path: root/doc/src/sgml/release-15.sgml

 <sect1 id="release-15">
  <title>Release 15</title>

  <formalpara>
   <title>Release date:</title>
   <para>CURRENT AS OF 2022-10-03</para>
  </formalpara>

  <sect2>
   <title>Overview</title>

   <para>
    <productname>PostgreSQL</productname> 15 contains many new features
    and enhancements, including:
   </para>

   <itemizedlist>
    <listitem>
     <para>
      Support for the <acronym>SQL</acronym>
      <link linkend="sql-merge"><command>MERGE</command></link> command.
     </para>
    </listitem>
    <listitem>
     <para>
      Selective publication of tables' contents within
      <link linkend="logical-replication">logical replication</link>
      publications, through the ability to specify column lists and
      row filter conditions.
     </para>
    </listitem>
    <listitem>
     <para>
      More options for compression, including support for Zstandard (zstd)
      compression.  This includes support for performing compression on
      the server side during
      <link linkend="app-pgbasebackup"><application>pg_basebackup</application></link>.
     </para>
    </listitem>
    <listitem>
     <para>
      Support for structured <link linkend="guc-log-destination">server
      log output</link> using the <acronym>JSON</acronym> format.
     </para>
    </listitem>
    <listitem>
     <para>
      Performance improvements, particularly for in-memory and on-disk
      sorting.
     </para>
    </listitem>
   </itemizedlist>

   <para>
    The above items and other new features of
    <productname>PostgreSQL</productname> 15 are explained in more detail
    in the sections below.
   </para>

  </sect2>

  <sect2>

   <title>Migration to Version 15</title>

    <para>
     A dump/restore using <xref linkend="app-pg-dumpall"/> or use of
     <xref linkend="pgupgrade"/> or logical replication is required for
     those wishing to migrate data from any previous release.  See <xref
     linkend="upgrading"/> for general information on migrating to new
     major releases.
    </para>

    <para>
     Version 15 contains a number of changes that may affect compatibility
     with previous releases.  Observe the following incompatibilities:
    </para>

   <itemizedlist>

<!--
Author: Noah Misch <noah@leadboat.com>
2021-09-09 [b073c3ccd] Revoke PUBLIC CREATE from public schema, now owned by pg
-->

    <listitem>
     <para>
      Remove <literal>PUBLIC</literal> creation permission on the <link
      linkend="ddl-schemas-public"><literal>public</literal> schema</link>
      (Noah Misch)
     </para>

     <para>
      The new default is one of the secure schema usage patterns that <xref
      linkend="ddl-schemas-patterns"/> has recommended since the security
      release for CVE-2018-1058.  The change applies to new database
      clusters and to newly-created databases in existing clusters.
      Upgrading a cluster or restoring a database dump will preserve
      <literal>public</literal>'s existing permissions.
     </para>

     <para>
      For existing databases, especially those having multiple users,
      consider revoking <literal>CREATE</literal> permission on
      the <literal>public</literal> schema to adopt this new default.
      For new databases having no need to defend against insider threats,
      granting <literal>CREATE</literal> permission will yield the behavior
      of prior releases.
     </para>
    </listitem>

<!--
Author: Noah Misch <noah@leadboat.com>
2021-09-09 [b073c3ccd] Revoke PUBLIC CREATE from public schema, now owned by pg
-->

    <listitem>
     <para>
      Change the owner of the <literal>public</literal> schema to be the
      new <literal>pg_database_owner</literal> role (Noah Misch)
     </para>

     <para>
      This allows each database's owner to have ownership privileges on
      the <literal>public</literal> schema within their database.
      Previously it was owned by the bootstrap superuser, so that
      non-superuser database owners could not do anything with it.
     </para>

     <para>
      This change applies to new database clusters and to newly-created
      databases in existing clusters.
      Upgrading a cluster or restoring a database dump will preserve
      <literal>public</literal>'s existing ownership specification.
     </para>
    </listitem>

<!--
Author: Stephen Frost <sfrost@snowman.net>
2022-04-06 [39969e2a1] Remove exclusive backup mode
-->

    <listitem>
     <para>
      Remove long-deprecated <link linkend="backup-base-backup">exclusive
      backup mode</link> (David Steele, Nathan Bossart)
     </para>

     <para>
      If the database server stops abruptly while in this mode, the
      server could fail to start.  The non-exclusive backup mode is
      considered superior for all purposes.  Functions
      <function>pg_start_backup()</function>/<function>pg_stop_backup()</function>
      have been renamed to
      <function>pg_backup_start()</function>/<function>pg_backup_stop()</function>,
      and the functions <function>pg_backup_start_time()</function>
      and <function>pg_is_in_backup()</function> have been removed.
     </para>
    </listitem>

<!--
Author: Peter Geoghegan <pg@bowt.ie>
2022-02-16 [8f388f6f5] Increase hash_mem_multiplier default to 2.0.
-->

    <listitem>
     <para>
      Increase <link
      linkend="guc-hash-mem-multiplier"><varname>hash_mem_multiplier</varname></link>
      default to 2.0 (Peter Geoghegan)
     </para>

     <para>
      This allows query hash operations to use more
      <link linkend="guc-work-mem"><varname>work_mem</varname></link>
      memory than other operations.
     </para>
    </listitem>

<!--
Author: Andres Freund <andres@anarazel.de>
2022-03-07 [76a29adee] plpython: Remove plpythonu, plpython2u and associated tr
-->

    <listitem>
     <para>
      Remove server-side language <link
      linkend="plpython"><literal>plpython2u</literal></link> and generic
      Python language <literal>plpythonu</literal> (Andres Freund)
     </para>

     <para>
      Python 2.x is no longer supported.  While the original intent of
      <literal>plpythonu</literal> was that it could eventually refer
      to <literal>plpython3u</literal>, changing it now seems more likely
      to cause problems than solve them, so it's just been removed.
     </para>
    </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2021-11-06 [cbe25dcff] Disallow making an empty lexeme via array_to_tsvector().
-->

    <listitem>
     <para>
      Generate an error if <link
      linkend="textsearch-functions-table"><function>array_to_tsvector()</function></link>
      is passed an empty-string array element (Jean-Christophe Arnu)
     </para>

     <para>
      This is prohibited because lexemes should never be empty.  Users of
      previous Postgres releases should verify that no empty lexemes
      are stored because they can lead to dump/restore failures and
      inconsistent results.
     </para>
    </listitem>

<!--
Author: Peter Eisentraut <peter@eisentraut.org>
2021-12-06 [e9e63b702] Fix inappropriate uses of PG_GETARG_UINT32()
-->

    <listitem>
     <para>
      Generate an error when <link
      linkend="functions-string-other"><function>chr()</function></link>
      is supplied with a negative argument (Peter Eisentraut)
     </para>
    </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2022-02-15 [2523928b2] Reject change of output-column collation in CREATE OR RE
-->

    <listitem>
     <para>
      Prevent <link linkend="sql-createview"><command>CREATE OR REPLACE
      VIEW</command></link> from changing the collation of an output column
      (Tom Lane)
     </para>
    </listitem>

<!--
Author: Peter Eisentraut <peter@eisentraut.org>
2022-01-12 [a18b6d2dc] ecpg: Catch zero-length Unicode identifiers correctly
-->

    <listitem>
     <para>
      Disallow zero-length <link
      linkend="sql-syntax-identifiers">Unicode identifiers</link>,
      e.g., <literal>U&amp;""</literal>
      (Peter Eisentraut)
     </para>

     <para>
      Non-Unicode zero-length identifiers were already disallowed.
     </para>
    </listitem>

<!--
Author: Peter Eisentraut <peter@eisentraut.org>
2022-02-16 [2549f0661] Reject trailing junk after numeric literals
-->

    <listitem>
     <para>
      Prevent <link linkend="sql-syntax-constants-numeric">numeric
      literals</link> from having non-numeric trailing characters (Peter
      Eisentraut)
     </para>

     <para>
      Previously, query text like <literal>123abc</literal> would be
      interpreted as <literal>123</literal> followed
      by a separate token <literal>abc</literal>.
     </para>
    </listitem>

<!--
Author: Peter Eisentraut <peter@eisentraut.org>
2022-03-28 [e26114c81] Make JSON path numeric literals more correct
-->

    <listitem>
     <para>
      Adjust <link linkend="datatype-json"><acronym>JSON</acronym></link>
      numeric literal processing to match the
      <acronym>SQL</acronym>/<acronym>JSON</acronym>-standard (Peter
      Eisentraut)
     </para>

     <para>
      This accepts numeric formats like <literal>.1</literal> and
      <literal>1.</literal>, and disallows trailing junk after numeric
      literals, like <literal>1.type()</literal>.
     </para>
    </listitem>

<!--
Author: Bruce Momjian <bruce@momjian.us>
2021-08-03 [95ab1e0a9] interval:  round values when spilling to months
-->

    <listitem>
     <para>
      When <link linkend="datatype-datetime"><type>interval</type></link>
      input provides a fractional value for a unit greater than months,
      round to the nearest month (Bruce Momjian)
     </para>

     <para>
      For example, convert <literal>1.99 years</literal> to <literal>2
      years</literal>, not <literal>1 year 11 months</literal> as before.
     </para>
    </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2022-04-03 [591e088dd] Fix portability issues in datetime parsing.
-->

    <listitem>
     <para>
      Improve consistency of <type>interval</type> parsing with trailing
      periods (Tom Lane)
     </para>

     <para>
      Numbers with trailing periods were rejected on some platforms.
     </para>
    </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2022-01-19 [a3d6264bb] interval_out() must be marked STABLE, not IMMUTABLE.
-->

    <listitem>
     <para>
      Mark the <type>interval</type> output
      function as stable, not immutable, since it depends on <link
      linkend="guc-intervalstyle"><varname>IntervalStyle</varname></link>
      (Tom Lane)
     </para>

     <para>
      This will, for example, cause creation of indexes relying on the
      text output of <type>interval</type> values to fail.
     </para>
    </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2022-02-28 [54bd1e43c] Handle integer overflow in interval justification functi
-->

    <listitem>
     <para>
      Detect integer overflow in <link
      linkend="functions-datetime-table">interval justification
      functions</link> (Joe Koshakow)
     </para>

     <para>
      The affected functions are <function>justify_interval()</function>,
      <function>justify_hours()</function>, and
      <function>justify_days()</function>.
     </para>
    </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2022-08-02 [c034b629c] Change type "char"'s I/O format for non-ASCII characters
-->

    <listitem>
     <para>
      Change the I/O format of type <type>"char"</type> for non-ASCII
      characters (Tom Lane)
     </para>

     <para>
      Bytes with the high bit set are now output as a backslash and three
      octal digits, to avoid encoding issues.
     </para>
    </listitem>

<!--
Author: Robert Haas <rhaas@postgresql.org>
2022-03-28 [79de9842a] Remove the ability of a role to administer itself.
-->

    <listitem>
     <para>
      Remove the default <link linkend="sql-createrole"><literal>ADMIN
      OPTION</literal></link> privilege a login role has on its own role
      membership (Robert Haas)
     </para>

     <para>
      Previously, a login role could add/remove members of its own role,
      even without <literal>ADMIN OPTION</literal> privilege.
     </para>
    </listitem>

<!--
Author: Jeff Davis <jdavis@postgresql.org>
2022-01-07 [a2ab9c06e] Respect permissions within logical replication.
-->

    <listitem>
     <para>
      Allow <link linkend="logical-replication">logical replication</link>
      to run as the owner of the subscription (Mark Dilger)
     </para>

     <para>
      Because row-level security policies are not checked, only superusers,
      roles with <literal>bypassrls</literal>, and table owners can
      replicate into tables with row-level security policies.
     </para>
    </listitem>

<!--
Author: Jeff Davis <jdavis@postgresql.org>
2022-01-08 [96a6f11c0] More cleanup of a2ab9c06ea.
-->

    <listitem>
     <para>
      Prevent <command>UPDATE</command> and <command>DELETE</command>
      <link linkend="logical-replication">logical replication</link>
      operations on tables where the subscription owner does not have
      <command>SELECT</command> permission on the table (Jeff Davis)
     </para>

     <para>
      <command>UPDATE</command> and <command>DELETE</command> commands
      typically involve reading the table as well, so require the
      subscription owner to have table <command>SELECT</command>
      permission.
     </para>
    </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2021-07-27 [48c5c9068] Use the "pg_temp" schema alias in EXPLAIN and related ou
-->

    <listitem>
     <para>
      When <link linkend="sql-explain"><command>EXPLAIN</command></link>
      references the session's temporary object schema, refer to it as
      <literal>pg_temp</literal> (Amul Sul)
     </para>

     <para>
      Previously the actual schema name was reported, leading to
      inconsistencies across sessions.
     </para>
    </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2022-03-24 [ce95c5437] Fix pg_statio_all_tables view for multiple TOAST indexes
-->

    <listitem>
     <para>
      Fix <link
      linkend="monitoring-pg-statio-all-tables-view"><structname>pg_statio_all_tables</structname></link>
      to sum values for the rare case of <acronym>TOAST</acronym> tables
      with multiple indexes (Andrei Zubkov)
     </para>

     <para>
      Previously such cases would show one row for each index.
     </para>
    </listitem>

<!--
Author: Peter Eisentraut <peter@eisentraut.org>
2021-12-01 [75d22069e] Warning on SET of nonexisting setting with a prefix rese
Author: Tom Lane <tgl@sss.pgh.pa.us>
2021-12-27 [2ed8a8cc5] Rethink handling of settings with a prefix reserved by a
Author: Tom Lane <tgl@sss.pgh.pa.us>
2022-02-21 [88103567c] Disallow setting bogus GUCs within an extension's reserv
-->

    <listitem>
     <para>
      Disallow setting <link linkend="runtime-config-custom">custom
      options</link> that match the name of an installed extension, but
      are not one of the extension's declared variables
      (Florin Irion, Tom Lane)
     </para>

     <para>
      This change causes any such pre-existing variables to be deleted
      during extension load, and then prevents new ones from being created
      later in the session.  The intent is to prevent confusion about
      whether a variable is associated with an extension or not.
     </para>
    </listitem>

<!--
Author: Andres Freund <andres@anarazel.de>
2022-04-06 [6f0cf8787] pgstat: remove stats_temp_directory.
-->

    <listitem>
     <para>
      Remove obsolete server variable
      <varname>stats_temp_directory</varname> (Andres Freund, Kyotaro
      Horiguchi)
     </para>
    </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2021-11-28 [3804539e4] Replace random(), pg_erand48(), etc with a better PRNG A
Author: Tom Lane <tgl@sss.pgh.pa.us>
2022-04-12 [d4f109e4a] Doc: update description of random() function.
-->

    <listitem>
     <para>
      Improve the algorithm used to compute <link
      linkend="functions-math-random-table"><function>random()</function></link>
      (Fabien Coelho)
     </para>

     <para>
      This will cause <function>random()</function>'s results to differ
      from what was emitted by prior versions, even for the same seed
      value.
     </para>
    </listitem>

<!--
Author: Alvaro Herrera <alvherre@alvh.no-ip.org>
2022-09-23 [bd8ac900d] Remove PQsendQuery support in pipeline mode
-->

    <listitem>
     <para>
      <application>libpq</application>'s <link
      linkend="libpq-PQsendQuery"><function>PQsendQuery()</function></link>
      function is no longer supported in pipeline mode (Álvaro Herrera)
     </para>

     <para>
      Applications that are using that combination will need to be
      modified to use <function>PQsendQueryParams()</function> instead.
     </para>
    </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2022-01-09 [376ce3e40] Prefer $HOME when looking up the current user's home dir
-->

    <listitem>
     <para>
      On non-Windows platforms, consult the <envar>HOME</envar> environment
      variable to find the user's home directory (Anders Kaseorg)
     </para>

     <para>
      If <envar>HOME</envar> is empty or unset, fall back to the previous
      method of checking the <literal>&lt;pwd.h&gt;</literal> database.
      This change affects <application>libpq</application> (for example,
      while looking up <filename>~/.pgpass</filename>) as well as various
      client application programs.
     </para>
    </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2021-12-15 [2a712066d] Remove pg_dump's - -no-synchronized-snapshots switch.
-->

    <listitem>
     <para>
      Remove <link
      linkend="app-pgdump"><application>pg_dump</application></link>'s
      <option>--no-synchronized-snapshots</option> option (Tom Lane)
     </para>

     <para>
      All still-supported server versions support synchronized snapshots,
      so there's no longer a need for this option.
     </para>
    </listitem>

<!--
Author: Michael Paquier <michael@paquier.xyz>
2022-06-15 [a3ff08e0b] Tweak behavior of psql - -single-transaction depending
-->

      <listitem>
       <para>
        After an error is detected in <link
        linkend="app-psql"><application>psql</application></link>'s
        <option>--single-transaction</option> mode, change the
        final <command>COMMIT</command> command
        to <command>ROLLBACK</command> only
        if <varname>ON_ERROR_STOP</varname> is set (Michael Paquier)
       </para>
      </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2021-11-12 [f8abb0f5e] postgres_fdw: suppress casts on constants in limited cas
-->

    <listitem>
     <para>
      Avoid unnecessary casting of constants in queries sent by <link
      linkend="postgres-fdw">postgres_fdw</link> (Dian Fay)
     </para>

     <para>
      When column types are intentionally different between local and
      remote databases, such casts could cause errors.
     </para>
    </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2022-02-14 [fd2abeb7c] Delete contrib/xml2's legacy implementation of xml_is_we
-->

    <listitem>
     <para>
      Remove <link linkend="xml2">xml2</link>'s
      <function>xml_is_well_formed()</function> function (Tom Lane)
     </para>

     <para>
      This function has been implemented in the core backend since
      Postgres 9.1.
     </para>
    </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2021-07-06 [955b3e0f9] Allow CustomScan providers to say whether they support p
-->

    <listitem>
     <para>
      Allow <link linkend="custom-scan">custom scan providers</link>
      to indicate if they support projections (Sven Klemm)
     </para>

     <para>
      The default is now that custom scan providers are assumed to not
      support projections;  those that do will need to be updated for
      this release.
     </para>
    </listitem>

   </itemizedlist>

  </sect2>

  <sect2>
   <title>Changes</title>

   <para>
    Below you will find a detailed account of the changes between
    <productname>PostgreSQL</productname> 15 and the previous major
    release.
   </para>

   <sect3>
    <title>Server</title>

    <itemizedlist>

<!--
Author: Peter Eisentraut <peter@eisentraut.org>
2022-02-14 [37851a8b8] Database-level collation version tracking
-->

     <listitem>
      <para>
       Record and check the collation version of each <link
       linkend="sql-createdatabase">database</link> (Peter Eisentraut)
      </para>

      <para>
       This feature is designed to detect collation version
       changes to avoid index corruption.  Function
       <function>pg_database_collation_actual_version()</function>
       reports the underlying operating system collation version, and
       <command>ALTER DATABASE ...  REFRESH</command> sets the recorded
       database collation version to match the operating system collation
       version.
      </para>
     </listitem>

<!--
Author: Peter Eisentraut <peter@eisentraut.org>
2022-03-17 [f2553d430] Add option to use ICU as global locale provider
-->

     <listitem>
      <para>
       Allow <link linkend="locale"><acronym>ICU</acronym></link>
       collations to be set as the default for clusters and databases
       (Peter Eisentraut)
      </para>

      <para>
       Previously, only <application>libc</application>-based
       collations could be selected at the cluster and database levels.
       <acronym>ICU</acronym> collations could only be used via explicit
       <literal>COLLATE</literal> clauses.
      </para>
     </listitem>

<!--
Author: Michael Paquier <michael@paquier.xyz>
2022-03-29 [a2c84990b] Add system view pg_ident_file_mappings
-->

     <listitem>
      <para>
       Add system view <link
       linkend="view-pg-ident-file-mappings"><structname>pg_ident_file_mappings</structname></link>
       to report <filename>pg_ident.conf</filename> information (Julien
       Rouhaud)
      </para>
     </listitem>

       </itemizedlist>

    <sect4>
     <title><link linkend="ddl-partitioning">Partitioning</link></title>

     <itemizedlist>

<!--
Author: David Rowley <drowley@postgresql.org>
2021-08-03 [475dbd0b7] Track a Bitmapset of non-pruned partitions in RelOptInfo
-->

      <listitem>
       <para>
        Improve planning time for queries referencing partitioned tables
        (David Rowley)
       </para>

       <para>
        This change helps when only a few of many partitions are relevant.
       </para>
      </listitem>

<!--
Author: David Rowley <drowley@postgresql.org>
2021-08-03 [db632fbca] Allow ordered partition scans in more cases
-->

      <listitem>
       <para>
        Allow ordered scans of partitions to avoid sorting in more cases
        (David Rowley)
       </para>

       <para>
        Previously, a partitioned table with a <literal>DEFAULT</literal>
        partition or a <literal>LIST</literal> partition containing
        multiple values could not be used for ordered partition scans.
        Now they can be used if such partitions are pruned during planning.
       </para>
      </listitem>

<!--
Author: Alvaro Herrera <alvherre@alvh.no-ip.org>
2022-03-20 [ba9a7e392] Enforce foreign key correctly during cross-partition upd
-->

      <listitem>
       <para>
        Improve foreign key behavior of updates on partitioned tables
        that move rows between partitions (Amit Langote)
       </para>

       <para>
        Previously, such updates ran a delete action on the source
        partition and an insert action on the target partition.
        <productname>PostgreSQL</productname> will now run an update action
        on the partition root, providing cleaner semantics.
       </para>
      </listitem>

<!--
Author: Alvaro Herrera <alvherre@alvh.no-ip.org>
2022-04-02 [cfdd03f45] Allow CLUSTER on partitioned tables
Author: Alvaro Herrera <alvherre@alvh.no-ip.org>
2022-04-14 [3f19e176a] Have CLUSTER ignore partitions not owned by caller
-->

      <listitem>
       <para>
        Allow <link linkend="sql-cluster"><command>CLUSTER</command></link>
        on partitioned tables (Justin Pryzby)
       </para>
      </listitem>

<!--
Author: Alvaro Herrera <alvherre@alvh.no-ip.org>
2021-07-22 [80ba4bb38] Make ALTER TRIGGER RENAME consistent for partitioned tab
-->

      <listitem>
       <para>
        Fix <link linkend="sql-altertable"><command>ALTER TRIGGER
        RENAME</command></link> on partitioned tables to properly rename
        triggers on all partitions (Arne Roland, Álvaro Herrera)
       </para>

       <para>
        Also prohibit cloned triggers from being renamed.
       </para>
      </listitem>

     </itemizedlist>

    </sect4>

    <sect4>
     <title>Indexes</title>

     <itemizedlist>

<!--
Author: Peter Geoghegan <pg@bowt.ie>
2021-10-02 [2903f1404] Enable deduplication in system catalog indexes.
-->

      <listitem>
       <para>
        Allow btree indexes on system and <link
        linkend="storage-toast"><acronym>TOAST</acronym></link>
        tables to efficiently store duplicates (Peter Geoghegan)
       </para>

       <para>
        Previously de-duplication was disabled for these types of indexes.
       </para>
      </listitem>

<!--
Author: Alexander Korotkov <akorotkov@postgresql.org>
2022-02-07 [f1ea98a79] Reduce non-leaf keys overlap in GiST indexes produced by
-->

      <listitem>
       <para>
        Improve lookup performance
        of <link linkend="gist"><acronym>GiST</acronym></link> indexes
        that were built using sorting (Aliaksandr Kalenik, Sergei
        Shoulbakov, Andrey Borodin)
       </para>
      </listitem>

<!--
Author: Peter Eisentraut <peter@eisentraut.org>
2022-02-03 [94aa7cc5f] Add UNIQUE null treatment option
-->

      <listitem>
       <para>
        Allow unique constraints and indexes to treat
        <literal>NULL</literal> values as not distinct (Peter Eisentraut)
       </para>

       <para>
        Previously <literal>NULL</literal> entries were always treated
        as distinct values, but this can now be changed by creating
        constraints and indexes using <literal>UNIQUE NULLS NOT
        DISTINCT</literal>.
       </para>
      </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2021-11-17 [a148f8bc0] Add a planner support function for starts_with().
-->

      <listitem>
       <para>
        Allow the <link
        linkend="functions-string-other"><literal>^@</literal></link>
        starts-with operator and the <function>starts_with()</function>
        function to use btree indexes if using the C collation (Tom Lane)
       </para>

       <para>
        Previously these could only use <link
        linkend="spgist"><acronym>SP-GiST</acronym></link> indexes.
       </para>
      </listitem>

     </itemizedlist>

    </sect4>

    <sect4>
     <title>Optimizer</title>

     <itemizedlist>

<!--
Author: Tomas Vondra <tomas.vondra@postgresql.org>
2022-01-16 [269b532ae] Add stxdinherit flag to pg_statistic_ext_data
-->

      <listitem>
       <para>
        Allow <link linkend="sql-createstatistics">extended
        statistics</link> to record statistics for a parent with all its
        children (Tomas Vondra, Justin Pryzby)
       </para>

       <para>
        Regular statistics already tracked parent and
        parent-plus-all-children statistics separately.
       </para>
      </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2022-03-24 [0bd7af082] Invent recursive_worktable_factor GUC to replace hard-wi
-->

      <listitem>
       <para>
        Add server variable <link
        linkend="guc-recursive-worktable-factor"><varname>recursive_worktable_factor</varname></link>
        to allow the user to specify the expected size of the working
        table of a <link linkend="queries-with-recursive">recursive
        query</link> (Simon Riggs)
       </para>
      </listitem>

     </itemizedlist>

    </sect4>

    <sect4>
     <title>General Performance</title>

     <itemizedlist>

<!--
Author: David Rowley <drowley@postgresql.org>
2021-07-07 [29f45e299] Use a hash table to speed up NOT IN(values)
-->

      <listitem>
       <para>
        Allow hash lookup for <link
        linkend="functions-subquery-notin"><literal>NOT IN</literal></link>
        clauses with many constants (David Rowley, James Coleman)
       </para>

       <para>
        Previously the code always sequentially scanned the list of values.
       </para>
      </listitem>

<!--
Author: David Rowley <drowley@postgresql.org>
2021-08-22 [22c4e88eb] Allow parallel DISTINCT
-->

     <listitem>
      <para>
       Allow <command>SELECT DISTINCT</command> to be parallelized
       (David Rowley)
      </para>
     </listitem>

<!--
Author: John Naylor <john.naylor@postgresql.org>
2021-12-20 [911588a3f] Add fast path for validating UTF-8 text
-->

      <listitem>
       <para>
        Speed up encoding validation of <acronym>UTF</acronym>-8 text
        by processing 16 bytes at a time
        (John Naylor, Heikki Linnakangas)
       </para>

       <para>
        This will improve text-heavy operations like <link
        linkend="sql-copy"><command>COPY FROM</command></link>.
       </para>
      </listitem>

<!--
Author: Heikki Linnakangas <heikki.linnakangas@iki.fi>
2021-10-18 [65014000b] Replace polyphase merge algorithm with a simple balanced
Author: Heikki Linnakangas <heikki.linnakangas@iki.fi>
2021-10-25 [166f94377] Clarify the logic in a few places in the new balanced me
-->

      <listitem>
       <para>
        Improve performance for sorts that exceed <link
        linkend="guc-work-mem"><varname>work_mem</varname></link>
        (Heikki Linnakangas)
       </para>

       <para>
        When the sort data no longer fits in <varname>work_mem</varname>,
        switch to a batch sorting algorithm that uses more output streams
        than before.
       </para>
      </listitem>

<!--
Author: David Rowley <drowley@postgresql.org>
2021-07-22 [91e9e89dc] Make nodeSort.c use Datum sorts for single column sorts
Author: David Rowley <drowley@postgresql.org>
2022-04-04 [40af10b57] Use Generation memory contexts to store tuples in sorts
Author: John Naylor <john.naylor@postgresql.org>
2022-04-02 [697492434] Specialize tuplesort routines for different kinds of abb
-->

      <listitem>
       <para>
        Improve performance and reduce memory consumption of in-memory
        sorts (Ronan Dunklau, David Rowley, Thomas Munro, John Naylor)
       </para>
      </listitem>

<!--
Author: Michael Paquier <michael@paquier.xyz>
2021-06-29 [4035cd5d4] Add support for LZ4 with compression of full-page writes
Author: Michael Paquier <michael@paquier.xyz>
2022-03-11 [e9537321a] Add support for zstd with compression of full-page write
-->

      <listitem>
       <para>
        Allow <acronym>WAL</acronym> <link
        linkend="guc-full-page-writes">full page writes</link> to use
        LZ4 and Zstandard compression (Andrey Borodin, Justin Pryzby)
       </para>

       <para>
        This is controlled by the <link
        linkend="guc-wal-compression"><varname>wal_compression</varname></link>
        server setting.
       </para>
      </listitem>

<!--
Author: Thomas Munro <tmunro@postgresql.org>
2021-07-19 [2dbe89057] Support direct I/O on macOS.
-->

      <listitem>
       <para>
        Add support for writing <acronym>WAL</acronym>
        using <link linkend="guc-wal-sync-method">direct I/O</link> on
        macOS (Thomas Munro)
       </para>

       <para>
        This only works if <literal>max_wal_senders = 0</literal>
        and <literal>wal_level = minimal</literal>.
       </para>
      </listitem>

<!--
Author: Peter Geoghegan <pg@bowt.ie>
2022-04-03 [0b018faba] Set relfrozenxid to oldest extant XID seen by VACUUM.
-->

      <listitem>
       <para>
        Allow <link linkend="routine-vacuuming">vacuum</link> to be more
        aggressive in setting the oldest frozen and multi transaction id
        (Peter Geoghegan)
       </para>
      </listitem>

<!--
Author: Etsuro Fujita <efujita@postgresql.org>
2022-04-06 [c2bb02bc2] Allow asynchronous execution in more cases.
-->

      <listitem>
       <para>
        Allow a query referencing multiple <link
        linkend="ddl-foreign-data">foreign tables</link> to perform
        parallel foreign table scans in more cases (Andrey Lepikhov,
        Etsuro Fujita)
       </para>
      </listitem>

<!--
Author: David Rowley <drowley@postgresql.org>
2022-04-08 [9d9c02ccd] Teach planner and executor about monotonic window funcs
-->

      <listitem>
       <para>
        Improve the performance of <link linkend="functions-window">window
        functions</link> that use <function>row_number()</function>,
        <function>rank()</function>, <function>dense_rank()</function> and
        <function>count()</function>
        (David Rowley)
       </para>
      </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2022-04-06 [a82a5eee3] Use ISB as a spin-delay instruction on ARM64.
-->

      <listitem>
       <para>
        Improve the performance of spinlocks on high-core-count ARM64
        systems (Geoffrey Blake)
       </para>
      </listitem>

     </itemizedlist>

    </sect4>

    <sect4>
     <title>Monitoring</title>

     <itemizedlist>

<!--
Author: Robert Haas <rhaas@postgresql.org>
2021-12-13 [64da07c41] Default to log_checkpoints=on, log_autovacuum_min_durati
-->

      <listitem>
       <para>
        Enable default logging of checkpoints and slow autovacuum
        operations (Bharath Rupireddy)
       </para>

       <para>
        This changes the default of <link
        linkend="guc-log-checkpoints"><varname>log_checkpoints</varname></link>
        to <literal>on</literal> and that of <link
        linkend="guc-log-autovacuum-min-duration"><varname>log_autovacuum_min_duration</varname></link>
        to 10 minutes.  This will cause even an idle server to generate
        some log output, which might cause problems on
        resource-constrained servers without log file rotation.  These
        defaults should be changed in such cases.
       </para>
      </listitem>

<!--
Author: Robert Haas <rhaas@postgresql.org>
2021-10-25 [9ce346eab] Report progress of startup operations that take a long t
Author: Alvaro Herrera <alvherre@alvh.no-ip.org>
2021-11-05 [e543906e2] Document default and changeability of log_startup_progre
-->

      <listitem>
       <para>
        Generate progress messages in the server log during slow server
        starts (Nitin Jadhav, Robert Haas)
       </para>

       <para>
        The messages report the cause of the delay.  The time interval for
        notification is controlled by the new server variable <link
        linkend="guc-log-startup-progress-interval"><varname>log_startup_progress_interval</varname></link>.
       </para>
      </listitem>

<!--
Author: Andres Freund <andres@anarazel.de>
2022-04-06 [5891c7a8e] pgstat: store statistics in shared memory.
Author: Andres Freund <andres@anarazel.de>
2022-04-07 [b3abca681] pgstat: Update docs to match the shared memory stats rea
-->

      <listitem>
       <para>
        Store <link linkend="monitoring-stats">cumulative statistics
        system</link> data in shared memory (Kyotaro Horiguchi, Andres
        Freund, Melanie Plageman)
       </para>

       <para>
        Previously this data was sent to a statistics collector process
        via <acronym>UDP</acronym> packets, and could only be read by
        sessions after transferring it via the file system.  There is no
        longer a separate statistics collector process.
       </para>
      </listitem>

<!--
Author: Peter Geoghegan <pg@bowt.ie>
2022-02-11 [872770fd6] Add VACUUM instrumentation for scanned pages, relfrozenx
Author: Peter Geoghegan <pg@bowt.ie>
2022-03-13 [6e20f4600] VACUUM VERBOSE: tweak scanned_pages logic.
Author: Peter Geoghegan <pg@bowt.ie>
2022-04-15 [bdb71dbe8] VACUUM VERBOSE: Show dead items for an empty table.
-->

      <listitem>
       <para>
        Add additional information to <command>VACUUM VERBOSE</command>
        and autovacuum logging messages (Peter Geoghegan)
       </para>
      </listitem>

<!--
Author: Michael Paquier <michael@paquier.xyz>
2022-04-08 [efb0ef909] Track I/O timing for temporary file blocks in EXPLAIN (B
-->

      <listitem>
       <para>
        Add <link linkend="sql-explain"><command>EXPLAIN
        (BUFFERS)</command></link> output for temporary file block I/O
        (Masahiko Sawada)
       </para>
      </listitem>

<!--
Author: Michael Paquier <michael@paquier.xyz>
2022-01-17 [dc686681e] Introduce log_destination=jsonlog
-->

      <listitem>
       <para>
        Allow <link linkend="guc-log-destination">log output</link> in
        <acronym>JSON</acronym> format (Sehrope Sarkuni, Michael Paquier)
       </para>

       <para>
        The new setting is <literal>log_destination = jsonlog</literal>.
       </para>
      </listitem>

<!--
Author: Fujii Masao <fujii@postgresql.org>
2021-09-02 [e04267844] Enhance pg_stat_reset_single_table_counters function.
-->

      <listitem>
       <para>
        Allow <link
        linkend="monitoring-stats-funcs-table"><function>pg_stat_reset_single_table_counters()</function></link>
        to reset the counters of relations shared across all databases
        (B Sadhu, Prasad Patro)
       </para>
      </listitem>

<!--
Author: Fujii Masao <fujii@postgresql.org>
2021-11-22 [1b06d7bac] Report wait events for local shell commands like archive
-->

      <listitem>
       <para>
        Add <link linkend="wait-event-table">wait events</link> for local
        shell commands (Fujii Masao)
       </para>

       <para>
        The new wait events are used when calling
        <varname>archive_command</varname>,
        <varname>archive_cleanup_command</varname>,
        <varname>restore_command</varname> and
        <varname>recovery_end_command</varname>.
       </para>
      </listitem>

     </itemizedlist>

    </sect4>

    <sect4>
     <title>Privileges</title>

     <itemizedlist>

<!--
Author: Dean Rasheed <dean.a.rasheed@gmail.com>
2022-03-22 [7faa5fc84] Add support for security invoker views.
-->

      <listitem>
       <para>
        Allow table accesses done by
        a <link linkend="sql-createview">view</link> to optionally be
        controlled by privileges of the view's caller (Christoph Heiss)
       </para>

       <para>
        Previously, view accesses were always treated as being done by the
        view's owner.  That's still the default.
       </para>
      </listitem>

<!--
Author: Robert Haas <rhaas@postgresql.org>
2022-01-28 [7f6772317] Adjust server-side backup to depend on pg_write_server_f
-->

      <listitem>
       <para>
        Allow members of the <link
        linkend="predefined-roles-table"><literal>pg_write_server_files</literal></link>
        predefined role to perform server-side base backups (Dagfinn
        Ilmari Mannsåker)
       </para>

       <para>
        Previously only superusers could perform such backups.
       </para>
      </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2022-04-06 [a0ffa885e] Allow granting SET and ALTER SYSTEM privileges on GUC pa
Author: Tom Lane <tgl@sss.pgh.pa.us>
2022-07-19 [a2944d872] Fix missed corner cases for grantable permissions on GUC
-->

      <listitem>
       <para>
        Allow <link linkend="sql-grant"><command>GRANT</command></link>
        to grant permissions to change individual server variables via
        <command>SET</command> and <command>ALTER SYSTEM</command>
        (Mark Dilger)
       </para>

       <para>
        The new function <function>has_parameter_privilege()</function>
        reports on this privilege.
       </para>
      </listitem>

<!--
Author: Jeff Davis <jdavis@postgresql.org>
2021-11-09 [4168a4745] Add pg_checkpointer predefined role for CHECKPOINT comma
Author: Robert Haas <rhaas@postgresql.org>
2022-07-05 [d3526e59f] Rename pg_checkpointer predefined role to pg_checkpoint.
-->

      <listitem>
       <para>
        Add predefined role <link
        linkend="predefined-roles-table"><literal>pg_checkpoint</literal></link>
        that allows members to run <command>CHECKPOINT</command>
        (Jeff Davis)
       </para>

       <para>
        Previously checkpoints could only be run by superusers.
       </para>
      </listitem>

<!--
Author: Jeff Davis <jdavis@postgresql.org>
2021-10-27 [77ea4f943] Grant memory views to pg_read_all_stats.
-->

      <listitem>
       <para>
        Allow members of the <link
        linkend="predefined-roles-table"><literal>pg_read_all_stats</literal></link>
        predefined role to access the views <link
        linkend="view-pg-backend-memory-contexts"><structname>pg_backend_memory_contexts</structname></link>
        and <link
        linkend="view-pg-shmem-allocations"><structname>pg_shmem_allocations</structname></link>
        (Bharath Rupireddy)
       </para>

       <para>
        Previously these views could only be accessed by superusers.
       </para>
      </listitem>

<!--
Author: Jeff Davis <jdavis@postgresql.org>
2021-10-26 [f0b051e32] Allow GRANT on pg_log_backend_memory_contexts().
-->

      <listitem>
       <para>
        Allow <link linkend="sql-grant"><command>GRANT</command></link>
        to grant permissions on <link
        linkend="functions-admin-signal"><function>pg_log_backend_memory_contexts()</function></link>
        (Jeff Davis)
       </para>

       <para>
        Previously this function could only be run by superusers.
       </para>
      </listitem>

     </itemizedlist>

    </sect4>

    <sect4>
     <title>Server Configuration</title>

     <itemizedlist>

<!--
Author: Michael Paquier <michael@paquier.xyz>
2021-09-08 [bd1788051] Introduce GUC shared_memory_size
Author: Michael Paquier <michael@paquier.xyz>
2021-09-09 [3b231596c] Make shared_memory_size a preset option
-->

      <listitem>
       <para>
        Add server variable <link
        linkend="guc-shared-memory-size"><varname>shared_memory_size</varname></link>
        to report the size of allocated shared memory (Nathan Bossart)
       </para>
      </listitem>

<!--
Author: Michael Paquier <michael@paquier.xyz>
2021-09-21 [43c1c4f65] Introduce GUC shared_memory_size_in_huge_pages
Author: Michael Paquier <michael@paquier.xyz>
2022-03-24 [bbd4951b7] doc: Improve postgres command for shared_memory_size_in_
-->

      <listitem>
       <para>
        Add server variable <link
        linkend="guc-shared-memory-size-in-huge-pages"><varname>shared_memory_size_in_huge_pages</varname></link>
        to report the number of huge memory pages required (Nathan Bossart)
       </para>

       <para>
        This is only supported on Linux.
       </para>
      </listitem>

<!--
Author: Jeff Davis <jdavis@postgresql.org>
2022-07-20 [2103266a3] Process shared_preload_libraries in single-user mode.
-->

      <listitem>
       <para>
        Honor server variable <link
        linkend="guc-shared-preload-libraries"><varname>shared_preload_libraries</varname></link>
        in single-user mode (Jeff Davis)
       </para>

       <para>
        This change supports use
        of <varname>shared_preload_libraries</varname> to load custom
        access methods and WAL resource managers, which would be essential
        for database access even in single-user mode.
       </para>
      </listitem>

<!--
Author: Thomas Munro <tmunro@postgresql.org>
2022-07-02 [a2b0719cc] Default to dynamic_shared_memory_type=sysv on Solaris.
-->

      <listitem>
       <para>
        On Solaris, make the default setting of <link
        linkend="guc-dynamic-shared-memory-type"><varname>dynamic_shared_memory_type</varname></link>
        be <literal>sysv</literal> (Thomas Munro)
       </para>

       <para>
        The previous default choice, <literal>posix</literal>, can result
        in spurious failures on this platform.
       </para>
      </listitem>

<!--
Author: Michael Paquier <michael@paquier.xyz>
2021-09-16 [0c39c2920] Support "postgres -C" with runtime-computed GUCs
-->

      <listitem>
       <para>
        Allow <link linkend="app-postgres"><command>postgres
        -C</command></link> to properly report runtime-computed values
        (Nathan Bossart)
       </para>

       <para>
        Previously runtime-computed values <link
        linkend="guc-data-checksums"><varname>data_checksums</varname></link>,
        <link
        linkend="guc-wal-segment-size"><varname>wal_segment_size</varname></link>,
        and <link
        linkend="guc-data-directory-mode"><varname>data_directory_mode</varname></link>
        would report values that would not be accurate on the running
        server.  However, this does not work on a running server.
       </para>
      </listitem>

     </itemizedlist>

    </sect4>

   </sect3>

   <sect3>
    <title>Streaming Replication and Recovery</title>

    <itemizedlist>

<!--
Author: Robert Haas <rhaas@postgresql.org>
2022-02-11 [dab298471] Add suport for server-side LZ4 base backup compression.
Author: Robert Haas <rhaas@postgresql.org>
2022-03-08 [7cf085f07] Add support for zstd base backup compression.
Author: Robert Haas <rhaas@postgresql.org>
2022-03-30 [51c0d186d] Allow parallel zstd compression when taking a base backu
-->

     <listitem>
      <para>
       Add support for LZ4 and Zstandard compression of server-side <link
       linkend="backup-base-backup">base backups</link> (Jeevan Ladhe,
       Robert Haas)
      </para>
     </listitem>

<!--
Author: Thomas Munro <tmunro@postgresql.org>
2021-08-02 [7ff23c6d2] Run checkpointer and bgwriter in crash recovery.
-->

     <listitem>
      <para>
       Run the checkpointer and bgwriter processes during crash recovery
       (Thomas Munro)
      </para>

      <para>
       This helps to speed up long crash recoveries.
      </para>
     </listitem>

<!--
Author: Thomas Munro <tmunro@postgresql.org>
2022-04-07 [5dc0418fa] Prefetch data referenced by the WAL, take II.
-->

     <listitem>
      <para>
       Allow <acronym>WAL</acronym> processing to pre-fetch needed file
       contents (Thomas Munro)
      </para>

      <para>
       This is controlled by the server variable <link
       linkend="guc-recovery-prefetch"><varname>recovery_prefetch</varname></link>.
      </para>
     </listitem>

<!--
Author: Robert Haas <rhaas@postgresql.org>
2022-02-03 [5ef1eefd7] Allow archiving via loadable modules.
-->

     <listitem>
      <para>
       Allow archiving via loadable modules (Nathan Bossart)
      </para>

      <para>
       Previously, archiving was only done by calling shell commands.
       The new server variable <link
       linkend="guc-archive-library"><varname>archive_library</varname></link>
       can be set to specify a library to be called for archiving.
      </para>
     </listitem>

<!--
Author: Jeff Davis <jdavis@postgresql.org>
2021-07-09 [8e7811e95] Eliminate replication protocol error related to IDENTIFY
-->

     <listitem>
      <para>
       No longer require <link
       linkend="protocol-replication"><literal>IDENTIFY_SYSTEM</literal></link>
       to be run before <literal>START_REPLICATION</literal> (Jeff Davis)
      </para>
     </listitem>

    </itemizedlist>

    <sect4>
     <title><link linkend="logical-replication">Logical Replication</link></title>

     <itemizedlist>

<!--
Author: Amit Kapila <akapila@postgresql.org>
2021-10-27 [5a2832465] Allow publishing the tables of schema.
Author: Amit Kapila <akapila@postgresql.org>
2021-12-08 [1a2aaeb0d] Fix changing the ownership of ALL TABLES IN SCHEMA publi
Author: Alvaro Herrera <alvherre@alvh.no-ip.org>
2022-09-22 [f256236fb] Remove ALL keyword from TABLES IN SCHEMA for publication
-->

      <listitem>
       <para>
        Allow <link linkend="sql-createpublication">publication</link> of
        all tables in a schema (Vignesh C, Hou Zhijie, Amit Kapila)
       </para>

       <para>
        For example, this syntax is now supported: <literal>CREATE
        PUBLICATION pub1 FOR TABLES IN SCHEMA s1,s2</literal>.
        <command>ALTER PUBLICATION</command> supports a similar syntax.
        Tables added later to the listed schemas will also be replicated.
       </para>
      </listitem>

<!--
Author: Amit Kapila <akapila@postgresql.org>
2022-02-22 [52e4f0cd4] Allow specifying row filters for logical replication of
Author: Tomas Vondra <tomas.vondra@postgresql.org>
2022-03-17 [5a0796622] Fix row filters with multiple publications
Author: Amit Kapila <akapila@postgresql.org>
2022-04-18 [676eeb6dd] Add additional documentation for row filters.
-->

      <listitem>
       <para>
        Allow publication content to be filtered using a
        <literal>WHERE</literal> clause (Hou Zhijie, Euler Taveira,
        Peter Smith, Ajin Cherian, Tomas Vondra, Amit Kapila)
       </para>

       <para>
        Rows not satisfying the <literal>WHERE</literal> clause are not
        published.
       </para>
      </listitem>

<!--
Author: Tomas Vondra <tomas.vondra@postgresql.org>
2022-03-26 [923def9a5] Allow specifying column lists for logical replication
-->

      <listitem>
       <para>
        Allow publication content to
        be restricted to specific columns (Tomas Vondra, Álvaro Herrera,
        Rahila Syed)
       </para>
      </listitem>

<!--
Author: Amit Kapila <akapila@postgresql.org>
2022-03-22 [208c5d65b] Add ALTER SUBSCRIPTION ... SKIP.
-->

      <listitem>
       <para>
        Allow skipping of transactions on a subscriber using <link
        linkend="sql-altersubscription"><command>ALTER SUBSCRIPTION
        ... SKIP</command></link> (Masahiko Sawada)
       </para>
      </listitem>

<!--
Author: Amit Kapila <akapila@postgresql.org>
2021-06-30 [cda03cfed] Allow enabling two-phase option via replication protocol
Author: Amit Kapila <akapila@postgresql.org>
2021-07-14 [a8fd13cab] Add support for prepared transactions to built-in logica
Author: Amit Kapila <akapila@postgresql.org>
2021-08-04 [63cf61cde] Add prepare API support for streaming transactions in lo
-->

      <listitem>
       <para>
        Add support for prepared (two-phase) transactions to logical
        replication (Peter Smith, Ajin Cherian, Amit Kapila, Nikhil
        Sontakke, Stas Kelvich)
       </para>

       <para>
        The new <link
        linkend="protocol-replication"><literal>CREATE_REPLICATION_SLOT</literal></link>
        option is called <literal>TWO_PHASE</literal>.
        <application>pg_recvlogical</application> now supports a new
        <option>--two-phase</option> option during slot creation.
       </para>
      </listitem>

<!--
Author: Amit Kapila <akapila@postgresql.org>
2022-03-30 [d5a9d86d8] Skip empty transactions for logical replication.
-->

      <listitem>
       <para>
        Prevent logical replication of empty transactions (Ajin Cherian,
        Hou Zhijie, Euler Taveira)
       </para>

       <para>
        Previously, publishers would send empty transactions to
        subscribers if subscribed tables were not modified.
       </para>
      </listitem>

<!--
Author: Michael Paquier <michael@paquier.xyz>
2021-11-23 [1922d7c6e] Add SQL functions to monitor the directory contents of r
-->

      <listitem>
       <para>
        Add <acronym>SQL</acronym> functions to monitor the directory
        contents of logical replication slots (Bharath Rupireddy)
       </para>

       <para>
        The new functions are <link
        linkend="functions-admin-genfile-table"><function>pg_ls_logicalsnapdir()</function></link>,
        <function>pg_ls_logicalmapdir()</function>, and
        <function>pg_ls_replslotdir()</function>.  They can be run by
        members of the predefined <literal>pg_monitor</literal> role.
       </para>
      </listitem>

<!--
Author: Amit Kapila <akapila@postgresql.org>
2022-03-14 [705e20f85] Optionally disable subscriptions on error.
-->

      <listitem>
       <para>
        Allow subscribers to stop the application of logical replication changes on error
        (Osumi Takamichi, Mark Dilger)
       </para>

       <para>
        This is enabled with the subscriber option <link
        linkend="sql-createsubscription"><literal>disable_on_error</literal></link>
        and avoids possible infinite error loops during stream application.
       </para>
      </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2021-11-02 [f3d4019da] Ensure consistent logical replication of datetime and fl
-->

      <listitem>
       <para>
        Adjust subscriber server variables to match the publisher so
        datetime and float8 values are interpreted consistently (Japin Li)
       </para>

       <para>
        Some publishers might be relying on inconsistent behavior.
       </para>
      </listitem>

<!--
Author: Amit Kapila <akapila@postgresql.org>
2021-11-30 [8d74fc96d] Add a view to show the stats of subscription workers.
Author: Amit Kapila <akapila@postgresql.org>
2022-03-01 [7a8507329] Reconsider pg_stat_subscription_workers view.
-->

      <listitem>
       <para>
        Add system view <link
        linkend="monitoring-pg-stat-subscription-stats"><structname>pg_stat_subscription_stats</structname></link>
        to report on subscriber activity (Masahiko Sawada)
       </para>

       <para>
        The new function <link
        linkend="monitoring-stats-functions"><function>pg_stat_reset_subscription_stats()</function></link>
        allows resetting these statistics counters.
       </para>
      </listitem>

<!--
Author: Amit Kapila <akapila@postgresql.org>
2021-12-08 [a61bff2bf] De-duplicate the result of pg_publication_tables view.
-->

      <listitem>
       <para>
        Suppress duplicate entries in the <link
        linkend="view-pg-publication-tables"><structname>pg_publication_tables</structname></link>
        system view (Hou Zhijie)
       </para>

       <para>
        In some cases a partition could appear more than once.
       </para>
      </listitem>

     </itemizedlist>

    </sect4>

   </sect3>

   <sect3>
    <title>Utility Commands</title>

    <itemizedlist>

<!--
Author: Alvaro Herrera <alvherre@alvh.no-ip.org>
2022-03-28 [7103ebb7a] Add support for MERGE SQL command
-->

     <listitem>
      <para>
       Add <acronym>SQL</acronym> <link
       linkend="sql-merge"><command>MERGE</command></link>
       command to adjust one table to match another (Simon Riggs, Pavan
       Deolasee, Álvaro Herrera, Amit Langote)
      </para>

      <para>
       This is similar to <command>INSERT ... ON CONFLICT</command>
       but more batch-oriented.
      </para>
     </listitem>

<!--
Author: Peter Eisentraut <peter@eisentraut.org>
2022-01-28 [43f33dc01] Add HEADER support to COPY text format
Author: Peter Eisentraut <peter@eisentraut.org>
2022-03-30 [072132f04] Add header matching mode to COPY FROM
-->

     <listitem>
      <para>
       Add support for <literal>HEADER</literal> option in <link
       linkend="sql-copy"><command>COPY</command></link> text format
       (Rémi Lapeyre)
      </para>

      <para>
       The new option causes the column names to be output, and optionally
       verified on input.
      </para>
     </listitem>

<!--
Author: Robert Haas <rhaas@postgresql.org>
2022-03-29 [9c08aea6a] Add new block-by-block strategy for CREATE DATABASE.
-->

     <listitem>
      <para>
       Add new <acronym>WAL</acronym>-logged method for <link
       linkend="sql-createdatabase">database creation</link> (Dilip Kumar)
      </para>

      <para>
       This is the new default method for copying the template database,
       as it avoids the need for checkpoints during database creation.
       However, it might be slow if the template database is large, so
       the old method is still available.
      </para>
     </listitem>

<!--
Author: Robert Haas <rhaas@postgresql.org>
2022-01-24 [aa0105141] pg_upgrade: Preserve database OIDs.
-->

     <listitem>
      <para>
       Allow <link linkend="sql-createdatabase"><command>CREATE
       DATABASE</command></link> to set the database <acronym>OID</acronym>
       (Shruthi KC, Antonin Houska)
      </para>
     </listitem>

<!--
Author: Thomas Munro <tmunro@postgresql.org>
2022-02-12 [4eb217631] Fix DROP {DATABASE,TABLESPACE} on Windows.
-->

     <listitem>
      <para>
       Prevent <link linkend="sql-dropdatabase"><command>DROP
       DATABASE</command></link>, <link
       linkend="sql-droptablespace"><command>DROP
       TABLESPACE</command></link>, and <link
       linkend="sql-alterdatabase"><command>ALTER DATABASE SET
       TABLESPACE</command></link> from occasionally failing during
       concurrent use on Windows (Thomas Munro)
      </para>
     </listitem>

<!--
Author: Peter Eisentraut <peter@eisentraut.org>
2021-12-08 [d6f96ed94] Allow specifying column list for foreign key ON DELETE S
-->

     <listitem>
      <para>
       Allow foreign key <link linkend="ddl-constraints-fk"><literal>ON
       DELETE SET</literal></link> actions to affect only specified columns
       (Paul Martinez)
      </para>

      <para>
       Previously, all of the columns in the foreign key were always
       affected.
      </para>
     </listitem>

<!--
Author: Michael Paquier <michael@paquier.xyz>
2021-07-28 [b0483263d] Add support for SET ACCESS METHOD in ALTER TABLE
-->

     <listitem>
      <para>
       Allow <link linkend="sql-altertable"><command>ALTER
       TABLE</command></link> to modify a table's <literal>ACCESS
       METHOD</literal> (Justin Pryzby, Jeff Davis)
      </para>
     </listitem>

<!--
Author: Michael Paquier <michael@paquier.xyz>
2021-08-10 [7b565843a] Add call to object access hook at the end of table rewri
-->

     <listitem>
      <para>
       Properly call object access hooks when <link
       linkend="sql-altertable"><command>ALTER TABLE</command></link>
       causes table rewrites (Michael Paquier)
      </para>
     </listitem>

<!--
Author: Peter Eisentraut <peter@eisentraut.org>
2022-04-07 [344d62fb9] Unlogged sequences
-->

     <listitem>
      <para>
       Allow creation of unlogged <link
       linkend="sql-createsequence">sequences</link> (Peter Eisentraut)
      </para>
     </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2022-07-22 [c2fa113dd] Close old gap in dependency checks for functions returni
-->

     <listitem>
      <para>
       Track dependencies on individual columns in the results of
       functions returning composite types (Tom Lane)
      </para>

      <para>
       Previously, if a view or rule contained a reference to a specific
       column within the result of a composite-returning function, that
       was not noted as a dependency; the view or rule was only considered
       to depend on the composite type as a whole.  This meant that
       dropping the individual column would be allowed, causing problems
       in later use of the view or rule.  The column-level dependency is
       now also noted, so that dropping such a column will be rejected
       unless the view is changed or dropped.
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title>Data Types</title>

    <itemizedlist>

<!--
Author: Dean Rasheed <dean.a.rasheed@gmail.com>
2021-07-26 [085f931f5] Allow numeric scale to be negative or greater than preci
-->

     <listitem>
      <para>
       Allow the scale of
       a <link linkend="datatype-numeric"><type>numeric</type></link>
       value to be negative, or greater than its precision (Dean Rasheed,
       Tom Lane)
      </para>

      <para>
       This allows rounding of values to the left of the decimal point,
       e.g., <literal>'1234'::numeric(4, -2)</literal> returns 1200.
      </para>
     </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2022-04-02 [e39f99046] Fix overflow hazards in interval input and output conver
-->

     <listitem>
      <para>
       Improve overflow detection when casting values to <link
       linkend="datatype-datetime">interval</link> (Joe Koshakow)
      </para>
     </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2022-08-02 [c034b629c] Change type "char"'s I/O format for non-ASCII characters
-->

    <listitem>
     <para>
      Change the I/O format of type <type>"char"</type> for non-ASCII
      characters (Tom Lane)
     </para>
    </listitem>

<!--
Author: John Naylor <john.naylor@postgresql.org>
2021-08-26 [bab982161] Update display widths as part of updating Unicode
Author: Peter Eisentraut <peter@eisentraut.org>
2021-09-15 [f7e56f1f5] Update Unicode data to Unicode 14.0.0
-->

     <listitem>
      <para>
       Update the display width information of modern Unicode characters,
       like emojis (Jacob Champion)
      </para>

      <para>
       Also update from Unicode 5.0 to 14.0.0.  There is now an automated
       way to keep Postgres updated with Unicode releases.
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title>Functions</title>

    <itemizedlist>

<!--
Author: Peter Eisentraut <peter@eisentraut.org>
2022-03-30 [7ae1619bc] Add range_agg with multirange inputs
-->

     <listitem>
      <para>
       Add multirange input to <link
       linkend="functions-aggregate-table"><function>range_agg()</function></link>
       (Paul Jungwirth)
      </para>
     </listitem>

<!--
Author: Fujii Masao <fujii@postgresql.org>
2022-02-10 [400fc6b64] Add min() and max() aggregates for xid8.
-->

     <listitem>
      <para>
       Add <link linkend="tutorial-agg"><function>MIN()</function></link>
       and <function>MAX()</function> aggregates for the <link
       linkend="datatype-int"><type>xid8</type></link> data type (Ken Kato)
      </para>
     </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2021-08-03 [642433707] Add assorted new regexp_xxx SQL functions.
-->

     <listitem>
      <para>
       Add regular expression functions for compatibility with other
       relational systems (Gilles Darold, Tom Lane)
      </para>

      <para>
       The new functions are <link
       linkend="functions-string-other"><function>regexp_count()</function></link>,
       <function>regexp_instr()</function>,
       <function>regexp_like()</function>, and
       <function>regexp_substr()</function>.  Some new optional arguments
       were also added to <function>regexp_replace()</function>.
      </para>
     </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2021-12-13 [c5c192d7b] Implement poly_distance().
-->

     <listitem>
      <para>
       Add the ability to compute the distance between <link
       linkend="datatype-polygon"><type>polygons</type></link> (Tom Lane)
      </para>
     </listitem>

<!--
Author: Robert Haas <rhaas@postgresql.org>
2022-03-14 [9dde82899] Support "of", "tzh", and "tzm" format codes.
-->

     <listitem>
      <para>
       Add <link
       linkend="functions-formatting-table"><function>to_char()</function></link>
       format codes <literal>of</literal>, <literal>tzh</literal>, and
       <literal>tzm</literal> (Nitin Jadhav)
      </para>

      <para>
       The upper-case equivalents of these were already supported.
      </para>
     </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2021-09-06 [388e71af8] Make timetz_zone() stable, and correct a bug for DYNTZ a
-->

     <listitem>
      <para>
       When applying <link
       linkend="functions-datetime-zoneconvert"><literal>AT
       TIME ZONE</literal></link> to a <type>time with time zone</type>
       value, use the transaction start time rather than wall clock time
       to determine whether DST applies (Aleksander Alekseev, Tom Lane)
      </para>

      <para>
       This allows the conversion to be considered stable rather than
       volatile, and it saves a kernel call per invocation.
      </para>
     </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2021-11-06 [cbe25dcff] Disallow making an empty lexeme via array_to_tsvector().
-->

     <listitem>
      <para>
       Ignore NULL array elements in <link
       linkend="textsearch-functions-table"><function>ts_delete()</function></link> and
       <function>setweight()</function> functions with array arguments
       (Jean-Christophe Arnu)
      </para>

      <para>
       These functions effectively ignore empty-string array elements
       (since those could never match a valid lexeme).  It seems
       consistent to let them ignore NULL elements too, instead of
       failing.
      </para>
     </listitem>

<!--
Author: David Rowley <drowley@postgresql.org>
2021-07-09 [ca2e4472b] Teach pg_size_pretty and pg_size_bytes about petabytes
-->

     <listitem>
      <para>
       Add support for petabyte units to <link
       linkend="functions-admin-dbsize"><function>pg_size_pretty()</function></link>
       and <function>pg_size_bytes()</function> (David Christensen)
      </para>
     </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2021-07-27 [024515cac] In event triggers, use "pg_temp" only for our own temp s
-->

     <listitem>
      <para>
       Change <link
       linkend="pg-event-trigger-ddl-command-end-functions"><function>pg_event_trigger_ddl_commands()</function></link>
       to output references to other sessions' temporary schemas using the
       actual schema name (Tom Lane)
      </para>

      <para>
       Previously this function reported all temporary schemas as
       <literal>pg_temp</literal>, but it's misleading to use that for any
       but the current session's temporary schema.
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title><link linkend="plpgsql">PL/pgSQL</link></title>

    <itemizedlist>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2022-04-30 [ccd10a9bf] Tighten enforcement of variable CONSTANT markings in plp
-->

     <listitem>
      <para>
       Fix enforcement of PL/pgSQL variable <literal>CONSTANT</literal>
       markings (Tom Lane)
      </para>

      <para>
       Previously, a variable could be used as a <link
       linkend="plpgsql-statements-calling-procedure"><command>CALL</command></link>
       output parameter or refcursor <command>OPEN</command> variable
       despite being marked <literal>CONSTANT</literal>.
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title><link linkend="libpq">libpq</link></title>

    <itemizedlist>

<!--
Author: Peter Eisentraut <peter@eisentraut.org>
2022-04-01 [c1932e542] libpq: Allow IP address SANs in server certificates
-->

     <listitem>
      <para>
       Allow <acronym>IP</acronym> address matching against a server
       certificate's Subject Alternative Name (Jacob Champion)
      </para>
     </listitem>

<!--
Author: Daniel Gustafsson <dgustafsson@postgresql.org>
2022-03-29 [ebc8b7d44] Enable SSL library detection via PQsslAttribute()
-->

     <listitem>
      <para>
       Allow <function>PQsslAttribute()</function> to report the
       <acronym>SSL</acronym> library type without requiring a libpq
       connection (Jacob Champion)
      </para>
     </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2022-01-18 [5987feb70] Make PQcancel use the PGconn's tcp_user_timeout and keep
-->

     <listitem>
      <para>
       Change query cancellations sent by the client to use the same
       <acronym>TCP</acronym> settings as normal client connections
       (Jelte Fennema)
      </para>

      <para>
       This allows configured <acronym>TCP</acronym> timeouts to apply
       to query cancel connections.
      </para>
     </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2022-02-18 [ce1e7a2f7] Don't let libpq "event" procs break the state of PGresul
Author: Tom Lane <tgl@sss.pgh.pa.us>
2022-02-18 [2e372869a] Don't let libpq PGEVT_CONNRESET callbacks break a PGconn
-->

     <listitem>
      <para>
       Prevent libpq event callback failures from forcing an error result
       (Tom Lane)
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title>Client Applications</title>

    <itemizedlist>

<!--
Author: Tatsuo Ishii <ishii@postgresql.org>
2022-03-23 [4a39f87ac] Allow pgbench to retry in some cases.
-->

     <listitem>
      <para>
       Allow <link
       linkend="pgbench"><application>pgbench</application></link> to
       retry after serialization and deadlock failures (Yugo Nagata,
       Marina Polyakova)
      </para>
     </listitem>

    </itemizedlist>

     <sect4>
      <title><xref linkend="app-psql"/></title>

      <itemizedlist>

<!--
Author: Heikki Linnakangas <heikki.linnakangas@iki.fi>
2021-07-14 [eec57115e] In psql \copy from, send data to server in larger chunks
-->

      <listitem>
       <para>
        Improve performance
        of <application>psql</application>'s <command>\copy</command>
        command, by sending data in larger chunks (Heikki Linnakangas)
       </para>
      </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2022-04-07 [3e707fbb4] psql: add \dconfig command to show server's configuratio
Author: Tom Lane <tgl@sss.pgh.pa.us>
2022-04-11 [5e70d8b5d] Tweak the default behavior of psql's \dconfig.
Author: Tom Lane <tgl@sss.pgh.pa.us>
2022-04-13 [139d46ee2] Further tweak the default behavior of psql's \dconfig.
-->

      <listitem>
       <para>
        Add <command>\dconfig</command> command to report server variables
        (Mark Dilger, Tom Lane)
       </para>

       <para>
        This is similar to the server-side <command>SHOW</command>
        command, but it can process patterns to show multiple variables
        conveniently.
       </para>
      </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2021-12-20 [33d3eeadb] Add a \getenv command to psql.
-->

      <listitem>
       <para>
        Add <command>\getenv</command> command
        to assign the value of an environment variable to a
        <application>psql</application> variable (Tom Lane)
       </para>
      </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2022-01-06 [328dfbdab] Extend psql's \lo_list/\dl to be able to print large obj
-->

      <listitem>
       <para>
        Add <literal>+</literal> option to the
        <literal>\lo_list</literal> and <literal>\dl</literal> commands to
        show large-object privileges (Pavel Luzanov)
       </para>
      </listitem>

<!--
Author: Thomas Munro <tmunro@postgresql.org>
2021-07-13 [7c09d2797] Add PSQL_WATCH_PAGER for psql's \watch command.
-->

      <listitem>
       <para>
        Add a pager option for the <command>\watch</command>
        command (Pavel Stehule, Thomas Munro)
       </para>

       <para>
        This is only supported on Unix, and is controlled by the
        <envar>PSQL_WATCH_PAGER</envar> environment variable.
       </para>
      </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2021-12-01 [83884682f] psql: include intra-query "- -" comments in what's sent t
Author: Tom Lane <tgl@sss.pgh.pa.us>
2021-12-01 [c2f654930] psql: treat "- -" comments between queries as separate hi
-->

      <listitem>
       <para>
        Make <application>psql</application> include intra-query double-hyphen
        comments in queries sent to the server (Tom Lane, Greg Nancarrow)
       </para>

       <para>
        Previously such comments were removed from the query
        before being sent.  Double-hyphen comments that are before any
        query text are not sent, and are not recorded as separate
        <application>psql</application> history entries.
       </para>
      </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2021-12-01 [3d858af07] psql: initialize comment-begin setting to a useful value
-->

      <listitem>
       <para>
        Adjust <application>psql</application> so
        that <application>Readline</application>'s
        meta-<literal>#</literal> command will insert a double-hyphen
        comment marker (Tom Lane)
       </para>

       <para>
        Previously a pound marker was inserted, unless the user had taken
        the trouble to configure a non-default comment marker.
       </para>
      </listitem>

<!--
Author: Peter Eisentraut <peter@eisentraut.org>
2022-04-04 [7844c9918] psql: Show all query results by default
-->

      <listitem>
       <para>
        Make <application>psql</application> output all results when multiple
        queries are passed to the server at once (Fabien Coelho)
       </para>

       <para>
        Previously, only the last query result was displayed.  The old
        behavior can be restored by setting
        the <literal>SHOW_ALL_RESULTS</literal> <application>psql</application>
        variable to <literal>off</literal>.
       </para>
      </listitem>

<!--
Author: Michael Paquier <michael@paquier.xyz>
2022-06-15 [a3ff08e0b] Tweak behavior of psql - -single-transaction depending
-->

      <listitem>
       <para>
        After an error is detected
        in <option>--single-transaction</option> mode, change the
        final <command>COMMIT</command> command
        to <command>ROLLBACK</command> only
        if <varname>ON_ERROR_STOP</varname> is set (Michael Paquier)
       </para>

       <para>
        Previously, detection of an error in a <option>-c</option> command
        or <option>-f</option> script file would lead to
        issuing <command>ROLLBACK</command> at the end, regardless of the
        value of <varname>ON_ERROR_STOP</varname>.
       </para>
      </listitem>

<!--
Author: Michael Paquier <michael@paquier.xyz>
2021-08-10 [e2ce88b58] Add tab completion for DECLARE .. ASENSITIVE in psql
Author: Michael Paquier <michael@paquier.xyz>
2021-08-25 [346511313] Add tab completion for EXPLAIN .. EXECUTE in psql
Author: Michael Paquier <michael@paquier.xyz>
2021-08-30 [d3fa87657] Add more tab completion support for ALTER TABLE ADD in p
Author: Michael Paquier <michael@paquier.xyz>
2021-08-31 [f2bbadce6] Add tab completion for data types after ALTER TABLE ADD
Author: Fujii Masao <fujii@postgresql.org>
2021-09-01 [b0c066297] Improve tab-completion for CREATE PUBLICATION.
Author: Fujii Masao <fujii@postgresql.org>
2021-10-05 [0b0d277c3] psql: Improve tab-completion for LOCK TABLE.
Author: Michael Paquier <michael@paquier.xyz>
2021-11-05 [a5b336b8b] Improve psql tab completion for COMMENT
Author: Michael Paquier <michael@paquier.xyz>
2021-11-19 [0cd6d3b3c] Improve psql tab completion for transforms, domains and
Author: Michael Paquier <michael@paquier.xyz>
2021-11-29 [f44ceb46e] Improve psql tab completion for views, FDWs, sequences a
Author: Michael Paquier <michael@paquier.xyz>
2021-12-01 [9270778f4] Improve psql tab completion for various DROP commands
Author: Tom Lane <tgl@sss.pgh.pa.us>
2022-01-03 [dfe67c0e8] Tab completion: don't offer valid constraints in VALIDAT
Author: Fujii Masao <fujii@postgresql.org>
2022-01-15 [74527c3e0] Add tab-completion for CREATE FOREIGN TABLE.
Author: Peter Eisentraut <peter@eisentraut.org>
2022-01-27 [fefce9ef9] psql: Add tab completion for ALTER COLLATION / REFRESH V
Author: Alvaro Herrera <alvherre@alvh.no-ip.org>
2022-01-28 [95787e849] Tab-complete ALTER PUBLICATION ADD TABLE with list of ta
Author: Tom Lane <tgl@sss.pgh.pa.us>
2022-01-30 [02b8048ba] psql: improve tab-complete's handling of variant SQL nam
Author: Tom Lane <tgl@sss.pgh.pa.us>
2022-02-01 [020258fbd] Treat case of tab-completion keywords a bit more careful
Author: Tom Lane <tgl@sss.pgh.pa.us>
2022-02-09 [f0cd9097c] Further tweaks for psql's new tab-completion logic.
Author: Tom Lane <tgl@sss.pgh.pa.us>
2022-03-20 [7fa3db367] psql: handle tab completion of timezone names after "SET
Author: Tomas Vondra <tomas.vondra@postgresql.org>
2022-03-25 [2d2232933] Update tab-completion for CREATE PUBLICATION with sequen
Author: Tom Lane <tgl@sss.pgh.pa.us>
2022-04-13 [b5607b074] Fix case sensitivity in psql's tab completion for GUC na
-->

      <listitem>
       <para>
        Improve <application>psql</application>'s tab completion (Shinya
        Kato, Dagfinn Ilmari Mannsåker, Peter Smith, Koyu Tanigawa,
        Ken Kato, David Fetter, Haiying Tang, Peter Eisentraut, Álvaro
        Herrera, Tom Lane, Masahiko Sawada)
       </para>
      </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2021-12-16 [cf0cab868] Remove psql support for server versions preceding 9.2.
-->

      <listitem>
       <para>
        Limit support of <application>psql</application>'s backslash
        commands to servers running <productname>PostgreSQL</productname>
        9.2 or later (Tom Lane)
       </para>

       <para>
        Remove code that was only used when running with an older server.
        Commands that do not require any version-specific adjustments
        compared to 9.2 will still work.
       </para>
      </listitem>

     </itemizedlist>

    </sect4>

    <sect4>
     <title><link linkend="app-pgdump"><application>pg_dump</application></link></title>

     <itemizedlist>

<!--
Author: Noah Misch <noah@leadboat.com>
2021-06-28 [a7a7be1f2] Dump public schema ownership and security labels.
Author: Noah Misch <noah@leadboat.com>
2021-06-28 [7ac10f692] Dump COMMENT ON SCHEMA public.
-->

      <listitem>
       <para>
        Make <application>pg_dump</application> dump
        <literal>public</literal> schema ownership changes and security
        labels (Noah Misch)
       </para>
      </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2021-12-06 [989596152] Avoid per-object queries in performance-critical paths i
Author: Tom Lane <tgl@sss.pgh.pa.us>
2021-12-06 [be85727a3] Use PREPARE/EXECUTE for repetitive per-object queries in
Author: Tom Lane <tgl@sss.pgh.pa.us>
2021-12-31 [d5e8930f5] pg_dump: minor performance improvements from eliminating
-->

      <listitem>
       <para>
        Improve performance of dumping databases with many objects
        (Tom Lane)
       </para>

       <para>
        This will also improve the performance of <link
        linkend="pgupgrade"><application>pg_upgrade</application></link>.
       </para>
      </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2021-12-06 [65aaed22a] Account for TOAST data while scheduling parallel dumps.
-->

      <listitem>
       <para>
        Improve parallel <application>pg_dump</application>'s performance
        for tables with large <acronym>TOAST</acronym> tables (Tom Lane)
       </para>
      </listitem>

<!--
Author: Michael Paquier <michael@paquier.xyz>
2022-01-17 [215862886] Add support for - -no-table-access-method in pg_{dump,dum
-->

      <listitem>
       <para>
        Add dump/restore option <option>--no-table-access-method</option>
        to force restore to only use the default table access method
        (Justin Pryzby)
       </para>
      </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2021-12-14 [30e7c175b] Remove pg_dump/pg_dumpall support for dumping from pre-9
-->

      <listitem>
       <para>
        Limit support of <application>pg_dump</application> and <link
        linkend="app-pg-dumpall"><application>pg_dumpall</application></link>
        to servers running <productname>PostgreSQL</productname> 9.2 or
        later (Tom Lane)
       </para>
      </listitem>

     </itemizedlist>

    </sect4>

   </sect3>

   <sect3>
    <title>Server Applications</title>

    <itemizedlist>

<!--
Author: Robert Haas <rhaas@postgresql.org>
2022-01-20 [3500ccc39] Support base backup targets.
-->

     <listitem>
      <para>
       Add new <link
       linkend="app-pgbasebackup"><application>pg_basebackup</application></link>
       option <option>--target</option> to control the base backup location
       (Robert Haas)
      </para>

      <para>
       The new options are <literal>server</literal> to write the
       backup locally and <literal>blackhole</literal> to discard the
       backup (for testing).
      </para>
     </listitem>

<!--
Author: Robert Haas <rhaas@postgresql.org>
2022-02-11 [751b8d23b] pg_basebackup: Allow client-side LZ4 (de)compression.
Author: Robert Haas <rhaas@postgresql.org>
2022-03-08 [7cf085f07] Add support for zstd base backup compression.
Author: Robert Haas <rhaas@postgresql.org>
2022-01-24 [0ad803291] Server-side gzip compression.
-->

     <listitem>
      <para>
       Allow <application>pg_basebackup</application> to do server-side
       gzip, LZ4, and Zstandard compression and client-side LZ4 and
       Zstandard compression of base backup files (Dipesh Pandit,
       Jeevan Ladhe)
      </para>

      <para>
       Client-side <literal>gzip</literal> compression was already
       supported.
      </para>
     </listitem>

<!--
Author: Robert Haas <rhaas@postgresql.org>
2022-01-28 [d45099425] Allow server-side compression to be used with -Fp.
-->

     <listitem>
      <para>
       Allow <application>pg_basebackup</application> to compress on
       the server side and decompress on the client side before storage
       (Dipesh Pandit)
      </para>

      <para>
       This is accomplished by specifying compression on the server side
       and plain output format.
      </para>
     </listitem>

<!--
Author: Michael Paquier <michael@paquier.xyz>
2022-01-21 [5c649fe15] Extend the options of pg_basebackup to control compressi
Author: Robert Haas <rhaas@postgresql.org>
2022-01-24 [0ad803291] Server-side gzip compression.
Author: Robert Haas <rhaas@postgresql.org>
2022-01-25 [e1f860f13] Tidy up a few cosmetic issues related to pg_basebackup.
-->

     <listitem>
      <para>
       Allow <application>pg_basebackup</application>'s
       <option>--compress</option> option to control the compression
       location (server or client), compression method, and compression
       options (Michael Paquier, Robert Haas)
      </para>
     </listitem>

<!--
Author: Michael Paquier <michael@paquier.xyz>
2021-11-05 [babbbb595] Add support for LZ4 compression in pg_receivewal
Author: Michael Paquier <michael@paquier.xyz>
2022-04-13 [042a923ad] Rework compression options of pg_receivewal
-->

     <listitem>
      <para>
       Add the LZ4 compression method to <link
       linkend="app-pgreceivewal"><application>pg_receivewal</application></link>
       (Georgios Kokolatos)
      </para>

      <para>
       This is enabled via <literal>--compress=lz4</literal> and requires
       binaries to be built using <option>--with-lz4</option>.
      </para>
     </listitem>

<!--
Author: Michael Paquier <michael@paquier.xyz>
2021-11-04 [d62bcc8b0] Rework compression options of pg_receivewal
-->

     <listitem>
      <para>
       Add additional capabilities to
       <application>pg_receivewal</application>'s
       <option>--compress</option> option (Georgios Kokolatos)
      </para>
     </listitem>

<!--
Author: Michael Paquier <michael@paquier.xyz>
2021-10-26 [f61e1dd2c] Allow pg_receivewal to stream from a slot's restart LSN
-->

     <listitem>
      <para>
       Improve <application>pg_receivewal</application>'s ability to
       restart at the proper <acronym>WAL</acronym> location (Ronan
       Dunklau)
      </para>

      <para>
       Previously, <application>pg_receivewal</application> would start
       based on the <acronym>WAL</acronym> file stored in the local archive
       directory, or at the sending server's current <acronym>WAL</acronym>
       flush location.  With this change, if the sending server is running
       Postgres 15 or later, the local archive directory is empty, and
       a replication slot is specified, the replication slot's restart
       point will be used.
      </para>
     </listitem>

<!--
Author: Michael Paquier <michael@paquier.xyz>
2022-04-07 [0d5c38757] Add option - -config-file to pg_rewind
-->

     <listitem>
      <para>
       Add <link
       linkend="app-pgrewind"><application>pg_rewind</application></link>
       option <option>--config-file</option> to simplify use when server
       configuration files are stored outside the data directory (Gunnar
       Bluth)
      </para>
     </listitem>

    </itemizedlist>

    <sect4>
     <title><link linkend="pgupgrade"><application>pg_upgrade</application></link></title>

     <itemizedlist>

<!--
Author: Michael Paquier <michael@paquier.xyz>
2022-02-06 [38bfae365] pg_upgrade: Move all the files generated internally to a
Author: Michael Paquier <michael@paquier.xyz>
2022-02-15 [a00849630] Fix thinko with subdirectories generated by pg_upgrade f
Author: Michael Paquier <michael@paquier.xyz>
2022-09-13 [f5047c129] Move any remaining files generated by pg_upgrade into an
-->

      <listitem>
       <para>
        Store <application>pg_upgrade</application>'s log and
        temporary files in a subdirectory of the new cluster called
        <filename>pg_upgrade_output.d</filename> (Justin Pryzby)
       </para>

       <para>
        Previously such files were left in the current directory,
        requiring manual cleanup.  Now they are automatically removed on
        successful completion of <application>pg_upgrade</application>.
       </para>
      </listitem>

<!--
Author: Andres Freund <andres@anarazel.de>
2022-02-21 [27b02e070] pg_upgrade: Don't print progress status when output is n
-->

      <listitem>
       <para>
        Disable default status reporting during
        <application>pg_upgrade</application> operation if the output is
        not a terminal (Andres Freund)
       </para>

       <para>
        The status reporting output can be enabled for non-tty usage by
        using <option>--verbose</option>.
       </para>
      </listitem>

<!--
Author: Daniel Gustafsson <dgustafsson@postgresql.org>
2022-03-24 [26ebb0e28] List offending databases in pg_upgrade datallowconn chec
-->

      <listitem>
       <para>
        Make <application>pg_upgrade</application> report all databases
        with invalid connection settings (Jeevan Ladhe)
       </para>

       <para>
        Previously only the first database with an invalid connection
        setting was reported.
       </para>
      </listitem>

<!--
Author: Robert Haas <rhaas@postgresql.org>
2022-01-17 [9a974cbcb] pg_upgrade: Preserve relfilenodes and tablespace OIDs.
Author: Robert Haas <rhaas@postgresql.org>
2022-01-24 [aa0105141] pg_upgrade: Preserve database OIDs.
Author: Robert Haas <rhaas@postgresql.org>
2022-07-28 [4ab5dae94] Use TRUNCATE to preserve relfilenode for pg_largeobject
-->

      <listitem>
       <para>
        Make <application>pg_upgrade</application> preserve tablespace
        and database OIDs, as well as relation relfilenode numbers
        (Shruthi KC, Antonin Houska)
       </para>
      </listitem>

<!--
Author: Michael Paquier <michael@paquier.xyz>
2021-12-18 [3d5ffccb6] Add option -N/- -no-sync to pg_upgrade
-->

      <listitem>
       <para>
        Add a <option>--no-sync</option> option to
        <application>pg_upgrade</application> (Michael Paquier)
       </para>

       <para>
        This is recommended only for testing.
       </para>
      </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2021-12-14 [e469f0aaf] Remove pg_upgrade support for upgrading from pre-9.2 ser
-->

      <listitem>
       <para>
        Limit support of <application>pg_upgrade</application> to old
        servers running <productname>PostgreSQL</productname> 9.2 or later
        (Tom Lane)
       </para>
      </listitem>

     </itemizedlist>

    </sect4>

    <sect4>
     <title><link linkend="pgwaldump"><application>pg_waldump</application></link></title>

     <itemizedlist>

<!--
Author: Thomas Munro <tmunro@postgresql.org>
2022-03-24 [127aea2a6] Add additional filtering options to pg_waldump.
Author: Thomas Munro <tmunro@postgresql.org>
2022-03-25 [52b556843] Improve command line options for pg_waldump.
-->

      <listitem>
       <para>
        Allow <application>pg_waldump</application> output to be filtered by
        relation file node, block number, fork number, and full page images
        (David Christensen, Thomas Munro)
       </para>
      </listitem>

<!--
Author: Michael Paquier <michael@paquier.xyz>
2021-12-02 [f2c52eeba] pg_waldump: Emit stats summary when interrupted by SIGIN
-->

      <listitem>
       <para>
        Make <application>pg_waldump</application> report statistics
        before an interrupted exit (Bharath Rupireddy)
       </para>

       <para>
        For example, issuing a control-C in a terminal running
        <command>pg_waldump --stats --follow</command> will report the
        current statistics before exiting.  This does not work on Windows.
       </para>
      </listitem>

<!--
Author: Michael Paquier <michael@paquier.xyz>
2021-12-13 [c8b733c4c] Improve description of some WAL records with transaction
-->

      <listitem>
       <para>
        Improve descriptions of some transaction <acronym>WAL</acronym>
        records reported by <application>pg_waldump</application>
        (Masahiko Sawada, Michael Paquier)
       </para>
      </listitem>

<!--
Author: Heikki Linnakangas <heikki.linnakangas@iki.fi>
2021-07-01 [c8bf5098c] Allow specifying pg_waldump - -rmgr option multiple times
-->

      <listitem>
       <para>
        Allow <application>pg_waldump</application> to dump information
        about multiple resource managers (Heikki Linnakangas)
       </para>

       <para>
        This is enabled by specifying the <option>--rmgr</option> option
        multiple times.
       </para>
      </listitem>

     </itemizedlist>

    </sect4>

   </sect3>

   <sect3>
    <title>Documentation</title>

    <itemizedlist>

<!--
Author: Fujii Masao <fujii@postgresql.org>
2021-10-05 [f6b5d05ba] doc: Document pg_encoding_to_char() and pg_char_to_encod
-->

     <listitem>
      <para>
       Add documentation for <link
       linkend="functions-info-catalog-table"><function>pg_encoding_to_char()</function></link>
       and <function>pg_char_to_encoding()</function> (Ian Lawrence
       Barwick)
      </para>
     </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2021-10-09 [2ae5d72f0] Doc: improve documentation for ^@ starts-with operator.
-->

     <listitem>
      <para>
       Document the <link
       linkend="functions-string-other"><literal>^@</literal></link>
       starts-with operator (Tom Lane)
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title>Source Code</title>

    <itemizedlist>

<!--
Author: Andres Freund <andres@anarazel.de>
2021-12-30 [93d973494] ci: Add continuous integration for github repositories v
-->

     <listitem>
      <para>
       Add support for continuous integration testing using cirrus-ci
       (Andres Freund, Thomas Munro, Melanie Plageman)
      </para>
     </listitem>

<!--
Author: Robert Haas <rhaas@postgresql.org>
2022-02-18 [6c417bbcc] Add support for building with ZSTD.
-->

     <listitem>
      <para>
       Add configure option <link
       linkend="configure-options-features"><option>--with-zstd</option></link>
       to enable Zstandard builds (Jeevan Ladhe, Robert Haas, Michael
       Paquier)
      </para>
     </listitem>

<!--
Author: Peter Eisentraut <peter@eisentraut.org>
2021-11-22 [d6d1dfcc9] Add ABI extra field to fmgr magic block
-->

     <listitem>
      <para>
       Add an ABI identifier field to the magic block in loadable
       libraries, allowing
       non-community <productname>PostgreSQL</productname> distributions
       to identify libraries that are not compatible with other builds
       (Peter Eisentraut)
      </para>

      <para>
       An ABI field mismatch will generate an error at load time.
      </para>
     </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2021-12-11 [07eee5a0d] Create a new type category for "internal use" types.
-->

     <listitem>
      <para>
       Create a new <link
       linkend="catalog-pg-type"><structfield>pg_type.typcategory</structfield></link>
       value for <type>"char"</type> (Tom Lane)
      </para>

      <para>
       Some other internal-use-only types have also been assigned to this
       category.
      </para>
     </listitem>

<!--
Author: Robert Haas <rhaas@postgresql.org>
2022-01-18 [cc333f323] Modify pg_basebackup to use a new COPY subprotocol for b
-->

     <listitem>
      <para>
       Add new protocol message <link
       linkend="protocol-replication-base-backup"><literal>TARGET</literal></link>
       to specify a new <command>COPY</command> method to be used for base
       backups (Robert Haas)
      </para>

      <para>
       <link
       linkend="app-pgbasebackup"><application>pg_basebackup</application></link>
       now uses this method.
      </para>
     </listitem>

<!--
Author: Robert Haas <rhaas@postgresql.org>
2022-01-24 [0ad803291] Server-side gzip compression.
Author: Robert Haas <rhaas@postgresql.org>
2022-03-23 [ffd53659c] Replace BASE_BACKUP COMPRESSION_LEVEL option with COMPRE
-->

     <listitem>
      <para>
       Add new protocol message <link
       linkend="protocol-replication-base-backup"><literal>COMPRESSION</literal></link>
       and <literal>COMPRESSION_DETAIL</literal> to specify the compression
       method and options (Robert Haas)
      </para>
     </listitem>

<!--
Author: Robert Haas <rhaas@postgresql.org>
2022-02-10 [9cd28c2e5] Remove server support for old BASE_BACKUP command syntax
Author: Robert Haas <rhaas@postgresql.org>
2022-02-10 [0d4513b61] Remove server support for the previous base backup proto
-->

     <listitem>
      <para>
       Remove server support for old <literal>BASE_BACKUP</literal>
       command syntax and base backup protocol (Robert Haas)
      </para>
     </listitem>

<!--
Author: Robert Haas <rhaas@postgresql.org>
2022-03-15 [e4ba69f3f] Allow extensions to add new backup targets.
-->

     <listitem>
      <para>
       Add support for extensions to set custom backup targets (Robert
       Haas)
      </para>
     </listitem>

<!--
Author: Jeff Davis <jdavis@postgresql.org>
2022-04-06 [5c279a6d3] Custom WAL Resource Managers.
-->

     <listitem>
      <para>
       Allow extensions to define custom <acronym>WAL</acronym>
       resource managers (Jeff Davis)
      </para>
     </listitem>

<!--
Author: Michael Paquier <michael@paquier.xyz>
2022-01-31 [d10e41d42] Introduce pg_settings_get_flags() to find flags associat
-->

     <listitem>
      <para>
       Add function <link
       linkend="functions-info-catalog-table"><function>pg_settings_get_flags()</function></link>
       to get the flags of server variables (Justin Pryzby)
      </para>
     </listitem>

<!--
Author: Robert Haas <rhaas@postgresql.org>
2022-04-08 [8ec569479] Apply PGDLLIMPORT markings broadly.
-->

     <listitem>
      <para>
       On Windows, export all the server's global variables using
       <literal>PGDLLIMPORT</literal> markers (Robert Haas)
      </para>

      <para>
       Previously, only specific variables were accessible to extensions
       on Windows.
      </para>
     </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2022-07-23 [3b474a2e6] Increase minimum supported GNU make version to 3.81.
-->

     <listitem>
      <para>
       Require GNU <application>make</application> version 3.81 or later
       to build <productname>PostgreSQL</productname> (Tom Lane)
      </para>
     </listitem>

<!--
Author: Peter Eisentraut <peter@eisentraut.org>
2021-11-05 [db7d1a7b0] pgcrypto: Remove non-OpenSSL support
-->

     <listitem>
      <para>
       Require OpenSSL to build the <link
       linkend="pgcrypto"><application>pgcrypto</application></link>
       extension (Peter Eisentraut)
      </para>
     </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2021-10-07 [92e6a98c3] Adjust configure to insist on Perl version &gt;= 5.8.3.
-->

     <listitem>
      <para>
       Require <application>Perl</application>
       version 5.8.3 or later (Dagfinn Ilmari Mannsåker)
      </para>
     </listitem>

<!--
Author: Andres Freund <andres@anarazel.de>
2022-02-16 [19252e8ec] plpython: Reject Python 2 during build configuration.
-->

     <listitem>
      <para>
       Require <application>Python</application>
       version 3.2 or later (Andres Freund)
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title>Additional Modules</title>

    <itemizedlist>

<!--
Author: Peter Eisentraut <peter@eisentraut.org>
2021-09-28 [c3b011d99] Support amcheck of sequences
-->

     <listitem>
      <para>
       Allow <link
       linkend="amcheck"><application>amcheck</application></link> to
       check sequences (Mark Dilger)
      </para>
     </listitem>

<!--
Author: Robert Haas <rhaas@postgresql.org>
2021-11-05 [bd807be69] amcheck: Add additional TOAST pointer checks.
-->

     <listitem>
      <para>
       Improve <application>amcheck</application> sanity checks for
       <acronym>TOAST</acronym> tables (Mark Dilger)
      </para>
     </listitem>

<!--
Author: Robert Haas <rhaas@postgresql.org>
2022-03-15 [c6306db24] Add 'basebackup_to_shell' contrib module.
Author: Robert Haas <rhaas@postgresql.org>
2022-03-30 [26a0c025e] Document basebackup_to_shell.required_role.
-->

     <listitem>
      <para>
       Add new module <application><link
       linkend="basebackup-to-shell">basebackup_to_shell</link></application>
       as an example of a custom backup target (Robert Haas)
      </para>
     </listitem>

<!--
Author: Robert Haas <rhaas@postgresql.org>
2022-02-03 [5ef1eefd7] Allow archiving via loadable modules.
-->

     <listitem>
      <para>
       Add new module <link
       linkend="basic-archive"><application>basic_archive</application></link>
       as an example of performing archiving via a library (Nathan Bossart)
      </para>
     </listitem>

<!--
Author: Tomas Vondra <tomas.vondra@postgresql.org>
2021-11-06 [57e3c5160] Add bool GiST opclass to btree_gist
Author: Tomas Vondra <tomas.vondra@postgresql.org>
2021-11-08 [e2fbb8837] Fix gist_bool_ops to use gbtreekey2
Author: Tomas Vondra <tomas.vondra@postgresql.org>
2021-12-11 [4c6145b51] Add bool to btree_gist documentation
-->

     <listitem>
      <para>
       Allow <link
       linkend="btree-gist"><application>btree_gist</application></link>
       indexes on boolean columns (Emre Hasegeli)
      </para>

      <para>
       These can be used for exclusion constraints.
      </para>
     </listitem>

<!--
Author: Michael Paquier <michael@paquier.xyz>
2021-07-12 [127404fbe] pageinspect: Improve page_header() for pages of 32kB
-->

     <listitem>
      <para>
       Fix <link
       linkend="pageinspect"><application>pageinspect</application></link>'s
       <function>page_header()</function> to handle 32-kilobyte page sizes
       (Quan Zongliang)
      </para>

      <para>
       Previously, improper negative values could be returned in certain
       cases.
      </para>
     </listitem>

<!--
Author: Michael Paquier <michael@paquier.xyz>
2022-04-08 [76cbf7edb] pg_stat_statements: Track I/O timing for temporary file
-->

     <listitem>
      <para>
       Add counters for temporary file block I/O to <link
       linkend="pgstatstatements"><application>pg_stat_statements</application></link>
       (Masahiko Sawada)
      </para>
     </listitem>

<!--
Author: Magnus Hagander <magnus@hagander.net>
2022-04-08 [57d6aea00] Add JIT counters to pg_stat_statements
-->

     <listitem>
      <para>
       Add <acronym>JIT</acronym> counters to pg_stat_statements (Magnus
       Hagander)
      </para>
     </listitem>

<!--
Author: Jeff Davis <jdavis@postgresql.org>
2022-04-08 [2258e76f9] Add contrib/pg_walinspect.
-->

     <listitem>
      <para>
       Add new module <link
       linkend="pgwalinspect"><application>pg_walinspect</application></link>
       (Bharath Rupireddy)
      </para>

      <para>
       This gives <acronym>SQL</acronym>-level output similar to <link
       linkend="pgwaldump"><application>pg_waldump</application></link>.
      </para>
     </listitem>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2022-01-12 [134d97463] Include permissive/enforcing state in sepgsql log messag
-->

     <listitem>
      <para>
       Indicate the permissive/enforcing state in <link
       linkend="sepgsql"><application>sepgsql</application></link> log
       messages (Dave Page)
      </para>
     </listitem>

    </itemizedlist>

    <sect4>
     <title><link linkend="postgres-fdw"><application>postgres_fdw</application></link></title>

     <itemizedlist>

<!--
Author: Tom Lane <tgl@sss.pgh.pa.us>
2021-07-30 [5d44fff01] In postgres_fdw, allow CASE expressions to be pushed to
-->

      <listitem>
       <para>
        Allow postgres_fdw to push down <literal>CASE</literal> expressions
        (Alexander Pyhalov)
       </para>
      </listitem>

<!--
Author: Fujii Masao <fujii@postgresql.org>
2021-09-07 [449ab6350] postgres_fdw: Allow application_name of remote connectio
Author: Fujii Masao <fujii@postgresql.org>
2021-12-24 [6e0cb3dec] postgres_fdw: Allow postgres_fdw.application_name to inc
Author: Fujii Masao <fujii@postgresql.org>
2022-02-18 [94c49d534] postgres_fdw: Make postgres_fdw.application_name support
-->

      <listitem>
       <para>
        Add server variable
        <varname>postgres_fdw.application_name</varname> to control the
        application name of postgres_fdw connections (Hayato Kuroda)
       </para>

       <para>
        Previously the remote session's <link
        linkend="guc-application-name"><varname>application_name</varname></link>
        could only be set on the remote server or via a
        <application>postgres_fdw</application> connection specification.
        <varname>postgres_fdw.application_name</varname> supports some
        escape sequences for customization, making it easier to tell such
        connections apart on the remote server.
       </para>
      </listitem>

<!--
Author: Etsuro Fujita <efujita@postgresql.org>
2022-02-24 [04e706d42] postgres_fdw: Add support for parallel commit.
-->

      <listitem>
       <para>
        Allow parallel commit on <application>postgres_fdw</application>
        servers (Etsuro Fujita)
       </para>

       <para>
        This is enabled with the <literal>CREATE SERVER</literal> option
        <literal>parallel_commit</literal>.
       </para>
      </listitem>

     </itemizedlist>

    </sect4>

   </sect3>

  </sect2>

  <sect2 id="release-15-acknowledgements">
   <title>Acknowledgments</title>

   <para>
    The following individuals (in alphabetical order) have contributed
    to this release as patch authors, committers, reviewers, testers,
    or reporters of issues.
   </para>

   <simplelist>
    <member>Abhijit Menon-Sen</member>
    <member>Adam Brusselback</member>
    <member>Adam Mackler</member>
    <member>Adrian Ho</member>
    <member>Ahsan Hadi</member>
    <member>Ajin Cherian</member>
    <member>Alastair McKinley</member>
    <member>Aleksander Alekseev</member>
    <member>Ales Zeleny</member>
    <member>Alex Kingsborough</member>
    <member>Alex Kozhemyakin</member>
    <member>Alexander Korotkov</member>
    <member>Alexander Kukushkin</member>
    <member>Alexander Lakhin</member>
    <member>Alexander Nawratil</member>
    <member>Alexander Pyhalov</member>
    <member>Alexey Borzov</member>
    <member>Alexey Ermakov</member>
    <member>Aliaksandr Kalenik</member>
    <member>Álvaro Herrera</member>
    <member>Amit Kapila</member>
    <member>Amit Khandekar</member>
    <member>Amit Langote</member>
    <member>Amul Sul</member>
    <member>Anastasia Lubennikova</member>
    <member>Anders Kaseorg</member>
    <member>Andreas Dijkman</member>
    <member>Andreas Grob</member>
    <member>Andreas Seltenreich</member>
    <member>Andrei Zubkov</member>
    <member>Andres Freund</member>
    <member>Andrew Alsup</member>
    <member>Andrew Bille</member>
    <member>Andrew Dunstan</member>
    <member>Andrew Gierth</member>
    <member>Andrew Kesper</member>
    <member>Andrey Borodin</member>
    <member>Andrey Lepikhov</member>
    <member>Andrey Sokolov</member>
    <member>Andy Fan</member>
    <member>Anton Melnikov</member>
    <member>Anton Voloshin</member>
    <member>Antonin Houska</member>
    <member>Arjan van de Ven</member>
    <member>Arne Roland</member>
    <member>Arthur Zakirov</member>
    <member>Ashutosh Bapat</member>
    <member>Ashutosh Sharma</member>
    <member>Ashwin Agrawal</member>
    <member>Asif Rehman</member>
    <member>Asim Praveen</member>
    <member>Atsushi Torikoshi</member>
    <member>Aya Iwata</member>
    <member>Bauyrzhan Sakhariyev</member>
    <member>Benoit Lobréau</member>
    <member>Bernd Dorn</member>
    <member>Bertrand Drouvot</member>
    <member>Bharath Rupireddy</member>
    <member>Björn Harrtell</member>
    <member>Boris Kolpackov</member>
    <member>Boris Korzun</member>
    <member>Brad Nicholson</member>
    <member>Brar Piening</member>
    <member>Bruce Momjian</member>
    <member>Bruno da Silva</member>
    <member>Bryn Llewellyn</member>
    <member>Carl Sopchak</member>
    <member>Cary Huang</member>
    <member>Chapman Flack</member>
    <member>Chen Jiaoqian</member>
    <member>Chris Bandy</member>
    <member>Chris Lowder</member>
    <member>Christian Quest</member>
    <member>Christoph Berg</member>
    <member>Christoph Heiss</member>
    <member>Christophe Pettus</member>
    <member>Christopher Painter-Wakefield</member>
    <member>Claudio Freire</member>
    <member>Clemens Zeidler</member>
    <member>Corey Huinker</member>
    <member>Dag Lem</member>
    <member>Dagfinn Ilmari Mannsåker</member>
    <member>Dan Kubb</member>
    <member>Daniel Cherniy</member>
    <member>Daniel Gustafsson</member>
    <member>Daniel Polski</member>
    <member>Daniel Vérité</member>
    <member>Daniel Westermann</member>
    <member>Daniele Varrazzo</member>
    <member>Daniil Anisimov</member>
    <member>Danny Shemesh</member>
    <member>Darafei Praliaskouski</member>
    <member>Daria Lepikhova</member>
    <member>Dave Cramer</member>
    <member>Dave Page</member>
    <member>David Christensen</member>
    <member>David Fetter</member>
    <member>David G. Johnston</member>
    <member>David Rowley</member>
    <member>David Steele</member>
    <member>David Zhang</member>
    <member>Dean Rasheed</member>
    <member>Dian Fay</member>
    <member>Dilip Kumar</member>
    <member>Dipesh Pandit</member>
    <member>Dmitry Dolgov</member>
    <member>Dmitry Koval</member>
    <member>Dmitry Marakasov</member>
    <member>Dominique Devienne</member>
    <member>Dong Wook</member>
    <member>Drew DeVault</member>
    <member>Eduard Català</member>
    <member>Egor Chindyaskin</member>
    <member>Egor Rogov</member>
    <member>Ekaterina Kiryanova</member>
    <member>Elena Indrupskaya</member>
    <member>Elvis Pranskevichus</member>
    <member>Emmanuel Quincerot</member>
    <member>Emre Hasegeli</member>
    <member>Eric Mutta</member>
    <member>Erica Zhang</member>
    <member>Erik Rijkers</member>
    <member>Erki Eessaar</member>
    <member>Etsuro Fujita</member>
    <member>Euler Taveira</member>
    <member>Fabien Coelho</member>
    <member>Fabrice Chapuis</member>
    <member>Fabrice Fontaine</member>
    <member>Fabrízio de Royes Mello</member>
    <member>Feike Steenbergen</member>
    <member>Filip Gospodinov</member>
    <member>Florin Irion</member>
    <member>Floris Van Nee</member>
    <member>Frédéric Yhuel</member>
    <member>Gabriela Serventi</member>
    <member>Gabriele Varrazzo</member>
    <member>Gaurab Dey</member>
    <member>Geoff Winkless</member>
    <member>Geoffrey Blake</member>
    <member>Georgios Kokolatos</member>
    <member>Gilles Darold</member>
    <member>Greg Nancarrow</member>
    <member>Greg Rychlewski</member>
    <member>Greg Sabino Mullane</member>
    <member>Greg Stark</member>
    <member>Gregory Smith</member>
    <member>Guillaume Lelarge</member>
    <member>Gunnar Bluth</member>
    <member>Gurjeet Singh</member>
    <member>Haiyang Wang</member>
    <member>Haiying Tang</member>
    <member>Hannu Krosing</member>
    <member>Hans Buschmann</member>
    <member>Hayato Kuroda</member>
    <member>Heikki Linnakangas</member>
    <member>Herwig Goemans</member>
    <member>Himanshu Upadhyaya</member>
    <member>Holly Roberts</member>
    <member>Hou Zhijie</member>
    <member>Hubert Lubaczewski</member>
    <member>Ian Barwick</member>
    <member>Ian Campbell</member>
    <member>Ibrar Ahmed</member>
    <member>Ildus Kurbangaliev</member>
    <member>Ilya Anfimov</member>
    <member>Itamar Gafni</member>
    <member>Jacob Champion</member>
    <member>Jaime Casanova</member>
    <member>Jakub Wartak</member>
    <member>James Coleman</member>
    <member>James Hilliard</member>
    <member>James Inform</member>
    <member>Jan Piotrowski</member>
    <member>Japin Li</member>
    <member>Jason Harvey</member>
    <member>Jason Kim</member>
    <member>Jean-Christophe Arnu</member>
    <member>Jeevan Ladhe</member>
    <member>Jeff Davis</member>
    <member>Jeff Janes</member>
    <member>Jehan-Guillaume de Rorthais</member>
    <member>Jelte Fennema</member>
    <member>Jeremy Evans</member>
    <member>Jeremy Schneider</member>
    <member>Jian Guo</member>
    <member>Jian He</member>
    <member>Jimmy Yih</member>
    <member>Jiri Fejfar</member>
    <member>Jitka Plesníková</member>
    <member>Joe Conway</member>
    <member>Joe Wildish</member>
    <member>Joel Jacobson</member>
    <member>Joey Bodoia</member>
    <member>John Naylor</member>
    <member>Jonathan Katz</member>
    <member>Josef Simanek</member>
    <member>Joseph Koshakow</member>
    <member>Josh Soref</member>
    <member>Joshua Brindle</member>
    <member>Juan José Santamaría Flecha</member>
    <member>Julien Rouhaud</member>
    <member>Julien Roze</member>
    <member>Junwang Zhao</member>
    <member>Jürgen Purtz</member>
    <member>Justin Pryzby</member>
    <member>Ken Kato</member>
    <member>Kevin Burke</member>
    <member>Kevin Grittner</member>
    <member>Kevin Humphreys</member>
    <member>Kevin McKibbin</member>
    <member>Kevin Sweet</member>
    <member>Kevin Zheng</member>
    <member>Klaudie Willis</member>
    <member>Konstantin Knizhnik</member>
    <member>Konstantina Skovola</member>
    <member>Kosei Masumura</member>
    <member>Kotaro Kawamoto</member>
    <member>Koyu Tanigawa</member>
    <member>Kuntal Ghosh</member>
    <member>Kyotaro Horiguchi</member>
    <member>Lars Kanis</member>
    <member>Lauren Fliksteen</member>
    <member>Laurent Hasson</member>
    <member>Laurenz Albe</member>
    <member>Leslie Lemaire</member>
    <member>Liam Bowen</member>
    <member>Lingjie Qiang</member>
    <member>Liu Huailing</member>
    <member>Louis Jachiet</member>
    <member>Lukas Fittl</member>
    <member>Ma Liangzhu</member>
    <member>Maciek Sakrejda</member>
    <member>Magnus Hagander</member>
    <member>Mahendra Singh Thalor</member>
    <member>Maksim Milyutin</member>
    <member>Marc Bachmann</member>
    <member>Marcin Krupowicz</member>
    <member>Marcus Gartner</member>
    <member>Marek Szuba</member>
    <member>Marina Polyakova</member>
    <member>Mario Emmenlauer</member>
    <member>Mark Dilger</member>
    <member>Mark Murawski</member>
    <member>Mark Wong</member>
    <member>Markus Wanner</member>
    <member>Markus Winand</member>
    <member>Martijn van Oosterhout</member>
    <member>Martin Jurca</member>
    <member>Martin Kalcher</member>
    <member>Martín Marqués</member>
    <member>Masahiko Sawada</member>
    <member>Masahiro Ikeda</member>
    <member>Masao Fujii</member>
    <member>Masaya Kawamoto</member>
    <member>Masayuki Hirose</member>
    <member>Matthias van de Meent</member>
    <member>Matthijs van der Vleuten</member>
    <member>Maxim Orlov</member>
    <member>Maxim Yablokov</member>
    <member>Melanie Plageman</member>
    <member>Michael Banck</member>
    <member>Michael Harris</member>
    <member>Michael J. Sullivan</member>
    <member>Michael Meskes</member>
    <member>Michael Mühlbeyer</member>
    <member>Michael Paquier</member>
    <member>Michael Powers</member>
    <member>Mike Fiedler</member>
    <member>Mike Oh</member>
    <member>Mikhail Kulagin</member>
    <member>Miles Delahunty</member>
    <member>Naoki Okano</member>
    <member>Nathan Bossart</member>
    <member>Nathan Long</member>
    <member>Nazir Bilal Yavuz</member>
    <member>Neha Sharma</member>
    <member>Neil Chen</member>
    <member>Nicola Contu</member>
    <member>Nicolas Lutic</member>
    <member>Nikhil Benesch</member>
    <member>Nikhil Shetty</member>
    <member>Nikhil Sontakke</member>
    <member>Nikita Glukhov</member>
    <member>Nikolai Berkoff</member>
    <member>Nikolay Samokhvalov</member>
    <member>Nikolay Shaplov</member>
    <member>Nitin Jadhav</member>
    <member>Noah Misch</member>
    <member>Noboru Saito</member>
    <member>Noriyoshi Shinoda</member>
    <member>Olaf Bohlen</member>
    <member>Olly Betts</member>
    <member>Onder Kalaci</member>
    <member>Oskar Stenberg</member>
    <member>Otto Kekalainen</member>
    <member>Paul Guo</member>
    <member>Paul Jungwirth</member>
    <member>Paul Martinez</member>
    <member>Pavan Deolasee</member>
    <member>Pavel Borisov</member>
    <member>Pavel Luzanov</member>
    <member>Pavel Stehule</member>
    <member>Peter Eisentraut</member>
    <member>Peter Geoghegan</member>
    <member>Peter Slavov</member>
    <member>Peter Smith</member>
    <member>Petr Jelínek</member>
    <member>Phil Florent</member>
    <member>Phil Krylov</member>
    <member>Pierre-Aurélien Georges</member>
    <member>Prabhat Sahu</member>
    <member>Quan Zongliang</member>
    <member>Rachel Heaton</member>
    <member>Rahila Syed</member>
    <member>Rajakavitha Kodhandapani</member>
    <member>Rajkumar Raghuwanshi</member>
    <member>Ranier Vilela</member>
    <member>Rei Kamigishi</member>
    <member>Reid Thompson</member>
    <member>Rémi Lapeyre</member>
    <member>Renan Soares Lopes</member>
    <member>Richard Guo</member>
    <member>Richard Wesley</member>
    <member>RKN Sai Krishna</member>
    <member>Robert Haas</member>
    <member>Robert Treat</member>
    <member>Roberto Mello</member>
    <member>Robins Tharakan</member>
    <member>Roger Mason</member>
    <member>Roman Zharkov</member>
    <member>Ronan Dunklau</member>
    <member>Rui Zhao</member>
    <member>Ryan Kelly</member>
    <member>Ryo Matsumura</member>
    <member>Ryohei Takahashi</member>
    <member>Sadhuprasad Patro</member>
    <member>Sait Talha Nisanci</member>
    <member>Sami Imseih</member>
    <member>Sandeep Thakkar</member>
    <member>Sebastian Kemper</member>
    <member>Sehrope Sarkuni</member>
    <member>Sergei Kornilov</member>
    <member>Sergei Shoulbakov</member>
    <member>Sergey Shinderuk</member>
    <member>Shay Rojansky</member>
    <member>Shenhao Wang</member>
    <member>Shi Yu</member>
    <member>Shinya Kato</member>
    <member>Shruthi Gowda</member>
    <member>Simon Perepelitsa</member>
    <member>Simon Riggs</member>
    <member>Sirisha Chamarthi</member>
    <member>Soumyadeep Chakraborty</member>
    <member>Stan Hu</member>
    <member>Stas Kelvich</member>
    <member>Stefen Hillman</member>
    <member>Stephen Frost</member>
    <member>Steve Chavez</member>
    <member>Sumanta Mukherjee</member>
    <member>Suraj Khamkar</member>
    <member>Suraj Kharage</member>
    <member>Sven Klemm</member>
    <member>Takamichi Osumi</member>
    <member>Takayuki Tsunakawa</member>
    <member>Takeshi Ideriha</member>
    <member>Tatsuhito Kasahara</member>
    <member>Tatsuo Ishii</member>
    <member>Tatsuro Yamada</member>
    <member>Teja Mupparti</member>
    <member>Teodor Sigaev</member>
    <member>Thibaud Walkowiak</member>
    <member>Thom Brown</member>
    <member>Thomas McKay</member>
    <member>Thomas Munro</member>
    <member>Tim McNamara</member>
    <member>Timo Stolz</member>
    <member>Timur Khanjanov</member>
    <member>Tom Lane</member>
    <member>Tomas Barton</member>
    <member>Tomas Vondra</member>
    <member>Tony Reix</member>
    <member>Troy Frericks</member>
    <member>Tushar Ahuja</member>
    <member>Victor Wagner</member>
    <member>Victor Yegorov</member>
    <member>Vignesh C</member>
    <member>Vik Fearing</member>
    <member>Vincas Dargis</member>
    <member>Vitaly Burovoy</member>
    <member>Vitaly Voronov</member>
    <member>Vladimir Sitnikov</member>
    <member>Wang Ke</member>
    <member>Wei Sun</member>
    <member>Wei Wang</member>
    <member>Whale Song</member>
    <member>Will Mortensen</member>
    <member>Wolfgang Walther</member>
    <member>Yanliang Lei</member>
    <member>Yaoguang Chen</member>
    <member>Yogendra Suralkar</member>
    <member>YoungHwan Joo</member>
    <member>Yugo Nagata</member>
    <member>Yukun Wang</member>
    <member>Yura Sokolov</member>
    <member>Yusuke Egashira</member>
    <member>Yuzuko Hosoya</member>
    <member>Zhang Mingli</member>
    <member>Zhang Wenjie</member>
    <member>Zhihong Yu</member>
    <member>Zhiyong Wu</member>
   </simplelist>
  </sect2>

 </sect1>