Karel,
   Daniel Baldoni)
Prevent query expressions from leaking memory (Tom)
Allow UPDATE of arrays elements (Tom)
Wake up lock waiters during cancel (Hiroshi)
Fix rare cursor crash when using hash join (Tom)
Fix for DROP TABLE/INDEX in rolled-back transaction (Hiroshi)
Fix psql crash from \l+ if MULTIBYTE enabled (Peter E)
Fix truncation of rule names during CREATE VIEW (Ross Reedstrom)
Fix PL/perl (Alex Kapranoff)
Disallow LOCK on views (Mark Hollomon)
Disallow INSERT/UPDATE/DELETE on views (Mark Hollomon)
Disallow DROP RULE, CREATE INDEX, TRUNCATE on views (Mark Hollomon)
Allow PL/pgSQL accept non-ASCII identifiers (Tatsuo)
Allow views to proper handle GROUP BY, aggregates, DISTINCT (Tom)
Fix rare failure with TRUNCATE command (Tom)
Allow UNION/INTERSECT/EXCEPT to be used with ALL, subqueries, views,
   DISTINCT, ORDER BY, SELECT...INTO (Tom)
Fix parser failures during aborted transactions (Tom)
Allow temporary relations to properly clean up indexes (Bruce)
Fix VACUUM problem with moving rows in same page (Tom)
Modify pg_dump to better handle user-defined items in template1 (Philip)
Allow LIMIT in VIEW (Tom)
Require cursor FETCH to honor LIMIT (Tom)
Allow PRIMARY/FOREIGN Key definitions on inherited columns (Stephan)
Allow ORDER BY, LIMIT in subqueries (Tom)
Allow UNION in CREATE RULE (Tom)
Make ALTER/DROP TABLE rollback-able (Vadim, Tom)
Store initdb collation in pg_control so collation cannot be changed (Tom)
Fix INSERT...SELECT with rules (Tom)
Fix FOR UPDATE inside views and subselects (Tom)
Fix OVERLAPS operators conform to SQL92 spec regarding NULLs (Tom)
Fix lpad() and rpad() to handle length less than input string (Tom)
Fix use of NOTIFY in some rules (Tom)
Overhaul btree code (Tom)
Fix NOT NULL use in Pl/pgSQL variables (Tom)
Overhaul GIST code (Oleg)
Fix CLUSTER to preserve constraints and column default (Tom)
Improved deadlock detection handling (Tom)
Allow multiple SERIAL columns in a table (Tom)
Prevent occasional index corruption (Vadim)

Enhancements
------------
Add OUTER JOINs (Tom)
Function manager overhaul (Tom)
Allow ALTER TABLE RENAME on indexes (Tom)
Improve CLUSTER (Tom)
Improve ps status display for more platforms (Peter E, Marc)
Improve CREATE FUNCTION failure message (Ross)
JDBC improvements (Peter, Travis Bauer, Christopher Cain, William Webber,
   Gunnar)
Grand Unified Configuration scheme/GUC.  Many options can now be set in
   data/postgresql.conf, postmaster/postgres flags, or SET commands (Peter E)
Improved handling of file descriptor cache (Tom)
New warning code about auto-created table alias entries (Bruce)
Overhaul initdb process (Tom, Peter E)
Overhaul of inherited tables; inherited tables now accessed by default;
  new ONLY key word prevents it (Chris Bitmead, Tom)
ODBC cleanups/improvements (Nick Gorham, Stephan Szabo, Zoltan Kovacs,
   Michael Fork)
Allow renaming of temp tables (Tom)
Overhaul memory manager contexts (Tom)
pg_dumpall uses CREATE USER or CREATE GROUP rather using COPY (Peter E)
Overhaul pg_dump (Philip Warner)
Allow pg_hba.conf secondary password file to specify only username (Peter E)
Allow TEMPORARY or TEMP key word when creating temporary tables (Bruce)
New memory leak checker (Karel)
New SET SESSION CHARACTERISTICS (Thomas)
Allow nested block comments (Thomas)
Add WITHOUT TIME ZONE type qualifier (Thomas)
New ALTER TABLE ADD CONSTRAINT (Stephan)
Use NUMERIC accumulators for INTEGER aggregates (Tom)
Overhaul aggregate code (Tom)
New VARIANCE and STDDEV() aggregates
Improve dependency ordering of pg_dump (Philip)
New pg_restore command (Philip)
New pg_dump tar output option (Philip)
New pg_dump of large objects  (Philip)
New ESCAPE option to LIKE (Thomas)
New case-insensitive LIKE - ILIKE (Thomas)
Allow functional indexes to use binary-compatible type (Tom)
Allow SQL functions to be used in more contexts (Tom)
New pg_config utility (Peter E)
New PL/pgSQL EXECUTE command which allows dynamic SQL and utility statements
   (Jan)
New PL/pgSQL GET DIAGNOSTICS statement for SPI value access (Jan)
New quote_identifiers() and quote_literal() functions (Jan)
New ALTER TABLE table OWNER TO user command (Mark Hollomon)
Allow subselects in FROM, i.e. FROM (SELECT ...) [AS] alias (Tom)
Update PyGreSQL to version 3.1 (D'Arcy)
Store tables as files named by OID (Vadim)
New SQL function setval(seq,val,bool) for use in pg_dump (Philip)
Require DROP VIEW to remove views, no DROP TABLE (Mark)
Allow DROP VIEW view1, view2 (Mark)
Allow multiple objects in DROP INDEX, DROP RULE, and DROP TYPE (Tom)
Allow automatic conversion to/from Unicode (Tatsuo, Eiji)
New /contrib/pgcrypto hashing functions (Marko Kreen)
New pg_dumpall --globals-only option (Peter E)
New CHECKPOINT command for WAL which creates new WAL log file (Vadim)
New AT TIME ZONE syntax (Thomas)
Allow location of Unix domain socket to be configurable (David J. MacKenzie)
Allow postmaster to listen on a specific IP address (David J. MacKenzie)
Allow socket path name to be specified in hostname by using leading slash
   (David J. MacKenzie)
Allow CREATE DATABASE to specify template database (Tom)
New utility to convert MySQL schema dumps to SQL92 and PostgreSQL (Thomas)
New /contrib/rserv replication toolkit (Vadim)
New file format for COPY BINARY (Tom)
New /contrib/oid2name to map numeric files to table names (B Palmer)
New "idle in transaction" ps status message (Marc)
Update to pgaccess 0.98.7 (Constantin Teodorescu)
pg_ctl now defaults to -w (wait) on shutdown, new -l (log) option
Add rudimentary dependency checking to pg_dump (Philip)

Types
-----
Fix INET/CIDR type ordering and add new functions (Tom)
Make OID behave as an unsigned type (Tom)
Allow BIGINT as synonym for INT8 (Peter E)
New int2 and int8 comparison operators (Tom)
New BIT and BIT VARYING types (Adriaan Joubert, Tom, Peter E)
CHAR() no longer faster than VARCHAR() because of TOAST (Tom)
New GIST seg/cube examples (Gene Selkov)
Improved round(numeric) handling (Tom)
Fix CIDR output formatting (Tom)
New CIDR abbrev() function (Tom)

Performance
-----------
Write-Ahead Log (WAL) to provide crash recovery with less performance
   overhead (Vadim)
ANALYZE stage of VACUUM no longer exclusively locks table (Bruce)
Reduced file seeks (Denis Perchine)
Improve BTREE code for duplicate keys (Tom)
Store all large objects in a single table (Denis Perchine, Tom)
Improve memory allocation performance (Karel, Tom)

Source Code
-----------
New function manager call conventions (Tom)
SGI portability fixes (David Kaelbling)
New configure --enable-syslog option (Peter E)
New BSDI README (Bruce)
configure script moved to top level, not /src (Peter E)
Makefile/configuration/compilation overhaul (Peter E)
New configure --with-python option (Peter E)
Solaris cleanups (Peter E)
Overhaul /contrib Makefiles (Karel)
New OpenSSL configuration option (Magnus, Peter E)
AIX fixes (Andreas)
QNX fixes (Maurizio)
New heap_open(), heap_openr() API (Tom)
Remove colon and semi-colon operators (Thomas)
New pg_class.relkind value for views (Mark Hollomon)
Rename ichar() to chr() (Karel)
New documentation for btrim(), ascii(), chr(), repeat() (Karel)
Fixes for NT/Cygwin (Pete Forman)
AIX port fixes (Andreas)
New BeOS port (David Reid, Cyril Velter)
Add proofreader's changes to docs (Addison-Wesley, Bruce)
New Alpha spinlock code (Adriaan Joubert, Compaq)
UnixWare port overhaul (Peter E)
New Darwin/Mac OS X port (Peter Bierman, Bruce Hartzler)
New FreeBSD Alpha port (Alfred)
Overhaul shared memory segments (Tom)
Add IBM S/390 support (Neale Ferguson)
Moved macmanuf to /contrib (Larry Rosenman)
Syslog improvements (Larry Rosenman)
New template0 database that contains no user additions (Tom)
New /contrib/cube and /contrib/seg GIST sample code (Gene Selkov)
Allow NetBSD's libedit instead of readline (Peter)
Improved assembly language source code format (Bruce)
New contrib/pg_logger
New --template option to createdb
New contrib/pg_control utility (Oliver)
New FreeBSD tools ipc_check, start-scripts/freebsd
     __________________________________________________________________

                                Release 7.0.3

     Release Date: 2000-11-11

   This has a variety of fixes from 7.0.2.
     __________________________________________________________________

Migration to Version 7.0.3

   A dump/restore is *not* required for those running 7.0.*.
     __________________________________________________________________

Changes

Jdbc fixes (Peter)
Large object fix (Tom)
Fix lean in COPY WITH OIDS leak (Tom)
Fix backwards-index-scan (Tom)
Fix SELECT ... FOR UPDATE so it checks for duplicate keys (Hiroshi)
Add --enable-syslog to configure (Marc)
Fix abort transaction at backend exit in rare cases (Tom)
Fix for psql \l+ when multibyte enabled (Tatsuo)
Allow PL/pgSQL to accept non ascii identifiers (Tatsuo)
Make vacuum always flush buffers (Tom)
Fix to allow cancel while waiting for a lock (Hiroshi)
Fix for memory allocation problem in user authentication code (Tom)
Remove bogus use of int4out() (Tom)
Fixes for multiple subqueries in COALESCE or BETWEEN (Tom)
Fix for failure of triggers on heap open in certain cases (Jeroen van
   Vianen)
Fix for erroneous selectivity of not-equals (Tom)
Fix for erroneous use of strcmp() (Tom)
Fix for bug where storage manager accesses items beyond end of file
   (Tom)
Fix to include kernel errno message in all smgr elog messages (Tom)
Fix for '.' not in PATH at build time (SL Baur)
Fix for out-of-file-descriptors error (Tom)
Fix to make pg_dump dump 'iscachable' flag for functions (Tom)
Fix for subselect in targetlist of Append node (Tom)
Fix for mergejoin plans (Tom)
Fix TRUNCATE failure on relations with indexes (Tom)
Avoid database-wide restart on write error (Hiroshi)
Fix nodeMaterial to honor chgParam by recomputing its output (Tom)
Fix VACUUM problem with moving chain of update row versions when source
   and destination of a row version lie on the same page (Tom)
Fix user.c CommandCounterIncrement (Tom)
Fix for AM/PM boundary problem in to_char() (Karel Zak)
Fix TIME aggregate handling (Tom)
Fix to_char() to avoid coredump on NULL input (Tom)
Buffer fix (Tom)
Fix for inserting/copying longer multibyte strings into char() data
   types (Tatsuo)
Fix for crash of backend, on abort (Tom)
     __________________________________________________________________

                                Release 7.0.2

     Release Date: 2000-06-05

   This is a repackaging of 7.0.1 with added documentation.
     __________________________________________________________________

Migration to Version 7.0.2

   A dump/restore is *not* required for those running 7.*.
     __________________________________________________________________

Changes

Added documentation to tarball.
     __________________________________________________________________

                                Release 7.0.1

     Release Date: 2000-06-01

   This is a cleanup release for 7.0.
     __________________________________________________________________

Migration to Version 7.0.1

   A dump/restore is *not* required for those running 7.0.
     __________________________________________________________________

Changes

Fix many CLUSTER failures (Tom)
Allow ALTER TABLE RENAME works on indexes (Tom)
Fix plpgsql to handle datetime->timestamp and timespan->interval (Bruce)
New configure --with-setproctitle switch to use setproctitle() (Marc, Bruce)
Fix the off by one errors in ResultSet from 6.5.3, and more.
jdbc ResultSet fixes (Joseph Shraibman)
optimizer tunings (Tom)
Fix create user for pgaccess
Fix for UNLISTEN failure
IRIX fixes (David Kaelbling)
QNX fixes (Andreas Kardos)
Reduce COPY IN lock level (Tom)
Change libpqeasy to use PQconnectdb() style parameters (Bruce)
Fix pg_dump to handle OID indexes (Tom)
Fix small memory leak (Tom)
Solaris fix for createdb/dropdb (Tatsuo)
Fix for non-blocking connections (Alfred Perlstein)
Fix improper recovery after RENAME TABLE failures (Tom)
Copy pg_ident.conf.sample into /lib directory in install (Bruce)
Add SJIS UDC (NEC selection IBM kanji) support (Eiji Tokuya)
Fix too long syslog message (Tatsuo)
Fix problem with quoted indexes that are too long (Tom)
JDBC ResultSet.getTimestamp() fix (Gregory Krasnow & Floyd Marinescu)
ecpg changes (Michael)
     __________________________________________________________________

                                 Release 7.0

     Release Date: 2000-05-08

   This release contains improvements in many areas, demonstrating the
   continued growth of PostgreSQL. There are more improvements and fixes
   in 7.0 than in any previous release. The developers have confidence
   that this is the best release yet; we do our best to put out only solid
   releases, and this one is no exception.

   Major changes in this release:

   Foreign Keys
          Foreign keys are now implemented, with the exception of PARTIAL
          MATCH foreign keys. Many users have been asking for this
          feature, and we are pleased to offer it.

   Optimizer Overhaul
          Continuing on work started a year ago, the optimizer has been
          improved, allowing better query plan selection and faster
          performance with less memory usage.

   Updated psql
          psql, our interactive terminal monitor, has been updated with a
          variety of new features. See the psql manual page for details.

   Join Syntax
          SQL92 join syntax is now supported, though only as INNER JOIN
          for this release. JOIN, NATURAL JOIN, JOIN/USING, and JOIN/ON
          are available, as are column correlation names.
     __________________________________________________________________

Migration to Version 7.0

   A dump/restore using pg_dump is required for those wishing to migrate
   data from any previous release of PostgreSQL. For those upgrading from
   6.5.*, you can instead use pg_upgrade to upgrade to this release;
   however, a full dump/reload installation is always the most robust
   method for upgrades.

   Interface and compatibility issues to consider for the new release
   include:

     * The date/time types datetime and timespan have been superseded by
       the SQL92-defined types timestamp and interval. Although there has
       been some effort to ease the transition by allowing PostgreSQL to
       recognize the deprecated type names and translate them to the new
       type names, this mechanism cannot be completely transparent to your
       existing application.
     * The optimizer has been substantially improved in the area of query
       cost estimation. In some cases, this will result in decreased query
       times as the optimizer makes a better choice for the preferred
       plan. However, in a small number of cases, usually involving
       pathological distributions of data, your query times might go up.
       If you are dealing with large amounts of data, you might want to
       check your queries to verify performance.
     * The JDBC and ODBC interfaces have been upgraded and extended.
     * The string function CHAR_LENGTH is now a native function. Previous
       versions translated this into a call to LENGTH, which could result
       in ambiguity with other types implementing LENGTH such as the
       geometric types.
     __________________________________________________________________

Changes

Bug Fixes
---------
Prevent function calls exceeding maximum number of arguments (Tom)
Improve CASE construct (Tom)
Fix SELECT coalesce(f1,0) FROM int4_tbl GROUP BY f1 (Tom)
Fix SELECT sentence.words[0] FROM sentence GROUP BY sentence.words[0] (Tom)
Fix GROUP BY scan bug (Tom)
Improvements in SQL grammar processing (Tom)
Fix for views involved in INSERT ... SELECT ... (Tom)
Fix for SELECT a/2, a/2 FROM test_missing_target GROUP BY a/2 (Tom)
Fix for subselects in INSERT ... SELECT (Tom)
Prevent INSERT ... SELECT ... ORDER BY (Tom)
Fixes for relations greater than 2GB, including vacuum
Improve propagating system table changes to other backends (Tom)
Improve propagating user table changes to other backends (Tom)
Fix handling of temp tables in complex situations (Bruce, Tom)
Allow table locking at table open, improving concurrent reliability (Tom)
Properly quote sequence names in pg_dump (Ross J. Reedstrom)
Prevent DROP DATABASE while others accessing
Prevent any rows from being returned by GROUP BY if no rows processed (Tom)
Fix SELECT COUNT(1) FROM table WHERE ...' if no rows matching WHERE (Tom)
Fix pg_upgrade so it works for MVCC (Tom)
Fix for SELECT ... WHERE x IN (SELECT ... HAVING SUM(x) > 1) (Tom)
Fix for "f1 datetime DEFAULT 'now'"  (Tom)
Fix problems with CURRENT_DATE used in DEFAULT (Tom)
Allow comment-only lines, and ;;; lines too. (Tom)
Improve recovery after failed disk writes, disk full (Hiroshi)
Fix cases where table is mentioned in FROM but not joined (Tom)
Allow HAVING clause without aggregate functions (Tom)
Fix for "--" comment and no trailing newline, as seen in perl interface
Improve pg_dump failure error reports (Bruce)
Allow sorts and hashes to exceed 2GB file sizes (Tom)
Fix for pg_dump dumping of inherited rules (Tom)
Fix for NULL handling comparisons (Tom)
Fix inconsistent state caused by failed CREATE/DROP commands (Hiroshi)
Fix for dbname with dash
Prevent DROP INDEX from interfering with other backends (Tom)
Fix file descriptor leak in verify_password()
Fix for "Unable to identify an operator =$" problem
Fix ODBC so no segfault if CommLog and Debug enabled (Dirk Niggemann)
Fix for recursive exit call (Massimo)
Fix for extra-long timezones (Jeroen van Vianen)
Make pg_dump preserve primary key information (Peter E)
Prevent databases with single quotes (Peter E)
Prevent DROP DATABASE inside  transaction (Peter E)
ecpg memory leak fixes (Stephen Birch)
Fix for SELECT null::text, SELECT int4fac(null) and SELECT 2 + (null) (Tom)
Y2K timestamp fix (Massimo)
Fix for VACUUM 'HEAP_MOVED_IN was not expected' errors (Tom)
Fix for views with tables/columns containing spaces  (Tom)
Prevent privileges on indexes (Peter E)
Fix for spinlock stuck problem when error is generated (Hiroshi)
Fix ipcclean on Linux
Fix handling of NULL constraint conditions (Tom)
Fix memory leak in odbc driver (Nick Gorham)
Fix for privilege check on UNION tables (Tom)
Fix to allow SELECT 'a' LIKE 'a' (Tom)
Fix for SELECT 1 + NULL (Tom)
Fixes to CHAR
Fix log() on numeric type (Tom)
Deprecate ':' and ';' operators
Allow vacuum of temporary tables
Disallow inherited columns with the same name as new columns
Recover or force failure when disk space is exhausted (Hiroshi)
Fix INSERT INTO ... SELECT with AS columns matching result columns
Fix INSERT ... SELECT ... GROUP BY groups by target columns not source columns (
Tom)
Fix CREATE TABLE test (a char(5) DEFAULT text '', b int4) with INSERT (Tom)
Fix UNION with LIMIT
Fix CREATE TABLE x AS SELECT 1 UNION SELECT 2
Fix CREATE TABLE test(col char(2) DEFAULT user)
Fix mismatched types in CREATE TABLE ... DEFAULT
Fix SELECT * FROM pg_class where oid in (0,-1)
Fix SELECT COUNT('asdf') FROM pg_class WHERE oid=12
Prevent user who can create databases can modifying pg_database table (Peter E)
Fix btree to give a useful elog when key > 1/2 (page - overhead) (Tom)
Fix INSERT of 0.0 into DECIMAL(4,4) field (Tom)

Enhancements
------------
New CLI interface include file sqlcli.h, based on SQL3/SQL98
Remove all limits on query length, row length limit still exists (Tom)
Update jdbc protocol to 2.0 (Jens Glaser <jens@jens.de>)
Add TRUNCATE command to quickly truncate relation (Mike Mascari)
Fix to give super user and createdb user proper update catalog rights (Peter E)
Allow ecpg bool variables to have NULL values (Christof)
Issue ecpg error if NULL value for variable with no NULL indicator (Christof)
Allow ^C to cancel COPY command (Massimo)
Add SET FSYNC and SHOW PG_OPTIONS commands(Massimo)
Function name overloading for dynamically-loaded C functions (Frankpitt)
Add CmdTuples() to libpq++(Vince)
New CREATE CONSTRAINT TRIGGER and SET CONSTRAINTS commands(Jan)
Allow CREATE FUNCTION/WITH clause to be used for all language types
configure --enable-debug adds -g (Peter E)
configure --disable-debug removes -g (Peter E)
Allow more complex default expressions (Tom)
First real FOREIGN KEY constraint trigger functionality (Jan)
Add FOREIGN KEY ... MATCH FULL ... ON DELETE CASCADE (Jan)
Add FOREIGN KEY ... MATCH <unspecified> referential actions (Don Baccus)
Allow WHERE restriction on ctid (physical heap location) (Hiroshi)
Move pginterface from contrib to interface directory, rename to pgeasy (Bruce)
Change pgeasy connectdb() parameter ordering (Bruce)
Require SELECT DISTINCT target list to have all ORDER BY columns (Tom)
Add Oracle's COMMENT ON command (Mike Mascari <mascarim@yahoo.com>)
libpq's PQsetNoticeProcessor function now returns previous hook(Peter E)
Prevent PQsetNoticeProcessor from being set to NULL (Peter E)
Make USING in COPY optional (Bruce)
Allow subselects in the target list (Tom)
Allow subselects on the left side of comparison operators (Tom)
New parallel regression test (Jan)
Change backend-side COPY to write files with permissions 644 not 666 (Tom)
Force permissions on PGDATA directory to be secure, even if it exists (Tom)
Added psql LASTOID variable to return last inserted oid (Peter E)
Allow concurrent vacuum and remove pg_vlock vacuum lock file (Tom)
Add privilege check for vacuum (Peter E)
New libpq functions to allow asynchronous connections: PQconnectStart(),
  PQconnectPoll(), PQresetStart(), PQresetPoll(), PQsetenvStart(),
  PQsetenvPoll(), PQsetenvAbort (Ewan Mellor)
New libpq PQsetenv() function (Ewan Mellor)
create/alter user extension (Peter E)
New postmaster.pid and postmaster.opts under $PGDATA (Tatsuo)
New scripts for create/drop user/db (Peter E)
Major psql overhaul (Peter E)
Add const to libpq interface (Peter E)
New libpq function PQoidValue (Peter E)
Show specific non-aggregate causing problem with GROUP BY (Tom)
Make changes to pg_shadow recreate pg_pwd file (Peter E)
Add aggregate(DISTINCT ...) (Tom)
Allow flag to control COPY input/output of NULLs (Peter E)
Make postgres user have a password by default (Peter E)
Add CREATE/ALTER/DROP GROUP (Peter E)
All administration scripts now support --long options (Peter E, Karel)
Vacuumdb script now supports --all option (Peter E)
ecpg new portable FETCH syntax
Add ecpg EXEC SQL IFDEF, EXEC SQL IFNDEF, EXEC SQL ELSE, EXEC SQL ELIF
       and EXEC SQL ENDIF directives
Add pg_ctl script to control backend start-up (Tatsuo)
Add postmaster.opts.default file to store start-up flags (Tatsuo)
Allow --with-mb=SQL_ASCII
Increase maximum number of index keys to 16 (Bruce)
Increase maximum number of function arguments to 16 (Bruce)
Allow configuration of maximum number of index keys and arguments (Bruce)
Allow unprivileged users to change their passwords (Peter E)
Password authentication enabled; required for new users (Peter E)
Disallow dropping a user who owns a database (Peter E)
Change initdb option --with-mb to --enable-multibyte
Add option for initdb to prompts for superuser password (Peter E)
Allow complex type casts like col::numeric(9,2) and col::int2::float8 (Tom)
Updated user interfaces on initdb, initlocation, pg_dump, ipcclean (Peter E)
New pg_char_to_encoding() and pg_encoding_to_char() functions (Tatsuo)
libpq non-blocking mode (Alfred Perlstein)
Improve conversion of types in casts that don't specify a length
New plperl internal programming language (Mark Hollomon)
Allow COPY IN to read file that do not end with a newline (Tom)
Indicate when long identifiers are truncated (Tom)
Allow aggregates to use type equivalency (Peter E)
Add Oracle's to_char(), to_date(), to_datetime(), to_timestamp(), to_number()
       conversion functions (Karel Zak <zakkr@zf.jcu.cz>)
Add SELECT DISTINCT ON (expr [, expr ...]) targetlist ... (Tom)
Check to be sure ORDER BY is compatible with the DISTINCT operation (Tom)
Add NUMERIC and int8 types to ODBC
Improve EXPLAIN results for Append, Group, Agg, Unique (Tom)
Add ALTER TABLE ... ADD FOREIGN KEY (Stephan Szabo)
Allow SELECT .. FOR UPDATE in PL/pgSQL (Hiroshi)
Enable backward sequential scan even after reaching EOF (Hiroshi)
Add btree indexing of boolean values, >= and <= (Don Baccus)
Print current line number when COPY FROM fails (Massimo)
Recognize POSIX time zone e.g. "PST+8" and "GMT-8" (Thomas)
Add DEC as synonym for DECIMAL (Thomas)
Add SESSION_USER as SQL92 key word, same as CURRENT_USER (Thomas)
Implement SQL92 column aliases (aka correlation names) (Thomas)
Implement SQL92 join syntax (Thomas)
Make INTERVAL reserved word allowed as a column identifier (Thomas)
Implement REINDEX command (Hiroshi)
Accept ALL in aggregate function SUM(ALL col) (Tom)
Prevent GROUP BY from using column aliases (Tom)
New psql \encoding option (Tatsuo)
Allow PQrequestCancel() to terminate when in waiting-for-lock state (Hiroshi)
Allow negation of a negative number in all cases
Add ecpg descriptors (Christof, Michael)
Allow CREATE VIEW v AS SELECT f1::char(8) FROM tbl
Allow casts with length, like foo::char(8)
New libpq functions PQsetClientEncoding(), PQclientEncoding() (Tatsuo)
Add support for SJIS user defined characters (Tatsuo)
Larger views/rules supported
Make libpq's PQconndefaults() thread-safe (Tom)
Disable // as comment to be ANSI conforming, should use -- (Tom)
Allow column aliases on views CREATE VIEW name (collist)
Fixes for views with subqueries (Tom)
Allow UPDATE table SET fld = (SELECT ...) (Tom)
SET command options no longer require quotes
Update pgaccess to 0.98.6
New SET SEED command
New pg_options.sample file
New SET FSYNC command (Massimo)
Allow pg_descriptions when creating tables
Allow pg_descriptions when creating types, columns, and functions
Allow psql \copy to allow delimiters (Peter E)
Allow psql to print nulls as distinct from "" [null] (Peter E)

Types
-----
Many array fixes (Tom)
Allow bare column names to be subscripted as arrays (Tom)
Improve type casting of int and float constants (Tom)
Cleanups for int8 inputs, range checking, and type conversion (Tom)
Fix for SELECT timespan('21:11:26'::time) (Tom)
netmask('x.x.x.x/0') is 255.255.255.255 instead of 0.0.0.0 (Oleg Sharoiko)
Add btree index on NUMERIC (Jan)
Perl fix for large objects containing NUL characters (Douglas Thomson)
ODBC fix for large objects (free)
Fix indexing of cidr data type
Fix for Ethernet MAC addresses (macaddr type) comparisons
Fix for date/time types when overflows happened in computations (Tom)
Allow array on int8 (Peter E)
Fix for rounding/overflow of NUMERIC type, like NUMERIC(4,4) (Tom)
Allow NUMERIC arrays
Fix bugs in NUMERIC ceil() and floor() functions (Tom)
Make char_length()/octet_length including trailing blanks (Tom)
Made abstime/reltime use int4 instead of time_t (Peter E)
New lztext data type for compressed text fields
Revise code to handle coercion of int and float constants (Tom)
Start at new code to implement a BIT and BIT VARYING type (Adriaan Joubert)
NUMERIC now accepts scientific notation (Tom)
NUMERIC to int4 rounds (Tom)
Convert float4/8 to NUMERIC properly (Tom)
Allow type conversion with NUMERIC (Thomas)
Make ISO date style (2000-02-16 09:33) the default (Thomas)
Add NATIONAL CHAR [ VARYING ] (Thomas)
Allow NUMERIC round and trunc to accept negative scales (Tom)
New TIME WITH TIME ZONE type (Thomas)
Add MAX()/MIN() on time type (Thomas)
Add abs(), mod(), fac() for int8 (Thomas)
Rename functions to round(), sqrt(), cbrt(), pow() for float8 (Thomas)
Add transcendental math functions (e.g. sin(), acos()) for float8 (Thomas)
Add exp() and ln() for NUMERIC type
Rename NUMERIC power() to pow() (Thomas)
Improved TRANSLATE() function (Edwin Ramirez, Tom)
Allow X=-Y operators  (Tom)
Allow SELECT float8(COUNT(*))/(SELECT COUNT(*) FROM t) FROM t GROUP BY f1; (Tom)
Allow LOCALE to use indexes in regular expression searches (Tom)
Allow creation of functional indexes to use default types

Performance
-----------
Prevent exponential space consumption with many AND's and OR's (Tom)
Collect attribute selectivity values for system columns (Tom)
Reduce memory usage of aggregates (Tom)
Fix for LIKE optimization to use indexes with multibyte encodings (Tom)
Fix r-tree index optimizer selectivity (Thomas)
Improve optimizer selectivity computations and functions (Tom)
Optimize btree searching for cases where many equal keys exist (Tom)
Enable fast LIKE index processing only if index present (Tom)
Re-use free space on index pages with duplicates (Tom)
Improve hash join processing (Tom)
Prevent descending sort if result is already sorted(Hiroshi)
Allow commuting of index scan query qualifications (Tom)
Prefer index scans in cases where ORDER BY/GROUP BY is required (Tom)
Allocate large memory requests in fix-sized chunks for performance (Tom)
Fix vacuum's performance by reducing memory allocation requests (Tom)
Implement constant-expression simplification (Bernard Frankpitt, Tom)
Use secondary columns to be used to determine start of index scan (Hiroshi)
Prevent quadruple use of disk space when doing internal sorting (Tom)
Faster sorting by calling fewer functions (Tom)
Create system indexes to match all system caches (Bruce, Hiroshi)
Make system caches use system indexes (Bruce)
Make all system indexes unique (Bruce)
Improve pg_statistics management for VACUUM speed improvement (Tom)
Flush backend cache less frequently (Tom, Hiroshi)
COPY now reuses previous memory allocation, improving performance (Tom)
Improve optimization cost estimation (Tom)
Improve optimizer estimate of range queries x > lowbound AND x < highbound (Tom)
Use DNF instead of CNF where appropriate (Tom, Taral)
Further cleanup for OR-of-AND WHERE-clauses (Tom)
Make use of index in OR clauses (x = 1 AND y = 2) OR (x = 2 AND y = 4) (Tom)
Smarter optimizer computations for random index page access (Tom)
New SET variable to control optimizer costs (Tom)
Optimizer queries based on LIMIT, OFFSET, and EXISTS qualifications (Tom)
Reduce optimizer internal housekeeping of join paths for speedup (Tom)
Major subquery speedup (Tom)
Fewer fsync writes when fsync is not disabled (Tom)
Improved LIKE optimizer estimates (Tom)
Prevent fsync in SELECT-only queries (Vadim)
Make index creation use psort code, because it is now faster (Tom)
Allow creation of sort temp tables > 1 Gig

Source Tree Changes
-------------------
Fix for linux PPC compile
New generic expression-tree-walker subroutine (Tom)
Change form() to varargform() to prevent portability problems
Improved range checking for large integers on Alphas
Clean up #include in /include directory (Bruce)
Add scripts for checking includes (Bruce)
Remove un-needed #include's from *.c files (Bruce)
Change #include's to use <> and "" as appropriate (Bruce)
Enable Windows compilation of libpq
Alpha spinlock fix from Uncle George <gatgul@voicenet.com>
Overhaul of optimizer data structures (Tom)
Fix to cygipc library (Yutaka Tanida)
Allow pgsql to work on newer Cygwin snapshots (Dan)
New catalog version number (Tom)
Add Linux ARM
Rename heap_replace to heap_update
Update for QNX (Dr. Andreas Kardos)
New platform-specific regression handling (Tom)
Rename oid8 -> oidvector and int28 -> int2vector (Bruce)
Included all yacc and lex files into the distribution (Peter E.)
Remove lextest, no longer needed (Peter E)
Fix for libpq and psql on Windows (Magnus)
Internally change datetime and timespan into timestamp and interval (Thomas)
Fix for plpgsql on BSD/OS
Add SQL_ASCII test case to the regression test (Tatsuo)
configure --with-mb now deprecated (Tatsuo)
NT fixes
NetBSD fixes (Johnny C. Lam <lamj@stat.cmu.edu>)
Fixes for Alpha compiles
New multibyte encodings
     __________________________________________________________________

                                Release 6.5.3

     Release Date: 1999-10-13

   This is basically a cleanup release for 6.5.2. We have added a new
   PgAccess that was missing in 6.5.2, and installed an NT-specific fix.
     __________________________________________________________________

Migration to Version 6.5.3

   A dump/restore is *not* required for those running 6.5.*.
     __________________________________________________________________

Changes

Updated version of pgaccess 0.98
NT-specific patch
Fix dumping rules on inherited tables
     __________________________________________________________________

                                Release 6.5.2

     Release Date: 1999-09-15

   This is basically a cleanup release for 6.5.1. We have fixed a variety
   of problems reported by 6.5.1 users.
     __________________________________________________________________

Migration to Version 6.5.2

   A dump/restore is *not* required for those running 6.5.*.
     __________________________________________________________________

Changes

subselect+CASE fixes(Tom)
Add SHLIB_LINK setting for solaris_i386 and solaris_sparc ports(Daren Sefcik)
Fixes for CASE in WHERE join clauses(Tom)
Fix BTScan abort(Tom)
Repair the check for redundant UNIQUE and PRIMARY KEY indexes(Thomas)
Improve it so that it checks for multicolumn constraints(Thomas)
Fix for Windows making problem with MB enabled(Hiroki Kataoka)
Allow BSD yacc and bison to compile pl code(Bruce)
Fix SET NAMES working
int8 fixes(Thomas)
Fix vacuum's memory consumption(Hiroshi,Tatsuo)
Reduce the total memory consumption of vacuum(Tom)
Fix for timestamp(datetime)
Rule deparsing bugfixes(Tom)
Fix quoting problems in mkMakefile.tcldefs.sh.in and mkMakefile.tkdefs.sh.in(Tom
)
This is to re-use space on index pages freed by vacuum(Vadim)
document -x for pg_dump(Bruce)
Fix for unary operators in rule deparser(Tom)
Comment out FileUnlink of excess segments during mdtruncate()(Tom)
IRIX linking fix from Yu Cao >yucao@falcon.kla-tencor.com<
Repair logic error in LIKE: should not return LIKE_ABORT
  when reach end of pattern before end of text(Tom)
Repair incorrect cleanup of heap memory allocation during transaction abort(Tom)
Updated version of pgaccess 0.98
     __________________________________________________________________

                                Release 6.5.1

     Release Date: 1999-07-15

   This is basically a cleanup release for 6.5. We have fixed a variety of
   problems reported by 6.5 users.
     __________________________________________________________________

Migration to Version 6.5.1

   A dump/restore is *not* required for those running 6.5.
     __________________________________________________________________

Changes

Add NT README file
Portability fixes for linux_ppc, IRIX, linux_alpha, OpenBSD, alpha
Remove QUERY_LIMIT, use SELECT...LIMIT
Fix for EXPLAIN on inheritance(Tom)
Patch to allow vacuum on multisegment tables(Hiroshi)
R-Tree optimizer selectivity fix(Tom)
ACL file descriptor leak fix(Atsushi Ogawa)
New expression subtree code(Tom)
Avoid disk writes for read-only transactions(Vadim)
Fix for removal of temp tables if last transaction was aborted(Bruce)
Fix to prevent too large row from being created(Bruce)
plpgsql fixes
Allow port numbers 32k - 64k(Bruce)
Add ^ precedence(Bruce)
Rename sort files called pg_temp to pg_sorttemp(Bruce)
Fix for microseconds in time values(Tom)
Tutorial source cleanup
New linux_m68k port
Fix for sorting of NULL's in some cases(Tom)
Shared library dependencies fixed (Tom)
Fixed glitches affecting GROUP BY in subselects(Tom)
Fix some compiler warnings (Tomoaki Nishiyama)
Add Win1250 (Czech) support (Pavel Behal)
     __________________________________________________________________

                                 Release 6.5

     Release Date: 1999-06-09

   This release marks a major step in the development team's mastery of
   the source code we inherited from Berkeley. You will see we are now
   easily adding major features, thanks to the increasing size and
   experience of our world-wide development team.

   Here is a brief summary of the more notable changes:

   Multiversion concurrency control(MVCC)
          This removes our old table-level locking, and replaces it with a
          locking system that is superior to most commercial database
          systems. In a traditional system, each row that is modified is
          locked until committed, preventing reads by other users. MVCC
          uses the natural multiversion nature of PostgreSQL to allow
          readers to continue reading consistent data during writer
          activity. Writers continue to use the compact pg_log transaction
          system. This is all performed without having to allocate a lock
          for every row like traditional database systems. So, basically,
          we no longer are restricted by simple table-level locking; we
          have something better than row-level locking.

   Hot backups from pg_dump
          pg_dump takes advantage of the new MVCC features to give a
          consistent database dump/backup while the database stays online
          and available for queries.

   Numeric data type
          We now have a true numeric data type, with user-specified
          precision.

   Temporary tables
          Temporary tables are guaranteed to have unique names within a
          database session, and are destroyed on session exit.

   New SQL features
          We now have CASE, INTERSECT, and EXCEPT statement support. We
          have new LIMIT/OFFSET, SET TRANSACTION ISOLATION LEVEL, SELECT
          ... FOR UPDATE, and an improved LOCK TABLE command.

   Speedups
          We continue to speed up PostgreSQL, thanks to the variety of
          talents within our team. We have sped up memory allocation,
          optimization, table joins, and row transfer routines.

   Ports
          We continue to expand our port list, this time including Windows
          NT/ix86 and NetBSD/arm32.

   Interfaces
          Most interfaces have new versions, and existing functionality
          has been improved.

   Documentation
          New and updated material is present throughout the
          documentation. New FAQs have been contributed for SGI and AIX
          platforms. The Tutorial has introductory information on SQL from
          Stefan Simkovics. For the User's Guide, there are reference
          pages covering the postmaster and more utility programs, and a
          new appendix contains details on date/time behavior. The
          Administrator's Guide has a new chapter on troubleshooting from
          Tom Lane. And the Programmer's Guide has a description of query
          processing, also from Stefan, and details on obtaining the
          PostgreSQL source tree via anonymous CVS and CVSup.
     __________________________________________________________________

Migration to Version 6.5

   A dump/restore using pg_dump is required for those wishing to migrate
   data from any previous release of PostgreSQL. pg_upgrade can *not* be
   used to upgrade to this release because the on-disk structure of the
   tables has changed compared to previous releases.

   The new Multiversion Concurrency Control (MVCC) features can give
   somewhat different behaviors in multiuser environments. *Read and
   understand the following section to ensure that your existing
   applications will give you the behavior you need.*
     __________________________________________________________________

Multiversion Concurrency Control

   Because readers in 6.5 don't lock data, regardless of transaction
   isolation level, data read by one transaction can be overwritten by
   another. In other words, if a row is returned by "SELECT" it doesn't
   mean that this row really exists at the time it is returned (i.e.
   sometime after the statement or transaction began) nor that the row is
   protected from being deleted or updated by concurrent transactions
   before the current transaction does a commit or rollback.

   To ensure the actual existence of a row and protect it against
   concurrent updates one must use "SELECT FOR UPDATE" or an appropriate
   "LOCK TABLE" statement. This should be taken into account when porting
   applications from previous releases of PostgreSQL and other
   environments.

   Keep the above in mind if you are using "contrib/refint.*" triggers for
   referential integrity. Additional techniques are required now. One way
   is to use "LOCK parent_table IN SHARE ROW EXCLUSIVE MODE" command if a
   transaction is going to update/delete a primary key and use "LOCK
   parent_table IN SHARE MODE" command if a transaction is going to
   update/insert a foreign key.

     Note: Note that if you run a transaction in SERIALIZABLE mode then
     you must execute the "LOCK" commands above before execution of any
     DML statement ("SELECT/INSERT/DELETE/UPDATE/FETCH/COPY_TO") in the
     transaction.

   These inconveniences will disappear in the future when the ability to
   read dirty (uncommitted) data (regardless of isolation level) and true
   referential integrity will be implemented.
     __________________________________________________________________

Changes

Bug Fixes
---------
Fix text<->float8 and text<->float4 conversion functions(Thomas)
Fix for creating tables with mixed-case constraints(Billy)
Change exp()/pow() behavior to generate error on underflow/overflow(Jan)
Fix bug in pg_dump -z
Memory overrun cleanups(Tatsuo)
Fix for lo_import crash(Tatsuo)
Adjust handling of data type names to suppress double quotes(Thomas)
Use type coercion for matching columns and DEFAULT(Thomas)
Fix deadlock so it only checks once after one second of sleep(Bruce)
Fixes for aggregates and PL/pgsql(Hiroshi)
Fix for subquery crash(Vadim)
Fix for libpq function PQfnumber and case-insensitive names(Bahman Rafatjoo)
Fix for large object write-in-middle, no extra block, memory consumption(Tatsuo)
Fix for pg_dump -d or -D and  quote special characters in INSERT
Repair serious problems with dynahash(Tom)
Fix INET/CIDR portability problems
Fix problem with selectivity error in ALTER TABLE ADD COLUMN(Bruce)
Fix executor so mergejoin of different column types works(Tom)
Fix for Alpha OR selectivity bug
Fix OR index selectivity problem(Bruce)
Fix so \d shows proper length for char()/varchar()(Ryan)
Fix tutorial code(Clark)
Improve destroyuser checking(Oliver)
Fix for Kerberos(Rodney McDuff)
Fix for dropping database while dirty buffers(Bruce)
Fix so sequence nextval() can be case-sensitive(Bruce)
Fix !!= operator
Drop buffers before destroying database files(Bruce)
Fix case where executor evaluates functions twice(Tatsuo)
Allow sequence nextval actions to be case-sensitive(Bruce)
Fix optimizer indexing not working for negative numbers(Bruce)
Fix for memory leak in executor with fjIsNull
Fix for aggregate memory leaks(Erik Riedel)
Allow user name containing a dash to grant privileges
Cleanup of NULL in inet types
Clean up system table bugs(Tom)
Fix problems of PAGER and \? command(Masaaki Sakaida)
Reduce default multisegment file size limit to 1GB(Peter)
Fix for dumping of CREATE OPERATOR(Tom)
Fix for backward scanning of cursors(Hiroshi Inoue)
Fix for COPY FROM STDIN when using \i(Tom)
Fix for subselect is compared inside an expression(Jan)
Fix handling of error reporting while returning rows(Tom)
Fix problems with reference to array types(Tom,Jan)
Prevent UPDATE SET oid(Jan)
Fix pg_dump so -t option can handle case-sensitive tablenames
Fixes for GROUP BY in special cases(Tom, Jan)
Fix for memory leak in failed queries(Tom)
DEFAULT now supports mixed-case identifiers(Tom)
Fix for multisegment uses of DROP/RENAME table, indexes(Ole Gjerde)
Disable use of pg_dump with both -o and -d options(Bruce)
Allow pg_dump to properly dump group privileges(Bruce)
Fix GROUP BY in INSERT INTO table SELECT * FROM table2(Jan)
Fix for computations in views(Jan)
Fix for aggregates on array indexes(Tom)
Fix for DEFAULT handles single quotes in value requiring too many quotes
Fix security problem with non-super users importing/exporting large objects(Tom)
Rollback of transaction that creates table cleaned up properly(Tom)
Fix to allow long table and column names to generate proper serial names(Tom)

Enhancements
------------
Add "vacuumdb" utility
Speed up libpq by allocating memory better(Tom)
EXPLAIN all indexes used(Tom)
Implement CASE, COALESCE, NULLIF  expression(Thomas)
New pg_dump table output format(Constantin)
Add string min()/max() functions(Thomas)
Extend new type coercion techniques to aggregates(Thomas)
New moddatetime contrib(Terry)
Update to pgaccess 0.96(Constantin)
Add routines for single-byte "char" type(Thomas)
Improved substr() function(Thomas)
Improved multibyte handling(Tatsuo)
Multiversion concurrency control/MVCC(Vadim)
New Serialized mode(Vadim)
Fix for tables over 2gigs(Peter)
New SET TRANSACTION ISOLATION LEVEL(Vadim)
New LOCK TABLE IN ... MODE(Vadim)
Update ODBC driver(Byron)
New NUMERIC data type(Jan)
New SELECT FOR UPDATE(Vadim)
Handle "NaN" and "Infinity" for input values(Jan)
Improved date/year handling(Thomas)
Improved handling of backend connections(Magnus)
New options ELOG_TIMESTAMPS and USE_SYSLOG options for log files(Massimo)
New TCL_ARRAYS option(Massimo)
New INTERSECT and EXCEPT(Stefan)
New pg_index.indisprimary for primary key tracking(D'Arcy)
New pg_dump option to allow dropping of tables before creation(Brook)
Speedup of row output routines(Tom)
New READ COMMITTED isolation level(Vadim)
New TEMP tables/indexes(Bruce)
Prevent sorting if result is already sorted(Jan)
New memory allocation optimization(Jan)
Allow psql to do \p\g(Bruce)
Allow multiple rule actions(Jan)
Added LIMIT/OFFSET functionality(Jan)
Improve optimizer when joining a large number of tables(Bruce)
New intro to SQL from S. Simkovics' Master's Thesis (Stefan, Thomas)
New intro to backend processing from S. Simkovics' Master's Thesis (Stefan)
Improved int8 support(Ryan Bradetich, Thomas, Tom)
New routines to convert between int8 and text/varchar types(Thomas)
New bushy plans, where meta-tables are joined(Bruce)
Enable right-hand queries by default(Bruce)
Allow reliable maximum number of backends to be set at configure time
     (--with-maxbackends and postmaster switch (-N backends))(Tom)
GEQO default now 10 tables because of optimizer speedups(Tom)
Allow NULL=Var for MS-SQL portability(Michael, Bruce)
Modify contrib check_primary_key() so either "automatic" or "dependent"(Anand)
Allow psql \d on a view show query(Ryan)
Speedup for LIKE(Bruce)
Ecpg fixes/features, see src/interfaces/ecpg/ChangeLog file(Michael)
JDBC fixes/features, see src/interfaces/jdbc/CHANGELOG(Peter)
Make % operator have precedence like /(Bruce)
Add new postgres -O option to allow system table structure changes(Bruce)
Update contrib/pginterface/findoidjoins script(Tom)
Major speedup in vacuum of deleted rows with indexes(Vadim)
Allow non-SQL functions to run different versions based on arguments(Tom)
Add -E option that shows actual queries sent by \dt and friends(Masaaki Sakaida)
Add version number in start-up banners for psql(Masaaki Sakaida)
New contrib/vacuumlo removes large objects not referenced(Peter)
New initialization for table sizes so non-vacuumed tables perform better(Tom)
Improve error messages when a connection is rejected(Tom)
Support for arrays of char() and varchar() fields(Massimo)
Overhaul of hash code to increase reliability and performance(Tom)
Update to PyGreSQL 2.4(D'Arcy)
Changed debug options so -d4 and -d5 produce different node displays(Jan)
New pg_options: pretty_plan, pretty_parse, pretty_rewritten(Jan)
Better optimization statistics for system table access(Tom)
Better handling of non-default block sizes(Massimo)
Improve GEQO optimizer memory consumption(Tom)
UNION now supports ORDER BY of columns not in target list(Jan)
Major libpq++ improvements(Vince Vielhaber)
pg_dump now uses -z(ACL's) as default(Bruce)
backend cache, memory speedups(Tom)
have pg_dump do everything in one snapshot transaction(Vadim)
fix for large object memory leakage, fix for pg_dumping(Tom)
INET type now respects netmask for comparisons
Make VACUUM ANALYZE only use a readlock(Vadim)
Allow VIEWs on UNIONS(Jan)
pg_dump now can generate consistent snapshots on active databases(Vadim)

Source Tree Changes
-------------------
Improve port matching(Tom)
Portability fixes for SunOS
Add Windows NT backend port and enable dynamic loading(Magnus and Daniel Horak)
New port to Cobalt Qube(Mips) running Linux(Tatsuo)
Port to NetBSD/m68k(Mr. Mutsuki Nakajima)
Port to NetBSD/sun3(Mr. Mutsuki Nakajima)
Port to NetBSD/macppc(Toshimi Aoki)
Fix for tcl/tk configuration(Vince)
Removed CURRENT key word for rule queries(Jan)
NT dynamic loading now works(Daniel Horak)
Add ARM32 support(Andrew McMurry)
Better support for HP-UX 11 and UnixWare
Improve file handling to be more uniform, prevent file descriptor leak(Tom)
New install commands for plpgsql(Jan)
     __________________________________________________________________

                                Release 6.4.2

     Release Date: 1998-12-20

   The 6.4.1 release was improperly packaged. This also has one additional
   bug fix.
     __________________________________________________________________

Migration to Version 6.4.2

   A dump/restore is *not* required for those running 6.4.*.
     __________________________________________________________________

Changes

Fix for datetime constant problem on some platforms(Thomas)
     __________________________________________________________________

                                Release 6.4.1

     Release Date: 1998-12-18

   This is basically a cleanup release for 6.4. We have fixed a variety of
   problems reported by 6.4 users.
     __________________________________________________________________

Migration to Version 6.4.1

   A dump/restore is *not* required for those running 6.4.
     __________________________________________________________________

Changes

Add pg_dump -N flag to force double quotes around identifiers.  This is
       the default(Thomas)
Fix for NOT in where clause causing crash(Bruce)
EXPLAIN VERBOSE coredump fix(Vadim)
Fix shared-library problems on Linux
Fix test for table existence to allow mixed-case and whitespace in
       the table name(Thomas)
Fix a couple of pg_dump bugs
Configure matches template/.similar entries better(Tom)
Change builtin function names from SPI_* to spi_*
OR WHERE clause fix(Vadim)
Fixes for mixed-case table names(Billy)
contrib/linux/postgres.init.csh/sh fix(Thomas)
libpq memory overrun fix
SunOS fixes(Tom)
Change exp() behavior to generate error on underflow(Thomas)
pg_dump fixes for memory leak, inheritance constraints, layout change
update pgaccess to 0.93
Fix prototype for 64-bit platforms
Multibyte fixes(Tatsuo)
New ecpg man page
Fix memory overruns(Tatsuo)
Fix for lo_import() crash(Bruce)
Better search for install program(Tom)
Timezone fixes(Tom)
HP-UX fixes(Tom)
Use implicit type coercion for matching DEFAULT values(Thomas)
Add routines to help with single-byte (internal) character type(Thomas)
Compilation of libpq for Windows fixes(Magnus)
Upgrade to PyGreSQL 2.2(D'Arcy)
     __________________________________________________________________

                                 Release 6.4

     Release Date: 1998-10-30

   There are *many* new features and improvements in this release. Thanks
   to our developers and maintainers, nearly every aspect of the system
   has received some attention since the previous release. Here is a
   brief, incomplete summary:

     * Views and rules are now functional thanks to extensive new code in
       the rewrite rules system from Jan Wieck. He also wrote a chapter on
       it for the Programmer's Guide.
     * Jan also contributed a second procedural language, PL/pgSQL, to go
       with the original PL/pgTCL procedural language he contributed last
       release.
     * We have optional multiple-byte character set support from Tatsuo
       Ishii to complement our existing locale support.
     * Client/server communications has been cleaned up, with better
       support for asynchronous messages and interrupts thanks to Tom
       Lane.
     * The parser will now perform automatic type coercion to match
       arguments to available operators and functions, and to match
       columns and expressions with target columns. This uses a generic
       mechanism which supports the type extensibility features of
       PostgreSQL. There is a new chapter in the User's Guide which covers
       this topic.
     * Three new data types have been added. Two types, inet and cidr,
       support various forms of IP network, subnet, and machine
       addressing. There is now an 8-byte integer type available on some
       platforms. See the chapter on data types in the User's Guide for
       details. A fourth type, serial, is now supported by the parser as
       an amalgam of the int4 type, a sequence, and a unique index.
     * Several more SQL92-compatible syntax features have been added,
       including "INSERT DEFAULT VALUES"
     * The automatic configuration and installation system has received
       some attention, and should be more robust for more platforms than
       it has ever been.
     __________________________________________________________________

Migration to Version 6.4

   A dump/restore using pg_dump or pg_dumpall is required for those
   wishing to migrate data from any previous release of PostgreSQL.
     __________________________________________________________________

Changes

Bug Fixes
---------
Fix for a tiny memory leak in PQsetdb/PQfinish(Bryan)
Remove char2-16 data types, use char/varchar(Darren)
Pqfn not handles a NOTICE message(Anders)
Reduced busywaiting overhead for spinlocks with many backends (dg)
Stuck spinlock detection (dg)
Fix up "ISO-style" timespan decoding and encoding(Thomas)
Fix problem with table drop after rollback of transaction(Vadim)
Change error message and remove non-functional update message(Vadim)
Fix for COPY array checking
Fix for SELECT 1 UNION SELECT NULL
Fix for buffer leaks in large object calls(Pascal)
Change owner from oid to int4 type(Bruce)
Fix a bug in the oracle compatibility functions btrim() ltrim() and rtrim()
Fix for shared invalidation cache overflow(Massimo)
Prevent file descriptor leaks in failed COPY's(Bruce)
Fix memory leak in libpgtcl's pg_select(Constantin)
Fix problems with username/passwords over 8 characters(Tom)
Fix problems with handling of asynchronous NOTIFY in backend(Tom)
Fix of many bad system table entries(Tom)

Enhancements
------------
Upgrade ecpg and ecpglib,see src/interfaces/ecpc/ChangeLog(Michael)
Show the index used in an EXPLAIN(Zeugswetter)
EXPLAIN  invokes  rule system and shows plan(s) for rewritten queries(Jan)
Multibyte awareness of many data types and functions, via configure(Tatsuo)
New configure --with-mb option(Tatsuo)
New initdb --pgencoding option(Tatsuo)
New createdb -E multibyte option(Tatsuo)
Select version(); now returns PostgreSQL version(Jeroen)
libpq now allows asynchronous clients(Tom)
Allow cancel from client of backend query(Tom)
psql now cancels query with Control-C(Tom)
libpq users need not issue dummy queries to get NOTIFY messages(Tom)
NOTIFY now sends sender's PID, so you can tell whether it was your own(Tom)
PGresult struct now includes associated error message, if any(Tom)
Define "tz_hour" and "tz_minute" arguments to date_part()(Thomas)
Add routines to convert between varchar and bpchar(Thomas)
Add routines to allow sizing of varchar and bpchar into target columns(Thomas)
Add bit flags to support timezonehour and minute in data retrieval(Thomas)
Allow more variations on valid floating point numbers (e.g. ".1", "1e6")(Thomas)
Fixes for unary minus parsing with leading spaces(Thomas)
Implement TIMEZONE_HOUR, TIMEZONE_MINUTE per SQL92 specs(Thomas)
Check for and properly ignore FOREIGN KEY column constraints(Thomas)
Define USER as synonym for CURRENT_USER per SQL92 specs(Thomas)
Enable HAVING clause but no fixes elsewhere yet.
Make "char" type a synonym for "char(1)" (actually implemented as bpchar)(Thomas
)
Save string type if specified for DEFAULT clause handling(Thomas)
Coerce operations involving different data types(Thomas)
Allow some index use for columns of different types(Thomas)
Add capabilities for automatic type conversion(Thomas)
Cleanups for large objects, so file is truncated on open(Peter)
Readline cleanups(Tom)
Allow psql  \f \ to make spaces as delimiter(Bruce)
Pass pg_attribute.atttypmod to the frontend for column field lengths(Tom,Bruce)
Msql compatibility library in /contrib(Aldrin)
Remove the requirement that ORDER/GROUP BY clause identifiers be
included in the target list(David)
Convert columns to match columns in UNION clauses(Thomas)
Remove fork()/exec() and only do fork()(Bruce)
Jdbc cleanups(Peter)
Show backend status on ps command line(only works on some platforms)(Bruce)
Pg_hba.conf now has a sameuser option in the database field
Make lo_unlink take oid param, not int4
New DISABLE_COMPLEX_MACRO for compilers that cannot handle our macros(Bruce)
Libpgtcl now handles NOTIFY as a Tcl event, need not send dummy queries(Tom)
libpgtcl cleanups(Tom)
Add -error option to libpgtcl's pg_result command(Tom)
New locale patch, see docs/README/locale(Oleg)
Fix for pg_dump so CONSTRAINT and CHECK syntax is correct(ccb)
New contrib/lo code for large object orphan removal(Peter)
New psql command "SET CLIENT_ENCODING TO 'encoding'" for multibytes
feature, see /doc/README.mb(Tatsuo)
contrib/noupdate code to revoke update permission on a column
libpq can now be compiled on Windows(Magnus)
Add PQsetdbLogin() in libpq
New 8-byte integer type, checked by configure for OS support(Thomas)
Better support for quoted table/column names(Thomas)
Surround table and column names with double-quotes in pg_dump(Thomas)
PQreset() now works with passwords(Tom)
Handle case of GROUP BY target list column number out of range(David)
Allow UNION in subselects
Add auto-size to screen to \d? commands(Bruce)
Use UNION to show all \d? results in one query(Bruce)
Add \d? field search feature(Bruce)
Pg_dump issues fewer \connect requests(Tom)
Make pg_dump -z flag work better, document it in manual page(Tom)
Add HAVING clause with full support for subselects and unions(Stephan)
Full text indexing routines in contrib/fulltextindex(Maarten)
Transaction ids now stored in shared memory(Vadim)
New PGCLIENTENCODING when issuing COPY command(Tatsuo)
Support for SQL92 syntax "SET NAMES"(Tatsuo)
Support for LATIN2-5(Tatsuo)
Add UNICODE regression test case(Tatsuo)
Lock manager cleanup, new locking modes for LLL(Vadim)
Allow index use with OR clauses(Bruce)
Allows "SELECT NULL ORDER BY 1;"
Explain VERBOSE prints the plan, and now pretty-prints the plan to
the postmaster log file(Bruce)
Add indexes display to \d command(Bruce)
Allow GROUP BY on functions(David)
New pg_class.relkind for large objects(Bruce)
New way to send libpq NOTICE messages to a different location(Tom)
New \w write command to psql(Bruce)
New /contrib/findoidjoins scans oid columns to find join relationships(Bruce)
Allow binary-compatible indexes to be considered when checking for valid
Indexes for restriction clauses containing a constant(Thomas)
New ISBN/ISSN code in /contrib/isbn_issn
Allow NOT LIKE, IN, NOT IN, BETWEEN, and NOT BETWEEN constraint(Thomas)
New rewrite system fixes many problems with rules and views(Jan)
       * Rules on relations work
       * Event qualifications on insert/update/delete work
       * New OLD variable to reference CURRENT, CURRENT will be remove in future
       * Update rules can reference NEW and OLD in rule qualifications/actions
       * Insert/update/delete rules on views work
       * Multiple rule actions are now supported, surrounded by parentheses
       * Regular users can create views/rules on tables they have RULE permits
       * Rules and views inherit the privileges of the creator
       * No rules at the column level
       * No UPDATE NEW/OLD rules
       * New pg_tables, pg_indexes, pg_rules and pg_views system views
       * Only a single action on SELECT rules
       * Total rewrite overhaul, perhaps for 6.5
       * handle subselects
       * handle aggregates on views
       * handle insert into select from view works
System indexes are now multikey(Bruce)
Oidint2, oidint4, and oidname types are removed(Bruce)
Use system cache for more system table lookups(Bruce)
New backend programming language PL/pgSQL in backend/pl(Jan)
New SERIAL data type, auto-creates sequence/index(Thomas)
Enable assert checking without a recompile(Massimo)
User lock enhancements(Massimo)
New setval() command to set sequence value(Massimo)
Auto-remove unix socket file on start-up if no postmaster running(Massimo)
Conditional trace package(Massimo)
New UNLISTEN command(Massimo)
psql and libpq now compile under Windows using win32.mak(Magnus)
Lo_read no longer stores trailing NULL(Bruce)
Identifiers are now truncated to 31 characters internally(Bruce)
Createuser options now available on the command line
Code for 64-bit integer supported added, configure tested, int8 type(Thomas)
Prevent file descriptor leaf from failed COPY(Bruce)
New pg_upgrade command(Bruce)
Updated /contrib directories(Massimo)
New CREATE TABLE DEFAULT VALUES statement available(Thomas)
New INSERT INTO TABLE DEFAULT VALUES statement available(Thomas)
New DECLARE and FETCH feature(Thomas)
libpq's internal structures now not exported(Tom)
Allow up to 8 key indexes(Bruce)
Remove ARCHIVE key word, that is no longer used(Thomas)
pg_dump -n flag to suppress quotes around indentifiers
disable system columns for views(Jan)
new INET and CIDR types for network addresses(TomH, Paul)
no more double quotes in psql output
pg_dump now dumps views(Terry)
new SET QUERY_LIMIT(Tatsuo,Jan)

Source Tree Changes
-------------------
/contrib cleanup(Jun)
Inline some small functions called for every row(Bruce)
Alpha/linux fixes
HP-UX cleanups(Tom)
Multibyte regression tests(Soonmyung.)
Remove --disabled options from configure
Define PGDOC to use POSTGRESDIR by default
Make regression optional
Remove extra braces code to pgindent(Bruce)
Add bsdi shared library support(Bruce)
New --without-CXX support configure option(Brook)
New FAQ_CVS
Update backend flowchart in tools/backend(Bruce)
Change atttypmod from int16 to int32(Bruce, Tom)
Getrusage() fix for platforms that do not have it(Tom)
Add PQconnectdb, PGUSER, PGPASSWORD to libpq man page
NS32K platform fixes(Phil Nelson, John Buller)
SCO 7/UnixWare 2.x fixes(Billy,others)
Sparc/Solaris 2.5 fixes(Ryan)
Pgbuiltin.3 is obsolete, move to doc files(Thomas)
Even more documentation(Thomas)
Nextstep support(Jacek)
Aix support(David)
pginterface manual page(Bruce)
shared libraries all have version numbers
merged all OS-specific shared library defines into one file
smarter TCL/TK configuration checking(Billy)
smarter perl configuration(Brook)
configure uses supplied install-sh if no install script found(Tom)
new Makefile.shlib for shared library configuration(Tom)
     __________________________________________________________________

                                Release 6.3.2

     Release Date: 1998-04-07

   This is a bug-fix release for 6.3.x. Refer to the release notes for
   version 6.3 for a more complete summary of new features.

   Summary:

     * Repairs automatic configuration support for some platforms,
       including Linux, from breakage inadvertently introduced in version
       6.3.1.
     * Correctly handles function calls on the left side of BETWEEN and
       LIKE clauses.

   A dump/restore is NOT required for those running 6.3 or 6.3.1. A make
   distclean, make, and make install is all that is required. This last
   step should be performed while the postmaster is not running. You
   should re-link any custom applications that use PostgreSQL libraries.

   For upgrades from pre-6.3 installations, refer to the installation and
   migration instructions for version 6.3.
     __________________________________________________________________

Changes

Configure detection improvements for tcl/tk(Brook Milligan, Alvin)
Manual page improvements(Bruce)
BETWEEN and LIKE fix(Thomas)
fix for psql \connect used by pg_dump(Oliver Elphick)
New odbc driver
pgaccess, version 0.86
qsort removed, now uses libc version, cleanups(Jeroen)
fix for buffer over-runs detected(Maurice Gittens)
fix for buffer overrun in libpgtcl(Randy Kunkee)
fix for UNION with DISTINCT or ORDER BY(Bruce)
gettimeofday configure check(Doug Winterburn)
Fix "indexes not used" bug(Vadim)
docs additions(Thomas)
Fix for backend memory leak(Bruce)
libreadline cleanup(Erwan MAS)
Remove DISTDIR(Bruce)
Makefile dependency cleanup(Jeroen van Vianen)
ASSERT fixes(Bruce)
     __________________________________________________________________

                                Release 6.3.1

     Release Date: 1998-03-23

   Summary:

     * Additional support for multibyte character sets.
     * Repair byte ordering for mixed-endian clients and servers.
     * Minor updates to allowed SQL syntax.
     * Improvements to the configuration autodetection for installation.

   A dump/restore is NOT required for those running 6.3. A make distclean,
   make, and make install is all that is required. This last step should
   be performed while the postmaster is not running. You should re-link
   any custom applications that use PostgreSQL libraries.

   For upgrades from pre-6.3 installations, refer to the installation and
   migration instructions for version 6.3.
     __________________________________________________________________

Changes

ecpg cleanup/fixes, now version 1.1(Michael Meskes)
pg_user cleanup(Bruce)
large object fix for pg_dump and tclsh (alvin)
LIKE fix for multiple adjacent underscores
fix for redefining builtin functions(Thomas)
ultrix4 cleanup
upgrade to pg_access 0.83
updated CLUSTER manual page
multibyte character set support, see doc/README.mb(Tatsuo)
configure --with-pgport fix
pg_ident fix
big-endian fix for backend communications(Kataoka)
SUBSTR() and substring() fix(Jan)
several jdbc fixes(Peter)
libpgtcl improvements, see libptcl/README(Randy Kunkee)
Fix for "Datasize = 0" error(Vadim)
Prevent \do from wrapping(Bruce)
Remove duplicate Russian character set entries
Sunos4 cleanup
Allow optional TABLE key word in LOCK and SELECT INTO(Thomas)
CREATE SEQUENCE options to allow a negative integer(Thomas)
Add "PASSWORD" as an allowed column identifier(Thomas)
Add checks for UNION target fields(Bruce)
Fix Alpha port(Dwayne Bailey)
Fix for text arrays containing quotes(Doug Gibson)
Solaris compile fix(Albert Chin-A-Young)
Better identify tcl and tk libs and includes(Bruce)
     __________________________________________________________________

                                 Release 6.3

     Release Date: 1998-03-01

   There are *many* new features and improvements in this release. Here is
   a brief, incomplete summary:

     * Many new SQL features, including full SQL92 subselect capability
       (everything is here but target-list subselects).
     * Support for client-side environment variables to specify time zone
       and date style.
     * Socket interface for client/server connection. This is the default
       now so you might need to start postmaster with the "-i" flag.
     * Better password authorization mechanisms. Default table privileges
       have changed.
     * Old-style time travel has been removed. Performance has been
       improved.

     Note: Bruce Momjian wrote the following notes to introduce the new
     release.

   There are some general 6.3 issues that I want to mention. These are
   only the big items that cannot be described in one sentence. A review
   of the detailed changes list is still needed.

   First, we now have subselects. Now that we have them, I would like to
   mention that without subselects, SQL is a very limited language.
   Subselects are a major feature, and you should review your code for
   places where subselects provide a better solution for your queries. I
   think you will find that there are more uses for subselects than you
   might think. Vadim has put us on the big SQL map with subselects, and
   fully functional ones too. The only thing you cannot do with subselects
   is to use them in the target list.

   Second, 6.3 uses Unix domain sockets rather than TCP/IP by default. To
   enable connections from other machines, you have to use the new
   postmaster -i option, and of course edit "pg_hba.conf". Also, for this
   reason, the format of "pg_hba.conf" has changed.

   Third, char() fields will now allow faster access than varchar() or
   text. Specifically, the text and varchar() have a penalty for access to
   any columns after the first column of this type. char() used to also
   have this access penalty, but it no longer does. This might suggest
   that you redesign some of your tables, especially if you have short
   character columns that you have defined as varchar() or text. This and
   other changes make 6.3 even faster than earlier releases.

   We now have passwords definable independent of any Unix file. There are
   new SQL USER commands. See the Administrator's Guide for more
   information. There is a new table, pg_shadow, which is used to store
   user information and user passwords, and it by default only SELECT-able
   by the postgres super-user. pg_user is now a view of pg_shadow, and is
   SELECT-able by PUBLIC. You should keep using pg_user in your
   application without changes.

   User-created tables now no longer have SELECT privilege to PUBLIC by
   default. This was done because the ANSI standard requires it. You can
   of course GRANT any privileges you want after the table is created.
   System tables continue to be SELECT-able by PUBLIC.

   We also have real deadlock detection code. No more sixty-second
   timeouts. And the new locking code implements a FIFO better, so there
   should be less resource starvation during heavy use.

   Many complaints have been made about inadequate documentation in
   previous releases. Thomas has put much effort into many new manuals for
   this release. Check out the doc/ directory.

   For performance reasons, time travel is gone, but can be implemented
   using triggers (see "pgsql/contrib/spi/README"). Please check out the
   new \d command for types, operators, etc. Also, views have their own
   privileges now, not based on the underlying tables, so privileges on
   them have to be set separately. Check "/pgsql/interfaces" for some new
   ways to talk to PostgreSQL.

   This is the first release that really required an explanation for
   existing users. In many ways, this was necessary because the new
   release removes many limitations, and the work-arounds people were
   using are no longer needed.
     __________________________________________________________________

Migration to Version 6.3

   A dump/restore using pg_dump or pg_dumpall is required for those
   wishing to migrate data from any previous release of PostgreSQL.
     __________________________________________________________________

Changes

Bug Fixes
---------
Fix binary cursors broken by MOVE implementation(Vadim)
Fix for tcl library crash(Jan)
Fix for array handling, from Gerhard Hintermayer
Fix acl error, and remove duplicate pqtrace(Bruce)
Fix psql \e for empty file(Bruce)
Fix for textcat on varchar() fields(Bruce)
Fix for DBT Sendproc (Zeugswetter Andres)
Fix vacuum analyze syntax problem(Bruce)
Fix for international identifiers(Tatsuo)
Fix aggregates on inherited tables(Bruce)
Fix substr() for out-of-bounds data
Fix for select 1=1 or 2=2, select 1=1 and 2=2, and select sum(2+2)(Bruce)
Fix notty output to show status result.  -q option still turns it off(Bruce)
Fix for count(*), aggs with views and multiple tables and sum(3)(Bruce)
Fix cluster(Bruce)
Fix for PQtrace start/stop several times(Bruce)
Fix a variety of locking problems like newer lock waiters getting
       lock before older waiters, and having readlock people not share
       locks if a writer is waiting for a lock, and waiting writers not
       getting priority over waiting readers(Bruce)
Fix crashes in psql when executing queries from external files(James)
Fix problem with multiple order by columns, with the first one having
       NULL values(Jeroen)
Use correct hash table support functions for float8 and int4(Thomas)
Re-enable JOIN= option in CREATE OPERATOR statement (Thomas)
Change precedence for boolean operators to match expected behavior(Thomas)
Generate elog(ERROR) on over-large integer(Bruce)
Allow multiple-argument functions in constraint clauses(Thomas)
Check boolean input literals for 'true','false','yes','no','1','0'
       and throw elog(ERROR) if unrecognized(Thomas)
Major large objects fix
Fix for GROUP BY showing duplicates(Vadim)
Fix for index scans in MergeJoin(Vadim)

Enhancements
------------
Subselects with EXISTS, IN, ALL, ANY key words (Vadim, Bruce, Thomas)
New User Manual(Thomas, others)
Speedup by inlining some frequently-called functions
Real deadlock detection, no more timeouts(Bruce)
Add SQL92 "constants" CURRENT_DATE, CURRENT_TIME, CURRENT_TIMESTAMP,
       CURRENT_USER(Thomas)
Modify constraint syntax to be SQL92-compliant(Thomas)
Implement SQL92 PRIMARY KEY and UNIQUE clauses using indexes(Thomas)
Recognize SQL92 syntax for FOREIGN KEY. Throw elog notice(Thomas)
Allow NOT NULL UNIQUE constraint clause (each allowed separately before)(Thomas)
Allow PostgreSQL-style casting ("::") of non-constants(Thomas)
Add support for SQL3 TRUE and FALSE boolean constants(Thomas)
Support SQL92 syntax for IS TRUE/IS FALSE/IS NOT TRUE/IS NOT FALSE(Thomas)
Allow shorter strings for boolean literals (e.g. "t", "tr", "tru")(Thomas)
Allow SQL92 delimited identifiers(Thomas)
Implement SQL92 binary and hexadecimal string decoding (b'10' and x'1F')(Thomas)
Support SQL92 syntax for type coercion of literal strings
       (e.g. "DATETIME 'now'")(Thomas)
Add conversions for int2, int4, and OID types to and from text(Thomas)
Use shared lock when building indexes(Vadim)
Free memory allocated for an user query inside transaction block after
       this query is done, was turned off in <= 6.2.1(Vadim)
New SQL statement CREATE PROCEDURAL LANGUAGE(Jan)
New PostgreSQL Procedural Language (PL) backend interface(Jan)
Rename pg_dump -H option to -h(Bruce)
Add Java support for passwords, European dates(Peter)
Use indexes for LIKE and ~, !~ operations(Bruce)
Add hash functions for datetime and timespan(Thomas)
Time Travel removed(Vadim, Bruce)
Add paging for \d and \z, and fix \i(Bruce)
Add Unix domain socket support to backend and to frontend library(Goran)
Implement CREATE DATABASE/WITH LOCATION and initlocation utility(Thomas)
Allow more SQL92 and/or PostgreSQL reserved words as column identifiers(Thomas)
Augment support for SQL92 SET TIME ZONE...(Thomas)
SET/SHOW/RESET TIME ZONE uses TZ backend environment variable(Thomas)
Implement SET keyword = DEFAULT and SET TIME ZONE DEFAULT(Thomas)
Enable SET TIME ZONE using TZ environment variable(Thomas)
Add PGDATESTYLE environment variable to frontend and backend initialization(Thom
as)
Add PGTZ, PGCOSTHEAP, PGCOSTINDEX, PGRPLANS, PGGEQO
       frontend library initialization environment variables(Thomas)
Regression tests time zone automatically set with "setenv PGTZ PST8PDT"(Thomas)
Add pg_description table for info on tables, columns, operators, types, and
       aggregates(Bruce)
Increase 16 char limit on system table/index names to 32 characters(Bruce)
Rename system indexes(Bruce)
Add 'GERMAN' option to SET DATESTYLE(Thomas)
Define an "ISO-style" timespan output format with "hh:mm:ss" fields(Thomas)
Allow fractional values for delta times (e.g. '2.5 days')(Thomas)
Validate numeric input more carefully for delta times(Thomas)
Implement day of year as possible input to date_part()(Thomas)
Define timespan_finite() and text_timespan() functions(Thomas)
Remove archive stuff(Bruce)
Allow for a pg_password authentication database that is separate from
       the system password file(Todd)
Dump ACLs, GRANT, REVOKE privileges(Matt)
Define text, varchar, and bpchar string length functions(Thomas)
Fix Query handling for inheritance, and cost computations(Bruce)
Implement CREATE TABLE/AS SELECT (alternative to SELECT/INTO)(Thomas)
Allow NOT, IS NULL, IS NOT NULL in constraints(Thomas)
Implement UNIONs for SELECT(Bruce)
Add UNION, GROUP, DISTINCT to INSERT(Bruce)
varchar() stores only necessary bytes on disk(Bruce)
Fix for BLOBs(Peter)
Mega-Patch for JDBC...see README_6.3 for list of changes(Peter)
Remove unused "option" from PQconnectdb()
New LOCK command and lock manual page describing deadlocks(Bruce)
Add new psql \da, \dd, \df, \do, \dS, and \dT commands(Bruce)
Enhance psql \z to show sequences(Bruce)
Show NOT NULL and DEFAULT in psql \d table(Bruce)
New psql .psqlrc file start-up(Andrew)
Modify sample start-up script in contrib/linux to show syslog(Thomas)
New types for IP and MAC addresses in contrib/ip_and_mac(TomH)
Unix system time conversions with date/time types in contrib/unixdate(Thomas)
Update of contrib stuff(Massimo)
Add Unix socket support to DBD::Pg(Goran)
New python interface (PyGreSQL 2.0)(D'Arcy)
New frontend/backend protocol has a version number, network byte order(Phil)
Security features in pg_hba.conf enhanced and documented, many cleanups(Phil)
CHAR() now faster access than VARCHAR() or TEXT
ecpg embedded SQL preprocessor
Reduce system column overhead(Vadmin)
Remove pg_time table(Vadim)
Add pg_type attribute to identify types that need length (bpchar, varchar)
Add report of offending line when COPY command fails
Allow VIEW privileges to be set separately from the underlying tables.
       For security, use GRANT/REVOKE on views as appropriate(Jan)
Tables now have no default GRANT SELECT TO PUBLIC.  You must
       explicitly grant such privileges.
Clean up tutorial examples(Darren)

Source Tree Changes
-------------------
Add new html development tools, and flow chart in /tools/backend
Fix for SCO compiles
Stratus computer port Robert Gillies
Added support for shlib for BSD44_derived & i386_solaris
Make configure more automated(Brook)
Add script to check regression test results
Break parser functions into smaller files, group together(Bruce)
Rename heap_create to heap_create_and_catalog, rename heap_creatr
       to heap_create()(Bruce)
Sparc/Linux patch for locking(TomS)
Remove PORTNAME and reorganize port-specific stuff(Marc)
Add optimizer README file(Bruce)
Remove some recursion in optimizer and clean up some code there(Bruce)
Fix for NetBSD locking(Henry)
Fix for libptcl make(Tatsuo)
AIX patch(Darren)
Change IS TRUE, IS FALSE, ... to expressions using "=" rather than
       function calls to istrue() or isfalse() to allow optimization(Thomas)
Various fixes NetBSD/Sparc related(TomH)
Alpha linux locking(Travis,Ryan)
Change elog(WARN) to elog(ERROR)(Bruce)
FAQ for FreeBSD(Marc)
Bring in the PostODBC source tree as part of our standard distribution(Marc)
A minor patch for HP/UX 10 vs 9(Stan)
New pg_attribute.atttypmod for type-specific info like varchar length(Bruce)
UnixWare patches(Billy)
New i386 'lock' for spinlock asm(Billy)
Support for multiplexed backends is removed
Start an OpenBSD port
Start an AUX port
Start a Cygnus port
Add string functions to regression suite(Thomas)
Expand a few function names formerly truncated to 16 characters(Thomas)
Remove un-needed malloc() calls and replace with palloc()(Bruce)
     __________________________________________________________________

                                Release 6.2.1

     Release Date: 1997-10-17

   6.2.1 is a bug-fix and usability release on 6.2.

   Summary:

     * Allow strings to span lines, per SQL92.
     * Include example trigger function for inserting user names on table
       updates.

   This is a minor bug-fix release on 6.2. For upgrades from pre-6.2
   systems, a full dump/reload is required. Refer to the 6.2 release notes
   for instructions.
     __________________________________________________________________

Migration from version 6.2 to version 6.2.1

   This is a minor bug-fix release. A dump/reload is not required from
   version 6.2, but is required from any release prior to 6.2.

   In upgrading from version 6.2, if you choose to dump/reload you will
   find that avg(money) is now calculated correctly. All other bug fixes
   take effect upon updating the executables.

   Another way to avoid dump/reload is to use the following SQL command
   from "psql" to update the existing system table:
update pg_aggregate set aggfinalfn = 'cash_div_flt8'
 where aggname = 'avg' and aggbasetype = 790;

   This will need to be done to every existing database, including
   template1.
     __________________________________________________________________

Changes

Allow TIME and TYPE column names(Thomas)
Allow larger range of true/false as boolean values(Thomas)
Support output of "now" and "current"(Thomas)
Handle DEFAULT with INSERT of NULL properly(Vadim)
Fix for relation reference counts problem in buffer manager(Vadim)
Allow strings to span lines, like ANSI(Thomas)
Fix for backward cursor with ORDER BY(Vadim)
Fix avg(cash) computation(Thomas)
Fix for specifying a column twice in ORDER/GROUP BY(Vadim)
Documented new libpq function to return affected rows, PQcmdTuples(Bruce)
Trigger function for inserting user names for INSERT/UPDATE(Brook Milligan)
     __________________________________________________________________

                                 Release 6.2

     Release Date: 1997-10-02

   A dump/restore is required for those wishing to migrate data from
   previous releases of PostgreSQL.
     __________________________________________________________________

Migration from version 6.1 to version 6.2

   This migration requires a complete dump of the 6.1 database and a
   restore of the database in 6.2.

   Note that the "pg_dump" and "pg_dumpall" utility from 6.2 should be
   used to dump the 6.1 database.
     __________________________________________________________________

Migration from version 1.x to version 6.2

   Those migrating from earlier 1.* releases should first upgrade to 1.09
   because the COPY output format was improved from the 1.02 release.
     __________________________________________________________________

Changes

Bug Fixes
---------
Fix problems with pg_dump for inheritance, sequences, archive tables(Bruce)
Fix compile errors on overflow due to shifts, unsigned, and bad prototypes
        from Solaris(Diab Jerius)
Fix bugs in geometric line arithmetic (bad intersection calculations)(Thomas)
Check for geometric intersections at endpoints to avoid rounding ugliness(Thomas
)
Catch non-functional delete attempts(Vadim)
Change time function names to be more consistent(Michael Reifenberg)
Check for zero divides(Michael Reifenberg)
Fix very old bug which made rows changed/inserted by a command
       visible to the command itself (so we had multiple update of
       updated rows, etc.)(Vadim)
Fix for SELECT null, 'fail' FROM pg_am (Patrick)
SELECT NULL as EMPTY_FIELD now allowed(Patrick)
Remove un-needed signal stuff from contrib/pginterface
Fix OR (where x != 1 or x isnull didn't return rows with x NULL) (Vadim)
Fix time_cmp function (Vadim)
Fix handling of functions with non-attribute first argument in
       WHERE clauses (Vadim)
Fix GROUP BY when order of entries is different from order
       in target list (Vadim)
Fix pg_dump for aggregates without sfunc1 (Vadim)

Enhancements
------------
Default genetic optimizer GEQO parameter is now 8(Bruce)
Allow use parameters in target list having aggregates in functions(Vadim)
Added JDBC driver as an interface(Adrian & Peter)
pg_password utility
Return number of rows inserted/affected by INSERT/UPDATE/DELETE etc.(Vadim)
Triggers implemented with CREATE TRIGGER (SQL3)(Vadim)
SPI (Server Programming Interface) allows execution of queries inside
       C-functions (Vadim)
NOT NULL implemented (SQL92)(Robson Paniago de Miranda)
Include reserved words for string handling, outer joins, and unions(Thomas)
Implement extended comments ("/* ... */") using exclusive states(Thomas)
Add "//" single-line comments(Bruce)
Remove some restrictions on characters in operator names(Thomas)
DEFAULT and CONSTRAINT for tables implemented (SQL92)(Vadim & Thomas)
Add text concatenation operator and function (SQL92)(Thomas)
Support WITH TIME ZONE syntax (SQL92)(Thomas)
Support INTERVAL unit TO unit syntax (SQL92)(Thomas)
Define types DOUBLE PRECISION, INTERVAL, CHARACTER,
       and CHARACTER VARYING (SQL92)(Thomas)
Define type FLOAT(p) and rudimentary DECIMAL(p,s), NUMERIC(p,s) (SQL92)(Thomas)
Define EXTRACT(), POSITION(), SUBSTRING(), and TRIM() (SQL92)(Thomas)
Define CURRENT_DATE, CURRENT_TIME, CURRENT_TIMESTAMP (SQL92)(Thomas)
Add syntax and warnings for UNION, HAVING, INNER and OUTER JOIN (SQL92)(Thomas)
Add more reserved words, mostly for SQL92 compliance(Thomas)
Allow hh:mm:ss time entry for timespan/reltime types(Thomas)
Add center() routines for lseg, path, polygon(Thomas)
Add distance() routines for circle-polygon, polygon-polygon(Thomas)
Check explicitly for points and polygons contained within polygons
       using an axis-crossing algorithm(Thomas)
Add routine to convert circle-box(Thomas)
Merge conflicting operators for different geometric data types(Thomas)
Replace distance operator "<===>" with "<->"(Thomas)
Replace "above" operator "!^" with ">^" and "below" operator "!|" with "<^"(Thom
as)
Add routines for text trimming on both ends, substring, and string position(Thom
as)
Added conversion routines circle(box) and poly(circle)(Thomas)
Allow internal sorts to be stored in memory rather than in files(Bruce & Vadim)
Allow functions and operators on internally-identical types to succeed(Bruce)
Speed up backend start-up after profiling analysis(Bruce)
Inline frequently called functions for performance(Bruce)
Reduce open() calls(Bruce)
psql:  Add PAGER for \h and \?,\C fix
Fix for psql pager when no tty(Bruce)
New entab utility(Bruce)
General trigger functions for referential integrity (Vadim)
General trigger functions for time travel (Vadim)
General trigger functions for AUTOINCREMENT/IDENTITY feature (Vadim)
MOVE implementation (Vadim)

Source Tree Changes
-------------------
HP-UX 10 patches (Vladimir Turin)
Added SCO support, (Daniel Harris)
MkLinux patches (Tatsuo Ishii)
Change geometric box terminology from "length" to "width"(Thomas)
Deprecate temporary unstored slope fields in geometric code(Thomas)
Remove restart instructions from INSTALL(Bruce)
Look in /usr/ucb first for install(Bruce)
Fix c++ copy example code(Thomas)
Add -o to psql manual page(Bruce)
Prevent relname unallocated string length from being copied into database(Bruce)
Cleanup for NAMEDATALEN use(Bruce)
Fix pg_proc names over 15 chars in output(Bruce)
Add strNcpy() function(Bruce)
remove some (void) casts that are unnecessary(Bruce)
new interfaces directory(Marc)
Replace fopen() calls with calls to fd.c functions(Bruce)
Make functions static where possible(Bruce)
enclose unused functions in #ifdef NOT_USED(Bruce)
Remove call to difftime() in timestamp support to fix SunOS(Bruce & Thomas)
Changes for Digital Unix
Portability fix for pg_dumpall(Bruce)
Rename pg_attribute.attnvals to attdispersion(Bruce)
"intro/unix" manual page now "pgintro"(Bruce)
"built-in" manual page now "pgbuiltin"(Bruce)
"drop" manual page now "drop_table"(Bruce)
Add "create_trigger", "drop_trigger" manual pages(Thomas)
Add constraints regression test(Vadim & Thomas)
Add comments syntax regression test(Thomas)
Add PGINDENT and support program(Bruce)
Massive commit to run PGINDENT on all *.c and *.h files(Bruce)
Files moved to /src/tools directory(Bruce)
SPI and Trigger programming guides (Vadim & D'Arcy)
     __________________________________________________________________

                                Release 6.1.1

     Release Date: 1997-07-22
     __________________________________________________________________

Migration from version 6.1 to version 6.1.1

   This is a minor bug-fix release. A dump/reload is not required from
   version 6.1, but is required from any release prior to 6.1. Refer to
   the release notes for 6.1 for more details.
     __________________________________________________________________

Changes

fix for SET with options (Thomas)
allow pg_dump/pg_dumpall to preserve ownership of all tables/objects(Bruce)
new psql \connect option allows changing usernames without changing databases
fix for initdb --debug option(Yoshihiko Ichikawa))
lextest cleanup(Bruce)
hash fixes(Vadim)
fix date/time month boundary arithmetic(Thomas)
fix timezone daylight handling for some ports(Thomas, Bruce, Tatsuo)
timestamp overhauled to use standard functions(Thomas)
other code cleanup in date/time routines(Thomas)
psql's \d now case-insensitive(Bruce)
psql's backslash commands can now have trailing semicolon(Bruce)
fix memory leak in psql when using \g(Bruce)
major fix for endian handling of communication to server(Thomas, Tatsuo)
Fix for Solaris assembler and include files(Yoshihiko Ichikawa)
allow underscores in usernames(Bruce)
pg_dumpall now returns proper status, portability fix(Bruce)
     __________________________________________________________________

                                 Release 6.1

     Release Date: 1997-06-08

   The regression tests have been adapted and extensively modified for the
   6.1 release of PostgreSQL.

   Three new data types (datetime, timespan, and circle) have been added
   to the native set of PostgreSQL types. Points, boxes, paths, and
   polygons have had their output formats made consistent across the data
   types. The polygon output in misc.out has only been spot-checked for
   correctness relative to the original regression output.

   PostgreSQL 6.1 introduces a new, alternate optimizer which uses genetic
   algorithms. These algorithms introduce a random behavior in the
   ordering of query results when the query contains multiple qualifiers
   or multiple tables (giving the optimizer a choice on order of
   evaluation). Several regression tests have been modified to explicitly
   order the results, and hence are insensitive to optimizer choices. A
   few regression tests are for data types which are inherently unordered
   (e.g. points and time intervals) and tests involving those types are
   explicitly bracketed with "set geqo to 'off'" and "reset geqo".

   The interpretation of array specifiers (the curly braces around atomic
   values) appears to have changed sometime after the original regression
   tests were generated. The current "./expected/*.out" files reflect this
   new interpretation, which might not be correct!

   The float8 regression test fails on at least some platforms. This is
   due to differences in implementations of pow() and exp() and the
   signaling mechanisms used for overflow and underflow conditions.

   The "random" results in the random test should cause the "random" test
   to be "failed", since the regression tests are evaluated using a simple
   diff. However, "random" does not seem to produce random results on my
   test machine (Linux/gcc/i686).
     __________________________________________________________________

Migration to Version 6.1

   This migration requires a complete dump of the 6.0 database and a
   restore of the database in 6.1.

   Those migrating from earlier 1.* releases should first upgrade to 1.09
   because the COPY output format was improved from the 1.02 release.
     __________________________________________________________________

Changes

Bug Fixes
---------
packet length checking in library routines
lock manager priority patch
check for under/over flow of float8(Bruce)
multitable join fix(Vadim)
SIGPIPE crash fix(Darren)
large object fixes(Sven)
allow btree indexes to handle NULLs(Vadim)
timezone fixes(D'Arcy)
select SUM(x) can return NULL on no rows(Thomas)
internal optimizer, executor bug fixes(Vadim)
fix problem where inner loop in < or <= has no rows(Vadim)
prevent re-commuting join index clauses(Vadim)
fix join clauses for multiple tables(Vadim)
fix hash, hashjoin for arrays(Vadim)
fix btree for abstime type(Vadim)
large object fixes(Raymond)
fix buffer leak in hash indexes (Vadim)
fix rtree for use in inner scan (Vadim)
fix gist for use in inner scan, cleanups (Vadim, Andrea)
avoid unnecessary local buffers allocation (Vadim, Massimo)
fix local buffers leak in transaction aborts (Vadim)
fix file manager memmory leaks, cleanups (Vadim, Massimo)
fix storage manager memmory leaks (Vadim)
fix btree duplicates handling (Vadim)
fix deleted rows reincarnation caused by vacuum (Vadim)
fix SELECT varchar()/char() INTO TABLE made zero-length fields(Bruce)
many psql, pg_dump, and libpq memory leaks fixed using Purify (Igor)

Enhancements
------------
attribute optimization statistics(Bruce)
much faster new btree bulk load code(Paul)
BTREE UNIQUE added to bulk load code(Vadim)
new lock debug code(Massimo)
massive changes to libpg++(Leo)
new GEQO optimizer speeds table multitable optimization(Martin)
new WARN message for non-unique insert into unique key(Marc)
update x=-3, no spaces, now valid(Bruce)
remove case-sensitive identifier handling(Bruce,Thomas,Dan)
debug backend now pretty-prints tree(Darren)
new Oracle character functions(Edmund)
new plaintext password functions(Dan)
no such class or insufficient privilege changed to distinct messages(Dan)
new ANSI timestamp function(Dan)
new ANSI Time and Date types (Thomas)
move large chunks of data in backend(Martin)
multicolumn btree indexes(Vadim)
new SET var TO value command(Martin)
update transaction status on reads(Dan)
new locale settings for character types(Oleg)
new SEQUENCE serial number generator(Vadim)
GROUP BY function now possible(Vadim)
re-organize regression test(Thomas,Marc)
new optimizer operation weights(Vadim)
new psql \z grant/permit option(Marc)
new MONEY data type(D'Arcy,Thomas)
tcp socket communication speed improved(Vadim)
new VACUUM option for attribute statistics, and for certain columns (Vadim)
many geometric type improvements(Thomas,Keith)
additional regression tests(Thomas)
new datestyle variable(Thomas,Vadim,Martin)
more comparison operators for sorting types(Thomas)
new conversion functions(Thomas)
new more compact btree format(Vadim)
allow pg_dumpall to preserve database ownership(Bruce)
new SET GEQO=# and R_PLANS variable(Vadim)
old (!GEQO) optimizer can use right-sided plans (Vadim)
typechecking improvement in SQL parser(Bruce)
new SET, SHOW, RESET commands(Thomas,Vadim)
new \connect database USER option
new destroydb -i option (Igor)
new \dt and \di psql commands (Darren)
SELECT "\n" now escapes newline (A. Duursma)
new geometry conversion functions from old format (Thomas)

Source tree changes
-------------------
new configuration script(Marc)
readline configuration option added(Marc)
OS-specific configuration options removed(Marc)
new OS-specific template files(Marc)
no more need to edit Makefile.global(Marc)
re-arrange include files(Marc)
nextstep patches (Gregor Hoffleit)
removed Windows-specific code(Bruce)
removed postmaster -e option, now only postgres -e option (Bruce)
merge duplicate library code in front/backends(Martin)
now works with eBones, international Kerberos(Jun)
more shared library support
c++ include file cleanup(Bruce)
warn about buggy flex(Bruce)
DG/UX, Ultrix, IRIX, AIX portability fixes
     __________________________________________________________________

                                 Release 6.0

     Release Date: 1997-01-29

   A dump/restore is required for those wishing to migrate data from
   previous releases of PostgreSQL.
     __________________________________________________________________

Migration from version 1.09 to version 6.0

   This migration requires a complete dump of the 1.09 database and a
   restore of the database in 6.0.
     __________________________________________________________________

Migration from pre-1.09 to version 6.0

   Those migrating from earlier 1.* releases should first upgrade to 1.09
   because the COPY output format was improved from the 1.02 release.
     __________________________________________________________________

Changes

Bug Fixes
---------
ALTER TABLE bug - running postgres process needs to re-read table definition
Allow vacuum to be run on one table or entire database(Bruce)
Array fixes
Fix array over-runs of memory writes(Kurt)
Fix elusive btree range/non-range bug(Dan)
Fix for hash indexes on some types like time and date
Fix for pg_log size explosion
Fix permissions on lo_export()(Bruce)
Fix uninitialized reads of memory(Kurt)
Fixed ALTER TABLE ... char(3) bug(Bruce)
Fixed a few small memory leaks
Fixed EXPLAIN handling of options and changed full_path option name
Fixed output of group acl privileges
Memory leaks (hunt and destroy with tools like Purify(Kurt)
Minor improvements to rules system
NOTIFY fixes
New asserts for run-checking
Overhauled parser/analyze code to properly report errors and increase speed
Pg_dump -d now handles NULL's properly(Bruce)
Prevent SELECT NULL from crashing server (Bruce)
Properly report errors when INSERT ... SELECT columns did not match
Properly report errors when insert column names were not correct
psql \g filename now works(Bruce)
psql fixed problem with multiple statements on one line with multiple outputs
Removed duplicate system OIDs
SELECT * INTO TABLE . GROUP/ORDER BY gives unlink error if table exists(Bruce)
Several fixes for queries that crashed the backend
Starting quote in insert string errors(Bruce)
Submitting an empty query now returns empty status, not just " " query(Bruce)

Enhancements
------------
Add EXPLAIN manual page(Bruce)
Add UNIQUE index capability(Dan)
Add hostname/user level access control rather than just hostname and user
Add synonym of != for <>(Bruce)
Allow "select oid,* from table"
Allow BY,ORDER BY to specify columns by number, or by non-alias table.column(Bru
ce)
Allow COPY from the frontend(Bryan)
Allow GROUP BY to use alias column name(Bruce)
Allow actual compression, not just reuse on the same page(Vadim)
Allow installation-configuration option to auto-add all local users(Bryan)
Allow libpq to distinguish between text value '' and null(Bruce)
Allow non-postgres users with createdb privs to destroydb's
Allow restriction on who can create C functions(Bryan)
Allow restriction on who can do backend COPY(Bryan)
Can shrink tables, pg_time and pg_log(Vadim & Erich)
Change debug level 2 to print queries only, changed debug heading layout(Bruce)
Change default decimal constant representation from float4 to float8(Bruce)
European date format now set when postmaster is started
Execute lowercase function names if not found with exact case
Fixes for aggregate/GROUP processing, allow 'select sum(func(x),sum(x+y) from z'
Gist now included in the distribution(Marc)
Idend authentication of local users(Bryan)
Implement BETWEEN qualifier(Bruce)
Implement IN qualifier(Bruce)
libpq has PQgetisnull()(Bruce)
libpq++ improvements
New options to initdb(Bryan)
Pg_dump allow dump of OIDs(Bruce)
Pg_dump create indexes after tables are loaded for speed(Bruce)
Pg_dumpall dumps all databases, and the user table
Pginterface additions for NULL values(Bruce)
Prevent postmaster from being run as root
psql \h and \? is now readable(Bruce)
psql allow backslashed, semicolons anywhere on the line(Bruce)
psql changed command prompt for lines in query or in quotes(Bruce)
psql char(3) now displays as (bp)char in \d output(Bruce)
psql return code now more accurate(Bryan?)
psql updated help syntax(Bruce)
Re-visit and fix vacuum(Vadim)
Reduce size of regression diffs, remove timezone name difference(Bruce)
Remove compile-time parameters to enable binary distributions(Bryan)
Reverse meaning of HBA masks(Bryan)
Secure Authentication of local users(Bryan)
Speed up vacuum(Vadim)
Vacuum now had VERBOSE option(Bruce)

Source tree changes
-------------------
All functions now have prototypes that are compared against the calls
Allow asserts to be disabled easily from Makefile.global(Bruce)
Change oid constants used in code to #define names
Decoupled sparc and solaris defines(Kurt)
Gcc -Wall compiles cleanly with warnings only from unfixable constructs
Major include file reorganization/reduction(Marc)
Make now stops on compile failure(Bryan)
Makefile restructuring(Bryan, Marc)
Merge bsdi_2_1 to bsdi(Bruce)
Monitor program removed
Name change from Postgres95 to PostgreSQL
New config.h file(Marc, Bryan)
PG_VERSION now set to 6.0 and used by postmaster
Portability additions, including Ultrix, DG/UX, AIX, and Solaris
Reduced the number of #define's, centralized #define's
Remove duplicate OIDS in system tables(Dan)
Remove duplicate system catalog info or report mismatches(Dan)
Removed many os-specific #define's
Restructured object file generation/location(Bryan, Marc)
Restructured port-specific file locations(Bryan, Marc)
Unused/uninitialized variables corrected
     __________________________________________________________________

                                Release 1.09

     Release Date: 1996-11-04

   Sorry, we didn't keep track of changes from 1.02 to 1.09. Some of the
   changes listed in 6.0 were actually included in the 1.02.1 to 1.09
   releases.
     __________________________________________________________________

                                Release 1.02

     Release Date: 1996-08-01
     __________________________________________________________________

Migration from version 1.02 to version 1.02.1

   Here is a new migration file for 1.02.1. It includes the 'copy' change
   and a script to convert old ASCII files.

     Note: The following notes are for the benefit of users who want to
     migrate databases from Postgres95 1.01 and 1.02 to Postgres95
     1.02.1.

     If you are starting afresh with Postgres95 1.02.1 and do not need to
     migrate old databases, you do not need to read any further.

   In order to upgrade older Postgres95 version 1.01 or 1.02 databases to
   version 1.02.1, the following steps are required:
    1. Start up a new 1.02.1 postmaster
    2. Add the new built-in functions and operators of 1.02.1 to 1.01 or
       1.02 databases. This is done by running the new 1.02.1 server
       against your own 1.01 or 1.02 database and applying the queries
       attached at the end of the file. This can be done easily through
       "psql". If your 1.01 or 1.02 database is named testdb and you have
       cut the commands from the end of this file and saved them in
       "addfunc.sql":
% psql testdb -f addfunc.sql
       Those upgrading 1.02 databases will get a warning when executing
       the last two statements in the file because they are already
       present in 1.02. This is not a cause for concern.
     __________________________________________________________________

Dump/Reload Procedure

   If you are trying to reload a pg_dump or text-mode, copy tablename to
   stdout generated with a previous version, you will need to run the
   attached "sed" script on the ASCII file before loading it into the
   database. The old format used '.' as end-of-data, while '\.' is now the
   end-of-data marker. Also, empty strings are now loaded in as '' rather
   than NULL. See the copy manual page for full details.
sed 's/^\.$/\\./g' <in_file >out_file

   If you are loading an older binary copy or non-stdout copy, there is no
   end-of-data character, and hence no conversion necessary.
-- following lines added by agc to reflect the case-insensitive
-- regexp searching for varchar (in 1.02), and bpchar (in 1.02.1)
create operator ~* (leftarg = bpchar, rightarg = text, procedure = texticregexeq
);
create operator !~* (leftarg = bpchar, rightarg = text, procedure = texticregexn
e);
create operator ~* (leftarg = varchar, rightarg = text, procedure = texticregexe
q);
create operator !~* (leftarg = varchar, rightarg = text, procedure = texticregex
ne);
     __________________________________________________________________

Changes

Source code maintenance and development
 * worldwide team of volunteers
 * the source tree now in CVS at ftp.ki.net

Enhancements
 * psql (and underlying libpq library) now has many more options for
   formatting output, including HTML
 * pg_dump now output the schema and/or the data, with many fixes to
   enhance completeness.
 * psql used in place of monitor in administration shell scripts.
   monitor to be deprecated in next release.
 * date/time functions enhanced
 * NULL insert/update/comparison fixed/enhanced
 * TCL/TK lib and shell fixed to work with both tck7.4/tk4.0 and tcl7.5/tk4.1

Bug Fixes (almost too numerous to mention)
 * indexes
 * storage management
 * check for NULL pointer before dereferencing
 * Makefile fixes

New Ports
 * added SolarisX86 port
 * added BSD/OS 2.1 port
 * added DG/UX port
     __________________________________________________________________

                                Release 1.01

     Release Date: 1996-02-23
     __________________________________________________________________

Migration from version 1.0 to version 1.01

   The following notes are for the benefit of users who want to migrate
   databases from Postgres95 1.0 to Postgres95 1.01.

   If you are starting afresh with Postgres95 1.01 and do not need to
   migrate old databases, you do not need to read any further.

   In order to Postgres95 version 1.01 with databases created with
   Postgres95 version 1.0, the following steps are required:
    1. Set the definition of NAMEDATALEN in "src/Makefile.global" to 16
       and OIDNAMELEN to 20.
    2. Decide whether you want to use Host based authentication.
         a. If you do, you must create a file name pg_hba in your
            top-level data directory (typically the value of your
            $PGDATA). "src/libpq/pg_hba" shows an example syntax.
         b. If you do not want host-based authentication, you can comment
            out the line:
HBA = 1
            in "src/Makefile.global"
            Note that host-based authentication is turned on by default,
            and if you do not take steps A or B above, the out-of-the-box
            1.01 will not allow you to connect to 1.0 databases.
    3. Compile and install 1.01, but DO NOT do the "initdb" step.
    4. Before doing anything else, terminate your 1.0 postmaster, and
       backup your existing $PGDATA directory.
    5. Set your PGDATA environment variable to your 1.0 databases, but set
       up path up so that 1.01 binaries are being used.
    6. Modify the file "$PGDATA/PG_VERSION" from 5.0 to 5.1
    7. Start up a new 1.01 postmaster
    8. Add the new built-in functions and operators of 1.01 to 1.0
       databases. This is done by running the new 1.01 server against your
       own 1.0 database and applying the queries attached and saving in
       the file 1.0_to_1.01.sql. This can be done easily through "psql".
       If your 1.0 database is name testdb:
% psql testdb -f 1.0_to_1.01.sql
       and then execute the following commands (cut and paste from here):
-- add builtin functions that are new to 1.01

create function int4eqoid (int4, oid) returns bool as 'foo'
language 'internal';
create function oideqint4 (oid, int4) returns bool as 'foo'
language 'internal';
create function char2icregexeq (char2, text) returns bool as 'foo'
language 'internal';
create function char2icregexne (char2, text) returns bool as 'foo'
language 'internal';
create function char4icregexeq (char4, text) returns bool as 'foo'
language 'internal';
create function char4icregexne (char4, text) returns bool as 'foo'
language 'internal';
create function char8icregexeq (char8, text) returns bool as 'foo'
language 'internal';
create function char8icregexne (char8, text) returns bool as 'foo'
language 'internal';
create function char16icregexeq (char16, text) returns bool as 'foo'
language 'internal';
create function char16icregexne (char16, text) returns bool as 'foo'
language 'internal';
create function texticregexeq (text, text) returns bool as 'foo'
language 'internal';
create function texticregexne (text, text) returns bool as 'foo'
language 'internal';

-- add builtin functions that are new to 1.01

create operator = (leftarg = int4, rightarg = oid, procedure = int4eqoid);
create operator = (leftarg = oid, rightarg = int4, procedure = oideqint4);
create operator ~* (leftarg = char2, rightarg = text, procedure = char2icregexeq
);
create operator !~* (leftarg = char2, rightarg = text, procedure = char2icregexn
e);
create operator ~* (leftarg = char4, rightarg = text, procedure = char4icregexeq
);
create operator !~* (leftarg = char4, rightarg = text, procedure = char4icregexn
e);
create operator ~* (leftarg = char8, rightarg = text, procedure = char8icregexeq
);
create operator !~* (leftarg = char8, rightarg = text, procedure = char8icregexn
e);
create operator ~* (leftarg = char16, rightarg = text, procedure = char16icregex
eq);
create operator !~* (leftarg = char16, rightarg = text, procedure = char16icrege
xne);
create operator ~* (leftarg = text, rightarg = text, procedure = texticregexeq);
create operator !~* (leftarg = text, rightarg = text, procedure = texticregexne)
;
     __________________________________________________________________

Changes

Incompatibilities:
 * 1.01 is backwards compatible with 1.0 database provided the user
   follow the steps outlined in the MIGRATION_from_1.0_to_1.01 file.
   If those steps are not taken, 1.01 is not compatible with 1.0 database.

Enhancements:
 * added PQdisplayTuples() to libpq and changed monitor and psql to use it
 * added NeXT port (requires SysVIPC implementation)
 * added CAST .. AS ... syntax
 * added ASC and DESC key words
 * added 'internal' as a possible language for CREATE FUNCTION
   internal functions are C functions which have been statically linked
   into the postgres backend.
 * a new type "name" has been added for system identifiers (table names,
   attribute names, etc.)  This replaces the old char16 type.   The
   of name is set by the NAMEDATALEN #define in src/Makefile.global
 * a readable reference manual that describes the query language.
 * added host-based access control.  A configuration file ($PGDATA/pg_hba)
   is used to hold the configuration data.  If host-based access control
   is not desired, comment out HBA=1 in src/Makefile.global.
 * changed regex handling to be uniform use of Henry Spencer's regex code
   regardless of platform.  The regex code is included in the distribution
 * added functions and operators for case-insensitive regular expressions.
   The operators are ~* and !~*.
 * pg_dump uses COPY instead of SELECT loop for better performance

Bug fixes:
 * fixed an optimizer bug that was causing core dumps when
   functions calls were used in comparisons in the WHERE clause
 * changed all uses of getuid to geteuid so that effective uids are used
 * psql now returns non-zero status on errors when using -c
 * applied public patches 1-14
     __________________________________________________________________

                                 Release 1.0

     Release Date: 1995-09-05
     __________________________________________________________________

Changes

Copyright change:
 * The copyright of Postgres 1.0 has been loosened to be freely modifiable
   and modifiable for any purpose.  Please read the COPYRIGHT file.
   Thanks to Professor Michael Stonebraker for making this possible.

Incompatibilities:
 *  date formats have to be MM-DD-YYYY (or DD-MM-YYYY if you're using
   EUROPEAN STYLE).  This follows SQL-92 specs.
 *  "delimiters" is now a key word

Enhancements:
 *  sql LIKE syntax has been added
 *  copy command now takes an optional USING DELIMITER specification.
   delimiters can be any single-character string.
 *  IRIX 5.3 port has been added.
   Thanks to Paul Walmsley and others.
 *  updated pg_dump to work with new libpq
 *  \d has been added psql
   Thanks to Keith Parks
 *  regexp performance for architectures that use POSIX regex has been
   improved due to caching of precompiled patterns.
   Thanks to Alistair Crooks
 *  a new version of libpq++
   Thanks to William Wanders

Bug fixes:
 *  arbitrary userids can be specified in the createuser script
 *  \c to connect to other databases in psql now works.
 *  bad pg_proc entry for float4inc() is fixed
 *  users with usecreatedb field set can now create databases without
   having to be usesuper
 *  remove access control entries when the entry no longer has any
   privileges
 *  fixed non-portable datetimes implementation
 *  added kerberos flags to the src/backend/Makefile
 *  libpq now works with kerberos
 *  typographic errors in the user manual have been corrected.
 *  btrees with multiple index never worked, now we tell you they don't
   work when you try to use them
     __________________________________________________________________

                           Postgres95 Release 0.03

     Release Date: 1995-07-21
     __________________________________________________________________

Changes

Incompatible changes:
 * BETA-0.3 IS INCOMPATIBLE WITH DATABASES CREATED WITH PREVIOUS VERSIONS
   (due to system catalog changes and indexing structure changes).
 * double-quote (") is deprecated as a quoting character for string literals;
   you need to convert them to single quotes (').
 * name of aggregates (eg. int4sum) are renamed in accordance with the
   SQL standard (eg. sum).
 * CHANGE ACL syntax is replaced by GRANT/REVOKE syntax.
 * float literals (eg. 3.14) are now of type float4 (instead of float8 in
   previous releases); you might have to do typecasting if you depend on it
   being of type float8.  If you neglect to do the typecasting and you assign
   a float literal to a field of type float8, you might get incorrect values
   stored!
 * LIBPQ has been totally revamped so that frontend applications
   can connect to multiple backends
 * the usesysid field in pg_user has been changed from int2 to int4 to
   allow wider range of Unix user ids.
 * the netbsd/freebsd/bsd o/s ports have been consolidated into a
   single BSD44_derived port.  (thanks to Alistair Crooks)

SQL standard-compliance (the following details changes that makes postgres95
more compliant to the SQL-92 standard):
 * the following SQL types are now built-in: smallint, int(eger), float, real,
   char(N), varchar(N), date and time.

   The following are aliases to existing postgres types:
                smallint -> int2
                integer, int -> int4
                float, real  -> float4
   char(N) and varchar(N) are implemented as truncated text types. In
   addition, char(N) does blank-padding.
 * single-quote (') is used for quoting string literals; '' (in addition to
   \') is supported as means of inserting a single quote in a string
 * SQL standard aggregate names (MAX, MIN, AVG, SUM, COUNT) are used
   (Also, aggregates can now be overloaded, i.e. you can define your
   own MAX aggregate to take in a user-defined type.)
 * CHANGE ACL removed. GRANT/REVOKE syntax added.
   - Privileges can be given to a group using the "GROUP" key word.
        For example:
                GRANT SELECT ON foobar TO GROUP my_group;
        The key word 'PUBLIC' is also supported to mean all users.

        Privileges can only be granted or revoked to one user or group
        at a time.

        "WITH GRANT OPTION" is not supported.  Only class owners can change
        access control
   - The default access control is to grant users readonly access.
     You must explicitly grant insert/update access to users.  To change
     this, modify the line in
                src/backend/utils/acl.h
     that defines ACL_WORLD_DEFAULT

Bug fixes:
 * the bug where aggregates of empty tables were not run has been fixed. Now,
   aggregates run on empty tables will return the initial conditions of the
   aggregates. Thus, COUNT of an empty  table will now properly return 0.
   MAX/MIN of an empty table will return a row of value NULL.
 * allow the use of \; inside the monitor
 * the LISTEN/NOTIFY asynchronous notification mechanism now work
 * NOTIFY in rule action bodies now work
 * hash indexes work, and access methods in general should perform better.
   creation of large btree indexes should be much faster.  (thanks to Paul
   Aoki)

Other changes and enhancements:
 * addition of an EXPLAIN statement used for explaining the query execution
   plan (eg. "EXPLAIN SELECT * FROM EMP" prints out the execution plan for
   the query).
 * WARN and NOTICE messages no longer have timestamps on them. To turn on
   timestamps of error messages, uncomment the line in
   src/backend/utils/elog.h:
        /* define ELOG_TIMESTAMPS */
 * On an access control violation, the message
        "Either no such class or insufficient privilege"
   will be given.  This is the same message that is returned when
   a class is not found.  This dissuades non-privileged users from
   guessing the existence of privileged classes.
 * some additional system catalog changes have been made that are not
   visible to the user.

libpgtcl changes:
 * The -oid option has been added to the "pg_result" tcl command.
   pg_result -oid returns oid of the last row inserted.   If the
   last command was not an INSERT, then pg_result -oid returns "".
 * the large object interface is available as pg_lo* tcl commands:
   pg_lo_open, pg_lo_close, pg_lo_creat, etc.

Portability enhancements and New Ports:
 * flex/lex problems have been cleared up.  Now, you should be able to use
   flex instead of lex on any platforms.  We no longer make assumptions of
   what lexer you use based on the platform you use.
 * The Linux-ELF port is now supported.  Various configuration have been
   tested:  The following configuration is known to work:
        kernel 1.2.10, gcc 2.6.3, libc 4.7.2, flex 2.5.2, bison 1.24
   with everything in ELF format,

New utilities:
 * ipcclean added to the distribution
   ipcclean usually does not need to be run, but if your backend crashes
   and leaves shared memory segments hanging around, ipcclean will
   clean them up for you.

New documentation:
 * the user manual has been revised and libpq documentation added.
     __________________________________________________________________

                           Postgres95 Release 0.02

     Release Date: 1995-05-25
     __________________________________________________________________

Changes

Incompatible changes:
 * The SQL statement for creating a database is 'CREATE DATABASE' instead
   of 'CREATEDB'. Similarly, dropping a database is 'DROP DATABASE' instead
   of 'DESTROYDB'. However, the names of the executables 'createdb' and
   'destroydb' remain the same.

New tools:
 * pgperl - a Perl (4.036) interface to Postgres95
 * pg_dump - a utility for dumping out a postgres database into a
        script file containing query commands. The script files are in a ASCII
        format and can be used to reconstruct the database, even on other
        machines and other architectures. (Also good for converting
        a Postgres 4.2 database to Postgres95 database.)

The following ports have been incorporated into postgres95-beta-0.02:
 * the NetBSD port by Alistair Crooks
 * the AIX port by Mike Tung
 * the Windows NT port by Jon Forrest (more stuff but not done yet)
 * the Linux ELF port by Brian Gallew

The following bugs have been fixed in postgres95-beta-0.02:
 * new lines not escaped in COPY OUT and problem with COPY OUT when first
   attribute is a '.'
 * cannot type return to use the default user id in createuser
 * SELECT DISTINCT on big tables crashes
 * Linux installation problems
 * monitor doesn't allow use of 'localhost' as PGHOST
 * psql core dumps when doing \c or \l
 * the "pgtclsh" target missing from src/bin/pgtclsh/Makefile
 * libpgtcl has a hard-wired default port number
 * SELECT DISTINCT INTO TABLE hangs
 * CREATE TYPE doesn't accept 'variable' as the internallength
 * wrong result using more than 1 aggregate in a SELECT
     __________________________________________________________________

                           Postgres95 Release 0.01

     Release Date: 1995-05-01

   Initial release.
