doc/src/sgml/release-15.sgml

   1  <sect1 id="release-15">
   2   <title>Release 15</title>
   3
   4   <formalpara>
   5    <title>Release date:</title>
   6    <para>AS OF 2022-06-11</para>
   7   </formalpara>
   8
   9   <sect2>
  10    <title>Overview</title>
  11
  12    <para>
  13     <productname>PostgreSQL</productname> 15 contains many new features
  14     and enhancements, including:
  15    </para>
  16
  17    <itemizedlist>
  18     <listitem><para></para></listitem>
  19    </itemizedlist>
  20
  21    <para>
  22     The above items and other new features of
  23     <productname>PostgreSQL</productname> 15 are explained in more detail
  24     in the sections below.
  25    </para>
  26
  27   </sect2>
  28
  29   <sect2>
  30
  31    <title>Migration to Version 15</title>
  32
  33     <para>
  34      A dump/restore using <xref linkend="app-pg-dumpall"/> or use of
  35      <xref linkend="pgupgrade"/> or logical replication is required for
  36      those wishing to migrate data from any previous release.  See <xref
  37      linkend="upgrading"/> for general information on migrating to new
  38      major releases.
  39     </para>
  40
  41     <para>
  42      Version 15 contains a number of changes that may affect compatibility
  43      with previous releases.  Observe the following incompatibilities:
  44     </para>
  45
  46    <itemizedlist>
  47
  48 <!--
  49 Author: Noah Misch <noah@leadboat.com>
  50 2021-09-09 [b073c3ccd] Revoke PUBLIC CREATE from public schema, now owned by pg
  51 -->
  52
  53     <listitem>
  54      <para>
  55       Remove <literal>PUBLIC</literal> creation permission on the <link
  56       linkend="ddl-schemas-public"><literal>public</literal> schema</link>
  57       (Noah Misch)
  58      </para>
  59
  60      <para>
  61       This is a change in the default for newly-created databases in
  62       existing clusters and for new clusters;  <literal>USAGE</literal>
  63       permissions on the <literal>public</literal> schema has not
  64       been changed.  Databases restored from previous Postgres releases
  65       will be restored with their current permissions.  Users wishing
  66       to have the old permissions on new objects will need to grant
  67       <literal>CREATE</literal> permission for <literal>PUBLIC</literal>
  68       on the <literal>public</literal> schema; this change can be made
  69       on <literal>template1</literal> to cause all new databases
  70       to have these permissions.  <literal>template1</literal>
  71       permissions for <application>pg_dumpall</application> and
  72       <application>pg_upgrade</application>?
  73      </para>
  74     </listitem>
  75
  76 <!--
  77 Author: Noah Misch <noah@leadboat.com>
  78 2021-09-09 [b073c3ccd] Revoke PUBLIC CREATE from public schema, now owned by pg
  79 -->
  80
  81     <listitem>
  82      <para>
  83       Change the owner of the <literal>public</literal> schema to
  84       <literal>pg_database_owner</literal> (Noah Misch)
  85      </para>
  86
  87      <para>
  88       Previously it was the literal user name of the database owner.
  89       Databases restored from previous Postgres releases will be restored
  90       with their current owner specification.
  91      </para>
  92     </listitem>
  93
  94 <!--
  95 Author: Stephen Frost <sfrost@snowman.net>
  96 2022-04-06 [39969e2a1] Remove exclusive backup mode
  97 -->
  98
  99     <listitem>
 100      <para>
 101       Remove long-deprecated exclusive <link
 102       linkend="backup-base-backup">backup mode</link> (David Steele,
 103       Nathan Bossart)
 104      </para>
 105
 106      <para>
 107       If the database server stops abruptly while in this mode, the
 108       server could fail to start.  The non-exclusive backup mode requires
 109       a continuous database connection during the backup.  Functions
 110       <function>pg_start_backup()</function>/<function>pg_stop_backup()</function>
 111       have been renamed to
 112       <function>pg_backup_start()</function>/<function>pg_backup_stop()</function>,
 113       and the functions <function>pg_backup_start_time()</function>
 114       and <function>pg_is_in_backup()</function> have been removed.
 115      </para>
 116     </listitem>
 117
 118 <!--
 119 Author: Peter Geoghegan <pg@bowt.ie>
 120 2022-02-16 [8f388f6f5] Increase hash_mem_multiplier default to 2.0.
 121 -->
 122
 123     <listitem>
 124      <para>
 125       Increase <link
 126       linkend="guc-hash-mem-multiplier"><varname>hash_mem_multiplier</varname></link>
 127       default to 2.0 (Peter Geoghegan)
 128      </para>
 129
 130      <para>
 131       This allows query hash operations to use double the amount of
 132       <link linkend="guc-work-mem"><varname>work_mem</varname></link>
 133       memory as other operations.
 134      </para>
 135     </listitem>
 136
 137 <!--
 138 Author: Andres Freund <andres@anarazel.de>
 139 2022-03-07 [76a29adee] plpython: Remove plpythonu, plpython2u and associated tr
 140 -->
 141
 142     <listitem>
 143      <para>
 144       Remove server-side language <link
 145       linkend="plpython"><literal>plpython2u</literal></link> and generic
 146       Python language <literal>plpythonu</literal> (Andres Freund)
 147      </para>
 148     </listitem>
 149
 150 <!--
 151 Author: Tom Lane <tgl@sss.pgh.pa.us>
 152 2022-01-19 [a3d6264bb] interval_out() must be marked STABLE, not IMMUTABLE.
 153 -->
 154
 155     <listitem>
 156      <para>
 157       Mark the <link
 158       linkend="datatype-datetime"><type>interval</type></link> output
 159       function as stable, not immutable, since it depends on <link
 160       linkend="guc-intervalstyle"><varname>IntervalStyle</varname></link>
 161       (Tom Lane)
 162      </para>
 163
 164      <para>
 165       This will cause the creation of indexes relying on the text output
 166       of <type>interval</type> values to fail.
 167      </para>
 168     </listitem>
 169
 170 <!--
 171 Author: Tom Lane <tgl@sss.pgh.pa.us>
 172 2021-11-06 [cbe25dcff] Disallow making an empty lexeme via array_to_tsvector().
 173 -->
 174
 175     <listitem>
 176      <para>
 177       Generate an error if <link
 178       linkend="textsearch-functions-table"><function>array_to_tsvector()</function></link>
 179       is passed an empty array element (Jean-Christophe Arnu)
 180      </para>
 181
 182      <para>
 183       This is prohibited because lexemes should never be empty.  Users of
 184       previous Postgres releases should verify that no empty lexemes
 185       are stored because they can lead to dump/restore failures and
 186       inconsistent results.
 187      </para>
 188     </listitem>
 189
 190 <!--
 191 Author: Peter Eisentraut <peter@eisentraut.org>
 192 2021-12-06 [e9e63b702] Fix inappropriate uses of PG_GETARG_UINT32()
 193 -->
 194
 195     <listitem>
 196      <para>
 197       Generate an error when <link
 198       linkend="functions-string-other"><function>chr()</function></link>
 199       is supplied with a negative argument (Peter Eisentraut)
 200      </para>
 201     </listitem>
 202
 203 <!--
 204 Author: Peter Eisentraut <peter@eisentraut.org>
 205 2022-01-12 [a18b6d2dc] ecpg: Catch zero-length Unicode identifiers correctly
 206 -->
 207
 208     <listitem>
 209      <para>
 210       Prevent Unicode zero-length <link
 211       linkend="sql-syntax-identifiers">identifiers</link>, e.g., U&amp;""
 212       (Peter Eisentraut)
 213      </para>
 214
 215      <para>
 216       Non-Unicode zero-length identifiers were already prevented.
 217      </para>
 218     </listitem>
 219
 220 <!--
 221 Author: Tom Lane <tgl@sss.pgh.pa.us>
 222 2021-12-15 [2a712066d] Remove pg_dump's - -no-synchronized-snapshots switch.
 223 -->
 224
 225     <listitem>
 226      <para>
 227       Remove <link
 228       linkend="sql-syntax-identifiers"><application>pg_dump</application></link>'s
 229       <option>--no-synchronized-snapshots</option> option since all
 230       supported server versions support synchronized snapshots (Tom Lane)
 231      </para>
 232     </listitem>
 233
 234 <!--
 235 Author: Tom Lane <tgl@sss.pgh.pa.us>
 236 2022-02-15 [2523928b2] Reject change of output-column collation in CREATE OR RE
 237 -->
 238
 239     <listitem>
 240      <para>
 241       Prevent <link linkend="sql-createview"><command>CREATE OR REPLACE
 242       VIEW</command></link> from changing the collation of an output column
 243       (Tom Lane)
 244      </para>
 245     </listitem>
 246
 247 <!--
 248 Author: Peter Eisentraut <peter@eisentraut.org>
 249 2022-02-16 [2549f0661] Reject trailing junk after numeric literals
 250 -->
 251
 252     <listitem>
 253      <para>
 254       Prevent <link linkend="sql-syntax-constants-numeric">numeric
 255       literals</link> from having non-numeric trailing characters (Peter
 256       Eisentraut)
 257      </para>
 258
 259      <para>
 260       Previously literals like <literal>123abc</literal> would be
 261       interpreted as <literal>123</literal> and <literal>abc</literal>.
 262      </para>
 263     </listitem>
 264
 265 <!--
 266 Author: Peter Eisentraut <peter@eisentraut.org>
 267 2022-03-28 [e26114c81] Make JSON path numeric literals more correct
 268 -->
 269
 270     <listitem>
 271      <para>
 272       Adjust <link linkend="datatype-json"><acronym>JSON</acronym></link>
 273       numeric literal processing to match the
 274       <acronym>SQL</acronym>/<acronym>JSON</acronym>-standard (Peter
 275       Eisentraut)
 276      </para>
 277
 278      <para>
 279       This accepts numeric formats like <literal>.1</literal> and
 280       <literal>1.</literal>, and disallows trailing junk after numeric
 281       literals, like <literal>1.type()</literal>.
 282      </para>
 283     </listitem>
 284
 285 <!--
 286 Author: Tom Lane <tgl@sss.pgh.pa.us>
 287 2022-04-03 [591e088dd] Fix portability issues in datetime parsing.
 288 -->
 289
 290     <listitem>
 291      <para>
 292       Improve consistency of <link
 293       linkend="datatype-datetime">interval</link> parsing with trailing
 294       periods (Tom Lane)
 295      </para>
 296
 297      <para>
 298       Some platforms disallowed trailing periods.
 299      </para>
 300     </listitem>
 301
 302 <!--
 303 Author: Bruce Momjian <bruce@momjian.us>
 304 2021-08-03 [95ab1e0a9] interval:  round values when spilling to months
 305 -->
 306
 307     <listitem>
 308      <para>
 309       When specifying fractional interval values in units greater than
 310       months, round to the nearest month (Bruce Momjian)
 311      </para>
 312
 313      <para>
 314       For example, report <literal>1.99 years</literal> as <literal>2
 315       years</literal>, not <literal>1 year 11 months</literal>.
 316      </para>
 317     </listitem>
 318
 319 <!--
 320 Author: Tom Lane <tgl@sss.pgh.pa.us>
 321 2022-02-28 [54bd1e43c] Handle integer overflow in interval justification functi
 322 -->
 323
 324     <listitem>
 325      <para>
 326       Detect integer overflow in <link
 327       linkend="functions-datetime-table">interval justification
 328       functions</link> (Joe Koshakow)
 329      </para>
 330
 331      <para>
 332       Specifically, functions <function>justify_interval()</function>,
 333       <function>justify_hours()</function>, and
 334       <function>justify_days()</function> are affected.
 335      </para>
 336     </listitem>
 337
 338 <!--
 339 Author: Robert Haas <rhaas@postgresql.org>
 340 2022-03-28 [79de9842a] Remove the ability of a role to administer itself.
 341 -->
 342
 343     <listitem>
 344      <para>
 345       Remove the default <link linkend="sql-createrole"><literal>ADMIN
 346       OPTION</literal></link> privilege a login role has on its own role
 347       membership (Robert Haas)
 348      </para>
 349
 350      <para>
 351       Previously, login roles could add/remove members of its own role,
 352       even without <literal>ADMIN OPTION</literal> privilege.
 353      </para>
 354     </listitem>
 355
 356 <!--
 357 Author: Jeff Davis <jdavis@postgresql.org>
 358 2022-01-07 [a2ab9c06e] Respect permissions within logical replication.
 359 -->
 360
 361     <listitem>
 362      <para>
 363       Allow <link linkend="logical-replication">logical replication</link>
 364       to run as the owner of the subscription (Mark Dilger)
 365      </para>
 366
 367      <para>
 368       Because row-level security policies are not checked, only superusers,
 369       roles with <literal>bypassrls</literal>, and table owners can
 370       replicate into tables with row-level security policies.
 371      </para>
 372     </listitem>
 373
 374 <!--
 375 Author: Jeff Davis <jdavis@postgresql.org>
 376 2022-01-08 [96a6f11c0] More cleanup of a2ab9c06ea.
 377 -->
 378
 379     <listitem>
 380      <para>
 381       Prevent <command>UPDATE</command> and <command>DELETE</command>
 382       <link linkend="logical-replication">logical replication</link>
 383       operations on tables where the subscription owner does not have
 384       <command>SELECT</command> permission on the table (Jeff Davis)
 385      </para>
 386
 387      <para>
 388       <command>UPDATE</command> and <command>DELETE</command> perform
 389       <command>SELECT</command>, so require the subscription owner to
 390       have table <command>SELECT</command> permission.
 391      </para>
 392     </listitem>
 393
 394 <!--
 395 Author: Tom Lane <tgl@sss.pgh.pa.us>
 396 2021-07-27 [48c5c9068] Use the "pg_temp" schema alias in EXPLAIN and related ou
 397 -->
 398
 399     <listitem>
 400      <para>
 401       When <link linkend="sql-explain"><command>EXPLAIN</command></link>
 402       references the temporary object schema, refer to it as
 403       <literal>pg_temp</literal> (Amul Sul)
 404      </para>
 405
 406      <para>
 407       Previously the actual schema name was used.
 408      </para>
 409     </listitem>
 410
 411 <!--
 412 Author: Tom Lane <tgl@sss.pgh.pa.us>
 413 2022-02-28 [2e517818f] Fix SPI's handling of errors during transaction commit.
 414 -->
 415
 416     <listitem>
 417      <para>
 418       Modify <link linkend="spi"><acronym>SPI</acronym></link>'s
 419       <function>SPI_commit()</function> and
 420       <function>SPI_commit_and_chain()</function> to automatically start
 421       a new transaction at completion (Peter Eisentraut, Tom Lane)
 422      </para>
 423
 424      <para>
 425       BACKPATCHED?
 426      </para>
 427     </listitem>
 428
 429 <!--
 430 Author: Tom Lane <tgl@sss.pgh.pa.us>
 431 2022-03-24 [ce95c5437] Fix pg_statio_all_tables view for multiple TOAST indexes
 432 -->
 433
 434     <listitem>
 435      <para>
 436       Fix <link
 437       linkend="monitoring-pg-statio-all-tables-view"><structname>pg_statio_all_tables</structname></link>
 438       to sum values for the rare case of <acronym>TOAST</acronym> tables
 439       with multiple indexes (Andrei Zubkov)
 440      </para>
 441
 442      <para>
 443       Previously such cases would have one row for each index.
 444      </para>
 445     </listitem>
 446
 447 <!--
 448 Author: Peter Eisentraut <peter@eisentraut.org>
 449 2021-12-01 [75d22069e] Warning on SET of nonexisting setting with a prefix rese
 450 Author: Tom Lane <tgl@sss.pgh.pa.us>
 451 2021-12-27 [2ed8a8cc5] Rethink handling of settings with a prefix reserved by a
 452 Author: Tom Lane <tgl@sss.pgh.pa.us>
 453 2022-02-21 [88103567c] Disallow setting bogus GUCs within an extension's reserv
 454 -->
 455
 456     <listitem>
 457      <para>
 458       Disallow setting of <link linkend="config-setting">server
 459       variables</link> matching the prefixes of installed extension
 460       (Florin Irion, Tom Lane)
 461      </para>
 462
 463      <para>
 464       This also deletes any matching server variables during extension
 465       load.
 466      </para>
 467     </listitem>
 468
 469 <!--
 470 Author: Andres Freund <andres@anarazel.de>
 471 2022-04-06 [6f0cf8787] pgstat: remove stats_temp_directory.
 472 -->
 473
 474     <listitem>
 475      <para>
 476       Remove unnecessary server variable
 477       <varname>stats_temp_directory</varname> (Andres Freund, Kyotaro
 478       Horiguchi)
 479      </para>
 480     </listitem>
 481
 482 <!--
 483 Author: Tom Lane <tgl@sss.pgh.pa.us>
 484 2021-11-28 [3804539e4] Replace random(), pg_erand48(), etc with a better PRNG A
 485 Author: Tom Lane <tgl@sss.pgh.pa.us>
 486 2022-04-12 [d4f109e4a] Doc: update description of random() function.
 487 -->
 488
 489     <listitem>
 490      <para>
 491       Improve the algorithm used to compute <link
 492       linkend="functions-math-random-table"><function>random()</function></link>
 493       (Fabien Coelho)
 494      </para>
 495
 496      <para>
 497       This will cause <function>random()</function> to differ from what
 498       was emitted by prior versions for the same seed values.
 499      </para>
 500     </listitem>
 501
 502 <!--
 503 Author: Tom Lane <tgl@sss.pgh.pa.us>
 504 2021-11-12 [f8abb0f5e] postgres_fdw: suppress casts on constants in limited cas
 505 -->
 506
 507     <listitem>
 508      <para>
 509       Reduce casting of constants in <link
 510       linkend="postgres-fdw">postgres_fdw</link> queries (Dian Fay)
 511      </para>
 512
 513      <para>
 514       If column types were mismatched between local and remote databases,
 515       such casting could cause errors.
 516      </para>
 517     </listitem>
 518
 519 <!--
 520 Author: Tom Lane <tgl@sss.pgh.pa.us>
 521 2022-02-14 [fd2abeb7c] Delete contrib/xml2's legacy implementation of xml_is_we
 522 -->
 523
 524     <listitem>
 525      <para>
 526       Remove <link linkend="xml2">xml2</link>'s function
 527       <function>xml_is_well_formed()</function> (Tom Lane)
 528      </para>
 529
 530      <para>
 531       This function has been implemented in the core backend since
 532       Postgres 9.1.
 533      </para>
 534     </listitem>
 535
 536 <!--
 537 Author: Tom Lane <tgl@sss.pgh.pa.us>
 538 2021-07-06 [955b3e0f9] Allow CustomScan providers to say whether they support p
 539 -->
 540
 541     <listitem>
 542      <para>
 543       Allow <link linkend="custom-scan">custom scan provders</link>
 544       to indicate if they support projections (Sven Klemm)
 545      </para>
 546
 547      <para>
 548       The default is now that custom scan providers can't support
 549       projections, so they need to be updated for this release.
 550      </para>
 551     </listitem>
 552
 553    </itemizedlist>
 554
 555   </sect2>
 556
 557   <sect2>
 558    <title>Changes</title>
 559
 560    <para>
 561     Below you will find a detailed account of the changes between
 562     <productname>PostgreSQL</productname> 15 and the previous major
 563     release.
 564    </para>
 565
 566    <sect3>
 567     <title>Server</title>
 568
 569     <itemizedlist>
 570
 571 <!--
 572 Author: Peter Eisentraut <peter@eisentraut.org>
 573 2022-02-14 [37851a8b8] Database-level collation version tracking
 574 -->
 575
 576      <listitem>
 577       <para>
 578        Record and check the collation of each <link
 579        linkend="sql-createdatabase">database</link> (Peter Eisentraut)
 580       </para>
 581
 582       <para>
 583        This is designed to detect collation
 584        mismatches to avoid data corruption.  Function
 585        <function>pg_database_collation_actual_version()</function>
 586        reports the underlying operating system collation version, and
 587        <command>ALTER DATABASE ...  REFRESH</command> sets the database
 588        to match the operating system collation version.  DETAILS?
 589       </para>
 590      </listitem>
 591
 592 <!--
 593 Author: Peter Eisentraut <peter@eisentraut.org>
 594 2022-03-17 [f2553d430] Add option to use ICU as global locale provider
 595 -->
 596
 597      <listitem>
 598       <para>
 599        Allow <link linkend="locale"><acronym>ICU</acronym></link>
 600        collations to be set as the default for clusters and databases
 601        (Peter Eisentraut)
 602       </para>
 603
 604       <para>
 605        Previously, <acronym>ICU</acronym> collations could only be
 606        specified in <link linkend="sql-createcollation"><command>CREATE
 607        COLLATION</command></link> and used with the
 608        <literal>COLLATE</literal> clause.
 609       </para>
 610      </listitem>
 611
 612 <!--
 613 Author: Michael Paquier <michael@paquier.xyz>
 614 2022-03-29 [a2c84990b] Add system view pg_ident_file_mappings
 615 -->
 616
 617      <listitem>
 618       <para>
 619        Add system view <link
 620        linkend="view-pg-ident-file-mappings"><structname>pg_ident_file_mappings</structname></link>
 621        to report <filename>pg_ident.conf</filename> information (Julien
 622        Rouhaud)
 623       </para>
 624      </listitem>
 625
 626        </itemizedlist>
 627
 628     <sect4>
 629      <title><link linkend="ddl-partitioning">Partitioning</link></title>
 630
 631      <itemizedlist>
 632
 633 <!--
 634 Author: David Rowley <drowley@postgresql.org>
 635 2021-08-03 [475dbd0b7] Track a Bitmapset of non-pruned partitions in RelOptInfo
 636 -->
 637
 638       <listitem>
 639        <para>
 640         Improve planning time for queries referencing partitioned tables
 641         (David Rowley)
 642        </para>
 643
 644        <para>
 645         Specifically this helps if only a small number of the many
 646         partitions are relevant.
 647        </para>
 648       </listitem>
 649
 650 <!--
 651 Author: David Rowley <drowley@postgresql.org>
 652 2021-08-03 [db632fbca] Allow ordered partition scans in more cases
 653 -->
 654
 655       <listitem>
 656        <para>
 657         Allow ordered scans of partitions to avoid sorting in more cases
 658         (David Rowley)
 659        </para>
 660
 661        <para>
 662         Previously, a partitioned table with a <literal>DEFAULT</literal>
 663         partition or a <literal>LIST</literal> partition containing
 664         multiple values could not be used for ordered partition scans.
 665         Now they can be used if these partitions are pruned.
 666        </para>
 667       </listitem>
 668
 669 <!--
 670 Author: Alvaro Herrera <alvherre@alvh.no-ip.org>
 671 2022-03-20 [ba9a7e392] Enforce foreign key correctly during cross-partition upd
 672 -->
 673
 674       <listitem>
 675        <para>
 676         Improve foreign key behavior of updates on partitioned tables
 677         that move rows between partitions (Amit Langote)
 678        </para>
 679
 680        <para>
 681         Previously, such updates ran delete actions on the source
 682         partition and insert actions on the target partition.
 683         <productname>PostgreSQL</productname> will now run update actions
 684         on the referenced partition root.
 685        </para>
 686       </listitem>
 687
 688 <!--
 689 Author: Alvaro Herrera <alvherre@alvh.no-ip.org>
 690 2022-04-02 [cfdd03f45] Allow CLUSTER on partitioned tables
 691 Author: Alvaro Herrera <alvherre@alvh.no-ip.org>
 692 2022-04-14 [3f19e176a] Have CLUSTER ignore partitions not owned by caller
 693 -->
 694
 695       <listitem>
 696        <para>
 697         Allow <link linkend="sql-cluster"><command>CLUSTER</command></link>
 698         on partitioned tables (Justin Pryzby)
 699        </para>
 700       </listitem>
 701
 702 <!--
 703 Author: Alvaro Herrera <alvherre@alvh.no-ip.org>
 704 2021-07-22 [80ba4bb38] Make ALTER TRIGGER RENAME consistent for partitioned tab
 705 -->
 706
 707       <listitem>
 708        <para>
 709         Fix <link linkend="sql-altertable"><command>ALTER TRIGGER
 710         RENAME</command></link> on partitioned tables to properly rename
 711         triggers an all partitions (Arne Roland, Álvaro Herrera)
 712        </para>
 713
 714        <para>
 715         Also prohibit cloned triggers from being renamed.
 716        </para>
 717       </listitem>
 718
 719      </itemizedlist>
 720
 721     </sect4>
 722
 723     <sect4>
 724      <title>Indexes</title>
 725
 726      <itemizedlist>
 727
 728 <!--
 729 Author: Peter Geoghegan <pg@bowt.ie>
 730 2021-10-02 [2903f1404] Enable deduplication in system catalog indexes.
 731 -->
 732
 733       <listitem>
 734        <para>
 735         Enable system and <link
 736         linkend="storage-toast"><acronym>TOAST</acronym></link> btree
 737         indexes to efficiently store duplicates (Peter Geoghegan)
 738        </para>
 739
 740        <para>
 741         Previously de-duplication was disabled for these types of indexes.
 742        </para>
 743       </listitem>
 744
 745 <!--
 746 Author: Alexander Korotkov <akorotkov@postgresql.org>
 747 2022-02-07 [f1ea98a79] Reduce non-leaf keys overlap in GiST indexes produced by
 748 -->
 749
 750       <listitem>
 751        <para>
 752         Improve lookup performance of <link
 753         linkend="gist"><acronym>GiST</acronym></link> indexes built using
 754         sorting (Aliaksandr Kalenik, Sergei Shoulbakov, Andrey Borodin)
 755        </para>
 756       </listitem>
 757
 758 <!--
 759 Author: Tomas Vondra <tomas.vondra@postgresql.org>
 760 2021-11-30 [5753d4ee3] Ignore BRIN indexes when checking for HOT udpates
 761 -->
 762
 763       <listitem>
 764        <para>
 765         Prevent changes to columns only indexed by <link
 766         linkend="brin"><acronym>BRIN</acronym></link> indexes from
 767         disabling <acronym>HOT</acronym> updates (Josef Simanek)
 768        </para>
 769       </listitem>
 770
 771 <!--
 772 Author: Peter Eisentraut <peter@eisentraut.org>
 773 2022-02-03 [94aa7cc5f] Add UNIQUE null treatment option
 774 -->
 775
 776       <listitem>
 777        <para>
 778         Allow unique constraints and indexes to treat
 779         <literal>NULL</literal> values as not distinct (Peter Eisentraut)
 780        </para>
 781
 782        <para>
 783         Previously <literal>NULL</literal> values were always indexed
 784         as distinct values, but this can now be changed by creating
 785         constraints and indexes using <literal>UNIQUE NULLS NOT
 786         DISTINCT</literal>.
 787        </para>
 788       </listitem>
 789
 790 <!--
 791 Author: Tom Lane <tgl@sss.pgh.pa.us>
 792 2021-11-17 [a148f8bc0] Add a planner support function for starts_with().
 793 -->
 794
 795       <listitem>
 796        <para>
 797         Allow <link
 798         linkend="functions-string-other"><literal>^@</literal></link>
 799         and <function>starts_with()</function> to use btree indexes if
 800         using a C collation (Tom Lane)
 801        </para>
 802
 803        <para>
 804         Previously these could only use <link
 805         linkend="spgist"><acronym>SP-GiST</acronym></link> indexes.
 806        </para>
 807       </listitem>
 808
 809      </itemizedlist>
 810
 811     </sect4>
 812
 813     <sect4>
 814      <title>Optimizer</title>
 815
 816      <itemizedlist>
 817
 818 <!--
 819 Author: Tomas Vondra <tomas.vondra@postgresql.org>
 820 2022-01-16 [269b532ae] Add stxdinherit flag to pg_statistic_ext_data
 821 -->
 822
 823       <listitem>
 824        <para>
 825         Allow <link linkend="sql-createstatistics">extended
 826         statistics</link> to record statistics for a parent with all its
 827         children (Tomas Vondra, Justin Pryzby)
 828        </para>
 829
 830        <para>
 831         Regular statistics already tracked parent and parent/all-children
 832         statistics separately.
 833        </para>
 834       </listitem>
 835
 836 <!--
 837 Author: Tomas Vondra <tomas.vondra@postgresql.org>
 838 2022-03-31 [db0d67db2] Optimize order of GROUP BY keys
 839 -->
 840
 841       <listitem>
 842        <para>
 843         Allow <link linkend="queries-group"><literal>GROUP
 844         BY</literal></link> sorting to optimize column order (Dmitry
 845         Dolgov, Teodor Sigaev, Tomas Vondra)
 846        </para>
 847
 848        <para>
 849         This optimization can be disabled using the server variable <link
 850         linkend="guc-enable-groupby-reordering"><varname>enable_group_by_reordering</varname></link>.
 851        </para>
 852       </listitem>
 853
 854 <!--
 855 Author: Tom Lane <tgl@sss.pgh.pa.us>
 856 2022-03-24 [0bd7af082] Invent recursive_worktable_factor GUC to replace hard-wi
 857 -->
 858
 859       <listitem>
 860        <para>
 861         Add server variable <link
 862         linkend="guc-recursive-worktable-factor"><varname>recursive_worktable_factor</varname></link>
 863         to allow the user to specify the expected recursive query worktable
 864         size (Simon Riggs)
 865        </para>
 866
 867        <para>
 868         WHAT IS A WORKTABLE?  NOT DEFINED.
 869        </para>
 870       </listitem>
 871
 872      </itemizedlist>
 873
 874     </sect4>
 875
 876     <sect4>
 877      <title>General Performance</title>
 878
 879      <itemizedlist>
 880
 881 <!--
 882 Author: David Rowley <drowley@postgresql.org>
 883 2021-07-07 [29f45e299] Use a hash table to speed up NOT IN(values)
 884 -->
 885
 886       <listitem>
 887        <para>
 888         Allow hash lookup for <link
 889         linkend="functions-subquery-notin"><literal>NOT IN</literal></link>
 890         clauses with many constants (David Rowley, James Coleman)
 891        </para>
 892
 893        <para>
 894         Previously the code always sequentially scanned the list of values.
 895        </para>
 896       </listitem>
 897
 898 <!--
 899 Author: John Naylor <john.naylor@postgresql.org>
 900 2021-12-20 [911588a3f] Add fast path for validating UTF-8 text
 901 -->
 902
 903       <listitem>
 904        <para>
 905         Improve validation of <acronym>UTF</acronym>-8 text (even if
 906         only <acronym>ASCII</acronym>) by processing 16 bytes at a time
 907         (John Naylor, Heikki Linnakangas)
 908        </para>
 909
 910        <para>
 911         This will improve text-heavy operations like <link
 912         linkend="sql-copy"><command>COPY FROM</command></link>.
 913        </para>
 914       </listitem>
 915
 916 <!--
 917 Author: Heikki Linnakangas <heikki.linnakangas@iki.fi>
 918 2021-10-18 [65014000b] Replace polyphase merge algorithm with a simple balanced
 919 Author: Heikki Linnakangas <heikki.linnakangas@iki.fi>
 920 2021-10-25 [166f94377] Clarify the logic in a few places in the new balanced me
 921 -->
 922
 923       <listitem>
 924        <para>
 925         Improve performance for sorts that exceed <link
 926         linkend="guc-work-mem"><varname>work_mem</varname></link>
 927         (Heikki Linnakangas)
 928        </para>
 929
 930        <para>
 931         Specifically, switch to a batch sorting algorithm that uses more
 932         output streams internally.
 933        </para>
 934       </listitem>
 935
 936 <!--
 937 Author: David Rowley <drowley@postgresql.org>
 938 2021-07-22 [91e9e89dc] Make nodeSort.c use Datum sorts for single column sorts
 939 Author: David Rowley <drowley@postgresql.org>
 940 2022-04-04 [40af10b57] Use Generation memory contexts to store tuples in sorts
 941 Author: John Naylor <john.naylor@postgresql.org>
 942 2022-04-02 [697492434] Specialize tuplesort routines for different kinds of abb
 943 -->
 944
 945       <listitem>
 946        <para>
 947         Improve performance and reduce memory consumption of in-memory
 948         sorts (Ronan Dunklau, David Rowley, Thomas Munro, John Naylor)
 949        </para>
 950       </listitem>
 951
 952 <!--
 953 Author: Michael Paquier <michael@paquier.xyz>
 954 2021-06-29 [4035cd5d4] Add support for LZ4 with compression of full-page writes
 955 Author: Michael Paquier <michael@paquier.xyz>
 956 2022-03-11 [e9537321a] Add support for zstd with compression of full-page write
 957 -->
 958
 959       <listitem>
 960        <para>
 961         Allow <acronym>WAL</acronym> <link
 962         linkend="guc-full-page-writes">full page writes</link> to use
 963         LZ4 and Zstandard compression (Andrey Borodin, Justin Pryzby)
 964        </para>
 965
 966        <para>
 967         This is controlled by the <link
 968         linkend="guc-wal-compression"><varname>wal_compression</varname></link>
 969         server setting.
 970        </para>
 971       </listitem>
 972
 973 <!--
 974 Author: Thomas Munro <tmunro@postgresql.org>
 975 2021-07-19 [2dbe89057] Support direct I/O on macOS.
 976 -->
 977
 978       <listitem>
 979        <para>
 980         Add <link linkend="guc-wal-sync-method">direct I/O</link> support
 981         to macOS (Thomas Munro)
 982        </para>
 983
 984        <para>
 985         This only works if <literal>max_wal_senders=0</literal>
 986         and <literal>wal_level=minimal</literal>, and only for
 987         <acronym>WAL</acronym>.
 988        </para>
 989       </listitem>
 990
 991 <!--
 992 Author: Peter Geoghegan <pg@bowt.ie>
 993 2022-04-03 [0b018faba] Set relfrozenxid to oldest extant XID seen by VACUUM.
 994 -->
 995
 996       <listitem>
 997        <para>
 998         Allow <link linkend="routine-vacuuming">vacuum</link> to be more
 999         aggressive in setting the oldest frozenxid (Peter Geoghegan)
1000        </para>
1001       </listitem>
1002
1003 <!--
1004 Author: Etsuro Fujita <efujita@postgresql.org>
1005 2022-04-06 [c2bb02bc2] Allow asynchronous execution in more cases.
1006 -->
1007
1008       <listitem>
1009        <para>
1010         Allow a query referencing multiple <link
1011         linkend="ddl-foreign-data">foreign tables</link> to perform
1012         parallel foreign table scans in more cases (Andrey Lepikhov,
1013         Etsuro Fujita)
1014        </para>
1015       </listitem>
1016
1017 <!--
1018 Author: David Rowley <drowley@postgresql.org>
1019 2022-04-08 [9d9c02ccd] Teach planner and executor about monotonic window funcs
1020 -->
1021
1022       <listitem>
1023        <para>
1024         Improve the performance of <link linkend="functions-window">window
1025         functions</link> that use <function>row_number()</function>,
1026         <function>rank()</function>, and <function>count()</function>
1027         (David Rowley)
1028        </para>
1029       </listitem>
1030
1031 <!--
1032 Author: Tom Lane <tgl@sss.pgh.pa.us>
1033 2022-04-06 [a82a5eee3] Use ISB as a spin-delay instruction on ARM64.
1034 -->
1035
1036       <listitem>
1037        <para>
1038         Improve the performance of spinlocks on high-core-count ARM64
1039         systems (Geoffrey Blake)
1040        </para>
1041       </listitem>
1042
1043      </itemizedlist>
1044
1045     </sect4>
1046
1047     <sect4>
1048      <title>Monitoring</title>
1049
1050      <itemizedlist>
1051
1052 <!--
1053 Author: Robert Haas <rhaas@postgresql.org>
1054 2021-12-13 [64da07c41] Default to log_checkpoints=on, log_autovacuum_min_durati
1055 -->
1056
1057       <listitem>
1058        <para>
1059         Enable default logging of checkpoints and slow autovacuum
1060         operations (Bharath Rupireddy)
1061        </para>
1062
1063        <para>
1064         Specifically, this changes the default of <link
1065         linkend="guc-log-checkpoints"><varname>log_checkpoints</varname></link>
1066         to on and <link
1067         linkend="guc-log-autovacuum-min-duration"><varname>log_autovacuum_min_duration</varname></link>
1068         to 10 minutes.  This will cause idle servers to generate log
1069         output, which might cause problems on resource-constrained
1070         servers with insufficient log file removal.  The defaults should
1071         be changed in such cases.
1072        </para>
1073       </listitem>
1074
1075 <!--
1076 Author: Robert Haas <rhaas@postgresql.org>
1077 2021-10-25 [9ce346eab] Report progress of startup operations that take a long t
1078 Author: Alvaro Herrera <alvherre@alvh.no-ip.org>
1079 2021-11-05 [e543906e2] Document default and changeability of log_startup_progre
1080 -->
1081
1082       <listitem>
1083        <para>
1084         Generate periodic log message during slow server starts (Nitin
1085         Jadhav, Robert Haas)
1086        </para>
1087
1088        <para>
1089         Messages report the cause of the delay.  The time interval for
1090         notification is controlled by the new server variable <link
1091         linkend="guc-log-startup-progress-interval"><varname>log_startup_progress_interval</varname></link>.
1092        </para>
1093       </listitem>
1094
1095 <!--
1096 Author: Andres Freund <andres@anarazel.de>
1097 2022-04-06 [5891c7a8e] pgstat: store statistics in shared memory.
1098 Author: Andres Freund <andres@anarazel.de>
1099 2022-04-07 [b3abca681] pgstat: Update docs to match the shared memory stats rea
1100 -->
1101
1102       <listitem>
1103        <para>
1104         Store <link linkend="monitoring-stats">server-level
1105         statistics</link> in shared memory (Kyotaro Horiguchi, Andres
1106         Freund, Melanie Plageman)
1107        </para>
1108
1109        <para>
1110         Previously this was updated via <acronym>UDP</acronym> packets,
1111         stored in the file system, and read by sessions.  There is no
1112         longer a statistics collector process.
1113        </para>
1114       </listitem>
1115
1116 <!--
1117 Author: Peter Geoghegan <pg@bowt.ie>
1118 2022-02-11 [872770fd6] Add VACUUM instrumentation for scanned pages, relfrozenx
1119 Author: Peter Geoghegan <pg@bowt.ie>
1120 2022-03-13 [6e20f4600] VACUUM VERBOSE: tweak scanned_pages logic.
1121 Author: Peter Geoghegan <pg@bowt.ie>
1122 2022-04-15 [bdb71dbe8] VACUUM VERBOSE: Show dead items for an empty table.
1123 -->
1124
1125       <listitem>
1126        <para>
1127         Add additional information to <command>VACUUM VERBOSE</command>
1128         and autovacuum logging messages (Peter Geoghegan)
1129        </para>
1130       </listitem>
1131
1132 <!--
1133 Author: Michael Paquier <michael@paquier.xyz>
1134 2022-04-08 [efb0ef909] Track I/O timing for temporary file blocks in EXPLAIN (B
1135 -->
1136
1137       <listitem>
1138        <para>
1139         Add <link linkend="sql-explain"><command>EXPLAIN
1140         (BUFFERS)</command></link> output for temporary file block I/O
1141         (Masahiko Sawada)
1142        </para>
1143       </listitem>
1144
1145 <!--
1146 Author: Michael Paquier <michael@paquier.xyz>
1147 2022-01-17 [dc686681e] Introduce log_destination=jsonlog
1148 -->
1149
1150       <listitem>
1151        <para>
1152         Allow <link linkend="guc-log-destination">log output</link> in
1153         <acronym>JSON</acronym> format (Sehrope Sarkuni, Michael Paquier)
1154        </para>
1155
1156        <para>
1157         The new setting is <literal>log_destination=jsonlog</literal>.
1158        </para>
1159       </listitem>
1160
1161 <!--
1162 Author: Fujii Masao <fujii@postgresql.org>
1163 2021-09-02 [e04267844] Enhance pg_stat_reset_single_table_counters function.
1164 -->
1165
1166       <listitem>
1167        <para>
1168         Allow <link
1169         linkend="monitoring-stats-funcs-table"><function>pg_stat_reset_single_table_counters()</function></link>
1170         to reset the counters of relations shared across all databases
1171         (B Sadhu, Prasad Patro)
1172        </para>
1173       </listitem>
1174
1175 <!--
1176 Author: Fujii Masao <fujii@postgresql.org>
1177 2021-11-22 [1b06d7bac] Report wait events for local shell commands like archive
1178 -->
1179
1180       <listitem>
1181        <para>
1182         Add <link linkend="wait-event-table">wait events</link> for local
1183         shell commands (Fujii Masao)
1184        </para>
1185
1186        <para>
1187         Specifically the new wait events are related to
1188         commands <varname>archive_command</varname>,
1189         <varname>archive_cleanup_command</varname>,
1190         <varname>restore_command</varname> and
1191         <varname>recovery_end_command</varname>.
1192        </para>
1193       </listitem>
1194
1195      </itemizedlist>
1196
1197     </sect4>
1198
1199     <sect4>
1200      <title>Privileges</title>
1201
1202      <itemizedlist>
1203
1204 <!--
1205 Author: Dean Rasheed <dean.a.rasheed@gmail.com>
1206 2022-03-22 [7faa5fc84] Add support for security invoker views.
1207 -->
1208
1209       <listitem>
1210        <para>
1211         Allow <link linkend="sql-createview">view access</link> to be
1212         controlled by privileges of the view user (Christoph Heiss)
1213        </para>
1214
1215        <para>
1216         Previously, view access could only be based on the view owner.
1217        </para>
1218       </listitem>
1219
1220 <!--
1221 Author: Robert Haas <rhaas@postgresql.org>
1222 2022-01-28 [7f6772317] Adjust server-side backup to depend on pg_write_server_f
1223 -->
1224
1225       <listitem>
1226        <para>
1227         Allow members of the <link
1228         linkend="predefined-roles-table"><literal>pg_write_server_files</literal></link>
1229         predefined role to perform server-side base backups (Dagfinn
1230         Ilmari Mannsåker)
1231        </para>
1232
1233        <para>
1234         Previously only the superusers could perform such backups.
1235        </para>
1236       </listitem>
1237
1238 <!--
1239 Author: Tom Lane <tgl@sss.pgh.pa.us>
1240 2022-04-06 [a0ffa885e] Allow granting SET and ALTER SYSTEM privileges on GUC pa
1241 -->
1242
1243       <listitem>
1244        <para>
1245         Allow <link linkend="sql-grant"><command>GRANT</command></link>
1246         to assign permission to change server variables via
1247         <command>SET</command> and <command>ALTER SYSTEM</command>
1248         (Mark Dilger)
1249        </para>
1250
1251        <para>
1252         New function <function>has_parameter_privilege()</function>
1253         reports on this privilege.
1254        </para>
1255       </listitem>
1256
1257 <!--
1258 Author: Jeff Davis <jdavis@postgresql.org>
1259 2021-11-09 [4168a4745] Add pg_checkpointer predefined role for CHECKPOINT comma
1260 -->
1261
1262       <listitem>
1263        <para>
1264         Add predefined role <link
1265         linkend="predefined-roles-table"><literal>pg_checkpointer</literal></link>
1266         that allows members to run <command>CHECKPOINT</command>
1267         (Jeff Davis)
1268        </para>
1269
1270        <para>
1271         Previously checkpoints could only be run by superusers.
1272        </para>
1273       </listitem>
1274
1275 <!--
1276 Author: Jeff Davis <jdavis@postgresql.org>
1277 2021-10-27 [77ea4f943] Grant memory views to pg_read_all_stats.
1278 -->
1279
1280       <listitem>
1281        <para>
1282         Allow members of the <link
1283         linkend="predefined-roles-table"><literal>pg_read_all_stats</literal></link>
1284         predefined role to access the views <link
1285         linkend="view-pg-backend-memory-contexts"><structname>pg_backend_memory_contexts</structname></link>
1286         and <link
1287         linkend="view-pg-shmem-allocations"><structname>pg_shmem_allocations</structname></link>
1288         (Bharath Rupireddy)
1289        </para>
1290
1291        <para>
1292         Previously these views could only be accessed by superusers.
1293        </para>
1294       </listitem>
1295
1296 <!--
1297 Author: Jeff Davis <jdavis@postgresql.org>
1298 2021-10-26 [f0b051e32] Allow GRANT on pg_log_backend_memory_contexts().
1299 -->
1300
1301       <listitem>
1302        <para>
1303         Allow <link linkend="sql-grant"><command>GRANT</command></link>
1304         to assign permissions on <link
1305         linkend="view-pg-backend-memory-contexts"><function>pg_log_backend_memory_contexts()</function></link>
1306         (Jeff Davis)
1307        </para>
1308
1309        <para>
1310         Previously this function could only be run by superusers.
1311        </para>
1312       </listitem>
1313
1314      </itemizedlist>
1315
1316     </sect4>
1317
1318     <sect4>
1319      <title>Server Configuration</title>
1320
1321      <itemizedlist>
1322
1323 <!--
1324 Author: Michael Paquier <michael@paquier.xyz>
1325 2021-09-08 [bd1788051] Introduce GUC shared_memory_size
1326 Author: Michael Paquier <michael@paquier.xyz>
1327 2021-09-09 [3b231596c] Make shared_memory_size a preset option
1328 -->
1329
1330       <listitem>
1331        <para>
1332         Add server variable <link
1333         linkend="guc-shared-memory-size"><varname>shared_memory_size</varname></link>
1334         to report the size of allocated shared memory (Nathan Bossart)
1335        </para>
1336       </listitem>
1337
1338 <!--
1339 Author: Michael Paquier <michael@paquier.xyz>
1340 2021-09-21 [43c1c4f65] Introduce GUC shared_memory_size_in_huge_pages
1341 Author: Michael Paquier <michael@paquier.xyz>
1342 2022-03-24 [bbd4951b7] doc: Improve postgres command for shared_memory_size_in_
1343 -->
1344
1345       <listitem>
1346        <para>
1347         Add server variable <link
1348         linkend="guc-shared-memory-size-in-huge-pages"><varname>shared_memory_size_in_huge_pages</varname></link>
1349         to report the number of huge memory pages required (Nathan Bossart)
1350        </para>
1351
1352        <para>
1353         This is only supported on Linux.
1354        </para>
1355       </listitem>
1356
1357 <!--
1358 Author: Michael Paquier <michael@paquier.xyz>
1359 2021-09-16 [0c39c2920] Support "postgres -C" with runtime-computed GUCs
1360 -->
1361
1362       <listitem>
1363        <para>
1364         Allow <link linkend="app-postgres"><command>postgres
1365         -C</command></link> to properly report runtime-computed values
1366         (Nathan Bossart)
1367        </para>
1368
1369        <para>
1370         Previously runtime-computed values <link
1371         linkend="guc-data-checksums"><varname>data_checksums</varname></link>,
1372         <link
1373         linkend="guc-wal-segment-size"><varname>wal_segment_size</varname></link>,
1374         and <link
1375         linkend="guc-data-directory-mode"><varname>data_directory_mode</varname></link>
1376         would report values that would not be accurate on the running
1377         server.  However, this does not work on a running server.
1378        </para>
1379       </listitem>
1380
1381      </itemizedlist>
1382
1383     </sect4>
1384
1385    </sect3>
1386
1387    <sect3>
1388     <title>Streaming Replication and Recovery</title>
1389
1390     <itemizedlist>
1391
1392 <!--
1393 Author: Robert Haas <rhaas@postgresql.org>
1394 2022-02-11 [dab298471] Add suport for server-side LZ4 base backup compression.
1395 Author: Robert Haas <rhaas@postgresql.org>
1396 2022-03-08 [7cf085f07] Add support for zstd base backup compression.
1397 Author: Robert Haas <rhaas@postgresql.org>
1398 2022-03-30 [51c0d186d] Allow parallel zstd compression when taking a base backu
1399 -->
1400
1401      <listitem>
1402       <para>
1403        Add support for LZ4 and Zstandard compression of server-side <link
1404        linkend="backup-base-backup">base backups</link> (Jeevan Ladhe,
1405        Robert Haas)
1406       </para>
1407      </listitem>
1408
1409 <!--
1410 Author: Thomas Munro <tmunro@postgresql.org>
1411 2021-08-02 [7ff23c6d2] Run checkpointer and bgwriter in crash recovery.
1412 -->
1413
1414      <listitem>
1415       <para>
1416        Run checkpointer and bgwriter during crash recovery (Thomas Munro)
1417       </para>
1418      </listitem>
1419
1420 <!--
1421 Author: Thomas Munro <tmunro@postgresql.org>
1422 2022-04-07 [5dc0418fa] Prefetch data referenced by the WAL, take II.
1423 -->
1424
1425      <listitem>
1426       <para>
1427        Allow <acronym>WAL</acronym> processing to pre-fetch needed file
1428        contents (Thomas Munro)
1429       </para>
1430
1431       <para>
1432        This is controlled by the server variable <link
1433        linkend="guc-recovery-prefetch"><varname>recovery_prefetch</varname></link>.
1434       </para>
1435      </listitem>
1436
1437 <!--
1438 Author: Robert Haas <rhaas@postgresql.org>
1439 2022-02-03 [5ef1eefd7] Allow archiving via loadable modules.
1440 -->
1441
1442      <listitem>
1443       <para>
1444        Add server variable <link
1445        linkend="guc-archive-library"><varname>archive_library</varname></link>
1446        to specify the library to be called for archiving (Nathan Bossart)
1447       </para>
1448
1449       <para>
1450        Previously only shell commands could be called to perform archiving.
1451       </para>
1452      </listitem>
1453
1454 <!--
1455 Author: Jeff Davis <jdavis@postgresql.org>
1456 2021-07-09 [8e7811e95] Eliminate replication protocol error related to IDENTIFY
1457 -->
1458
1459      <listitem>
1460       <para>
1461        No longer require <link
1462        linkend="protocol-replication"><literal>IDENTIFY_SYSTEM</literal></link>
1463        to be run before <literal>START_REPLICATION</literal> (Jeff Davis)
1464       </para>
1465      </listitem>
1466
1467     </itemizedlist>
1468
1469     <sect4>
1470      <title><link linkend="logical-replication">Logical Replication</link></title>
1471
1472      <itemizedlist>
1473
1474 <!--
1475 Author: Amit Kapila <akapila@postgresql.org>
1476 2021-10-27 [5a2832465] Allow publishing the tables of schema.
1477 Author: Amit Kapila <akapila@postgresql.org>
1478 2021-12-08 [1a2aaeb0d] Fix changing the ownership of ALL TABLES IN SCHEMA publi
1479 -->
1480
1481       <listitem>
1482        <para>
1483         Allow publication of all tables in a schema (Vignesh C, Hou Zhijie,
1484         Amit Kapila)
1485        </para>
1486
1487        <para>
1488         For example, this syntax is now supported:  <link
1489         linkend="sql-createpublication"><command>CREATE PUBLICATION pub1
1490         FOR ALL TABLES IN SCHEMA s1,s2;</command></link>  <command>ALTER
1491         PUBLICATION</command> supports a similar syntax.  Tables added
1492         to the listed schemas in the future will also be replicated.
1493        </para>
1494       </listitem>
1495
1496 <!--
1497 Author: Amit Kapila <akapila@postgresql.org>
1498 2022-02-22 [52e4f0cd4] Allow specifying row filters for logical replication of
1499 Author: Tomas Vondra <tomas.vondra@postgresql.org>
1500 2022-03-17 [5a0796622] Fix row filters with multiple publications
1501 Author: Amit Kapila <akapila@postgresql.org>
1502 2022-04-18 [676eeb6dd] Add additional documentation for row filters.
1503 -->
1504
1505       <listitem>
1506        <para>
1507         Allow publication content to be filtered using a
1508         <literal>WHERE</literal> clause (Hou Zhijie, Euler Taveira,
1509         Peter Smith, Ajin Cherian, Tomas Vondra, Amit Kapila)
1510        </para>
1511       </listitem>
1512
1513 <!--
1514 Author: Tomas Vondra <tomas.vondra@postgresql.org>
1515 2022-03-26 [923def9a5] Allow specifying column lists for logical replication
1516 -->
1517
1518       <listitem>
1519        <para>
1520         Allow <link linkend="sql-createpublication">publications</link> to
1521         be restricted to specific columns (Tomas Vondra, Álvaro Herrera,
1522         Rahila Syed)
1523        </para>
1524       </listitem>
1525
1526 <!--
1527 Author: Amit Kapila <akapila@postgresql.org>
1528 2022-03-22 [208c5d65b] Add ALTER SUBSCRIPTION ... SKIP.
1529 -->
1530
1531       <listitem>
1532        <para>
1533         Allow skipping of transactions on a subscriber using <link
1534         linkend="sql-altersubscription"><command>ALTER SUBSCRIPTION
1535         ... SKIP</command></link> (Masahiko Sawada)
1536        </para>
1537       </listitem>
1538
1539 <!--
1540 Author: Amit Kapila <akapila@postgresql.org>
1541 2021-07-14 [a8fd13cab] Add support for prepared transactions to built-in logica
1542 Author: Amit Kapila <akapila@postgresql.org>
1543 2021-08-04 [63cf61cde] Add prepare API support for streaming transactions in lo
1544 -->
1545
1546       <listitem>
1547        <para>
1548         Add support for prepared transactions to built-in logical
1549         replication (Peter Smith, Ajin Cherian, Amit Kapila, Nikhil
1550         Sontakke, Stas Kelvich)
1551        </para>
1552       </listitem>
1553
1554 <!--
1555 Author: Amit Kapila <akapila@postgresql.org>
1556 2021-06-30 [cda03cfed] Allow enabling two-phase option via replication protocol
1557 -->
1558
1559       <listitem>
1560        <para>
1561         Add two-phase information to the logical replication stream
1562         (Ajin Cherian)
1563        </para>
1564
1565        <para>
1566         The new <link
1567         linkend="protocol-replication"><literal>CREATE_REPLICATION_SLOT</literal></link>
1568         option is called <literal>TWO_PHASE</literal>.
1569         <application>pg_recvlogical</application> now supports a new
1570         <option>--two-phase</option> option during slot creation.
1571        </para>
1572       </listitem>
1573
1574 <!--
1575 Author: Amit Kapila <akapila@postgresql.org>
1576 2022-03-30 [d5a9d86d8] Skip empty transactions for logical replication.
1577 -->
1578
1579       <listitem>
1580        <para>
1581         Prevent logical replication of empty transactions (Ajin Cherian,
1582         Hou Zhijie, Euler Taveira)
1583        </para>
1584
1585        <para>
1586         Previously, write transactions would send empty transactions to
1587         subscribers if subscribed tables were not modified.
1588        </para>
1589       </listitem>
1590
1591 <!--
1592 Author: Michael Paquier <michael@paquier.xyz>
1593 2021-11-23 [1922d7c6e] Add SQL functions to monitor the directory contents of r
1594 -->
1595
1596       <listitem>
1597        <para>
1598         Add <acronym>SQL</acronym> functions to monitor the directory
1599         contents of logical replication slots (Bharath Rupireddy)
1600        </para>
1601
1602        <para>
1603         Specifically, the functions are <link
1604         linkend="functions-admin-genfile-table"><function>pg_ls_logicalsnapdir()</function></link>,
1605         <function>pg_ls_logicalmapdir()</function>, and
1606         <function>pg_ls_replslotdir()</function>.  They can be run by
1607         members of the predefined <literal>pg_monitor</literal> role.
1608        </para>
1609       </listitem>
1610
1611 <!--
1612 Author: Amit Kapila <akapila@postgresql.org>
1613 2022-03-14 [705e20f85] Optionally disable subscriptions on error.
1614 -->
1615
1616       <listitem>
1617        <para>
1618         Allow subscribers to stop logical replication application on error
1619         (Osumi Takamichi, Mark Dilger)
1620        </para>
1621
1622        <para>
1623         This is enabled with the subscriber option <link
1624         linkend="sql-createsubscription"><literal>disable_on_error</literal></link>
1625         and avoids possible infinite error loops during stream application.
1626        </para>
1627       </listitem>
1628
1629 <!--
1630 Author: Tom Lane <tgl@sss.pgh.pa.us>
1631 2021-11-02 [f3d4019da] Ensure consistent logical replication of datetime and fl
1632 -->
1633
1634       <listitem>
1635        <para>
1636         Adjust subscriber server variables to match the publisher so
1637         datetime and float8 values are interpreted consistently (Japin Li)
1638        </para>
1639
1640        <para>
1641         Some publishers might be relying on inconsistent behavior.
1642        </para>
1643       </listitem>
1644
1645 <!--
1646 Author: Amit Kapila <akapila@postgresql.org>
1647 2021-11-30 [8d74fc96d] Add a view to show the stats of subscription workers.
1648 Author: Amit Kapila <akapila@postgresql.org>
1649 2022-03-01 [7a8507329] Reconsider pg_stat_subscription_workers view.
1650 -->
1651
1652       <listitem>
1653        <para>
1654         Add system view <link
1655         linkend="monitoring-pg-stat-subscription-stats"><structname>pg_stat_subscription_stats</structname></link>
1656         to report on subscriber activity (Masahiko Sawada)
1657        </para>
1658
1659        <para>
1660         New function <link
1661         linkend="monitoring-stats-functions"><function>pg_stat_reset_subscription_stats()</function></link>
1662         allows the resetting of subscriber statistics.
1663        </para>
1664       </listitem>
1665
1666 <!--
1667 Author: Amit Kapila <akapila@postgresql.org>
1668 2021-12-08 [a61bff2bf] De-duplicate the result of pg_publication_tables view.
1669 -->
1670
1671       <listitem>
1672        <para>
1673         Remove incorrect duplicate partitions in system view <link
1674         linkend="view-pg-publication-tables"><structname>pg_publication_tables</structname></link>
1675         (Hou Zhijie)
1676        </para>
1677       </listitem>
1678
1679      </itemizedlist>
1680
1681     </sect4>
1682
1683    </sect3>
1684
1685    <sect3>
1686     <title><link linkend="sql-select"><command>SELECT</command></link>, <link linkend="sql-insert"><command>INSERT</command></link></title>
1687
1688     <itemizedlist>
1689
1690 <!--
1691 Author: David Rowley <drowley@postgresql.org>
1692 2021-08-22 [22c4e88eb] Allow parallel DISTINCT
1693 -->
1694
1695      <listitem>
1696       <para>
1697        Allow <command>SELECT DISTINCT</command> to be parallelized
1698        (David Rowley)
1699       </para>
1700      </listitem>
1701
1702     </itemizedlist>
1703
1704    </sect3>
1705
1706    <sect3>
1707     <title>Utility Commands</title>
1708
1709     <itemizedlist>
1710
1711 <!--
1712 Author: Alvaro Herrera <alvherre@alvh.no-ip.org>
1713 2022-03-28 [7103ebb7a] Add support for MERGE SQL command
1714 -->
1715
1716      <listitem>
1717       <para>
1718        Add <acronym>SQL</acronym> <command>MERGE</command> command to
1719        adjust one table to match another (Simon Riggs, Pavan Deolasee,
1720        Álvaro Herrera, Amit Langote)
1721       </para>
1722
1723       <para>
1724        This is similar to <command>INSERT ... ON CONFLICT</command>
1725        but more batch-oriented.
1726       </para>
1727      </listitem>
1728
1729 <!--
1730 Author: Peter Eisentraut <peter@eisentraut.org>
1731 2022-01-28 [43f33dc01] Add HEADER support to COPY text format
1732 Author: Peter Eisentraut <peter@eisentraut.org>
1733 2022-03-30 [072132f04] Add header matching mode to COPY FROM
1734 -->
1735
1736      <listitem>
1737       <para>
1738        Add support for <literal>HEADER</literal> option in <link
1739        linkend="sql-copy"><command>COPY</command></link> text format
1740        (Rémi Lapeyre)
1741       </para>
1742
1743       <para>
1744        The new option causes the column names to be output, and optionally
1745        verified on input.
1746       </para>
1747      </listitem>
1748
1749 <!--
1750 Author: Robert Haas <rhaas@postgresql.org>
1751 2022-03-29 [9c08aea6a] Add new block-by-block strategy for CREATE DATABASE.
1752 -->
1753
1754      <listitem>
1755       <para>
1756        Add new default <acronym>WAL</acronym>-logged method for <link
1757        linkend="sql-createdatabase">database creation</link> (Dilip Kumar)
1758       </para>
1759
1760       <para>
1761        This avoids the need for checkpoints during database creation;
1762        the old method is still available.
1763       </para>
1764      </listitem>
1765
1766 <!--
1767 Author: Robert Haas <rhaas@postgresql.org>
1768 2022-01-24 [aa0105141] pg_upgrade: Preserve database OIDs.
1769 -->
1770
1771      <listitem>
1772       <para>
1773        Allow <link linkend="sql-createdatabase"><command>CREATE
1774        DATABASE</command></link> to set the database <acronym>OID</acronym>
1775        (Shruthi KC, Antonin Houska)
1776       </para>
1777      </listitem>
1778
1779 <!--
1780 Author: Thomas Munro <tmunro@postgresql.org>
1781 2022-02-12 [4eb217631] Fix DROP {DATABASE,TABLESPACE} on Windows.
1782 -->
1783
1784      <listitem>
1785       <para>
1786        Prevent <link linkend="sql-dropdatabase"><command>DROP
1787        DATABASE</command></link>, <link
1788        linkend="sql-droptablespace"><command>DROP
1789        TABLESPACE</command></link>, and <link
1790        linkend="sql-alterdatabase"><command>ALTER DATABASE SET
1791        TABLESPACE</command></link> from occasionally failing during
1792        concurrent use on Windows (Thomas Munro)
1793       </para>
1794      </listitem>
1795
1796 <!--
1797 Author: Peter Eisentraut <peter@eisentraut.org>
1798 2021-12-08 [d6f96ed94] Allow specifying column list for foreign key ON DELETE S
1799 -->
1800
1801      <listitem>
1802       <para>
1803        Allow foreign key <link linkend="ddl-constraints-fk"><literal>ON
1804        DELETE SET</literal></link> actions to affect only specified columns
1805        (Paul Martinez)
1806       </para>
1807
1808       <para>
1809        Previously, all of the columns in the foreign key were always
1810        affected.
1811       </para>
1812      </listitem>
1813
1814 <!--
1815 Author: Michael Paquier <michael@paquier.xyz>
1816 2021-07-28 [b0483263d] Add support for SET ACCESS METHOD in ALTER TABLE
1817 -->
1818
1819      <listitem>
1820       <para>
1821        Allow <link linkend="sql-altertable"><command>ALTER
1822        TABLE</command></link> to modify a table's <literal>ACCESS
1823        METHOD</literal> (Justin Pryzby, Jeff Davis)
1824       </para>
1825      </listitem>
1826
1827 <!--
1828 Author: Michael Paquier <michael@paquier.xyz>
1829 2021-08-10 [7b565843a] Add call to object access hook at the end of table rewri
1830 -->
1831
1832      <listitem>
1833       <para>
1834        Properly call object access hooks when <link
1835        linkend="sql-altertable"><command>ALTER TABLE</command></link>
1836        causes table rewrites (Michael Paquier)
1837       </para>
1838      </listitem>
1839
1840     </itemizedlist>
1841
1842    </sect3>
1843
1844    <sect3>
1845     <title>Data Types</title>
1846
1847     <itemizedlist>
1848
1849 <!--
1850 Author: Dean Rasheed <dean.a.rasheed@gmail.com>
1851 2021-07-26 [085f931f5] Allow numeric scale to be negative or greater than preci
1852 -->
1853
1854      <listitem>
1855       <para>
1856        Allow <link linkend="datatype-numeric"><type>numeric</type></link>
1857        scale to be negative or greater than precision (Dean Rasheed,
1858        Tom Lane)
1859       </para>
1860
1861       <para>
1862        This allows rounding of values to the left of the decimal point,
1863        e.g., <literal>'1234'::numeric(4, -2)</literal> returns 1200.
1864       </para>
1865      </listitem>
1866
1867 <!--
1868 Author: Tom Lane <tgl@sss.pgh.pa.us>
1869 2022-04-02 [e39f99046] Fix overflow hazards in interval input and output conver
1870 -->
1871
1872      <listitem>
1873       <para>
1874        Improve overflow detection when casting values to <link
1875        linkend="datatype-datetime">interval</link> (Joe Koshakow)
1876       </para>
1877      </listitem>
1878
1879 <!--
1880 Author: Peter Eisentraut <peter@eisentraut.org>
1881 2022-04-07 [344d62fb9] Unlogged sequences
1882 -->
1883
1884      <listitem>
1885       <para>
1886        Allow the creation of unlogged <link
1887        linkend="sql-createsequence">sequences</link> (Peter Eisentraut)
1888       </para>
1889      </listitem>
1890
1891 <!--
1892 Author: John Naylor <john.naylor@postgresql.org>
1893 2021-08-26 [bab982161] Update display widths as part of updating Unicode
1894 Author: Peter Eisentraut <peter@eisentraut.org>
1895 2021-09-15 [f7e56f1f5] Update Unicode data to Unicode 14.0.0
1896 -->
1897
1898      <listitem>
1899       <para>
1900        Update the display width information of modern Unicode characters,
1901        like emojis (Jacob Champion)
1902       </para>
1903
1904       <para>
1905        Also update from Unicode 5.0 to 14.0.0.  There is now an automated
1906        way to keep Postgres updated with Unicode releases.
1907       </para>
1908      </listitem>
1909
1910     </itemizedlist>
1911
1912    </sect3>
1913
1914    <sect3>
1915     <title>Functions</title>
1916
1917     <itemizedlist>
1918
1919 <!--
1920 Author: Peter Eisentraut <peter@eisentraut.org>
1921 2022-03-30 [7ae1619bc] Add range_agg with multirange inputs
1922 -->
1923
1924      <listitem>
1925       <para>
1926        Add multirange input to <link
1927        linkend="functions-aggregate-table"><function>range_agg()</function></link>
1928        (Paul Jungwirth)
1929       </para>
1930      </listitem>
1931
1932 <!--
1933 Author: Fujii Masao <fujii@postgresql.org>
1934 2022-02-10 [400fc6b64] Add min() and max() aggregates for xid8.
1935 -->
1936
1937      <listitem>
1938       <para>
1939        Add <link linkend="tutorial-agg"><function>MIN()</function></link>
1940        and <function>MAX()</function> aggregates for the <link
1941        linkend="datatype-int"><type>xid8</type></link> data type (Ken Kato)
1942       </para>
1943      </listitem>
1944
1945 <!--
1946 Author: Tom Lane <tgl@sss.pgh.pa.us>
1947 2021-08-03 [642433707] Add assorted new regexp_xxx SQL functions.
1948 -->
1949
1950      <listitem>
1951       <para>
1952        Add regular expression functions for compatibility with other
1953        relational systems (Gilles Darold, Tom Lane)
1954       </para>
1955
1956       <para>
1957        Specifically, the new functions are <link
1958        linkend="functions-string-other"><function>regexp_count()</function></link>,
1959        <function>regexp_instr()</function>,
1960        <function>regexp_like()</function>, and
1961        <function>regexp_substr()</function>.  Some new optional arguments
1962        were also added to <function>regexp_replace()</function>.
1963       </para>
1964      </listitem>
1965
1966 <!--
1967 Author: Tom Lane <tgl@sss.pgh.pa.us>
1968 2021-12-13 [c5c192d7b] Implement poly_distance().
1969 -->
1970
1971      <listitem>
1972       <para>
1973        Add the ability to compute the distance between <link
1974        linkend="datatype-polygon"><type>polygons</type></link> (Tom Lane)
1975       </para>
1976      </listitem>
1977
1978 <!--
1979 Author: Robert Haas <rhaas@postgresql.org>
1980 2022-03-14 [9dde82899] Support "of", "tzh", and "tzm" format codes.
1981 -->
1982
1983      <listitem>
1984       <para>
1985        Add <link
1986        linkend="functions-formatting-table"><function>to_char()</function></link>
1987        format codes <literal>of</literal>, <literal>tzh</literal>, and
1988        <literal>tzm</literal> format codes (Nitin Jadhav)
1989       </para>
1990
1991       <para>
1992        The upper-case versions of these were already supported.
1993       </para>
1994      </listitem>
1995
1996 <!--
1997 Author: Tom Lane <tgl@sss.pgh.pa.us>
1998 2021-09-06 [388e71af8] Make timetz_zone() stable, and correct a bug for DYNTZ a
1999 -->
2000
2001      <listitem>
2002       <para>
2003        Improve the optimization of <function>timetz_zone()</function> by
2004        stabilizing its value at transaction start (Aleksander Alekseev,
2005        Tom Lane)
2006       </para>
2007
2008       <para>
2009        HOW IS THIS USED?
2010       </para>
2011      </listitem>
2012
2013 <!--
2014 Author: Tom Lane <tgl@sss.pgh.pa.us>
2015 2021-11-06 [cbe25dcff] Disallow making an empty lexeme via array_to_tsvector().
2016 -->
2017
2018      <listitem>
2019       <para>
2020        Allow <function>tsvector_delete_arr()</function> and
2021        <function>tsvector_setweight_by_filter()</function> to accept
2022        empty array elements (Jean-Christophe Arnu)
2023       </para>
2024
2025       <para>
2026        These lexemes are not stored so the acceptance of empty array
2027        elements is not a problem.  NOT DOCUMENTED, USER API?
2028       </para>
2029      </listitem>
2030
2031 <!--
2032 Author: David Rowley <drowley@postgresql.org>
2033 2021-07-09 [ca2e4472b] Teach pg_size_pretty and pg_size_bytes about petabytes
2034 -->
2035
2036      <listitem>
2037       <para>
2038        Add support for petabyte units to <link
2039        linkend="functions-admin-dbsize"><function>pg_size_pretty()</function></link>
2040        and <function>pg_size_bytes()</function> (David Christensen)
2041       </para>
2042      </listitem>
2043
2044 <!--
2045 Author: Tom Lane <tgl@sss.pgh.pa.us>
2046 2021-07-27 [024515cac] In event triggers, use "pg_temp" only for our own temp s
2047 -->
2048
2049      <listitem>
2050       <para>
2051        Change <link
2052        linkend="pg-event-trigger-ddl-command-end-functions"><function>pg_event_trigger_ddl_commands()</function></link>
2053        to output references to non-local temporary schemas using the
2054        actual schema name (Tom Lane)
2055       </para>
2056
2057       <para>
2058        Previously this function referred to temporary schemas as
2059        <literal>pg_temp</literal>.
2060       </para>
2061      </listitem>
2062
2063     </itemizedlist>
2064
2065     <sect4>
2066      <title><acronym>JSON</acronym></title>
2067
2068      <itemizedlist>
2069
2070 <!--
2071 Author: Andrew Dunstan <andrew@dunslane.net>
2072 2022-03-27 [f79b803dc] Common SQL/JSON clauses
2073 Author: Andrew Dunstan <andrew@dunslane.net>
2074 2022-03-27 [f4fb45d15] SQL/JSON constructors
2075 Author: Andrew Dunstan <andrew@dunslane.net>
2076 2022-03-30 [606948b05] SQL JSON functions
2077 Author: Andrew Dunstan <andrew@dunslane.net>
2078 2022-03-31 [49082c2cc] RETURNING clause for JSON() and JSON_SCALAR()
2079 Author: Andrew Dunstan <andrew@dunslane.net>
2080 2022-04-07 [a6baa4bad] Documentation for SQL/JSON features
2081 -->
2082
2083       <listitem>
2084        <para>
2085         Add <acronym>SQL</acronym>/<acronym>JSON</acronym>-standard
2086         <acronym>JSON</acronym> constructors (Nikita Glukhov)
2087        </para>
2088
2089        <para>
2090         The construction functions are <link
2091         linkend="functions-sqljson-producing"><function>json()</function></link>,
2092         <function>json_scalar()</function>, and
2093         <function>json_serialize()</function>,
2094         <function>json_array()</function>,
2095         <function>json_arrayagg()</function>,
2096         <function>json_object()</function>, and
2097         <function>json_objectagg()</function>.  They have a few functional
2098         advantages over the existing JSON functions.
2099        </para>
2100       </listitem>
2101
2102 <!--
2103 Author: Andrew Dunstan <andrew@dunslane.net>
2104 2022-03-29 [1a36bc9db] SQL/JSON query functions
2105 -->
2106
2107       <listitem>
2108        <para>
2109         Add <acronym>SQL</acronym>/<acronym>JSON</acronym>
2110         query functions <link
2111         linkend="functions-sqljson-querying"><function>json_exists()</function></link>,
2112         <function>json_query()</function>, and
2113         <function>json_value()</function> (Nikita Glukhov)
2114        </para>
2115       </listitem>
2116
2117 <!--
2118 Author: Andrew Dunstan <andrew@dunslane.net>
2119 2022-03-28 [33a377608] IS JSON predicate
2120 -->
2121
2122       <listitem>
2123        <para>
2124         Add <acronym>JSON</acronym> predicates to test
2125         <type>JSON</type>/<type>JSONB</type> values (Nikita Glukhov)
2126        </para>
2127
2128        <para>
2129         The clauses are <link linkend="functions-sqljson-misc"><literal>IS
2130         JSON</literal></link> [ <literal>VALUE</literal> |
2131         <literal>ARRAY</literal>
2132       | <literal>OBJECT</literal> | <literal>SCALAR</literal> |
2133         [<literal>WITH</literal> | <literal>WITHOUT</literal> ]
2134         <literal>UNIQUE KEYS</literal> ].
2135        </para>
2136       </listitem>
2137
2138 <!--
2139 Author: Andrew Dunstan <andrew@dunslane.net>
2140 2022-04-04 [4e34747c8] JSON_TABLE
2141 Author: Andrew Dunstan <andrew@dunslane.net>
2142 2022-04-05 [fadb48b00] PLAN clauses for JSON_TABLE
2143 -->
2144
2145       <listitem>
2146        <para>
2147         Add function <link
2148         linkend="functions-sqljson-table"><function>JSON_TABLE()</function></link>
2149         to cause <acronym>JSON</acronym> data to be treated as a table
2150         (Nikita Glukhov)
2151        </para>
2152       </listitem>
2153
2154      </itemizedlist>
2155
2156     </sect4>
2157
2158    </sect3>
2159
2160    <sect3>
2161     <title><link linkend="plpgsql">PL/pgSQL</link></title>
2162
2163     <itemizedlist>
2164
2165 <!--
2166 Author: Tom Lane <tgl@sss.pgh.pa.us>
2167 2022-04-30 [ccd10a9bf] Tighten enforcement of variable CONSTANT markings in plp
2168 -->
2169
2170      <listitem>
2171       <para>
2172        Fix enforcement of PL/pgSQL variable <literal>CONSTANT</literal>
2173        markings (Tom Lane)
2174       </para>
2175
2176       <para>
2177        Previously, a variable used as a <link
2178        linkend="plpgsql-statements-calling-procedure"><command>CALL</command></link>
2179        output parameter or refcursor <command>OPEN</command> variable
2180        would not enforce <literal>CONSTANT</literal>.
2181       </para>
2182      </listitem>
2183
2184     </itemizedlist>
2185
2186    </sect3>
2187
2188    <sect3>
2189     <title><link linkend="libpq">libpq</link></title>
2190
2191     <itemizedlist>
2192
2193 <!--
2194 Author: Peter Eisentraut <peter@eisentraut.org>
2195 2022-04-01 [c1932e542] libpq: Allow IP address SANs in server certificates
2196 -->
2197
2198      <listitem>
2199       <para>
2200        Allow <acronym>IP</acronym> address matching against a server
2201        certificate's Subject Alternative Name (Jacob Champion)
2202       </para>
2203      </listitem>
2204
2205 <!--
2206 Author: Daniel Gustafsson <dgustafsson@postgresql.org>
2207 2022-03-29 [ebc8b7d44] Enable SSL library detection via PQsslAttribute()
2208 -->
2209
2210      <listitem>
2211       <para>
2212        Allow <function>PQsslAttribute()</function> to report the
2213        <acronym>SSL</acronym> library type without requiring a libpq
2214        connection (Jacob Champion)
2215       </para>
2216      </listitem>
2217
2218 <!--
2219 Author: Tom Lane <tgl@sss.pgh.pa.us>
2220 2022-01-18 [5987feb70] Make PQcancel use the PGconn's tcp_user_timeout and keep
2221 -->
2222
2223      <listitem>
2224       <para>
2225        Change query cancellations sent by the client to use the same
2226        <acronym>TCP</acronym> settings as normal client connections
2227        (Jelte Fennema)
2228       </para>
2229
2230       <para>
2231        This allows configured <acronym>TCP</acronym> timeouts to apply
2232        to query cancel connections.
2233       </para>
2234      </listitem>
2235
2236 <!--
2237 Author: Tom Lane <tgl@sss.pgh.pa.us>
2238 2022-02-18 [ce1e7a2f7] Don't let libpq "event" procs break the state of PGresul
2239 Author: Tom Lane <tgl@sss.pgh.pa.us>
2240 2022-02-18 [2e372869a] Don't let libpq PGEVT_CONNRESET callbacks break a PGconn
2241 -->
2242
2243      <listitem>
2244       <para>
2245        Prevent libpq event callback failures from forcing an error result
2246        (Tom Lane)
2247       </para>
2248      </listitem>
2249
2250     </itemizedlist>
2251
2252    </sect3>
2253
2254    <sect3>
2255     <title>Client Applications</title>
2256
2257     <itemizedlist>
2258
2259 <!--
2260 Author: Tom Lane <tgl@sss.pgh.pa.us>
2261 2022-01-09 [376ce3e40] Prefer $HOME when looking up the current user's home dir
2262 -->
2263
2264      <listitem>
2265       <para>
2266        On Unix platforms, have client applications like <link
2267        linkend="app-psql"><application>psql</application></link>
2268        check <envar>HOME</envar> environment variable for the user's
2269        home directory before checking the operating system definition
2270        (Anders Kaseorg)
2271       </para>
2272      </listitem>
2273
2274     </itemizedlist>
2275
2276      <sect4>
2277       <title><xref linkend="app-psql"/></title>
2278
2279       <itemizedlist>
2280
2281 <!--
2282 Author: Heikki Linnakangas <heikki.linnakangas@iki.fi>
2283 2021-07-14 [eec57115e] In psql \copy from, send data to server in larger chunks
2284 -->
2285
2286        <listitem>
2287         <para>
2288         Improve performance of <application>psql</application>'s \copy
2289         command (Heikki Linnakangas)
2290        </para>
2291       </listitem>
2292
2293 <!--
2294 Author: Tom Lane <tgl@sss.pgh.pa.us>
2295 2021-12-20 [33d3eeadb] Add a \getenv command to psql.
2296 -->
2297
2298       <listitem>
2299        <para>
2300         Add <application>psql</application> command \getenv
2301         to assign the value of an environment variable to a
2302         <application>psql</application> variable (Tom Lane)
2303        </para>
2304       </listitem>
2305
2306 <!--
2307 Author: Tom Lane <tgl@sss.pgh.pa.us>
2308 2022-01-06 [328dfbdab] Extend psql's \lo_list/\dl to be able to print large obj
2309 -->
2310
2311       <listitem>
2312        <para>
2313         Add '+' option to <application>psql</application>'s
2314         <literal>\lo_list</literal>/<literal>\dl</literal> to show object
2315         privileges (Pavel Luzanov)
2316        </para>
2317       </listitem>
2318
2319 <!--
2320 Author: Tom Lane <tgl@sss.pgh.pa.us>
2321 2022-04-07 [3e707fbb4] psql: add \dconfig command to show server's configuratio
2322 Author: Tom Lane <tgl@sss.pgh.pa.us>
2323 2022-04-11 [5e70d8b5d] Tweak the default behavior of psql's \dconfig.
2324 Author: Tom Lane <tgl@sss.pgh.pa.us>
2325 2022-04-13 [139d46ee2] Further tweak the default behavior of psql's \dconfig.
2326 -->
2327
2328       <listitem>
2329        <para>
2330         Add <application>psql</application> \dconfig to report server
2331         variables (Mark Dilger, Tom Lane)
2332        </para>
2333
2334        <para>
2335         This is similar to the server-side <command>SHOW</command>
2336         command but can process patterns.
2337        </para>
2338       </listitem>
2339
2340 <!--
2341 Author: Thomas Munro <tmunro@postgresql.org>
2342 2021-07-13 [7c09d2797] Add PSQL_WATCH_PAGER for psql's \watch command.
2343 -->
2344
2345       <listitem>
2346        <para>
2347         Add pager option for <application>psql</application>'s \watch
2348         command (Pavel Stehule, Thomas Munro)
2349        </para>
2350
2351        <para>
2352         This is only supported on Unix, and is controlled by
2353         <envar>PSQL_WATCH_PAGER</envar>.
2354        </para>
2355       </listitem>
2356
2357 <!--
2358 Author: Tom Lane <tgl@sss.pgh.pa.us>
2359 2021-12-01 [83884682f] psql: include intra-query "- -" comments in what's sent t
2360 Author: Tom Lane <tgl@sss.pgh.pa.us>
2361 2021-12-01 [c2f654930] psql: treat "- -" comments between queries as separate hi
2362 -->
2363
2364       <listitem>
2365        <para>
2366         Have <application>psql</application> send intra-query double-hyphen
2367         comments to the server (Tom Lane, Greg Nancarrow)
2368        </para>
2369
2370        <para>
2371         Previously such comments were removed from the query
2372         before being sent.  Double-hyphen comments that are before
2373         query text are not sent, and are not recorded as separate
2374         <application>psql</application> history entries.
2375        </para>
2376       </listitem>
2377
2378 <!--
2379 Author: Tom Lane <tgl@sss.pgh.pa.us>
2380 2021-12-01 [3d858af07] psql: initialize comment-begin setting to a useful value
2381 -->
2382
2383       <listitem>
2384        <para>
2385         Adjust <application>psql</application>'s readline meta-# to insert
2386         a double-hyphen comment marker (Tom Lane)
2387        </para>
2388
2389        <para>
2390         Previously an unhelpful pound marker was inserted.
2391        </para>
2392       </listitem>
2393
2394 <!--
2395 Author: Peter Eisentraut <peter@eisentraut.org>
2396 2022-04-04 [7844c9918] psql: Show all query results by default
2397 -->
2398
2399       <listitem>
2400        <para>
2401         Have <application>psql</application> output all results if multiple
2402         queries are passed to the server at once (Fabien Coelho)
2403        </para>
2404
2405        <para>
2406         This can be disabled by setting <envar>SHOW_ALL_RESULTS</envar>.
2407        </para>
2408       </listitem>
2409
2410 <!--
2411 Author: Michael Paquier <michael@paquier.xyz>
2412 2021-08-10 [e2ce88b58] Add tab completion for DECLARE .. ASENSITIVE in psql
2413 Author: Michael Paquier <michael@paquier.xyz>
2414 2021-08-25 [346511313] Add tab completion for EXPLAIN .. EXECUTE in psql
2415 Author: Michael Paquier <michael@paquier.xyz>
2416 2021-08-30 [d3fa87657] Add more tab completion support for ALTER TABLE ADD in p
2417 Author: Michael Paquier <michael@paquier.xyz>
2418 2021-08-31 [f2bbadce6] Add tab completion for data types after ALTER TABLE ADD
2419 Author: Fujii Masao <fujii@postgresql.org>
2420 2021-09-01 [b0c066297] Improve tab-completion for CREATE PUBLICATION.
2421 Author: Fujii Masao <fujii@postgresql.org>
2422 2021-10-05 [0b0d277c3] psql: Improve tab-completion for LOCK TABLE.
2423 Author: Michael Paquier <michael@paquier.xyz>
2424 2021-11-05 [a5b336b8b] Improve psql tab completion for COMMENT
2425 Author: Michael Paquier <michael@paquier.xyz>
2426 2021-11-19 [0cd6d3b3c] Improve psql tab completion for transforms, domains and
2427 Author: Michael Paquier <michael@paquier.xyz>
2428 2021-11-29 [f44ceb46e] Improve psql tab completion for views, FDWs, sequences a
2429 Author: Michael Paquier <michael@paquier.xyz>
2430 2021-12-01 [9270778f4] Improve psql tab completion for various DROP commands
2431 Author: Tom Lane <tgl@sss.pgh.pa.us>
2432 2022-01-03 [dfe67c0e8] Tab completion: don't offer valid constraints in VALIDAT
2433 Author: Fujii Masao <fujii@postgresql.org>
2434 2022-01-15 [74527c3e0] Add tab-completion for CREATE FOREIGN TABLE.
2435 Author: Peter Eisentraut <peter@eisentraut.org>
2436 2022-01-27 [fefce9ef9] psql: Add tab completion for ALTER COLLATION / REFRESH V
2437 Author: Alvaro Herrera <alvherre@alvh.no-ip.org>
2438 2022-01-28 [95787e849] Tab-complete ALTER PUBLICATION ADD TABLE with list of ta
2439 Author: Tom Lane <tgl@sss.pgh.pa.us>
2440 2022-01-30 [02b8048ba] psql: improve tab-complete's handling of variant SQL nam
2441 Author: Tom Lane <tgl@sss.pgh.pa.us>
2442 2022-02-01 [020258fbd] Treat case of tab-completion keywords a bit more careful
2443 Author: Tom Lane <tgl@sss.pgh.pa.us>
2444 2022-02-09 [f0cd9097c] Further tweaks for psql's new tab-completion logic.
2445 Author: Tom Lane <tgl@sss.pgh.pa.us>
2446 2022-03-20 [7fa3db367] psql: handle tab completion of timezone names after "SET
2447 Author: Tomas Vondra <tomas.vondra@postgresql.org>
2448 2022-03-25 [2d2232933] Update tab-completion for CREATE PUBLICATION with sequen
2449 Author: Tom Lane <tgl@sss.pgh.pa.us>
2450 2022-04-13 [b5607b074] Fix case sensitivity in psql's tab completion for GUC na
2451 -->
2452
2453       <listitem>
2454        <para>
2455         Improve <application>psql</application>'s tab completion (Shinya
2456         Kato, Dagfinn Ilmari Mannsåker, Peter Smith, Koyu Tanigawa,
2457         Ken Kato, David Fetter, Haiying Tang, Peter Eisentraut, Álvaro
2458         Herrera, Tom Lane, Masahiko Sawada)
2459        </para>
2460       </listitem>
2461
2462 <!--
2463 Author: Tom Lane <tgl@sss.pgh.pa.us>
2464 2021-12-16 [cf0cab868] Remove psql support for server versions preceding 9.2.
2465 -->
2466
2467       <listitem>
2468        <para>
2469         Limit support of <application>psql</application> to servers running
2470         <productname>PostgreSQL</productname> 9.2 and later (Tom Lane)
2471        </para>
2472       </listitem>
2473
2474      </itemizedlist>
2475
2476     </sect4>
2477
2478    </sect3>
2479
2480    <sect3>
2481     <title>Server Applications</title>
2482
2483     <itemizedlist>
2484
2485 <!--
2486 Author: Robert Haas <rhaas@postgresql.org>
2487 2022-01-20 [3500ccc39] Support base backup targets.
2488 -->
2489
2490      <listitem>
2491       <para>
2492        Add new <link
2493        linkend="app-pgbasebackup"><application>pg_basebackup</application></link>
2494        option <option>--target</option> to control the base backup location
2495        (Robert Haas)
2496       </para>
2497
2498       <para>
2499        New output options are <literal>server</literal> to write the
2500        backup locally and <literal>blackhole</literal> to discard the
2501        backup (for testing).
2502       </para>
2503      </listitem>
2504
2505 <!--
2506 Author: Robert Haas <rhaas@postgresql.org>
2507 2022-02-11 [751b8d23b] pg_basebackup: Allow client-side LZ4 (de)compression.
2508 Author: Robert Haas <rhaas@postgresql.org>
2509 2022-03-08 [7cf085f07] Add support for zstd base backup compression.
2510 -->
2511
2512      <listitem>
2513       <para>
2514        Allow <application>pg_basebackup</application> to use LZ4 and
2515        Zstandard compression on server-side base backup files (Dipesh
2516        Pandit, Jeevan Ladhe)
2517       </para>
2518      </listitem>
2519
2520 <!--
2521 Author: Michael Paquier <michael@paquier.xyz>
2522 2022-01-21 [5c649fe15] Extend the options of pg_basebackup to control compressi
2523 Author: Robert Haas <rhaas@postgresql.org>
2524 2022-01-24 [0ad803291] Server-side gzip compression.
2525 Author: Robert Haas <rhaas@postgresql.org>
2526 2022-01-25 [e1f860f13] Tidy up a few cosmetic issues related to pg_basebackup.
2527 -->
2528
2529      <listitem>
2530       <para>
2531        Allow <application>pg_basebackup</application>'s
2532        <option>--compress</option> option to control the compression
2533        method and options (Michael Paquier, Robert Haas)
2534       </para>
2535
2536       <para>
2537        New options include <literal>server-gzip</literal> (gzip
2538        on the server), <literal>client-gzip</literal> (same as
2539        <literal>gzip</literal>).
2540       </para>
2541      </listitem>
2542
2543 <!--
2544 Author: Robert Haas <rhaas@postgresql.org>
2545 2022-01-28 [d45099425] Allow server-side compression to be used with -Fp.
2546 -->
2547
2548      <listitem>
2549       <para>
2550        Allow <application>pg_basebackup</application> to compress on
2551        the server side and decompress on the client side before storage
2552        (Dipesh Pandit)
2553       </para>
2554
2555       <para>
2556        This is accomplished by specifying compression on the server side
2557        and plain output format.
2558       </para>
2559      </listitem>
2560
2561 <!--
2562 Author: Michael Paquier <michael@paquier.xyz>
2563 2021-11-05 [babbbb595] Add support for LZ4 compression in pg_receivewal
2564 Author: Michael Paquier <michael@paquier.xyz>
2565 2022-04-13 [042a923ad] Rework compression options of pg_receivewal
2566 -->
2567
2568      <listitem>
2569       <para>
2570        Add the LZ4 compression method to <link
2571        linkend="app-pgreceivewal"><application>pg_receivewal</application></link>
2572        (Georgios Kokolatos)
2573       </para>
2574
2575       <para>
2576        This is enabled via <literal>--compress=lz4</literal> and requires
2577        binaries to be built using <option>--with-lz4</option>.
2578       </para>
2579      </listitem>
2580
2581 <!--
2582 Author: Michael Paquier <michael@paquier.xyz>
2583 2021-11-04 [d62bcc8b0] Rework compression options of pg_receivewal
2584 -->
2585
2586      <listitem>
2587       <para>
2588        Add additional capabilities to
2589        <application>pg_receivewal</application>'s
2590        <option>--compress</option> option (Georgios Kokolatos)
2591       </para>
2592      </listitem>
2593
2594 <!--
2595 Author: Michael Paquier <michael@paquier.xyz>
2596 2021-10-26 [f61e1dd2c] Allow pg_receivewal to stream from a slot's restart LSN
2597 -->
2598
2599      <listitem>
2600       <para>
2601        Improve <application>pg_receivewal</application>'s ability to
2602        restart at the proper <acronym>WAL</acronym> location (Ronan
2603        Dunklau)
2604       </para>
2605
2606       <para>
2607        Previously, <application>pg_receivewal</application> would start
2608        based on the <acronym>WAL</acronym> file stored in the local archive
2609        directory, or at the sending server's current <acronym>WAL</acronym>
2610        flush location.  With this change, if the sending server is running
2611        Postgres 15 or later, the local archive directory is empty, and
2612        a replication slot is specified, the replication slot's restart
2613        point will be used.
2614       </para>
2615      </listitem>
2616
2617 <!--
2618 Author: Michael Paquier <michael@paquier.xyz>
2619 2022-04-07 [0d5c38757] Add option - -config-file to pg_rewind
2620 -->
2621
2622      <listitem>
2623       <para>
2624        Add <application>pg_rewind</application> option
2625        <option>--config-file</option> to simplify use when server
2626        configuration files are stored outside the data directory (Gunnar
2627        Bluth)
2628       </para>
2629      </listitem>
2630
2631 <!--
2632 Author: Tatsuo Ishii <ishii@postgresql.org>
2633 2022-03-23 [4a39f87ac] Allow pgbench to retry in some cases.
2634 -->
2635
2636      <listitem>
2637       <para>
2638        Allow <link
2639        linkend="pgbench"><application>pgbench</application></link> to
2640        retry after serialization and deadlock failures (Yugo Nagata,
2641        Marina Polyakova)
2642       </para>
2643      </listitem>
2644
2645     </itemizedlist>
2646
2647     <sect4>
2648      <title><link linkend="app-pgdump"><application>pg_dump</application></link></title>
2649
2650      <itemizedlist>
2651
2652 <!--
2653 Author: Noah Misch <noah@leadboat.com>
2654 2021-06-28 [a7a7be1f2] Dump public schema ownership and security labels.
2655 Author: Noah Misch <noah@leadboat.com>
2656 2021-06-28 [7ac10f692] Dump COMMENT ON SCHEMA public.
2657 -->
2658
2659       <listitem>
2660        <para>
2661         Have <application>pg_dump</application> dump
2662         <literal>public</literal> schema ownership changes and security
2663         labels (Noah Misch)
2664        </para>
2665
2666        <para>
2667         It also dumps <literal>public</literal> schema comments.
2668        </para>
2669       </listitem>
2670
2671 <!--
2672 Author: Tom Lane <tgl@sss.pgh.pa.us>
2673 2021-12-06 [989596152] Avoid per-object queries in performance-critical paths i
2674 Author: Tom Lane <tgl@sss.pgh.pa.us>
2675 2021-12-06 [be85727a3] Use PREPARE/EXECUTE for repetitive per-object queries in
2676 Author: Tom Lane <tgl@sss.pgh.pa.us>
2677 2021-12-31 [d5e8930f5] pg_dump: minor performance improvements from eliminating
2678 -->
2679
2680       <listitem>
2681        <para>
2682         Improve performance of dumping databases with many objects
2683         (Tom Lane)
2684        </para>
2685
2686        <para>
2687         This will also improve the performance of <link
2688         linkend="pgupgrade"><application>pg_upgrade</application></link>.
2689        </para>
2690       </listitem>
2691
2692 <!--
2693 Author: Tom Lane <tgl@sss.pgh.pa.us>
2694 2021-12-06 [65aaed22a] Account for TOAST data while scheduling parallel dumps.
2695 -->
2696
2697       <listitem>
2698        <para>
2699         Improve the parallel <application>pg_dump</application> performance
2700         of <acronym>TOAST</acronym> tables (Tom Lane)
2701        </para>
2702       </listitem>
2703
2704 <!--
2705 Author: Michael Paquier <michael@paquier.xyz>
2706 2022-01-17 [215862886] Add support for - -no-table-access-method in pg_{dump,dum
2707 -->
2708
2709       <listitem>
2710        <para>
2711         Add dump/restore option <option>--no-table-access-method</option>
2712         to force restore to only use the default table access method
2713         (Justin Pryzby)
2714        </para>
2715       </listitem>
2716
2717 <!--
2718 Author: Tom Lane <tgl@sss.pgh.pa.us>
2719 2021-12-14 [30e7c175b] Remove pg_dump/pg_dumpall support for dumping from pre-9
2720 -->
2721
2722       <listitem>
2723        <para>
2724         Limit support of <application>pg_dump</application> and <link
2725         linkend="app-pg-dumpall"><application>pg_dumpall</application></link>
2726         to servers running <productname>PostgreSQL</productname> 9.2 and
2727         later (Tom Lane)
2728        </para>
2729       </listitem>
2730
2731      </itemizedlist>
2732
2733     </sect4>
2734
2735     <sect4>
2736      <title><link linkend="pgupgrade"><application>pg_upgrade</application></link></title>
2737
2738      <itemizedlist>
2739
2740 <!--
2741 Author: Andres Freund <andres@anarazel.de>
2742 2022-02-21 [27b02e070] pg_upgrade: Don't print progress status when output is n
2743 -->
2744
2745       <listitem>
2746        <para>
2747         Disable default status reporting during
2748         <application>pg_upgrade</application> operation if the output is
2749         not a terminal (Andres Freund)
2750        </para>
2751
2752        <para>
2753         The status reporting output can be enabled for non-tty usage by
2754         using <option>--verbose</option>.
2755        </para>
2756       </listitem>
2757
2758 <!--
2759 Author: Daniel Gustafsson <dgustafsson@postgresql.org>
2760 2022-03-24 [26ebb0e28] List offending databases in pg_upgrade datallowconn chec
2761 -->
2762
2763       <listitem>
2764        <para>
2765         Have <application>pg_upgrade</application> report all databases
2766         with invalid connection settings (Jeevan Ladhe)
2767        </para>
2768
2769        <para>
2770         Previously only the first database with an invalid connection
2771         setting was reported.
2772        </para>
2773       </listitem>
2774
2775 <!--
2776 Author: Michael Paquier <michael@paquier.xyz>
2777 2022-02-06 [38bfae365] pg_upgrade: Move all the files generated internally to a
2778 Author: Michael Paquier <michael@paquier.xyz>
2779 2022-02-15 [a00849630] Fix thinko with subdirectories generated by pg_upgrade f
2780 -->
2781
2782       <listitem>
2783        <para>
2784         Store <application>pg_upgrade</application>
2785         temporary files in a new cluster subdirectory called
2786         <filename>pg_upgrade_output.d</filename> (Justin Pryzby)
2787        </para>
2788
2789        <para>
2790         Previously temporary files were stored in the current directory.
2791        </para>
2792       </listitem>
2793
2794 <!--
2795 Author: Robert Haas <rhaas@postgresql.org>
2796 2022-01-17 [9a974cbcb] pg_upgrade: Preserve relfilenodes and tablespace OIDs.
2797 Author: Robert Haas <rhaas@postgresql.org>
2798 2022-01-24 [aa0105141] pg_upgrade: Preserve database OIDs.
2799 -->
2800
2801       <listitem>
2802        <para>
2803         Have <application>pg_upgrade</application> preserve relfilenodes,
2804         tablespace, and database OIDs between old and new clusters
2805         (Shruthi KC, Antonin Houska)
2806        </para>
2807       </listitem>
2808
2809 <!--
2810 Author: Michael Paquier <michael@paquier.xyz>
2811 2021-12-18 [3d5ffccb6] Add option -N/- -no-sync to pg_upgrade
2812 -->
2813
2814       <listitem>
2815        <para>
2816         Add a <option>--no-sync</option> option to
2817         <application>pg_upgrade</application> (Michael Paquier)
2818        </para>
2819
2820        <para>
2821         This useful only for testing.
2822        </para>
2823       </listitem>
2824
2825 <!--
2826 Author: Tom Lane <tgl@sss.pgh.pa.us>
2827 2021-12-14 [e469f0aaf] Remove pg_upgrade support for upgrading from pre-9.2 ser
2828 -->
2829
2830       <listitem>
2831        <para>
2832         Limit support of <application>pg_upgrade</application> to old
2833         servers running <productname>PostgreSQL</productname> 9.2 and later
2834         (Tom Lane)
2835        </para>
2836       </listitem>
2837
2838      </itemizedlist>
2839
2840     </sect4>
2841
2842     <sect4>
2843      <title><link linkend="pgwaldump"><application>pg_waldump</application></link></title>
2844
2845      <itemizedlist>
2846
2847 <!--
2848 Author: Thomas Munro <tmunro@postgresql.org>
2849 2022-03-24 [127aea2a6] Add additional filtering options to pg_waldump.
2850 Author: Thomas Munro <tmunro@postgresql.org>
2851 2022-03-25 [52b556843] Improve command line options for pg_waldump.
2852 -->
2853
2854       <listitem>
2855        <para>
2856         Allow <application>pg_waldump</application> to be filtered by
2857         relation file node, block number, fork number, and full page images
2858         (David Christensen, Thomas Munro)
2859        </para>
2860       </listitem>
2861
2862 <!--
2863 Author: Michael Paquier <michael@paquier.xyz>
2864 2021-12-02 [f2c52eeba] pg_waldump: Emit stats summary when interrupted by SIGIN
2865 -->
2866
2867       <listitem>
2868        <para>
2869         Have <application>pg_waldump</application> report statistics
2870         before an interrupted exit (Bharath Rupireddy)
2871        </para>
2872
2873        <para>
2874         For example, issuing a control-C in a terminal running
2875         <command>pg_waldump --stats --follow</command> will report the
2876         current statistics before exiting.  This does not work on Windows.
2877        </para>
2878       </listitem>
2879
2880 <!--
2881 Author: Michael Paquier <michael@paquier.xyz>
2882 2021-12-13 [c8b733c4c] Improve description of some WAL records with transaction
2883 -->
2884
2885       <listitem>
2886        <para>
2887         Improve descriptions of some transaction <acronym>WAL</acronym>
2888         records reported by <application>pg_waldump</application>
2889         (Masahiko Sawada, Michael Paquier)
2890        </para>
2891       </listitem>
2892
2893 <!--
2894 Author: Heikki Linnakangas <heikki.linnakangas@iki.fi>
2895 2021-07-01 [c8bf5098c] Allow specifying pg_waldump - -rmgr option multiple times
2896 -->
2897
2898       <listitem>
2899        <para>
2900         Allow <application>pg_waldump</application> to dump information
2901         about multiple resource managers (Heikki Linnakangas)
2902        </para>
2903
2904        <para>
2905         This is enabled by specifying the <option>--rmgr</option> option
2906         multiple times.
2907        </para>
2908       </listitem>
2909
2910      </itemizedlist>
2911
2912     </sect4>
2913
2914    </sect3>
2915
2916    <sect3>
2917     <title>Documentation</title>
2918
2919     <itemizedlist>
2920
2921 <!--
2922 Author: Fujii Masao <fujii@postgresql.org>
2923 2021-10-05 [f6b5d05ba] doc: Document pg_encoding_to_char() and pg_char_to_encod
2924 -->
2925
2926      <listitem>
2927       <para>
2928        Add documentation for <link
2929        linkend="functions-info-catalog-table"><function>pg_encoding_to_char()</function></link>
2930        and <function>pg_char_to_encoding()</function> (Ian Lawrence
2931        Barwick)
2932       </para>
2933      </listitem>
2934
2935 <!--
2936 Author: Tom Lane <tgl@sss.pgh.pa.us>
2937 2021-10-09 [2ae5d72f0] Doc: improve documentation for ^@ starts-with operator.
2938 -->
2939
2940      <listitem>
2941       <para>
2942        Document the <link
2943        linkend="functions-string-other"><literal>^@</literal></link>
2944        starts-with operator (Tom Lane)
2945       </para>
2946      </listitem>
2947
2948     </itemizedlist>
2949
2950    </sect3>
2951
2952    <sect3>
2953     <title>Source Code</title>
2954
2955     <itemizedlist>
2956
2957 <!--
2958 Author: Andres Freund <andres@anarazel.de>
2959 2021-12-30 [93d973494] ci: Add continuous integration for github repositories v
2960 -->
2961
2962      <listitem>
2963       <para>
2964        Add support for continuous integration testing using cirrus-ci
2965        (Andres Freund, Thomas Munro, Melanie Plageman)
2966       </para>
2967      </listitem>
2968
2969 <!--
2970 Author: Robert Haas <rhaas@postgresql.org>
2971 2022-02-18 [6c417bbcc] Add support for building with ZSTD.
2972 -->
2973
2974      <listitem>
2975       <para>
2976        Add configure option <link
2977        linkend="configure-options-features"><option>--with-zstd</option></link>
2978        to enable Zstandard builds (Jeevan Ladhe, Robert Haas, Michael
2979        Paquier)
2980       </para>
2981      </listitem>
2982
2983 <!--
2984 Author: Peter Eisentraut <peter@eisentraut.org>
2985 2021-11-22 [d6d1dfcc9] Add ABI extra field to fmgr magic block
2986 -->
2987
2988      <listitem>
2989       <para>
2990        Add module field which can be customized for non-community
2991        <productname>PostgreSQL</productname> distributions (Peter
2992        Eisentraut)
2993       </para>
2994
2995       <para>
2996        A module field mismatch would generate an error.
2997       </para>
2998      </listitem>
2999
3000 <!--
3001 Author: Tom Lane <tgl@sss.pgh.pa.us>
3002 2021-12-11 [07eee5a0d] Create a new type category for "internal use" types.
3003 -->
3004
3005      <listitem>
3006       <para>
3007        Create a new <link
3008        linkend="catalog-pg-type"><structfield>pg_type.typcategory</structfield></link>
3009        value for <type>"char"</type> (Tom Lane)
3010       </para>
3011
3012       <para>
3013        Some internal-use-only types have also been assigned this column.
3014       </para>
3015      </listitem>
3016
3017 <!--
3018 Author: Robert Haas <rhaas@postgresql.org>
3019 2022-01-18 [cc333f323] Modify pg_basebackup to use a new COPY subprotocol for b
3020 -->
3021
3022      <listitem>
3023       <para>
3024        Add new protocol message <link
3025        linkend="protocol-replication-base-backup"><literal>TARGET</literal></link>
3026        to specify a new <command>COPY</command> method to be for base
3027        backups (Robert Haas)
3028       </para>
3029
3030       <para>
3031        Modify <link
3032        linkend="app-pgbasebackup"><application>pg_basebackup</application></link>
3033        to use this method.
3034       </para>
3035      </listitem>
3036
3037 <!--
3038 Author: Robert Haas <rhaas@postgresql.org>
3039 2022-01-24 [0ad803291] Server-side gzip compression.
3040 Author: Robert Haas <rhaas@postgresql.org>
3041 2022-03-23 [ffd53659c] Replace BASE_BACKUP COMPRESSION_LEVEL option with COMPRE
3042 -->
3043
3044      <listitem>
3045       <para>
3046        Add new protocol message <link
3047        linkend="protocol-replication-base-backup"><literal>COMPRESSION</literal></link>
3048        and <literal>COMPRESSION_DETAIL</literal> to specify the compression
3049        method and options (Robert Haas)
3050       </para>
3051      </listitem>
3052
3053 <!--
3054 Author: Robert Haas <rhaas@postgresql.org>
3055 2022-02-10 [9cd28c2e5] Remove server support for old BASE_BACKUP command syntax
3056 Author: Robert Haas <rhaas@postgresql.org>
3057 2022-02-10 [0d4513b61] Remove server support for the previous base backup proto
3058 -->
3059
3060      <listitem>
3061       <para>
3062        Remove server support for old <literal>BASE_BACKUP</literal>
3063        command syntax and base backup protocol (Robert Haas)
3064       </para>
3065      </listitem>
3066
3067 <!--
3068 Author: Robert Haas <rhaas@postgresql.org>
3069 2022-03-15 [e4ba69f3f] Allow extensions to add new backup targets.
3070 -->
3071
3072      <listitem>
3073       <para>
3074        Add support for extensions to set custom backup targets (Robert
3075        Haas)
3076       </para>
3077      </listitem>
3078
3079 <!--
3080 Author: Jeff Davis <jdavis@postgresql.org>
3081 2022-04-06 [5c279a6d3] Custom WAL Resource Managers.
3082 -->
3083
3084      <listitem>
3085       <para>
3086        Allow extensions to define their own <acronym>WAL</acronym>
3087        resource managers (Jeff Davis)
3088       </para>
3089      </listitem>
3090
3091 <!--
3092 Author: Michael Paquier <michael@paquier.xyz>
3093 2022-01-31 [d10e41d42] Introduce pg_settings_get_flags() to find flags associat
3094 -->
3095
3096      <listitem>
3097       <para>
3098        Add function <link
3099        linkend="functions-info-catalog-table"><function>pg_settings_get_flags()</function></link>
3100        to get the flags of server-side variables (Justin Pryzby)
3101       </para>
3102      </listitem>
3103
3104 <!--
3105 Author: Thomas Munro <tmunro@postgresql.org>
3106 2022-01-15 [7170f2159] Allow "in place" tablespaces.
3107 -->
3108
3109      <listitem>
3110       <para>
3111        Add server variable <link
3112        linkend="guc-allow-in-place-tablespaces"><varname>allow_in_place_tablespaces</varname></link>
3113        for tablespace testing (Thomas Munro)
3114       </para>
3115      </listitem>
3116
3117 <!--
3118 Author: Robert Haas <rhaas@postgresql.org>
3119 2022-04-08 [8ec569479] Apply PGDLLIMPORT markings broadly.
3120 -->
3121
3122      <listitem>
3123       <para>
3124        Export all server variables on Windows using
3125        <literal>PGDLLIMPORT</literal> (Robert Haas)
3126       </para>
3127
3128       <para>
3129        Previously only specific variables where exported.
3130       </para>
3131      </listitem>
3132
3133 <!--
3134 Author: Peter Eisentraut <peter@eisentraut.org>
3135 2021-11-05 [db7d1a7b0] pgcrypto: Remove non-OpenSSL support
3136 -->
3137
3138      <listitem>
3139       <para>
3140        Require OpenSSL to build <link
3141        linkend="pgcrypto"><application>pgcrypto</application></link>
3142        binaries (Peter Eisentraut)
3143       </para>
3144      </listitem>
3145
3146 <!--
3147 Author: Andres Freund <andres@anarazel.de>
3148 2022-02-16 [19252e8ec] plpython: Reject Python 2 during build configuration.
3149 -->
3150
3151      <listitem>
3152       <para>
3153        Disallow building with <application>Python 2</application>
3154        (Andres Freund)
3155       </para>
3156      </listitem>
3157
3158 <!--
3159 Author: Tom Lane <tgl@sss.pgh.pa.us>
3160 2021-10-07 [92e6a98c3] Adjust configure to insist on Perl version &gt;= 5.8.3.
3161 -->
3162
3163      <listitem>
3164       <para>
3165        Adjust configure to require <application>Perl</application>
3166        version 5.8.3 or later (Dagfinn Ilmari Mannsåker)
3167       </para>
3168      </listitem>
3169
3170     </itemizedlist>
3171
3172    </sect3>
3173
3174    <sect3>
3175     <title>Additional Modules</title>
3176
3177     <itemizedlist>
3178
3179 <!--
3180 Author: Jeff Davis <jdavis@postgresql.org>
3181 2022-04-08 [2258e76f9] Add contrib/pg_walinspect.
3182 -->
3183
3184      <listitem>
3185       <para>
3186        Add new module <link
3187        linkend="pgwalinspect"><application>pg_walinspect</application></link>
3188        (Bharath Rupireddy)
3189       </para>
3190
3191       <para>
3192        This gives <acronym>SQL</acronym>-level output similar to <link
3193        linkend="pgwaldump"><application>pg_waldump</application></link>.
3194       </para>
3195      </listitem>
3196
3197 <!--
3198 Author: Robert Haas <rhaas@postgresql.org>
3199 2022-02-03 [5ef1eefd7] Allow archiving via loadable modules.
3200 -->
3201
3202      <listitem>
3203       <para>
3204        Add module <link
3205        linkend="basic-archive"><application>basic_archive</application></link>
3206        to perform archiving via a library (Nathan Bossart)
3207       </para>
3208      </listitem>
3209
3210 <!--
3211 Author: Robert Haas <rhaas@postgresql.org>
3212 2022-03-15 [c6306db24] Add 'basebackup_to_shell' contrib module.
3213 Author: Robert Haas <rhaas@postgresql.org>
3214 2022-03-30 [26a0c025e] Document basebackup_to_shell.required_role.
3215 -->
3216
3217      <listitem>
3218       <para>
3219        Add module <application><link
3220        linkend="basebackup-to-shell">basebackup_to_shell</link></application>
3221        as a custom backup target (Robert Haas) contrib module.
3222       </para>
3223      </listitem>
3224
3225 <!--
3226 Author: Michael Paquier <michael@paquier.xyz>
3227 2022-04-08 [76cbf7edb] pg_stat_statements: Track I/O timing for temporary file
3228 -->
3229
3230      <listitem>
3231       <para>
3232        Add <link
3233        linkend="pgstatstatements"><application>pg_stat_statements</application></link>
3234        output for temporary file block I/O (Masahiko Sawada)
3235       </para>
3236      </listitem>
3237
3238 <!--
3239 Author: Magnus Hagander <magnus@hagander.net>
3240 2022-04-08 [57d6aea00] Add JIT counters to pg_stat_statements
3241 -->
3242
3243      <listitem>
3244       <para>
3245        Add <acronym>JIT</acronym> counters to pg_stat_statements (Magnus
3246        Hagander)
3247       </para>
3248      </listitem>
3249
3250 <!--
3251 Author: Peter Eisentraut <peter@eisentraut.org>
3252 2021-09-28 [c3b011d99] Support amcheck of sequences
3253 -->
3254
3255      <listitem>
3256       <para>
3257        Allow <link
3258        linkend="amcheck"><application>amcheck</application></link> to
3259        check sequences (Mark Dilger)
3260       </para>
3261      </listitem>
3262
3263 <!--
3264 Author: Robert Haas <rhaas@postgresql.org>
3265 2021-11-05 [bd807be69] amcheck: Add additional TOAST pointer checks.
3266 -->
3267
3268      <listitem>
3269       <para>
3270        Improve <application>amcheck</application> sanity checks for
3271        <acronym>TOAST</acronym> tables (Mark Dilger)
3272       </para>
3273      </listitem>
3274
3275 <!--
3276 Author: Tomas Vondra <tomas.vondra@postgresql.org>
3277 2021-11-06 [57e3c5160] Add bool GiST opclass to btree_gist
3278 Author: Tomas Vondra <tomas.vondra@postgresql.org>
3279 2021-11-08 [e2fbb8837] Fix gist_bool_ops to use gbtreekey2
3280 Author: Tomas Vondra <tomas.vondra@postgresql.org>
3281 2021-12-11 [4c6145b51] Add bool to btree_gist documentation
3282 -->
3283
3284      <listitem>
3285       <para>
3286        Allow <link
3287        linkend="btree-gist"><application>btree_gist</application></link>
3288        indexes on boolean columns (Emre Hasegeli)
3289       </para>
3290
3291       <para>
3292        These can be used for exclusion constraints.
3293       </para>
3294      </listitem>
3295
3296 <!--
3297 Author: Tom Lane <tgl@sss.pgh.pa.us>
3298 2022-01-12 [134d97463] Include permissive/enforcing state in sepgsql log messag
3299 -->
3300
3301      <listitem>
3302       <para>
3303        Indicate the permissive/enforcing state in <link
3304        linkend="sepgsql"><application>sepgsql</application></link> log
3305        messages (Dave Page)
3306       </para>
3307      </listitem>
3308
3309 <!--
3310 Author: Michael Paquier <michael@paquier.xyz>
3311 2021-07-12 [127404fbe] pageinspect: Improve page_header() for pages of 32kB
3312 -->
3313
3314      <listitem>
3315       <para>
3316        Fix <link
3317        linkend="pageinspect"><application>pageinspect</application></link>'s
3318        <function>page_header()</function> to handle 32 kilobyte page sizes
3319        (Quan Zongliang)
3320       </para>
3321
3322       <para>
3323        Previously improper negative values could be returned in certain
3324        cases.
3325       </para>
3326      </listitem>
3327
3328     </itemizedlist>
3329
3330     <sect4>
3331      <title><link linkend="postgres-fdw"><application>postgres_fdw</application></link></title>
3332
3333      <itemizedlist>
3334
3335 <!--
3336 Author: Tom Lane <tgl@sss.pgh.pa.us>
3337 2021-07-30 [5d44fff01] In postgres_fdw, allow CASE expressions to be pushed to
3338 -->
3339
3340       <listitem>
3341        <para>
3342         Allow postgres_fdw to push down <literal>CASE</literal> expressions
3343         (Alexander Pyhalov)
3344        </para>
3345       </listitem>
3346
3347 <!--
3348 Author: Fujii Masao <fujii@postgresql.org>
3349 2021-09-07 [449ab6350] postgres_fdw: Allow application_name of remote connectio
3350 Author: Fujii Masao <fujii@postgresql.org>
3351 2021-12-24 [6e0cb3dec] postgres_fdw: Allow postgres_fdw.application_name to inc
3352 Author: Fujii Masao <fujii@postgresql.org>
3353 2022-02-18 [94c49d534] postgres_fdw: Make postgres_fdw.application_name support
3354 -->
3355
3356       <listitem>
3357        <para>
3358         Add server variable
3359         <varname>postgres_fdw.application_name</varname> to control the
3360         application name of postgres_fdw connections (Hayato Kuroda)
3361        </para>
3362
3363        <para>
3364         Previously the remote <link
3365         linkend="guc-application-name"><varname>application_name</varname></link>
3366         could only be set on the remote server or via
3367         <application>postgres_fdw</application> connection specification.
3368         <varname>postgres_fdw.application_name</varname> also supports
3369         escape sequences for customization.
3370        </para>
3371       </listitem>
3372
3373 <!--
3374 Author: Etsuro Fujita <efujita@postgresql.org>
3375 2022-02-24 [04e706d42] postgres_fdw: Add support for parallel commit.
3376 -->
3377
3378       <listitem>
3379        <para>
3380         Allow parallel commit on <application>postgres_fdw</application>
3381         servers (Etsuro Fujita)
3382        </para>
3383
3384        <para>
3385         This is enabled with the <literal>CREATE SERVER</literal> option
3386         <literal>parallel_commit</literal> when using postgres_fdw.
3387        </para>
3388       </listitem>
3389
3390      </itemizedlist>
3391
3392     </sect4>
3393
3394    </sect3>
3395
3396   </sect2>
3397
3398   <sect2 id="release-15-acknowledgements">
3399    <title>Acknowledgments</title>
3400
3401    <para>
3402     The following individuals (in alphabetical order) have contributed
3403     to this release as patch authors, committers, reviewers, testers,
3404     or reporters of issues.
3405    </para>
3406
3407    <simplelist>
3408     <member></member>
3409    </simplelist>
3410   </sect2>
3411
3412  </sect1>