doc/src/sgml/release-8.2.sgml

   1 <!-- $PostgreSQL$ -->
   2 <!-- See header comment in release.sgml about typical markup -->
   3
   4  <sect1 id="release-8-2-13">
   5   <title>Release 8.2.13</title>
   6
   7   <note>
   8   <title>Release date</title>
   9   <simpara>2009-03-16</simpara>
  10   </note>
  11
  12   <para>
  13    This release contains a variety of fixes from 8.2.12.
  14    For information about new features in the 8.2 major release, see
  15    <xref linkend="release-8-2">.
  16   </para>
  17
  18   <sect2>
  19    <title>Migration to Version 8.2.13</title>
  20
  21    <para>
  22     A dump/restore is not required for those running 8.2.X.
  23     However, if you are upgrading from a version earlier than 8.2.11,
  24     see the release notes for 8.2.11.
  25    </para>
  26
  27   </sect2>
  28
  29   <sect2>
  30    <title>Changes</title>
  31
  32    <itemizedlist>
  33
  34     <listitem>
  35      <para>
  36       Prevent error recursion crashes when encoding conversion fails (Tom)
  37      </para>
  38
  39      <para>
  40       This change extends fixes made in the last two minor releases for
  41       related failure scenarios.  The previous fixes were narrowly tailored
  42       for the original problem reports, but we have now recognized that
  43       <emphasis>any</> error thrown by an encoding conversion function could
  44       potentially lead to infinite recursion while trying to report the
  45       error.  The solution therefore is to disable translation and encoding
  46       conversion and report the plain-ASCII form of any error message,
  47       if we find we have gotten into a recursive error reporting situation.
  48       (CVE-2009-0922)
  49      </para>
  50     </listitem>
  51
  52     <listitem>
  53      <para>
  54       Disallow <command>CREATE CONVERSION</> with the wrong encodings
  55       for the specified conversion function (Heikki)
  56      </para>
  57
  58      <para>
  59       This prevents one possible scenario for encoding conversion failure.
  60       The previous change is a backstop to guard against other kinds of
  61       failures in the same area.
  62      </para>
  63     </listitem>
  64
  65     <listitem>
  66      <para>
  67       Fix core dump when <function>to_char()</> is given format codes that
  68       are inappropriate for the type of the data argument (Tom)
  69      </para>
  70     </listitem>
  71
  72     <listitem>
  73      <para>
  74       Fix possible failure in <filename>contrib/tsearch2</> when C locale is
  75       used with a multi-byte encoding (Teodor)
  76      </para>
  77
  78      <para>
  79       Crashes were possible on platforms where <type>wchar_t</> is narrower
  80       than <type>int</>; Windows in particular.
  81      </para>
  82     </listitem>
  83
  84     <listitem>
  85      <para>
  86       Fix extreme inefficiency in <filename>contrib/tsearch2</> parser's
  87       handling of an email-like string containing multiple <literal>@</>
  88       characters (Heikki)
  89      </para>
  90     </listitem>
  91
  92     <listitem>
  93      <para>
  94       Fix decompilation of <literal>CASE WHEN</> with an implicit coercion
  95       (Tom)
  96      </para>
  97
  98      <para>
  99       This mistake could lead to Assert failures in an Assert-enabled build,
 100       or an <quote>unexpected CASE WHEN clause</> error message in other
 101       cases, when trying to examine or dump a view.
 102      </para>
 103     </listitem>
 104
 105     <listitem>
 106      <para>
 107       Fix possible misassignment of the owner of a TOAST table's rowtype (Tom)
 108      </para>
 109
 110      <para>
 111       If <command>CLUSTER</> or a rewriting variant of <command>ALTER TABLE</>
 112       were executed by someone other than the table owner, the
 113       <structname>pg_type</> entry for the table's TOAST table would end up
 114       marked as owned by that someone.  This caused no immediate problems,
 115       since the permissions on the TOAST rowtype aren't examined by any
 116       ordinary database operation.  However, it could lead to unexpected
 117       failures if one later tried to drop the role that issued the command
 118       (in 8.1 or 8.2), or <quote>owner of data type appears to be invalid</>
 119       warnings from <application>pg_dump</> after having done so (in 8.3).
 120      </para>
 121     </listitem>
 122
 123     <listitem>
 124      <para>
 125       Fix PL/pgSQL to not treat <literal>INTO</> after <command>INSERT</> as
 126       an INTO-variables clause anywhere in the string, not only at the start;
 127       in particular, don't fail for <command>INSERT INTO</> within
 128       <command>CREATE RULE</> (Tom)
 129      </para>
 130     </listitem>
 131
 132     <listitem>
 133      <para>
 134       Clean up PL/pgSQL error status variables fully at block exit
 135       (Ashesh Vashi and Dave Page)
 136      </para>
 137
 138      <para>
 139       This is not a problem for PL/pgSQL itself, but the omission could cause
 140       the PL/pgSQL Debugger to crash while examining the state of a function.
 141      </para>
 142     </listitem>
 143
 144     <listitem>
 145      <para>
 146       Retry failed calls to <function>CallNamedPipe()</> on Windows
 147       (Steve Marshall, Magnus)
 148      </para>
 149
 150      <para>
 151       It appears that this function can sometimes fail transiently;
 152       we previously treated any failure as a hard error, which could
 153       confuse <command>LISTEN</>/<command>NOTIFY</> as well as other
 154       operations.
 155      </para>
 156     </listitem>
 157
 158     <listitem>
 159      <para>
 160       Add <literal>MUST</> (Mauritius Island Summer Time) to the default list
 161       of known timezone abbreviations (Xavier Bugaud)
 162      </para>
 163     </listitem>
 164
 165    </itemizedlist>
 166
 167   </sect2>
 168  </sect1>
 169
 170  <sect1 id="release-8-2-12">
 171   <title>Release 8.2.12</title>
 172
 173   <note>
 174   <title>Release date</title>
 175   <simpara>2009-02-02</simpara>
 176   </note>
 177
 178   <para>
 179    This release contains a variety of fixes from 8.2.11.
 180    For information about new features in the 8.2 major release, see
 181    <xref linkend="release-8-2">.
 182   </para>
 183
 184   <sect2>
 185    <title>Migration to Version 8.2.12</title>
 186
 187    <para>
 188     A dump/restore is not required for those running 8.2.X.
 189     However, if you are upgrading from a version earlier than 8.2.11,
 190     see the release notes for 8.2.11.
 191    </para>
 192
 193   </sect2>
 194
 195   <sect2>
 196    <title>Changes</title>
 197
 198    <itemizedlist>
 199
 200     <listitem>
 201      <para>
 202       Improve handling of URLs in <function>headline()</> function (Teodor)
 203      </para>
 204     </listitem>
 205
 206     <listitem>
 207      <para>
 208       Improve handling of overlength headlines in <function>headline()</>
 209       function (Teodor)
 210      </para>
 211     </listitem>
 212
 213     <listitem>
 214      <para>
 215       Prevent possible Assert failure or misconversion if an encoding
 216       conversion is created with the wrong conversion function for the
 217       specified pair of encodings (Tom, Heikki)
 218      </para>
 219     </listitem>
 220
 221     <listitem>
 222      <para>
 223       Fix possible Assert failure if a statement executed in PL/pgSQL is
 224       rewritten into another kind of statement, for example if an
 225       <command>INSERT</> is rewritten into an <command>UPDATE</> (Heikki)
 226      </para>
 227     </listitem>
 228
 229     <listitem>
 230      <para>
 231       Ensure that a snapshot is available to datatype input functions (Tom)
 232      </para>
 233
 234      <para>
 235       This primarily affects domains that are declared with <literal>CHECK</>
 236       constraints involving user-defined stable or immutable functions.  Such
 237       functions typically fail if no snapshot has been set.
 238      </para>
 239     </listitem>
 240
 241     <listitem>
 242      <para>
 243       Make it safer for SPI-using functions to be used within datatype I/O;
 244       in particular, to be used in domain check constraints (Tom)
 245      </para>
 246     </listitem>
 247
 248     <listitem>
 249      <para>
 250       Avoid unnecessary locking of small tables in <command>VACUUM</>
 251       (Heikki)
 252      </para>
 253     </listitem>
 254
 255     <listitem>
 256      <para>
 257       Fix a problem that made <literal>UPDATE RETURNING tableoid</>
 258       return zero instead of the correct OID (Tom)
 259      </para>
 260     </listitem>
 261
 262     <listitem>
 263      <para>
 264       Fix planner misestimation of selectivity when transitive equality
 265       is applied to an outer-join clause (Tom)
 266      </para>
 267
 268      <para>
 269       This could result in bad plans for queries like
 270       <literal>... from a left join b on a.a1 = b.b1 where a.a1 = 42 ...</>
 271      </para>
 272     </listitem>
 273
 274     <listitem>
 275      <para>
 276       Improve optimizer's handling of long <literal>IN</> lists (Tom)
 277      </para>
 278
 279      <para>
 280       This change avoids wasting large amounts of time on such lists
 281       when constraint exclusion is enabled.
 282      </para>
 283     </listitem>
 284
 285     <listitem>
 286      <para>
 287       Ensure that the contents of a holdable cursor don't depend on the
 288       contents of TOAST tables (Tom)
 289      </para>
 290
 291      <para>
 292       Previously, large field values in a cursor result might be represented
 293       as TOAST pointers, which would fail if the referenced table got dropped
 294       before the cursor is read, or if the large value is deleted and then
 295       vacuumed away.  This cannot happen with an ordinary cursor,
 296       but it could with a cursor that is held past its creating transaction.
 297      </para>
 298     </listitem>
 299
 300     <listitem>
 301      <para>
 302       Fix memory leak when a set-returning function is terminated without
 303       reading its whole result (Tom)
 304      </para>
 305     </listitem>
 306
 307     <listitem>
 308      <para>
 309       Fix <filename>contrib/dblink</>'s
 310       <function>dblink_get_result(text,bool)</> function (Joe)
 311      </para>
 312     </listitem>
 313
 314     <listitem>
 315      <para>
 316       Fix possible garbage output from <filename>contrib/sslinfo</> functions
 317       (Tom)
 318      </para>
 319     </listitem>
 320
 321     <listitem>
 322      <para>
 323       Fix <application>configure</> script to properly report failure when
 324       unable to obtain linkage information for PL/Perl (Andrew)
 325      </para>
 326     </listitem>
 327
 328     <listitem>
 329      <para>
 330       Make all documentation reference <literal>pgsql-bugs</> and/or
 331       <literal>pgsql-hackers</> as appropriate, instead of the
 332       now-decommissioned <literal>pgsql-ports</> and <literal>pgsql-patches</>
 333       mailing lists (Tom)
 334      </para>
 335     </listitem>
 336
 337     <listitem>
 338      <para>
 339       Update time zone data files to <application>tzdata</> release 2009a (for
 340       Kathmandu and historical DST corrections in Switzerland, Cuba)
 341      </para>
 342     </listitem>
 343
 344    </itemizedlist>
 345
 346   </sect2>
 347  </sect1>
 348
 349  <sect1 id="release-8-2-11">
 350   <title>Release 8.2.11</title>
 351
 352   <note>
 353   <title>Release date</title>
 354   <simpara>2008-11-03</simpara>
 355   </note>
 356
 357   <para>
 358    This release contains a variety of fixes from 8.2.10.
 359    For information about new features in the 8.2 major release, see
 360    <xref linkend="release-8-2">.
 361   </para>
 362
 363   <sect2>
 364    <title>Migration to Version 8.2.11</title>
 365
 366    <para>
 367     A dump/restore is not required for those running 8.2.X.
 368     However, if you are upgrading from a version earlier than 8.2.7,
 369     see the release notes for 8.2.7.  Also, if you were running a previous
 370     8.2.X release, it is recommended to <command>REINDEX</> all GiST
 371     indexes after the upgrade.
 372    </para>
 373
 374   </sect2>
 375
 376   <sect2>
 377    <title>Changes</title>
 378
 379    <itemizedlist>
 380
 381     <listitem>
 382      <para>
 383       Fix GiST index corruption due to marking the wrong index entry
 384       <quote>dead</> after a deletion (Teodor)
 385      </para>
 386
 387      <para>
 388       This would result in index searches failing to find rows they
 389       should have found.  Corrupted indexes can be fixed with
 390       <command>REINDEX</>.
 391      </para>
 392     </listitem>
 393
 394     <listitem>
 395      <para>
 396       Fix backend crash when the client encoding cannot represent a localized
 397       error message (Tom)
 398      </para>
 399
 400      <para>
 401       We have addressed similar issues before, but it would still fail if
 402       the <quote>character has no equivalent</> message itself couldn't
 403       be converted.  The fix is to disable localization and send the plain
 404       ASCII error message when we detect such a situation.
 405      </para>
 406     </listitem>
 407
 408     <listitem>
 409      <para>
 410       Fix possible crash when deeply nested functions are invoked from
 411       a trigger (Tom)
 412      </para>
 413     </listitem>
 414
 415     <listitem>
 416      <para>
 417       Improve optimization of <replaceable>expression</> <literal>IN</>
 418       (<replaceable>expression-list</>) queries (Tom, per an idea from Robert
 419       Haas)
 420      </para>
 421
 422      <para>
 423       Cases in which there are query variables on the right-hand side had been
 424       handled less efficiently in 8.2.x and 8.3.x than in prior versions.
 425       The fix restores 8.1 behavior for such cases.
 426      </para>
 427     </listitem>
 428
 429     <listitem>
 430      <para>
 431       Fix mis-expansion of rule queries when a sub-<literal>SELECT</> appears
 432       in a function call in <literal>FROM</>,  a multi-row <literal>VALUES</>
 433       list, or a <literal>RETURNING</> list (Tom)
 434      </para>
 435
 436      <para>
 437       The usual symptom of this problem is an <quote>unrecognized node type</>
 438       error.
 439      </para>
 440     </listitem>
 441
 442     <listitem>
 443      <para>
 444       Fix memory leak during rescan of a hashed aggregation plan (Neil)
 445      </para>
 446     </listitem>
 447
 448     <listitem>
 449      <para>
 450       Ensure an error is reported when a newly-defined PL/pgSQL trigger
 451       function is invoked as a normal function (Tom)
 452      </para>
 453     </listitem>
 454
 455     <listitem>
 456      <para>
 457       Prevent possible collision of <structfield>relfilenode</> numbers
 458       when moving a table to another tablespace with <command>ALTER SET
 459       TABLESPACE</> (Heikki)
 460      </para>
 461
 462      <para>
 463       The command tried to re-use the existing filename, instead of
 464       picking one that is known unused in the destination directory.
 465      </para>
 466     </listitem>
 467
 468     <listitem>
 469      <para>
 470       Fix incorrect tsearch2 headline generation when single query
 471       item matches first word of text (Sushant Sinha)
 472      </para>
 473     </listitem>
 474
 475     <listitem>
 476      <para>
 477       Fix improper display of fractional seconds in interval values when
 478       using a non-ISO datestyle in an <option>--enable-integer-datetimes</>
 479       build (Ron Mayer)
 480      </para>
 481     </listitem>
 482
 483     <listitem>
 484      <para>
 485       Ensure <function>SPI_getvalue</> and <function>SPI_getbinval</>
 486       behave correctly when the passed tuple and tuple descriptor have
 487       different numbers of columns (Tom)
 488      </para>
 489
 490      <para>
 491       This situation is normal when a table has had columns added or removed,
 492       but these two functions didn't handle it properly.
 493       The only likely consequence is an incorrect error indication.
 494      </para>
 495     </listitem>
 496
 497     <listitem>
 498      <para>
 499       Fix <application>ecpg</>'s parsing of <command>CREATE ROLE</> (Michael)
 500      </para>
 501     </listitem>
 502
 503     <listitem>
 504      <para>
 505       Fix recent breakage of <literal>pg_ctl restart</> (Tom)
 506      </para>
 507     </listitem>
 508
 509     <listitem>
 510      <para>
 511       Ensure <filename>pg_control</> is opened in binary mode
 512       (Itagaki Takahiro)
 513      </para>
 514
 515      <para>
 516       <application>pg_controldata</> and <application>pg_resetxlog</>
 517       did this incorrectly, and so could fail on Windows.
 518      </para>
 519     </listitem>
 520
 521     <listitem>
 522      <para>
 523       Update time zone data files to <application>tzdata</> release 2008i (for
 524       DST law changes in Argentina, Brazil, Mauritius, Syria)
 525      </para>
 526     </listitem>
 527
 528    </itemizedlist>
 529
 530   </sect2>
 531  </sect1>
 532
 533  <sect1 id="release-8-2-10">
 534   <title>Release 8.2.10</title>
 535
 536   <note>
 537   <title>Release date</title>
 538   <simpara>2008-09-22</simpara>
 539   </note>
 540
 541   <para>
 542    This release contains a variety of fixes from 8.2.9.
 543    For information about new features in the 8.2 major release, see
 544    <xref linkend="release-8-2">.
 545   </para>
 546
 547   <sect2>
 548    <title>Migration to Version 8.2.10</title>
 549
 550    <para>
 551     A dump/restore is not required for those running 8.2.X.
 552     However, if you are upgrading from a version earlier than 8.2.7,
 553     see the release notes for 8.2.7.
 554    </para>
 555
 556   </sect2>
 557
 558   <sect2>
 559    <title>Changes</title>
 560
 561    <itemizedlist>
 562
 563     <listitem>
 564      <para>
 565       Fix bug in btree WAL recovery code (Heikki)
 566      </para>
 567
 568      <para>
 569       Recovery failed if the WAL ended partway through a page split operation.
 570      </para>
 571     </listitem>
 572
 573     <listitem>
 574      <para>
 575       Fix potential miscalculation of <structfield>datfrozenxid</> (Alvaro)
 576      </para>
 577
 578      <para>
 579       This error may explain some recent reports of failure to remove old
 580       <structname>pg_clog</> data.
 581      </para>
 582     </listitem>
 583
 584     <listitem>
 585      <para>
 586       Widen local lock counters from 32 to 64 bits (Tom)
 587      </para>
 588
 589      <para>
 590       This responds to reports that the counters could overflow in
 591       sufficiently long transactions, leading to unexpected <quote>lock is
 592       already held</> errors.
 593      </para>
 594     </listitem>
 595
 596     <listitem>
 597      <para>
 598       Fix possible duplicate output of tuples during a GiST index scan (Teodor)
 599      </para>
 600     </listitem>
 601
 602     <listitem>
 603      <para>
 604       Fix missed permissions checks when a view contains a simple
 605       <literal>UNION ALL</> construct (Heikki)
 606      </para>
 607
 608      <para>
 609       Permissions for the referenced tables were checked properly, but not
 610       permissions for the view itself.
 611      </para>
 612     </listitem>
 613
 614     <listitem>
 615      <para>
 616       Add checks in executor startup to ensure that the tuples produced by an
 617       <command>INSERT</> or <command>UPDATE</> will match the target table's
 618       current rowtype (Tom)
 619      </para>
 620
 621      <para>
 622       <command>ALTER COLUMN TYPE</>, followed by re-use of a previously
 623       cached plan, could produce this type of situation.  The check protects
 624       against data corruption and/or crashes that could ensue.
 625      </para>
 626     </listitem>
 627
 628     <listitem>
 629      <para>
 630       Fix possible repeated drops during <command>DROP OWNED</> (Tom)
 631      </para>
 632
 633      <para>
 634       This would typically result in strange errors such as <quote>cache
 635       lookup failed for relation NNN</>.
 636      </para>
 637     </listitem>
 638
 639     <listitem>
 640      <para>
 641       Fix <literal>AT TIME ZONE</> to first try to interpret its timezone
 642       argument as a timezone abbreviation, and only try it as a full timezone
 643       name if that fails, rather than the other way around as formerly (Tom)
 644      </para>
 645
 646      <para>
 647       The timestamp input functions have always resolved ambiguous zone names
 648       in this order.  Making <literal>AT TIME ZONE</> do so as well improves
 649       consistency, and fixes a compatibility bug introduced in 8.1:
 650       in ambiguous cases we now behave the same as 8.0 and before did,
 651       since in the older versions <literal>AT TIME ZONE</> accepted
 652       <emphasis>only</> abbreviations.
 653      </para>
 654     </listitem>
 655
 656     <listitem>
 657      <para>
 658       Fix datetime input functions to correctly detect integer overflow when
 659       running on a 64-bit platform (Tom)
 660      </para>
 661     </listitem>
 662
 663     <listitem>
 664      <para>
 665       Prevent integer overflows during units conversion when displaying a
 666       configuration parameter that has units (Tom)
 667      </para>
 668     </listitem>
 669
 670     <listitem>
 671      <para>
 672       Improve performance of writing very long log messages to syslog (Tom)
 673      </para>
 674     </listitem>
 675
 676     <listitem>
 677      <para>
 678       Allow spaces in the suffix part of an LDAP URL in
 679       <filename>pg_hba.conf</> (Tom)
 680      </para>
 681     </listitem>
 682
 683     <listitem>
 684      <para>
 685       Fix bug in backwards scanning of a cursor on a <literal>SELECT DISTINCT
 686       ON</> query (Tom)
 687      </para>
 688     </listitem>
 689
 690     <listitem>
 691      <para>
 692       Fix planner bug with nested sub-select expressions (Tom)
 693      </para>
 694
 695      <para>
 696       If the outer sub-select has no direct dependency on the parent query,
 697       but the inner one does, the outer value might not get recalculated
 698       for new parent query rows.
 699      </para>
 700     </listitem>
 701
 702     <listitem>
 703      <para>
 704       Fix planner to estimate that <literal>GROUP BY</> expressions yielding
 705       boolean results always result in two groups, regardless of the
 706       expressions' contents (Tom)
 707      </para>
 708
 709      <para>
 710       This is very substantially more accurate than the regular <literal>GROUP
 711       BY</> estimate for certain boolean tests like <replaceable>col</>
 712       <literal>IS NULL</>.
 713      </para>
 714     </listitem>
 715
 716     <listitem>
 717      <para>
 718       Fix PL/PgSQL to not fail when a <literal>FOR</> loop's target variable
 719       is a record containing composite-type fields (Tom)
 720      </para>
 721     </listitem>
 722
 723     <listitem>
 724      <para>
 725       Fix PL/Tcl to behave correctly with Tcl 8.5, and to be more careful
 726       about the encoding of data sent to or from Tcl (Tom)
 727      </para>
 728     </listitem>
 729
 730     <listitem>
 731      <para>
 732       On Windows, work around a Microsoft bug by preventing
 733       <application>libpq</> from trying to send more than 64kB per system call
 734       (Magnus)
 735      </para>
 736     </listitem>
 737
 738     <listitem>
 739      <para>
 740       Improve <application>pg_dump</> and <application>pg_restore</>'s
 741       error reporting after failure to send a SQL command (Tom)
 742      </para>
 743     </listitem>
 744
 745     <listitem>
 746      <para>
 747       Fix <application>pg_ctl</> to properly preserve postmaster
 748       command-line arguments across a <literal>restart</> (Bruce)
 749      </para>
 750     </listitem>
 751
 752     <listitem>
 753      <para>
 754       Update time zone data files to <application>tzdata</> release 2008f (for
 755       DST law changes in Argentina, Bahamas, Brazil, Mauritius, Morocco,
 756       Pakistan, Palestine, and Paraguay)
 757      </para>
 758     </listitem>
 759
 760    </itemizedlist>
 761
 762   </sect2>
 763  </sect1>
 764
 765  <sect1 id="release-8-2-9">
 766   <title>Release 8.2.9</title>
 767
 768   <note>
 769   <title>Release date</title>
 770   <simpara>2008-06-12</simpara>
 771   </note>
 772
 773   <para>
 774    This release contains one serious and one minor bug fix over 8.2.8.
 775    For information about new features in the 8.2 major release, see
 776    <xref linkend="release-8-2">.
 777   </para>
 778
 779   <sect2>
 780    <title>Migration to Version 8.2.9</title>
 781
 782    <para>
 783     A dump/restore is not required for those running 8.2.X.
 784     However, if you are upgrading from a version earlier than 8.2.7,
 785     see the release notes for 8.2.7.
 786    </para>
 787
 788   </sect2>
 789
 790   <sect2>
 791    <title>Changes</title>
 792
 793    <itemizedlist>
 794
 795     <listitem>
 796      <para>
 797       Make <function>pg_get_ruledef()</> parenthesize negative constants (Tom)
 798      </para>
 799
 800      <para>
 801       Before this fix, a negative constant in a view or rule might be dumped
 802       as, say, <literal>-42::integer</>, which is subtly incorrect: it should
 803       be <literal>(-42)::integer</> due to operator precedence rules.
 804       Usually this would make little difference, but it could interact with
 805       another recent patch to cause
 806       <productname>PostgreSQL</> to reject what had been a valid
 807       <command>SELECT DISTINCT</> view query.  Since this could result in
 808       <application>pg_dump</> output failing to reload, it is being treated
 809       as a high-priority fix.  The only released versions in which dump
 810       output is actually incorrect are 8.3.1 and 8.2.7.
 811      </para>
 812     </listitem>
 813
 814     <listitem>
 815      <para>
 816       Make <command>ALTER AGGREGATE ... OWNER TO</> update
 817       <structname>pg_shdepend</> (Tom)
 818      </para>
 819
 820      <para>
 821       This oversight could lead to problems if the aggregate was later
 822       involved in a <command>DROP OWNED</> or <command>REASSIGN OWNED</>
 823       operation.
 824      </para>
 825     </listitem>
 826
 827    </itemizedlist>
 828
 829   </sect2>
 830  </sect1>
 831
 832  <sect1 id="release-8-2-8">
 833   <title>Release 8.2.8</title>
 834
 835   <note>
 836   <title>Release date</title>
 837   <simpara>never released</simpara>
 838   </note>
 839
 840   <para>
 841    This release contains a variety of fixes from 8.2.7.
 842    For information about new features in the 8.2 major release, see
 843    <xref linkend="release-8-2">.
 844   </para>
 845
 846   <sect2>
 847    <title>Migration to Version 8.2.8</title>
 848
 849    <para>
 850     A dump/restore is not required for those running 8.2.X.
 851     However, if you are upgrading from a version earlier than 8.2.7,
 852     see the release notes for 8.2.7.
 853    </para>
 854
 855   </sect2>
 856
 857   <sect2>
 858    <title>Changes</title>
 859
 860    <itemizedlist>
 861
 862     <listitem>
 863      <para>
 864       Fix <literal>ERRORDATA_STACK_SIZE exceeded</literal> crash that
 865       occurred on Windows when using UTF-8 database encoding and a different
 866       client encoding (Tom)
 867      </para>
 868     </listitem>
 869
 870     <listitem>
 871      <para>
 872       Fix <command>ALTER TABLE ADD COLUMN ... PRIMARY KEY</> so that the new
 873       column is correctly checked to see if it's been initialized to all
 874       non-nulls (Brendan Jurd)
 875      </para>
 876
 877      <para>
 878       Previous versions neglected to check this requirement at all.
 879      </para>
 880     </listitem>
 881
 882     <listitem>
 883      <para>
 884       Fix possible <command>CREATE TABLE</> failure when inheriting the
 885       <quote>same</> constraint from multiple parent relations that
 886       inherited that constraint from a common ancestor (Tom)
 887      </para>
 888     </listitem>
 889
 890     <listitem>
 891      <para>
 892       Fix <function>pg_get_ruledef()</> to show the alias, if any, attached
 893       to the target table of an <command>UPDATE</> or <command>DELETE</>
 894       (Tom)
 895      </para>
 896     </listitem>
 897
 898     <listitem>
 899      <para>
 900       Fix GIN bug that could result in a <literal>too many LWLocks
 901       taken</literal> failure (Teodor)
 902      </para>
 903     </listitem>
 904
 905     <listitem>
 906      <para>
 907       Avoid possible crash when decompressing corrupted data
 908       (Zdenek Kotala)
 909      </para>
 910     </listitem>
 911
 912     <listitem>
 913      <para>
 914       Repair two places where SIGTERM exit of a backend could leave corrupted
 915       state in shared memory (Tom)
 916      </para>
 917
 918      <para>
 919       Neither case is very important if SIGTERM is used to shut down the
 920       whole database cluster together, but there was a problem if someone
 921       tried to SIGTERM individual backends.
 922      </para>
 923     </listitem>
 924
 925     <listitem>
 926      <para>
 927       Fix conversions between ISO-8859-5 and other encodings to handle
 928       Cyrillic <quote>Yo</> characters (<literal>e</> and <literal>E</> with
 929       two dots) (Sergey Burladyan)
 930      </para>
 931     </listitem>
 932
 933     <listitem>
 934      <para>
 935       Fix several datatype input functions, notably <function>array_in()</>,
 936       that were allowing unused bytes in their results to contain
 937       uninitialized, unpredictable values (Tom)
 938      </para>
 939
 940      <para>
 941       This could lead to failures in which two apparently identical literal
 942       values were not seen as equal, resulting in the parser complaining
 943       about unmatched <literal>ORDER BY</> and <literal>DISTINCT</>
 944       expressions.
 945      </para>
 946     </listitem>
 947
 948     <listitem>
 949      <para>
 950       Fix a corner case in regular-expression substring matching
 951       (<literal>substring(<replaceable>string</> from
 952       <replaceable>pattern</>)</literal>) (Tom)
 953      </para>
 954
 955      <para>
 956       The problem occurs when there is a match to the pattern overall but
 957       the user has specified a parenthesized subexpression and that
 958       subexpression hasn't got a match.  An example is
 959       <literal>substring('foo' from 'foo(bar)?')</>.
 960       This should return NULL, since <literal>(bar)</> isn't matched, but
 961       it was mistakenly returning the whole-pattern match instead (ie,
 962       <literal>foo</>).
 963      </para>
 964     </listitem>
 965
 966     <listitem>
 967      <para>
 968       Update time zone data files to <application>tzdata</> release 2008c (for
 969       DST law changes in Morocco, Iraq, Choibalsan, Pakistan, Syria, Cuba, and
 970       Argentina/San_Luis)
 971      </para>
 972     </listitem>
 973
 974     <listitem>
 975      <para>
 976       Fix incorrect result from <application>ecpg</>'s
 977       <function>PGTYPEStimestamp_sub()</> function (Michael)
 978      </para>
 979     </listitem>
 980
 981     <listitem>
 982      <para>
 983       Fix broken GiST comparison function for <filename>contrib/tsearch2</>'s
 984       <type>tsquery</> type (Teodor)
 985      </para>
 986     </listitem>
 987
 988     <listitem>
 989      <para>
 990       Fix possible crashes in <filename>contrib/cube</> functions (Tom)
 991      </para>
 992     </listitem>
 993
 994     <listitem>
 995      <para>
 996       Fix core dump in <filename>contrib/xml2</>'s
 997       <function>xpath_table()</> function when the input query returns a
 998       NULL value (Tom)
 999      </para>
1000     </listitem>
1001
1002     <listitem>
1003      <para>
1004       Fix <filename>contrib/xml2</>'s makefile to not override
1005       <literal>CFLAGS</> (Tom)
1006      </para>
1007     </listitem>
1008
1009     <listitem>
1010      <para>
1011       Fix <literal>DatumGetBool</> macro to not fail with <application>gcc</>
1012       4.3 (Tom)
1013      </para>
1014
1015      <para>
1016       This problem affects <quote>old style</> (V0) C functions that
1017       return boolean.  The fix is already in 8.3, but the need to
1018       back-patch it was not realized at the time.
1019      </para>
1020     </listitem>
1021
1022    </itemizedlist>
1023
1024   </sect2>
1025  </sect1>
1026
1027  <sect1 id="release-8-2-7">
1028   <title>Release 8.2.7</title>
1029
1030   <note>
1031   <title>Release date</title>
1032   <simpara>2008-03-17</simpara>
1033   </note>
1034
1035   <para>
1036    This release contains a variety of fixes from 8.2.6.
1037    For information about new features in the 8.2 major release, see
1038    <xref linkend="release-8-2">.
1039   </para>
1040
1041   <sect2>
1042    <title>Migration to Version 8.2.7</title>
1043
1044    <para>
1045     A dump/restore is not required for those running 8.2.X.
1046     However, you might need to <command>REINDEX</> indexes on textual
1047     columns after updating, if you are affected by the Windows locale
1048     issue described below.
1049    </para>
1050
1051   </sect2>
1052
1053   <sect2>
1054    <title>Changes</title>
1055
1056    <itemizedlist>
1057
1058     <listitem>
1059      <para>
1060       Fix character string comparison for Windows locales that consider
1061       different character combinations as equal (Tom)
1062      </para>
1063
1064      <para>
1065       This fix applies only on Windows and only when using UTF-8
1066       database encoding.  The same fix was made for all other cases
1067       over two years ago, but Windows with UTF-8 uses a separate code
1068       path that was not updated.  If you are using a locale that
1069       considers some non-identical strings as equal, you may need to
1070       <command>REINDEX</> to fix existing indexes on textual columns.
1071      </para>
1072     </listitem>
1073
1074     <listitem>
1075      <para>
1076       Repair potential deadlock between concurrent <command>VACUUM FULL</>
1077       operations on different system catalogs (Tom)
1078      </para>
1079     </listitem>
1080
1081     <listitem>
1082      <para>
1083       Fix longstanding <command>LISTEN</>/<command>NOTIFY</>
1084       race condition (Tom)
1085      </para>
1086
1087      <para>
1088       In rare cases a session that had just executed a
1089       <command>LISTEN</> might not get a notification, even though
1090       one would be expected because the concurrent transaction executing
1091       <command>NOTIFY</> was observed to commit later.
1092      </para>
1093
1094      <para>
1095       A side effect of the fix is that a transaction that has executed
1096       a not-yet-committed <command>LISTEN</> command will not see any
1097       row in <structname>pg_listener</> for the <command>LISTEN</>,
1098       should it choose to look; formerly it would have.  This behavior
1099       was never documented one way or the other, but it is possible that
1100       some applications depend on the old behavior.
1101      </para>
1102     </listitem>
1103
1104     <listitem>
1105      <para>
1106       Disallow <command>LISTEN</> and <command>UNLISTEN</> within a
1107       prepared transaction (Tom)
1108      </para>
1109
1110      <para>
1111       This was formerly allowed but trying to do it had various unpleasant
1112       consequences, notably that the originating backend could not exit
1113       as long as an <command>UNLISTEN</> remained uncommitted.
1114      </para>
1115     </listitem>
1116
1117     <listitem>
1118      <para>
1119       Disallow dropping a temporary table within a
1120       prepared transaction (Heikki)
1121      </para>
1122
1123      <para>
1124       This was correctly disallowed by 8.1, but the check was inadvertently
1125       broken in 8.2.
1126      </para>
1127     </listitem>
1128
1129     <listitem>
1130      <para>
1131       Fix rare crash when an error occurs during a query using a hash index
1132       (Heikki)
1133      </para>
1134     </listitem>
1135
1136     <listitem>
1137      <para>
1138       Fix memory leaks in certain usages of set-returning functions (Neil)
1139      </para>
1140     </listitem>
1141
1142     <listitem>
1143      <para>
1144       Fix input of datetime values for February 29 in years BC (Tom)
1145      </para>
1146
1147      <para>
1148       The former coding was mistaken about which years were leap years.
1149      </para>
1150     </listitem>
1151
1152     <listitem>
1153      <para>
1154       Fix <quote>unrecognized node type</> error in some variants of
1155       <command>ALTER OWNER</> (Tom)
1156      </para>
1157     </listitem>
1158
1159     <listitem>
1160      <para>
1161       Ensure <structname>pg_stat_activity</>.<structfield>waiting</> flag
1162       is cleared when a lock wait is aborted (Tom)
1163      </para>
1164     </listitem>
1165
1166     <listitem>
1167      <para>
1168       Fix handling of process permissions on Windows Vista (Dave, Magnus)
1169      </para>
1170
1171      <para>
1172       In particular, this fix allows starting the server as the Administrator
1173       user.
1174      </para>
1175     </listitem>
1176
1177     <listitem>
1178      <para>
1179       Update time zone data files to <application>tzdata</> release 2008a
1180       (in particular, recent Chile changes); adjust timezone abbreviation
1181       <literal>VET</> (Venezuela) to mean UTC-4:30, not UTC-4:00 (Tom)
1182      </para>
1183     </listitem>
1184
1185     <listitem>
1186      <para>
1187       Fix <application>pg_ctl</> to correctly extract the postmaster's port
1188       number from command-line options (Itagaki Takahiro, Tom)
1189      </para>
1190
1191      <para>
1192       Previously, <literal>pg_ctl start -w</> could try to contact the
1193       postmaster on the wrong port, leading to bogus reports of startup
1194       failure.
1195      </para>
1196     </listitem>
1197
1198     <listitem>
1199      <para>
1200       Use <option>-fwrapv</> to defend against possible misoptimization
1201       in recent <application>gcc</> versions (Tom)
1202      </para>
1203
1204      <para>
1205       This is known to be necessary when building <productname>PostgreSQL</>
1206       with <application>gcc</> 4.3 or later.
1207      </para>
1208     </listitem>
1209
1210
1211     <listitem>
1212      <para>
1213       Correctly enforce <varname>statement_timeout</> values longer
1214       than <literal>INT_MAX</> microseconds (about 35 minutes) (Tom)
1215      </para>
1216
1217      <para>
1218       This bug affects only builds with <option>--enable-integer-datetimes</>.
1219      </para>
1220     </listitem>
1221
1222     <listitem>
1223      <para>
1224       Fix <quote>unexpected PARAM_SUBLINK ID</> planner error when
1225       constant-folding simplifies a sub-select (Tom)
1226      </para>
1227     </listitem>
1228
1229     <listitem>
1230      <para>
1231       Fix logical errors in constraint-exclusion handling of <literal>IS
1232       NULL</> and <literal>NOT</> expressions (Tom)
1233      </para>
1234
1235      <para>
1236       The planner would sometimes exclude partitions that should not
1237       have been excluded because of the possibility of NULL results.
1238      </para>
1239     </listitem>
1240
1241     <listitem>
1242      <para>
1243       Fix another cause of <quote>failed to build any N-way joins</>
1244       planner errors (Tom)
1245      </para>
1246
1247      <para>
1248       This could happen in cases where a clauseless join needed to be
1249       forced before a join clause could be exploited.
1250      </para>
1251     </listitem>
1252
1253     <listitem>
1254      <para>
1255       Fix incorrect constant propagation in outer-join planning (Tom)
1256      </para>
1257
1258      <para>
1259       The planner could sometimes incorrectly conclude that a variable
1260       could be constrained to be equal to a constant, leading
1261       to wrong query results.
1262      </para>
1263     </listitem>
1264
1265     <listitem>
1266      <para>
1267       Fix display of constant expressions in <literal>ORDER BY</>
1268       and <literal>GROUP BY</> (Tom)
1269      </para>
1270
1271      <para>
1272       An explictly casted constant would be shown incorrectly.  This could
1273       for example lead to corruption of a view definition during
1274       dump and reload.
1275      </para>
1276     </listitem>
1277
1278     <listitem>
1279      <para>
1280       Fix <application>libpq</> to handle NOTICE messages correctly
1281       during COPY OUT (Tom)
1282      </para>
1283
1284      <para>
1285       This failure has only been observed to occur when a user-defined
1286       datatype's output routine issues a NOTICE, but there is no
1287       guarantee it couldn't happen due to other causes.
1288      </para>
1289     </listitem>
1290
1291    </itemizedlist>
1292
1293   </sect2>
1294  </sect1>
1295
1296  <sect1 id="release-8-2-6">
1297   <title>Release 8.2.6</title>
1298
1299   <note>
1300   <title>Release date</title>
1301   <simpara>2008-01-07</simpara>
1302   </note>
1303
1304   <para>
1305    This release contains a variety of fixes from 8.2.5,
1306    including fixes for significant security issues.
1307    For information about new features in the 8.2 major release, see
1308    <xref linkend="release-8-2">.
1309   </para>
1310
1311   <sect2>
1312    <title>Migration to Version 8.2.6</title>
1313
1314    <para>
1315     A dump/restore is not required for those running 8.2.X.
1316    </para>
1317
1318   </sect2>
1319
1320   <sect2>
1321    <title>Changes</title>
1322
1323    <itemizedlist>
1324
1325     <listitem>
1326      <para>
1327       Prevent functions in indexes from executing with the privileges of
1328       the user running <command>VACUUM</>, <command>ANALYZE</>, etc (Tom)
1329      </para>
1330
1331      <para>
1332       Functions used in index expressions and partial-index
1333       predicates are evaluated whenever a new table entry is made.  It has
1334       long been understood that this poses a risk of trojan-horse code
1335       execution if one modifies a table owned by an untrustworthy user.
1336       (Note that triggers, defaults, check constraints, etc. pose the
1337       same type of risk.)  But functions in indexes pose extra danger
1338       because they will be executed by routine maintenance operations
1339       such as <command>VACUUM FULL</>, which are commonly performed
1340       automatically under a superuser account.  For example, a nefarious user
1341       can execute code with superuser privileges by setting up a
1342       trojan-horse index definition and waiting for the next routine vacuum.
1343       The fix arranges for standard maintenance operations
1344       (including <command>VACUUM</>, <command>ANALYZE</>, <command>REINDEX</>,
1345       and <command>CLUSTER</>) to execute as the table owner rather than
1346       the calling user, using the same privilege-switching mechanism already
1347       used for <literal>SECURITY DEFINER</> functions.  To prevent bypassing
1348       this security measure, execution of <command>SET SESSION
1349       AUTHORIZATION</> and <command>SET ROLE</> is now forbidden within a
1350       <literal>SECURITY DEFINER</> context.  (CVE-2007-6600)
1351      </para>
1352     </listitem>
1353
1354     <listitem>
1355      <para>
1356       Repair assorted bugs in the regular-expression package (Tom, Will Drewry)
1357      </para>
1358
1359      <para>
1360       Suitably crafted regular-expression patterns could cause crashes,
1361       infinite or near-infinite looping, and/or massive memory consumption,
1362       all of which pose denial-of-service hazards for applications that
1363       accept regex search patterns from untrustworthy sources.
1364       (CVE-2007-4769, CVE-2007-4772, CVE-2007-6067)
1365      </para>
1366     </listitem>
1367
1368     <listitem>
1369      <para>
1370       Require non-superusers who use <filename>/contrib/dblink</> to use only
1371       password authentication, as a security measure (Joe)
1372      </para>
1373
1374      <para>
1375       The fix that appeared for this in 8.2.5 was incomplete, as it plugged
1376       the hole for only some <filename>dblink</> functions.  (CVE-2007-6601,
1377       CVE-2007-3278)
1378      </para>
1379     </listitem>
1380
1381     <listitem>
1382      <para>
1383       Fix bugs in WAL replay for GIN indexes (Teodor)
1384      </para>
1385     </listitem>
1386
1387     <listitem>
1388      <para>
1389       Fix GIN index build to work properly when
1390       <varname>maintenance_work_mem</> is 4GB or more (Tom)
1391      </para>
1392     </listitem>
1393
1394     <listitem>
1395      <para>
1396       Update time zone data files to <application>tzdata</> release 2007k
1397       (in particular, recent Argentina changes) (Tom)
1398      </para>
1399     </listitem>
1400
1401     <listitem>
1402      <para>
1403       Improve planner's handling of LIKE/regex estimation in non-C locales
1404       (Tom)
1405      </para>
1406     </listitem>
1407
1408     <listitem>
1409      <para>
1410       Fix planning-speed problem for deep outer-join nests, as well as
1411       possible poor choice of join order (Tom)
1412      </para>
1413     </listitem>
1414
1415     <listitem>
1416      <para>
1417       Fix planner failure in some cases of <literal>WHERE false AND var IN
1418       (SELECT ...)</> (Tom)
1419      </para>
1420     </listitem>
1421
1422     <listitem>
1423      <para>
1424       Make <command>CREATE TABLE ... SERIAL</> and
1425       <command>ALTER SEQUENCE ... OWNED BY</> not change the
1426       <function>currval()</> state of the sequence (Tom)
1427      </para>
1428     </listitem>
1429
1430     <listitem>
1431      <para>
1432       Preserve the tablespace and storage parameters of indexes that are
1433       rebuilt by <command>ALTER TABLE ... ALTER COLUMN TYPE</> (Tom)
1434      </para>
1435     </listitem>
1436
1437     <listitem>
1438      <para>
1439       Make archive recovery always start a new WAL timeline, rather than only
1440       when a recovery stop time was used (Simon)
1441      </para>
1442
1443      <para>
1444       This avoids a corner-case risk of trying to overwrite an existing
1445       archived copy of the last WAL segment, and seems simpler and cleaner
1446       than the original definition.
1447      </para>
1448     </listitem>
1449
1450     <listitem>
1451      <para>
1452       Make <command>VACUUM</> not use all of <varname>maintenance_work_mem</>
1453       when the table is too small for it to be useful (Alvaro)
1454      </para>
1455     </listitem>
1456
1457     <listitem>
1458      <para>
1459       Fix potential crash in <function>translate()</> when using a multibyte
1460       database encoding (Tom)
1461      </para>
1462     </listitem>
1463
1464     <listitem>
1465      <para>
1466       Make <function>corr()</> return the correct result for negative
1467       correlation values (Neil)
1468      </para>
1469     </listitem>
1470
1471     <listitem>
1472      <para>
1473       Fix overflow in <literal>extract(epoch from interval)</> for intervals
1474       exceeding 68 years (Tom)
1475      </para>
1476     </listitem>
1477
1478     <listitem>
1479      <para>
1480       Fix PL/Perl to not fail when a UTF-8 regular expression is used
1481       in a trusted function (Andrew)
1482      </para>
1483     </listitem>
1484
1485     <listitem>
1486      <para>
1487       Fix PL/Perl to cope when platform's Perl defines type <literal>bool</>
1488       as <literal>int</> rather than <literal>char</> (Tom)
1489      </para>
1490
1491      <para>
1492       While this could theoretically happen anywhere, no standard build of
1493       Perl did things this way ... until <productname>Mac OS X</> 10.5.
1494      </para>
1495     </listitem>
1496
1497     <listitem>
1498      <para>
1499       Fix PL/Python to work correctly with Python 2.5 on 64-bit machines
1500       (Marko Kreen)
1501      </para>
1502     </listitem>
1503
1504     <listitem>
1505      <para>
1506       Fix PL/Python to not crash on long exception messages (Alvaro)
1507      </para>
1508     </listitem>
1509
1510     <listitem>
1511      <para>
1512       Fix <application>pg_dump</> to correctly handle inheritance child tables
1513       that have default expressions different from their parent's (Tom)
1514      </para>
1515     </listitem>
1516
1517     <listitem>
1518      <para>
1519       Fix <application>libpq</> crash when <varname>PGPASSFILE</> refers
1520       to a file that is not a plain file (Martin Pitt)
1521      </para>
1522     </listitem>
1523
1524     <listitem>
1525      <para>
1526       <application>ecpg</> parser fixes (Michael)
1527      </para>
1528     </listitem>
1529
1530     <listitem>
1531      <para>
1532       Make <filename>contrib/pgcrypto</> defend against
1533       <application>OpenSSL</> libraries that fail on keys longer than 128
1534       bits; which is the case at least on some Solaris versions (Marko Kreen)
1535      </para>
1536     </listitem>
1537
1538     <listitem>
1539      <para>
1540       Make <filename>contrib/tablefunc</>'s <function>crosstab()</> handle
1541       NULL rowid as a category in its own right, rather than crashing (Joe)
1542      </para>
1543     </listitem>
1544
1545     <listitem>
1546      <para>
1547       Fix <type>tsvector</> and <type>tsquery</> output routines to
1548       escape backslashes correctly (Teodor, Bruce)
1549      </para>
1550     </listitem>
1551
1552     <listitem>
1553      <para>
1554       Fix crash of <function>to_tsvector()</> on huge input strings (Teodor)
1555      </para>
1556     </listitem>
1557
1558     <listitem>
1559      <para>
1560       Require a specific version of <productname>Autoconf</> to be used
1561       when re-generating the <command>configure</> script (Peter)
1562      </para>
1563
1564      <para>
1565       This affects developers and packagers only.  The change was made
1566       to prevent accidental use of untested combinations of
1567       <productname>Autoconf</> and <productname>PostgreSQL</> versions.
1568       You can remove the version check if you really want to use a
1569       different <productname>Autoconf</> version, but it's
1570       your responsibility whether the result works or not.
1571      </para>
1572     </listitem>
1573
1574     <listitem>
1575      <para>
1576       Update <function>gettimeofday</> configuration check so that
1577       <productname>PostgreSQL</> can be built on newer versions of
1578       <productname>MinGW</> (Magnus)
1579      </para>
1580     </listitem>
1581
1582    </itemizedlist>
1583
1584   </sect2>
1585  </sect1>
1586
1587  <sect1 id="release-8-2-5">
1588   <title>Release 8.2.5</title>
1589
1590   <note>
1591   <title>Release date</title>
1592   <simpara>2007-09-17</simpara>
1593   </note>
1594
1595   <para>
1596    This release contains a variety of fixes from 8.2.4.
1597    For information about new features in the 8.2 major release, see
1598    <xref linkend="release-8-2">.
1599   </para>
1600
1601   <sect2>
1602    <title>Migration to Version 8.2.5</title>
1603
1604    <para>
1605     A dump/restore is not required for those running 8.2.X.
1606    </para>
1607
1608   </sect2>
1609
1610   <sect2>
1611    <title>Changes</title>
1612
1613    <itemizedlist>
1614
1615     <listitem>
1616      <para>
1617       Prevent index corruption when a transaction inserts rows and
1618       then aborts close to the end of a concurrent <command>VACUUM</>
1619       on the same table (Tom)
1620      </para>
1621     </listitem>
1622
1623     <listitem>
1624      <para>
1625       Fix <literal>ALTER DOMAIN ADD CONSTRAINT</> for cases involving
1626       domains over domains (Tom)
1627      </para>
1628     </listitem>
1629
1630     <listitem>
1631      <para>
1632       Make <command>CREATE DOMAIN ... DEFAULT NULL</> work properly (Tom)
1633      </para>
1634     </listitem>
1635
1636     <listitem>
1637      <para>
1638       Fix some planner problems with outer joins, notably poor
1639       size estimation for <literal>t1 LEFT JOIN t2 WHERE t2.col IS NULL</>
1640       (Tom)
1641      </para>
1642     </listitem>
1643
1644     <listitem>
1645      <para>
1646       Allow the <type>interval</> data type to accept input consisting only of
1647       milliseconds or microseconds (Neil)
1648      </para>
1649     </listitem>
1650
1651     <listitem>
1652      <para>
1653       Allow timezone name to appear before the year in <type>timestamp</> input (Tom)
1654      </para>
1655     </listitem>
1656
1657     <listitem>
1658      <para>
1659       Fixes for <acronym>GIN</> indexes used by <filename>/contrib/tsearch2</> (Teodor)
1660      </para>
1661     </listitem>
1662
1663     <listitem>
1664      <para>
1665       Speed up rtree index insertion (Teodor)
1666      </para>
1667     </listitem>
1668
1669     <listitem>
1670      <para>
1671       Fix excessive logging of <acronym>SSL</> error messages (Tom)
1672      </para>
1673     </listitem>
1674
1675     <listitem>
1676      <para>
1677       Fix logging so that log messages are never interleaved when using
1678       the syslogger process (Andrew)
1679      </para>
1680     </listitem>
1681
1682     <listitem>
1683      <para>
1684       Fix crash when <varname>log_min_error_statement</> logging runs out
1685       of memory (Tom)
1686      </para>
1687     </listitem>
1688
1689     <listitem>
1690      <para>
1691       Fix incorrect handling of some foreign-key corner cases (Tom)
1692      </para>
1693     </listitem>
1694
1695     <listitem>
1696      <para>
1697       Fix <function>stddev_pop(numeric)</> and <function>var_pop(numeric)</> (Tom)
1698      </para>
1699     </listitem>
1700
1701     <listitem>
1702      <para>
1703       Prevent <command>REINDEX</> and <command>CLUSTER</> from failing
1704       due to attempting to process temporary tables of other sessions (Alvaro)
1705      </para>
1706     </listitem>
1707
1708     <listitem>
1709      <para>
1710       Update the time zone database rules, particularly New Zealand's upcoming changes (Tom)
1711      </para>
1712     </listitem>
1713
1714     <listitem>
1715      <para>
1716       Windows socket and semaphore improvements (Magnus)
1717      </para>
1718     </listitem>
1719
1720     <listitem>
1721      <para>
1722       Make <command>pg_ctl -w</> work properly in Windows service mode (Dave Page)
1723      </para>
1724     </listitem>
1725
1726     <listitem>
1727      <para>
1728       Fix memory allocation bug when using <application>MIT Kerberos</> on Windows (Magnus)
1729      </para>
1730     </listitem>
1731
1732     <listitem>
1733      <para>
1734       Suppress timezone name (<literal>%Z</>) in log timestamps on Windows
1735       because of possible encoding mismatches (Tom)
1736      </para>
1737     </listitem>
1738
1739     <listitem>
1740      <para>
1741       Require non-superusers who use <filename>/contrib/dblink</> to use only
1742       password authentication, as a security measure (Joe)
1743      </para>
1744     </listitem>
1745
1746     <listitem>
1747      <para>
1748       Restrict <filename>/contrib/pgstattuple</> functions to superusers, for security reasons (Tom)
1749      </para>
1750     </listitem>
1751
1752     <listitem>
1753      <para>
1754       Do not let <filename>/contrib/intarray</> try to make its GIN opclass
1755       the default (this caused problems at dump/restore) (Tom)
1756      </para>
1757     </listitem>
1758
1759    </itemizedlist>
1760
1761   </sect2>
1762  </sect1>
1763
1764  <sect1 id="release-8-2-4">
1765   <title>Release 8.2.4</title>
1766
1767   <note>
1768   <title>Release date</title>
1769   <simpara>2007-04-23</simpara>
1770   </note>
1771
1772   <para>
1773    This release contains a variety of fixes from 8.2.3,
1774    including a security fix.
1775    For information about new features in the 8.2 major release, see
1776    <xref linkend="release-8-2">.
1777   </para>
1778
1779   <sect2>
1780    <title>Migration to Version 8.2.4</title>
1781
1782    <para>
1783     A dump/restore is not required for those running 8.2.X.
1784    </para>
1785
1786   </sect2>
1787
1788   <sect2>
1789    <title>Changes</title>
1790
1791    <itemizedlist>
1792
1793     <listitem>
1794      <para>
1795       Support explicit placement of the temporary-table schema within
1796       <varname>search_path</>, and disable searching it for functions
1797       and operators (Tom)
1798      </para>
1799
1800      <para>
1801       This is needed to allow a security-definer function to set a
1802       truly secure value of <varname>search_path</>.  Without it,
1803       an unprivileged SQL user can use temporary objects to execute code
1804       with the privileges of the security-definer function (CVE-2007-2138).
1805       See <command>CREATE FUNCTION</> for more information.
1806      </para>
1807     </listitem>
1808
1809     <listitem>
1810      <para>
1811       Fix <varname>shared_preload_libraries</> for Windows
1812       by forcing reload in each backend (Korry Douglas)
1813      </para>
1814     </listitem>
1815
1816     <listitem>
1817      <para>
1818       Fix <function>to_char()</> so it properly upper/lower cases localized day or month
1819       names (Pavel Stehule)
1820      </para>
1821     </listitem>
1822
1823     <listitem>
1824      <para>
1825       <filename>/contrib/tsearch2</> crash fixes (Teodor)
1826      </para>
1827     </listitem>
1828
1829     <listitem>
1830      <para>
1831       Require <command>COMMIT PREPARED</> to be executed in the same
1832       database as the transaction was prepared in (Heikki)
1833      </para>
1834     </listitem>
1835
1836     <listitem>
1837      <para>
1838       Allow <command>pg_dump</> to do binary backups larger than two gigabytes
1839       on Windows (Magnus)
1840      </para>
1841     </listitem>
1842
1843     <listitem>
1844      <para>
1845       New traditional (Taiwan) Chinese <acronym>FAQ</> (Zhou Daojing)
1846      </para>
1847     </listitem>
1848
1849     <listitem>
1850      <para>
1851       Prevent the statistics collector from writing to disk too frequently (Tom)
1852      </para>
1853     </listitem>
1854
1855     <listitem>
1856      <para>
1857       Fix potential-data-corruption bug in how <command>VACUUM FULL</> handles
1858       <command>UPDATE</> chains (Tom, Pavan Deolasee)
1859      </para>
1860     </listitem>
1861
1862     <listitem>
1863      <para>
1864       Fix bug in domains that use array types (Tom)
1865      </para>
1866     </listitem>
1867
1868     <listitem>
1869      <para>
1870       Fix <command>pg_dump</> so it can dump a serial column's sequence
1871       using <option>-t</> when not also dumping the owning table
1872       (Tom)
1873      </para>
1874     </listitem>
1875
1876     <listitem>
1877      <para>
1878       Planner fixes, including improving outer join and bitmap scan
1879       selection logic (Tom)
1880      </para>
1881     </listitem>
1882
1883     <listitem>
1884      <para>
1885       Fix possible wrong answers or crash when a PL/pgSQL function tries
1886       to <literal>RETURN</> from within an <literal>EXCEPTION</> block
1887       (Tom)
1888      </para>
1889     </listitem>
1890
1891     <listitem>
1892      <para>
1893       Fix PANIC during enlargement of a hash index (Tom)
1894      </para>
1895     </listitem>
1896
1897     <listitem>
1898      <para>
1899       Fix POSIX-style timezone specs to follow new USA DST rules (Tom)
1900      </para>
1901     </listitem>
1902
1903    </itemizedlist>
1904
1905   </sect2>
1906  </sect1>
1907
1908  <sect1 id="release-8-2-3">
1909   <title>Release 8.2.3</title>
1910
1911   <note>
1912   <title>Release date</title>
1913   <simpara>2007-02-07</simpara>
1914   </note>
1915
1916   <para>
1917    This release contains two fixes from 8.2.2.
1918    For information about new features in the 8.2 major release, see
1919    <xref linkend="release-8-2">.
1920   </para>
1921
1922   <sect2>
1923    <title>Migration to Version 8.2.3</title>
1924
1925    <para>
1926     A dump/restore is not required for those running 8.2.X.
1927    </para>
1928
1929   </sect2>
1930
1931   <sect2>
1932    <title>Changes</title>
1933
1934    <itemizedlist>
1935
1936     <listitem>
1937      <para>
1938       Remove overly-restrictive check for type length in constraints and
1939       functional indexes(Tom)
1940      </para>
1941     </listitem>
1942
1943     <listitem>
1944      <para>
1945       Fix optimization so MIN/MAX in subqueries can again use indexes (Tom)
1946      </para>
1947     </listitem>
1948
1949    </itemizedlist>
1950
1951   </sect2>
1952  </sect1>
1953
1954  <sect1 id="release-8-2-2">
1955   <title>Release 8.2.2</title>
1956
1957   <note>
1958   <title>Release date</title>
1959   <simpara>2007-02-05</simpara>
1960   </note>
1961
1962   <para>
1963    This release contains a variety of fixes from 8.2.1, including
1964    a security fix.
1965    For information about new features in the 8.2 major release, see
1966    <xref linkend="release-8-2">.
1967   </para>
1968
1969   <sect2>
1970    <title>Migration to Version 8.2.2</title>
1971
1972    <para>
1973     A dump/restore is not required for those running 8.2.X.
1974    </para>
1975
1976   </sect2>
1977
1978   <sect2>
1979    <title>Changes</title>
1980
1981    <itemizedlist>
1982
1983     <listitem>
1984      <para>
1985       Remove security vulnerabilities that allowed connected users
1986       to read backend memory (Tom)
1987      </para>
1988
1989      <para>
1990       The vulnerabilities involve suppressing the normal check that a SQL
1991       function returns the data type it's declared to, and changing the
1992       data type of a table column (CVE-2007-0555, CVE-2007-0556).  These
1993       errors can easily be exploited to cause a backend crash, and in
1994       principle might be used to read database content that the user
1995       should not be able to access.
1996      </para>
1997     </listitem>
1998
1999     <listitem>
2000      <para>
2001       Fix not-so-rare-anymore bug wherein btree index page splits could fail
2002       due to choosing an infeasible split point (Heikki Linnakangas)
2003      </para>
2004     </listitem>
2005
2006     <listitem>
2007      <para>
2008       Fix Borland C compile scripts (L Bayuk)
2009      </para>
2010     </listitem>
2011
2012     <listitem>
2013      <para>
2014       Properly handle <function>to_char('CC')</> for years ending in
2015       <literal>00</> (Tom)
2016      </para>
2017
2018      <para>
2019       Year 2000 is in the twentieth century, not the twenty-first.
2020      </para>
2021     </listitem>
2022
2023     <listitem>
2024      <para>
2025       <filename>/contrib/tsearch2</> localization improvements (Tatsuo, Teodor)
2026      </para>
2027     </listitem>
2028
2029     <listitem>
2030      <para>
2031       Fix incorrect permission check in
2032       <literal>information_schema.key_column_usage</> view (Tom)
2033      </para>
2034
2035      <para>
2036       The symptom is <quote>relation with OID nnnnn does not exist</> errors.
2037       To get this fix without using <command>initdb</>, use <command>CREATE OR
2038       REPLACE VIEW</> to install the corrected definition found in
2039       <filename>share/information_schema.sql</>.  Note you will need to do
2040       this in each database.
2041      </para>
2042     </listitem>
2043
2044     <listitem>
2045      <para>
2046       Improve <command>VACUUM</> performance for databases with many tables (Tom)
2047      </para>
2048     </listitem>
2049
2050     <listitem>
2051      <para>
2052       Fix for rare Assert() crash triggered by <literal>UNION</> (Tom)
2053      </para>
2054     </listitem>
2055
2056     <listitem>
2057      <para>
2058       Fix potentially incorrect results from index searches using
2059       <literal>ROW</> inequality conditions (Tom)
2060      </para>
2061     </listitem>
2062
2063     <listitem>
2064      <para>
2065       Tighten security of multi-byte character processing for UTF8 sequences
2066       over three bytes long (Tom)
2067      </para>
2068     </listitem>
2069
2070     <listitem>
2071      <para>
2072       Fix bogus <quote>permission denied</> failures occurring on Windows
2073       due to attempts to fsync already-deleted files (Magnus, Tom)
2074      </para>
2075     </listitem>
2076
2077     <listitem>
2078      <para>
2079       Fix bug that could cause the statistics collector
2080       to hang on Windows (Magnus)
2081      </para>
2082
2083      <para>
2084       This would in turn lead to autovacuum not working.
2085      </para>
2086     </listitem>
2087
2088     <listitem>
2089      <para>
2090       Fix possible crashes when an already-in-use PL/pgSQL function is
2091       updated (Tom)
2092      </para>
2093     </listitem>
2094
2095     <listitem>
2096      <para>
2097       Improve PL/pgSQL handling of domain types (Sergiy Vyshnevetskiy, Tom)
2098      </para>
2099     </listitem>
2100
2101     <listitem>
2102      <para>
2103       Fix possible errors in processing PL/pgSQL exception blocks (Tom)
2104      </para>
2105     </listitem>
2106
2107    </itemizedlist>
2108
2109   </sect2>
2110  </sect1>
2111
2112  <sect1 id="release-8-2-1">
2113   <title>Release 8.2.1</title>
2114
2115   <note>
2116   <title>Release date</title>
2117   <simpara>2007-01-08</simpara>
2118   </note>
2119
2120   <para>
2121    This release contains a variety of fixes from 8.2.
2122    For information about new features in the 8.2 major release, see
2123    <xref linkend="release-8-2">.
2124   </para>
2125
2126   <sect2>
2127    <title>Migration to Version 8.2.1</title>
2128
2129    <para>
2130     A dump/restore is not required for those running 8.2.
2131    </para>
2132
2133   </sect2>
2134
2135   <sect2>
2136    <title>Changes</title>
2137
2138    <itemizedlist>
2139
2140     <listitem>
2141      <para>
2142       Fix crash with <literal>SELECT</> ... <literal>LIMIT ALL</> (also
2143       <literal>LIMIT NULL</>) (Tom)
2144      </para>
2145     </listitem>
2146
2147     <listitem>
2148      <para>
2149       <filename>Several /contrib/tsearch2</> fixes (Teodor)
2150      </para>
2151     </listitem>
2152
2153     <listitem>
2154      <para>
2155       On Windows, make log messages coming from the operating system use
2156       <acronym>ASCII</> encoding (Hiroshi Saito)
2157      </para>
2158
2159      <para>
2160       This fixes a conversion problem when there is a mismatch between
2161       the encoding of the operating system and database server.
2162      </para>
2163     </listitem>
2164
2165     <listitem>
2166      <para>
2167       Fix Windows linking of <application>pg_dump</> using
2168       <filename>win32.mak</>
2169       (Hiroshi Saito)
2170      </para>
2171     </listitem>
2172
2173     <listitem>
2174      <para>
2175       Fix planner mistakes for outer join queries (Tom)
2176      </para>
2177     </listitem>
2178
2179     <listitem>
2180      <para>
2181       Fix several problems in queries involving sub-SELECTs (Tom)
2182      </para>
2183     </listitem>
2184
2185     <listitem>
2186      <para>
2187       Fix potential crash in SPI during subtransaction abort (Tom)
2188      </para>
2189
2190      <para>
2191       This affects all PL functions since they all use SPI.
2192      </para>
2193     </listitem>
2194
2195     <listitem>
2196      <para>
2197       Improve build speed of <acronym>PDF</> documentation (Peter)
2198      </para>
2199     </listitem>
2200
2201     <listitem>
2202      <para>
2203       Re-add <acronym>JST</> (Japan) timezone abbreviation (Tom)
2204      </para>
2205     </listitem>
2206
2207     <listitem>
2208      <para>
2209       Improve optimization decisions related to index scans (Tom)
2210      </para>
2211     </listitem>
2212
2213     <listitem>
2214      <para>
2215       Have <application>psql</> print multi-byte combining characters as
2216       before, rather than output as <literal>\u</> (Tom)
2217      </para>
2218     </listitem>
2219
2220     <listitem>
2221      <para>
2222       Improve index usage of regular expressions that use parentheses (Tom)
2223      </para>
2224
2225      <para>
2226       This improves <application>psql</> <literal>\d</> performance also.
2227      </para>
2228     </listitem>
2229
2230     <listitem>
2231      <para>
2232       Make <application>pg_dumpall</> assume that databases have public
2233       <literal>CONNECT</> privilege, when dumping from a pre-8.2 server (Tom)
2234      </para>
2235
2236      <para>
2237       This preserves the previous behavior that anyone can connect to a
2238       database if allowed by <filename>pg_hba.conf</>.
2239      </para>
2240     </listitem>
2241
2242    </itemizedlist>
2243
2244   </sect2>
2245  </sect1>
2246
2247  <sect1 id="release-8-2">
2248   <title>Release 8.2</title>
2249
2250   <note>
2251    <title>Release date</title>
2252    <simpara>2006-12-05</simpara>
2253   </note>
2254
2255   <sect2>
2256    <title>Overview</title>
2257
2258    <para>
2259     This release adds many functionality and performance improvements that
2260     were requested by users, including:
2261
2262    <itemizedlist>
2263
2264      <listitem>
2265       <para>
2266        Query language enhancements including <command>INSERT/UPDATE/DELETE
2267        RETURNING</command>, multirow <literal>VALUES</literal> lists, and
2268        optional target-table alias in
2269        <command>UPDATE</>/<command>DELETE</command>
2270       </para>
2271      </listitem>
2272
2273      <listitem>
2274       <para>
2275        Index creation without blocking concurrent
2276        <command>INSERT</>/<command>UPDATE</>/<command>DELETE</>
2277        operations
2278       </para>
2279      </listitem>
2280
2281      <listitem>
2282       <para>
2283        Many query optimization improvements, including support for
2284        reordering outer joins
2285       </para>
2286      </listitem>
2287
2288      <listitem>
2289       <para>
2290        Improved sorting performance with lower memory usage
2291       </para>
2292      </listitem>
2293
2294      <listitem>
2295       <para>
2296        More efficient locking with better concurrency
2297       </para>
2298      </listitem>
2299
2300      <listitem>
2301       <para>
2302        More efficient vacuuming
2303       </para>
2304      </listitem>
2305
2306      <listitem>
2307       <para>
2308        Easier administration of warm standby servers
2309       </para>
2310      </listitem>
2311
2312      <listitem>
2313       <para>
2314        New <literal>FILLFACTOR</literal> support for tables and indexes
2315       </para>
2316      </listitem>
2317
2318      <listitem>
2319       <para>
2320        Monitoring, logging, and performance tuning additions
2321       </para>
2322      </listitem>
2323
2324      <listitem>
2325       <para>
2326        More control over creating and dropping objects
2327       </para>
2328      </listitem>
2329
2330      <listitem>
2331       <para>
2332        Table inheritance relationships can be defined
2333        for and removed from pre-existing tables
2334       </para>
2335      </listitem>
2336
2337      <listitem>
2338       <para>
2339        <command>COPY TO</command> can copy the output of an arbitrary
2340        <command>SELECT</command> statement
2341       </para>
2342      </listitem>
2343
2344      <listitem>
2345       <para>
2346        Array improvements, including nulls in arrays
2347       </para>
2348      </listitem>
2349
2350      <listitem>
2351       <para>
2352        Aggregate-function improvements, including multiple-input
2353        aggregates and SQL:2003 statistical functions
2354       </para>
2355      </listitem>
2356
2357      <listitem>
2358       <para>
2359        Many <filename>contrib/</filename> improvements
2360       </para>
2361      </listitem>
2362
2363     </itemizedlist>
2364
2365    </para>
2366
2367   </sect2>
2368
2369   <sect2>
2370    <title>Migration to Version 8.2</title>
2371
2372    <para>
2373     A dump/restore using <application>pg_dump</application> is
2374     required for those wishing to migrate data from any previous
2375     release.
2376    </para>
2377
2378    <para>
2379     Observe the following incompatibilities:
2380    </para>
2381
2382    <itemizedlist>
2383
2384      <listitem>
2385       <para>
2386        Set <link
2387        linkend="guc-escape-string-warning"><varname>escape_string_warning</></link>
2388        to <literal>on</> by default (Bruce)
2389       </para>
2390
2391       <para>
2392        This issues a warning if backslash escapes are used in
2393        <link linkend="sql-syntax-strings">non-escape (non-<literal>E''</>)
2394        strings</link>.
2395       </para>
2396      </listitem>
2397
2398      <listitem>
2399       <para>
2400        Change the <link linkend="sql-syntax-row-constructors">row
2401        constructor syntax</link> (<literal>ROW(...)</>) so that
2402        list elements <literal>foo.*</> will be expanded to a list
2403        of their member fields, rather than creating a nested
2404        row type field as formerly (Tom)
2405       </para>
2406
2407       <para>
2408        The new behavior is substantially more useful since it
2409        allows, for example, triggers to check for data changes
2410        with <literal>IF row(new.*) IS DISTINCT FROM row(old.*)</>.
2411        The old behavior is still available by omitting <literal>.*</>.
2412       </para>
2413      </listitem>
2414
2415      <listitem>
2416       <para>
2417        Make <link linkend="row-wise-comparison">row comparisons</link>
2418        follow <acronym>SQL</> standard semantics and allow them
2419        to be used in index scans (Tom)
2420       </para>
2421
2422       <para>
2423        Previously, row = and &lt;&gt; comparisons followed the
2424        standard but &lt; &lt;= &gt; &gt;= did not.  A row comparison
2425        can now be used as an index constraint for a multicolumn
2426        index matching the row value.
2427       </para>
2428      </listitem>
2429
2430      <listitem>
2431       <para>
2432        Make <link linkend="functions-comparison">row <literal>IS <optional>NOT</> NULL</literal></link>
2433        tests follow <acronym>SQL</> standard semantics (Tom)
2434       </para>
2435
2436       <para>
2437        The former behavior conformed to the standard for simple cases
2438        with <literal>IS NULL</>, but <literal>IS NOT NULL</> would return
2439        true if any row field was non-null, whereas the standard says it
2440        should return true only when all fields are non-null.
2441       </para>
2442      </listitem>
2443
2444      <listitem>
2445       <para>
2446        Make <link linkend="SQL-SET-CONSTRAINTS"><command>SET
2447        CONSTRAINT</></link> affect only one constraint (Kris Jurka)
2448       </para>
2449
2450       <para>
2451        In previous releases, <command>SET CONSTRAINT</> modified
2452        all constraints with a matching name.  In this release,
2453        the schema search path is used to modify only the first
2454        matching constraint.  A schema specification is also
2455        supported.  This more nearly conforms to the SQL standard.
2456       </para>
2457      </listitem>
2458
2459      <listitem>
2460       <para>
2461        Remove <literal>RULE</> permission for tables, for security reasons
2462        (Tom)
2463       </para>
2464
2465       <para>
2466        As of this release, only a table's owner can create or modify
2467        rules for the table.  For backwards compatibility,
2468        <command>GRANT</>/<command>REVOKE RULE</> is still accepted,
2469        but it does nothing.
2470       </para>
2471      </listitem>
2472
2473      <listitem>
2474       <para>
2475        Array comparison improvements (Tom)
2476       </para>
2477
2478       <para>
2479        Now array dimensions are also compared.
2480       </para>
2481      </listitem>
2482
2483      <listitem>
2484       <para>
2485        Change <link linkend="functions-array">array concatenation</link>
2486        to match documented behavior (Tom)
2487       </para>
2488
2489       <para>
2490        This changes the previous behavior where concatenation
2491        would modify the array lower bound.
2492       </para>
2493      </listitem>
2494
2495      <listitem>
2496       <para>
2497        Make command-line options of <application>postmaster</>
2498        and <link linkend="app-postgres"><application>postgres</></link>
2499        identical (Peter)
2500       </para>
2501
2502       <para>
2503        This allows the postmaster to pass arguments to each backend
2504        without using <literal>-o</>.  Note that some options are now
2505        only available as long-form options, because there were conflicting
2506        single-letter options.
2507       </para>
2508      </listitem>
2509
2510      <listitem>
2511       <para>
2512        Deprecate use of <application>postmaster</> symbolic link (Peter)
2513       </para>
2514
2515       <para>
2516        <application>postmaster</> and <application>postgres</>
2517        commands now act identically, with the behavior determined
2518        by command-line options.  The <application>postmaster</> symbolic link is
2519        kept for compatibility, but is not really needed.
2520       </para>
2521      </listitem>
2522
2523      <listitem>
2524       <para>
2525        Change <link
2526        linkend="guc-log-duration"><varname>log_duration</></link>
2527        to output even if the query is not output (Tom)
2528       </para>
2529
2530       <para>
2531        In prior releases, <varname>log_duration</> only printed if
2532        the query appeared earlier in the log.
2533       </para>
2534      </listitem>
2535
2536      <listitem>
2537       <para>
2538        Make <link
2539        linkend="functions-formatting"><function>to_char(time)</></link>
2540        and <link
2541        linkend="functions-formatting"><function>to_char(interval)</></link>
2542        treat <literal>HH</> and <literal>HH12</> as 12-hour
2543        intervals
2544       </para>
2545
2546       <para>
2547        Most applications should use <literal>HH24</> unless they
2548        want a 12-hour display.
2549       </para>
2550      </listitem>
2551
2552      <listitem>
2553       <para>
2554        Zero unmasked bits in conversion from <link
2555        linkend="datatype-inet"><type>INET</></link> to <link
2556        linkend="datatype-inet"><type>CIDR</></link> (Tom)
2557       </para>
2558
2559       <para>
2560        This ensures that the converted value is actually valid for
2561        <type>CIDR</>.
2562       </para>
2563      </listitem>
2564
2565      <listitem>
2566       <para>
2567        Remove <varname>australian_timezones</> configuration variable
2568        (Joachim Wieland)
2569       </para>
2570
2571       <para>
2572        This variable has been superseded by a more general facility
2573        for configuring timezone abbreviations.
2574       </para>
2575      </listitem>
2576
2577      <listitem>
2578       <para>
2579        Improve cost estimation for nested-loop index scans (Tom)
2580       </para>
2581
2582       <para>
2583        This might eliminate the need to set unrealistically small
2584        values of <link
2585        linkend="guc-random-page-cost"><varname>random_page_cost</></link>.
2586        If you have been using a very small <varname>random_page_cost</>,
2587        please recheck your test cases.
2588       </para>
2589      </listitem>
2590
2591      <listitem>
2592       <para>
2593        Change behavior of <command>pg_dump</> <literal>-n</> and
2594        <literal>-t</> options.  (Greg Sabino Mullane)
2595       </para>
2596       <para>
2597        See the <command>pg_dump</> manual page for details.
2598       </para>
2599      </listitem>
2600
2601      <listitem>
2602       <para>
2603        Change <link linkend="libpq"><application>libpq</></link>
2604        <function>PQdsplen()</> to return a useful value (Martijn
2605        van Oosterhout)
2606       </para>
2607      </listitem>
2608
2609      <listitem>
2610       <para>
2611        Declare <link linkend="libpq"><application>libpq</></link>
2612        <function>PQgetssl()</> as returning <literal>void *</>,
2613        rather than <literal>SSL *</> (Martijn van Oosterhout)
2614       </para>
2615
2616       <para>
2617        This allows applications to use the function without including
2618        the OpenSSL headers.
2619       </para>
2620      </listitem>
2621
2622      <listitem>
2623       <para>
2624        C-language loadable modules must now include a
2625        <link linkend="xfunc-c-dynload"><literal>PG_MODULE_MAGIC</></link>
2626        macro call for version compatibility checking
2627        (Martijn van Oosterhout)
2628       </para>
2629      </listitem>
2630
2631      <listitem>
2632       <para>
2633        For security's sake, modules used by a PL/PerlU function are no
2634        longer available to PL/Perl functions (Andrew)
2635       </para>
2636       <note>
2637        <para>
2638         This also implies that data can no longer be shared between a PL/Perl
2639         function and a PL/PerlU function.
2640         Some Perl installations have not been compiled with the correct flags
2641         to allow multiple interpreters to exist within a single process.
2642         In this situation PL/Perl and PL/PerlU cannot both be used in a
2643         single backend. The solution is to get a Perl installation which
2644         supports multiple interpreters.
2645        </para>
2646       </note>
2647      </listitem>
2648
2649      <listitem>
2650       <para>
2651        In <filename>contrib/xml2/</>, rename <function>xml_valid()</> to
2652        <function>xml_is_well_formed()</> (Tom)
2653       </para>
2654
2655       <para>
2656        <function>xml_valid()</> will remain for backward compatibility,
2657        but its behavior will change to do schema checking in a future
2658        release.
2659       </para>
2660      </listitem>
2661
2662      <listitem>
2663       <para>
2664        Remove <filename>contrib/ora2pg/</>, now at <ulink
2665        url="http://www.samse.fr/GPL/ora2pg"></ulink>
2666       </para>
2667      </listitem>
2668
2669      <listitem>
2670       <para>
2671        Remove contrib modules that have been migrated to PgFoundry:
2672        <filename>adddepend</>, <filename>dbase</>, <filename>dbmirror</>,
2673        <filename>fulltextindex</>, <filename>mac</>, <filename>userlock</>
2674       </para>
2675      </listitem>
2676
2677      <listitem>
2678       <para>
2679        Remove abandoned contrib modules:
2680        <filename>mSQL-interface</>, <filename>tips</>
2681       </para>
2682      </listitem>
2683
2684      <listitem>
2685       <para>
2686        Remove <acronym>QNX</> and <acronym>BEOS</> ports (Bruce)
2687       </para>
2688
2689       <para>
2690        These ports no longer had active maintainers.
2691       </para>
2692      </listitem>
2693
2694    </itemizedlist>
2695   </sect2>
2696
2697   <sect2>
2698    <title>Changes</title>
2699
2700    <para>
2701     Below you will find a detailed account of the
2702     changes between <productname>PostgreSQL</productname> 8.2 and
2703     the previous major release.
2704    </para>
2705
2706    <sect3>
2707     <title>Performance Improvements</title>
2708     <itemizedlist>
2709
2710      <listitem>
2711       <para>
2712        Allow the planner to reorder <link linkend="queries-join">outer
2713        joins</link> in some circumstances (Tom)
2714       </para>
2715
2716       <para>
2717        In previous releases, outer joins would always be evaluated in
2718        the order written in the query. This change allows the
2719        query optimizer to consider reordering outer joins, in cases where
2720        it can determine that the join order can be changed without
2721        altering the meaning of the query.  This can make a
2722        considerable performance difference for queries involving
2723        multiple outer joins or mixed inner and outer joins.
2724       </para>
2725      </listitem>
2726
2727      <listitem>
2728       <para>
2729        Improve efficiency of <link
2730        linkend="functions-comparisons"><literal>IN</>
2731        (list-of-expressions)</link> clauses (Tom)
2732       </para>
2733      </listitem>
2734
2735      <listitem>
2736       <para>
2737        Improve sorting speed and reduce memory usage (Simon, Tom)
2738       </para>
2739      </listitem>
2740
2741      <listitem>
2742       <para>
2743        Improve subtransaction performance (Alvaro, Itagaki Takahiro,
2744        Tom)
2745       </para>
2746      </listitem>
2747
2748      <listitem>
2749       <para>
2750        Add <literal>FILLFACTOR</> to <link
2751        linkend="SQL-CREATETABLE">table</link> and <link
2752        linkend="SQL-CREATEINDEX">index</link> creation (ITAGAKI
2753        Takahiro)
2754       </para>
2755
2756       <para>
2757        This leaves extra free space in each table or index page,
2758        allowing improved performance as the database grows.  This
2759        is particularly valuable to maintain clustering.
2760       </para>
2761      </listitem>
2762
2763      <listitem>
2764       <para>
2765        Increase default values for <link
2766        linkend="guc-shared-buffers"><varname>shared_buffers</></link>
2767        and <varname>max_fsm_pages</>
2768        (Andrew)
2769       </para>
2770      </listitem>
2771
2772      <listitem>
2773       <para>
2774        Improve locking performance by breaking the lock manager tables into
2775        sections
2776        (Tom)
2777       </para>
2778
2779       <para>
2780        This allows locking to be more fine-grained, reducing
2781        contention.
2782       </para>
2783      </listitem>
2784
2785      <listitem>
2786       <para>
2787        Reduce locking requirements of sequential scans (Qingqing
2788        Zhou)
2789       </para>
2790      </listitem>
2791
2792      <listitem>
2793       <para>
2794        Reduce locking required for database creation and destruction
2795        (Tom)
2796       </para>
2797      </listitem>
2798
2799      <listitem>
2800       <para>
2801        Improve the optimizer's selectivity estimates for <link
2802        linkend="functions-like"><literal>LIKE</></link>, <link
2803        linkend="functions-like"><literal>ILIKE</></link>, and
2804        <link linkend="functions-posix-regexp">regular expression</link>
2805        operations (Tom)
2806       </para>
2807      </listitem>
2808
2809      <listitem>
2810       <para>
2811        Improve planning of joins to <link linkend="ddl-inherit">inherited
2812        tables</link> and <link linkend="queries-union"><literal>UNION
2813        ALL</></link> views (Tom)
2814       </para>
2815      </listitem>
2816
2817      <listitem>
2818       <para>
2819        Allow <link linkend="guc-constraint-exclusion">constraint
2820        exclusion</link> to be applied to <link
2821        linkend="ddl-inherit">inherited</link> <command>UPDATE</> and
2822        <command>DELETE</> queries (Tom)
2823       </para>
2824
2825       <para>
2826        <command>SELECT</> already honored constraint exclusion.
2827       </para>
2828      </listitem>
2829
2830      <listitem>
2831       <para>
2832        Improve planning of constant <literal>WHERE</> clauses, such as
2833        a condition that depends only on variables inherited from an
2834        outer query level (Tom)
2835       </para>
2836      </listitem>
2837
2838      <listitem>
2839       <para>
2840        Protocol-level unnamed prepared statements are re-planned
2841        for each set of <literal>BIND</> values (Tom)
2842       </para>
2843
2844       <para>
2845        This improves performance because the exact parameter values
2846        can be used in the plan.
2847       </para>
2848      </listitem>
2849
2850      <listitem>
2851       <para>
2852        Speed up vacuuming of B-Tree indexes (Heikki Linnakangas,
2853        Tom)
2854       </para>
2855      </listitem>
2856
2857      <listitem>
2858       <para>
2859        Avoid extra scan of tables without indexes during <link
2860        linkend="SQL-VACUUM"><command>VACUUM</></link> (Greg Stark)
2861       </para>
2862      </listitem>
2863
2864      <listitem>
2865       <para>
2866        Improve multicolumn <link linkend="GiST"><acronym>GiST</></link>
2867        indexing (Oleg, Teodor)
2868       </para>
2869      </listitem>
2870
2871      <listitem>
2872       <para>
2873        Remove dead index entries before B-Tree page split (Junji
2874        Teramoto)
2875       </para>
2876      </listitem>
2877
2878     </itemizedlist>
2879
2880    </sect3>
2881
2882    <sect3>
2883     <title>Server Changes</title>
2884     <itemizedlist>
2885
2886      <listitem>
2887       <para>
2888        Allow a forced switch to a new transaction log file (Simon, Tom)
2889       </para>
2890
2891       <para>
2892        This is valuable for keeping warm standby slave servers
2893        in sync with the master.  Transaction log file switching now also happens
2894        automatically during <link
2895        linkend="functions-admin"><function>pg_stop_backup()</></link>.
2896        This ensures that all
2897        transaction log files needed for recovery can be archived immediately.
2898       </para>
2899      </listitem>
2900
2901      <listitem>
2902       <para>
2903        Add <acronym>WAL</> informational functions (Simon)
2904       </para>
2905
2906       <para>
2907        Add functions for interrogating the current transaction log insertion
2908        point and determining <acronym>WAL</> filenames from the
2909        hex <acronym>WAL</> locations displayed by <link
2910        linkend="functions-admin"><function>pg_stop_backup()</></link>
2911        and related functions.
2912       </para>
2913      </listitem>
2914
2915      <listitem>
2916       <para>
2917        Improve recovery from a crash during <acronym>WAL</> replay (Simon)
2918       </para>
2919
2920       <para>
2921        The server now does periodic checkpoints during <acronym>WAL</>
2922        recovery, so if there is a crash, future <acronym>WAL</>
2923        recovery is shortened.  This also eliminates the need for
2924        warm standby servers to replay the entire log since the
2925        base backup if they crash.
2926       </para>
2927      </listitem>
2928
2929      <listitem>
2930       <para>
2931        Improve reliability of long-term <acronym>WAL</> replay
2932        (Heikki, Simon, Tom)
2933       </para>
2934
2935       <para>
2936        Formerly, trying to roll forward through more than 2 billion
2937        transactions would not work due to XID wraparound.  This meant
2938        warm standby servers had to be reloaded
2939        from fresh base backups periodically.
2940       </para>
2941      </listitem>
2942
2943      <listitem>
2944       <para>
2945        Add <link
2946        linkend="guc-archive-timeout"><varname>archive_timeout</></link>
2947        to force transaction log file switches at a given interval (Simon)
2948       </para>
2949
2950       <para>
2951        This enforces a maximum replication delay for warm standby servers.
2952       </para>
2953      </listitem>
2954
2955      <listitem>
2956       <para>
2957        Add native <link linkend="auth-ldap"><acronym>LDAP</></link>
2958        authentication (Magnus Hagander)
2959       </para>
2960
2961       <para>
2962        This is particularly useful for platforms that do not
2963        support <acronym>PAM</>, such as Windows.
2964       </para>
2965      </listitem>
2966
2967      <listitem>
2968       <para>
2969        Add <link linkend="sql-grant-description-objects"><literal>GRANT
2970        CONNECT ON DATABASE</></link> (Gevik Babakhani)
2971       </para>
2972
2973       <para>
2974        This gives SQL-level control over database access.  It works as
2975        an additional filter on top of the existing
2976        <link linkend="auth-pg-hba-conf"><filename>pg_hba.conf</></link>
2977        controls.
2978       </para>
2979      </listitem>
2980
2981      <listitem>
2982       <para>
2983        Add support for <link linkend="ssl-tcp"><acronym>SSL</>
2984        Certificate Revocation List</link> (<acronym>CRL</>) files
2985        (Libor Hoho&scaron;)
2986       </para>
2987
2988       <para>
2989        The server and <application>libpq</> both recognize <acronym>CRL</>
2990        files now.
2991       </para>
2992      </listitem>
2993
2994      <listitem>
2995       <para>
2996        <link linkend="GiST"><acronym>GiST</></link> indexes are
2997        now clusterable (Teodor)
2998       </para>
2999      </listitem>
3000
3001      <listitem>
3002       <para>
3003        Remove routine autovacuum server log entries (Bruce)
3004       </para>
3005
3006       <para>
3007        <link
3008        linkend="monitoring-stats-views-table"><literal>pg_stat_activity</></link>
3009        now shows autovacuum activity.
3010       </para>
3011      </listitem>
3012
3013      <listitem>
3014       <para>
3015        Track maximum XID age within individual tables, instead of whole databases (Alvaro)
3016       </para>
3017
3018       <para>
3019        This reduces the overhead involved in preventing transaction
3020        ID wraparound, by avoiding unnecessary VACUUMs.
3021       </para>
3022      </listitem>
3023
3024      <listitem>
3025       <para>
3026        Add last vacuum and analyze timestamp columns to the stats
3027        collector (Larry Rosenman)
3028       </para>
3029
3030       <para>
3031        These values now appear in the <link
3032        linkend="monitoring-stats-views-table"><literal>pg_stat_*_tables</></link>
3033        system views.
3034       </para>
3035      </listitem>
3036
3037      <listitem>
3038       <para>
3039        Improve performance of statistics monitoring, especially
3040        <varname>stats_command_string</>
3041        (Tom, Bruce)
3042       </para>
3043
3044       <para>
3045        This release enables <varname>stats_command_string</> by
3046        default, now that its overhead is minimal.  This means
3047        <link
3048        linkend="monitoring-stats-views-table"><literal>pg_stat_activity</></link>
3049        will now show all active queries by default.
3050       </para>
3051      </listitem>
3052
3053      <listitem>
3054       <para>
3055        Add a <literal>waiting</> column to <link
3056        linkend="monitoring-stats-views-table"><literal>pg_stat_activity</></link>
3057        (Tom)
3058       </para>
3059
3060       <para>
3061        This allows <structname>pg_stat_activity</> to show all the
3062        information included in the <application>ps</> display.
3063       </para>
3064      </listitem>
3065
3066      <listitem>
3067       <para>
3068        Add configuration parameter <link
3069        linkend="guc-update-process-title"><varname>update_process_title</></link>
3070        to control whether the <application>ps</> display is updated
3071        for every command (Bruce)
3072       </para>
3073
3074       <para>
3075        On platforms where it is expensive to update the <application>ps</>
3076        display, it might be worthwhile to turn this off and rely solely on
3077        <structname>pg_stat_activity</> for status information.
3078       </para>
3079      </listitem>
3080
3081      <listitem>
3082       <para>
3083        Allow units to be specified in configuration settings
3084        (Peter)
3085       </para>
3086
3087       <para>
3088        For example, you can now set <link
3089        linkend="guc-shared-buffers"><varname>shared_buffers</></link>
3090        to <literal>32MB</> rather than mentally converting sizes.
3091       </para>
3092      </listitem>
3093
3094      <listitem>
3095       <para>
3096        Add support for <link linkend="config-setting">include
3097        directives</link> in <filename>postgresql.conf</> (Joachim
3098        Wieland)
3099       </para>
3100      </listitem>
3101
3102      <listitem>
3103       <para>
3104        Improve logging of protocol-level prepare/bind/execute
3105        messages (Bruce, Tom)
3106       </para>
3107
3108       <para>
3109        Such logging now shows statement names, bind parameter
3110        values, and the text of the query being executed.  Also,
3111        the query text is properly included in logged error messages
3112        when enabled by <varname>log_min_error_statement</>.
3113       </para>
3114      </listitem>
3115
3116      <listitem>
3117       <para>
3118        Prevent <link
3119        linkend="guc-max-stack-depth"><varname>max_stack_depth</></link>
3120        from being set to unsafe values
3121       </para>
3122
3123       <para>
3124        On platforms where we can determine the actual kernel stack depth
3125        limit (which is most), make sure that the initial default value of
3126        <varname>max_stack_depth</> is safe, and reject attempts to set it
3127        to unsafely large values.
3128       </para>
3129      </listitem>
3130
3131      <listitem>
3132       <para>
3133        Enable highlighting of error location in query in more
3134        cases (Tom)
3135       </para>
3136
3137       <para>
3138        The server is now able to report a specific error location for
3139        some semantic errors (such as unrecognized column name), rather
3140        than just for basic syntax errors as before.
3141       </para>
3142      </listitem>
3143
3144      <listitem>
3145       <para>
3146        Fix <quote>failed to re-find parent key</> errors in
3147        <command>VACUUM</> (Tom)
3148       </para>
3149      </listitem>
3150
3151      <listitem>
3152       <para>
3153        Clean out <filename>pg_internal.init</> cache files during server
3154        restart (Simon)
3155       </para>
3156
3157       <para>
3158        This avoids a hazard that the cache files might contain stale
3159        data after PITR recovery.
3160       </para>
3161      </listitem>
3162
3163      <listitem>
3164       <para>
3165        Fix race condition for truncation of a large relation across a
3166        gigabyte boundary by <command>VACUUM</> (Tom)
3167       </para>
3168      </listitem>
3169
3170      <listitem>
3171       <para>
3172        Fix bug causing needless deadlock errors on row-level locks (Tom)
3173       </para>
3174      </listitem>
3175
3176      <listitem>
3177       <para>
3178        Fix bugs affecting multi-gigabyte hash indexes (Tom)
3179       </para>
3180      </listitem>
3181
3182      <listitem>
3183       <para>
3184        Each backend process is now its own process group leader (Tom)
3185       </para>
3186
3187       <para>
3188        This allows query cancel to abort subprocesses invoked from a
3189        backend or archive/recovery process.
3190       </para>
3191      </listitem>
3192
3193     </itemizedlist>
3194
3195    </sect3>
3196
3197    <sect3>
3198     <title>Query Changes</title>
3199     <itemizedlist>
3200
3201      <listitem>
3202       <para>
3203        Add <link linkend="SQL-INSERT"><command>INSERT</></link>/<link
3204        linkend="SQL-UPDATE"><command>UPDATE</></link>/<link
3205        linkend="SQL-DELETE"><command>DELETE</></link>
3206        <literal>RETURNING</> (Jonah Harris, Tom)
3207       </para>
3208
3209       <para>
3210        This allows these commands to return values, such as the
3211        computed serial key for a new row.  In the <command>UPDATE</>
3212        case, values from the updated version of the row are returned.
3213       </para>
3214      </listitem>
3215
3216      <listitem>
3217       <para>
3218        Add support for multiple-row <link
3219        linkend="queries-values"><literal>VALUES</></link> clauses,
3220        per SQL standard (Joe, Tom)
3221       </para>
3222
3223       <para>
3224        This allows <command>INSERT</> to insert multiple rows of
3225        constants, or queries to generate result sets using constants.
3226        For example, <literal>INSERT ...  VALUES (...), (...),
3227        ....</>, and <literal>SELECT * FROM (VALUES (...), (...),
3228        ....) AS alias(f1, ...)</>.
3229       </para>
3230      </listitem>
3231
3232      <listitem>
3233       <para>
3234        Allow <link linkend="SQL-UPDATE"><command>UPDATE</></link>
3235        and <link linkend="SQL-DELETE"><command>DELETE</></link>
3236        to use an alias for the target table (Atsushi Ogawa)
3237       </para>
3238
3239       <para>
3240        The SQL standard does not permit an alias in these commands, but
3241        many database systems allow one anyway for notational convenience.
3242       </para>
3243      </listitem>
3244
3245      <listitem>
3246       <para>
3247        Allow <link linkend="SQL-UPDATE"><command>UPDATE</></link>
3248        to set multiple columns with a list of values (Susanne
3249        Ebrecht)
3250       </para>
3251
3252       <para>
3253        This is basically a short-hand for assigning the columns
3254        and values in pairs.  The syntax is <literal>UPDATE tab
3255        SET (<replaceable>column</>, ...) = (<replaceable>val</>, ...)</>.
3256       </para>
3257      </listitem>
3258
3259      <listitem>
3260       <para>
3261        Make row comparisons work per standard (Tom)
3262       </para>
3263
3264       <para>
3265        The forms &lt;, &lt;=, &gt;, &gt;= now compare rows lexicographically,
3266        that is, compare the first elements, if equal compare the second
3267        elements, and so on.  Formerly they expanded to an AND condition
3268        across all the elements, which was neither standard nor very useful.
3269       </para>
3270      </listitem>
3271
3272      <listitem>
3273       <para>
3274        Add <link linkend="SQL-TRUNCATE"><literal>CASCADE</></link>
3275        option to <command>TRUNCATE</> (Joachim Wieland)
3276       </para>
3277
3278       <para>
3279        This causes <command>TRUNCATE</> to automatically include all tables
3280        that reference the specified table(s) via foreign keys.  While
3281        convenient, this is a dangerous tool &mdash; use with caution!
3282       </para>
3283      </listitem>
3284
3285      <listitem>
3286       <para>
3287        Support <literal>FOR UPDATE</> and <literal>FOR SHARE</>
3288        in the same <link linkend="SQL-INSERT"><literal>SELECT</></link>
3289        command (Tom)
3290       </para>
3291      </listitem>
3292
3293      <listitem>
3294       <para>
3295        Add <link linkend="functions-comparisons"><literal>IS NOT
3296        DISTINCT FROM</></link> (Pavel Stehule)
3297       </para>
3298
3299       <para>
3300        This operator is similar to equality (<literal>=</>), but
3301        evaluates to true when both left and right operands are
3302        <literal>NULL</>, and to false when just one is, rather than
3303        yielding <literal>NULL</> in these cases.
3304       </para>
3305      </listitem>
3306
3307      <listitem>
3308       <para>
3309        Improve the length output used by <link
3310        linkend="queries-union"><literal>UNION</></link>/<literal>INTERSECT</>/<literal>EXCEPT</>
3311        (Tom)
3312       </para>
3313
3314       <para>
3315        When all corresponding columns are of the same defined length, that
3316        length is used for the result, rather than a generic length.
3317       </para>
3318      </listitem>
3319
3320      <listitem>
3321       <para>
3322        Allow <link linkend="functions-like"><literal>ILIKE</></link>
3323        to work for multi-byte encodings (Tom)
3324       </para>
3325
3326       <para>
3327        Internally, <literal>ILIKE</> now calls <function>lower()</>
3328        and then uses <literal>LIKE</>.  Locale-specific regular
3329        expression patterns still do not work in these encodings.
3330       </para>
3331      </listitem>
3332
3333      <listitem>
3334       <para>
3335        Enable <link
3336        linkend="guc-standard-conforming-strings"><varname>standard_conforming_strings</></link>
3337        to be turned <literal>on</> (Kevin Grittner)
3338       </para>
3339
3340       <para>
3341        This allows backslash escaping in strings to be disabled,
3342        making <productname>PostgreSQL</> more
3343        standards-compliant.  The default is <literal>off</> for backwards
3344        compatibility, but future releases will default this to <literal>on</>.
3345       </para>
3346      </listitem>
3347
3348      <listitem>
3349       <para>
3350        Do not flatten subqueries that contain <literal>volatile</>
3351        functions in their target lists (Jaime Casanova)
3352       </para>
3353
3354       <para>
3355        This prevents surprising behavior due to multiple evaluation
3356        of a <literal>volatile</> function (such as <function>random()</>
3357        or <function>nextval()</>).  It might cause performance
3358        degradation in the presence of functions that are unnecessarily
3359        marked as <literal>volatile</>.
3360       </para>
3361      </listitem>
3362
3363      <listitem>
3364       <para>
3365        Add system views <link
3366        linkend="view-pg-prepared-statements"><literal>pg_prepared_statements</></link>
3367        and <link
3368        linkend="view-pg-cursors"><literal>pg_cursors</></link>
3369        to show prepared statements and open cursors (Joachim Wieland, Neil)
3370       </para>
3371
3372       <para>
3373        These are very useful in pooled connection setups.
3374       </para>
3375      </listitem>
3376
3377      <listitem>
3378       <para>
3379        Support portal parameters in <link
3380        linkend="SQL-EXPLAIN"><command>EXPLAIN</></link> and <link
3381        linkend="SQL-EXECUTE"><command>EXECUTE</></link> (Tom)
3382       </para>
3383
3384       <para>
3385        This allows, for example, <acronym>JDBC</> <literal>?</> parameters to
3386        work in these commands.
3387       </para>
3388      </listitem>
3389
3390      <listitem>
3391       <para>
3392        If <acronym>SQL</>-level <link
3393        linkend="SQL-PREPARE"><command>PREPARE</></link> parameters
3394        are unspecified, infer their types from the content of the
3395        query (Neil)
3396       </para>
3397
3398       <para>
3399        Protocol-level <command>PREPARE</> already did this.
3400       </para>
3401      </listitem>
3402
3403      <listitem>
3404       <para>
3405        Allow <literal>LIMIT</> and <literal>OFFSET</> to exceed
3406        two billion (Dhanaraj M)
3407       </para>
3408      </listitem>
3409
3410     </itemizedlist>
3411
3412    </sect3>
3413
3414    <sect3>
3415     <title>Object Manipulation Changes</title>
3416     <itemizedlist>
3417
3418      <listitem>
3419       <para>
3420        Add <literal>TABLESPACE</> clause to <link
3421        linkend="SQL-CREATETABLEAS"><command>CREATE TABLE AS</></link>
3422        (Neil)
3423       </para>
3424
3425       <para>
3426        This allows a tablespace to be specified for the new table.
3427       </para>
3428      </listitem>
3429
3430      <listitem>
3431       <para>
3432        Add <literal>ON COMMIT</> clause to <link
3433        linkend="SQL-CREATETABLEAS"><command>CREATE TABLE AS</></link>
3434        (Neil)
3435       </para>
3436
3437       <para>
3438        This allows temporary tables to be truncated or dropped on
3439        transaction commit.  The default behavior is for the table
3440        to remain until the session ends.
3441       </para>
3442      </listitem>
3443
3444      <listitem>
3445       <para>
3446        Add <literal>INCLUDING CONSTRAINTS</> to <link
3447        linkend="SQL-CREATETABLE"><command>CREATE TABLE LIKE</></link>
3448        (Greg Stark)
3449       </para>
3450
3451       <para>
3452        This allows easy copying of <literal>CHECK</> constraints to a new
3453        table.
3454       </para>
3455      </listitem>
3456
3457      <listitem>
3458       <para>
3459        Allow the creation of placeholder (shell) <link
3460        linkend="SQL-CREATETYPE">types</link> (Martijn van Oosterhout)
3461       </para>
3462
3463       <para>
3464        A shell type declaration creates a type name, without specifying
3465        any of the details of the type.  Making a shell type is useful
3466        because it allows cleaner declaration of the type's input/output
3467        functions, which must exist before the type can be defined <quote>for
3468        real</>.  The syntax is <command>CREATE TYPE <replaceable
3469        class="parameter">typename</replaceable></>.
3470       </para>
3471      </listitem>
3472
3473      <listitem>
3474       <para>
3475        <link linkend="SQL-CREATEAGGREGATE">Aggregate functions</link>
3476        now support multiple input parameters (Sergey Koposov, Tom)
3477       </para>
3478      </listitem>
3479
3480      <listitem>
3481       <para>
3482        Add new aggregate creation <link
3483        linkend="SQL-CREATEAGGREGATE">syntax</link> (Tom)
3484       </para>
3485
3486       <para>
3487        The new syntax is <command>CREATE AGGREGATE
3488        <replaceable>aggname</> (<replaceable>input_type</>)
3489        (<replaceable>parameter_list</>)</command>.  This more
3490        naturally supports the new multi-parameter aggregate
3491        functionality.  The previous syntax is still supported.
3492       </para>
3493      </listitem>
3494
3495      <listitem>
3496       <para>
3497        Add <link
3498        linkend="SQL-ALTERROLE"><command>ALTER ROLE PASSWORD NULL</></link>
3499        to remove a previously set role password (Peter)
3500       </para>
3501      </listitem>
3502
3503      <listitem>
3504       <para>
3505        Add <command>DROP</> object <literal>IF EXISTS</> for many
3506        object types (Andrew)
3507       </para>
3508
3509       <para>
3510        This allows <command>DROP</> operations on non-existent
3511        objects without generating an error.
3512       </para>
3513      </listitem>
3514
3515      <listitem>
3516       <para>
3517        Add <link linkend="SQL-DROP-OWNED"><literal>DROP OWNED</></link>
3518        to drop all objects owned by a role (Alvaro)
3519       </para>
3520      </listitem>
3521
3522      <listitem>
3523       <para>
3524        Add <link linkend="SQL-REASSIGN-OWNED"><literal>REASSIGN
3525        OWNED</></link> to reassign ownership of all objects owned
3526        by a role (Alvaro)
3527       </para>
3528
3529       <para>
3530        This, and <literal>DROP OWNED</> above, facilitate dropping
3531        roles.
3532       </para>
3533      </listitem>
3534
3535      <listitem>
3536       <para>
3537        Add <link linkend="SQL-GRANT"><command>GRANT ON SEQUENCE</></link>
3538        syntax (Bruce)
3539       </para>
3540
3541       <para>
3542        This was added for setting sequence-specific permissions.
3543        <literal>GRANT ON TABLE</> for sequences is still supported
3544        for backward compatibility.
3545       </para>
3546      </listitem>
3547
3548      <listitem>
3549       <para>
3550        Add <link linkend="SQL-GRANT"><literal>USAGE</></link>
3551        permission for sequences that allows only <function>currval()</>
3552        and <function>nextval()</>, not <function>setval()</>
3553        (Bruce)
3554       </para>
3555
3556       <para>
3557        <literal>USAGE</> permission allows more fine-grained
3558        control over sequence access.  Granting <literal>USAGE</>
3559        allows users to increment
3560        a sequence, but prevents them from setting the sequence to
3561        an arbitrary value using <function>setval()</>.
3562       </para>
3563      </listitem>
3564
3565      <listitem>
3566       <para>
3567        Add <link linkend="SQL-ALTERTABLE"><literal>ALTER TABLE
3568        [ NO ] INHERIT</></link> (Greg Stark)
3569       </para>
3570
3571       <para>
3572        This allows inheritance to be adjusted dynamically, rather than
3573        just at table creation and destruction.  This is very valuable
3574        when using inheritance to implement table partitioning.
3575       </para>
3576      </listitem>
3577
3578      <listitem>
3579       <para>
3580        Allow <link linkend="SQL-COMMENT">comments</link> on global
3581        objects to be stored globally (Kris Jurka)
3582       </para>
3583
3584       <para>
3585        Previously, comments attached to databases were stored in individual
3586        databases, making them ineffective, and there was no provision
3587        at all for comments on roles or tablespaces.  This change adds a new
3588        shared catalog <link
3589        linkend="catalog-pg-shdescription"><structname>pg_shdescription</structname></link>
3590        and stores comments on databases, roles, and tablespaces therein.
3591       </para>
3592      </listitem>
3593
3594     </itemizedlist>
3595
3596    </sect3>
3597
3598    <sect3>
3599     <title>Utility Command Changes</title>
3600     <itemizedlist>
3601
3602      <listitem>
3603       <para>
3604        Add option to allow indexes to be created without blocking
3605        concurrent writes to the table (Greg Stark, Tom)
3606       </para>
3607
3608       <para>
3609        The new syntax is <link linkend="SQL-CREATEINDEX"><command>CREATE
3610        INDEX CONCURRENTLY</></link>.  The default behavior is
3611        still to block table modification while a index is being
3612        created.
3613       </para>
3614      </listitem>
3615
3616      <listitem>
3617       <para>
3618        Provide <link linkend="functions-advisory-locks">advisory
3619        locking</link> functionality (Abhijit Menon-Sen, Tom)
3620       </para>
3621
3622       <para>
3623        This is a new locking API designed to replace what used to be
3624        in /contrib/userlock.  The userlock code is now on pgfoundry.
3625       </para>
3626      </listitem>
3627
3628      <listitem>
3629       <para>
3630        Allow <link linkend="SQL-COPY"><command>COPY</></link> to
3631        dump a <command>SELECT</> query (Zoltan Boszormenyi, Karel
3632        Zak)
3633       </para>
3634
3635       <para>
3636        This allows <command>COPY</> to dump arbitrary <acronym>SQL</>
3637        queries. The syntax is <literal>COPY (SELECT ...) TO</>.
3638       </para>
3639      </listitem>
3640
3641      <listitem>
3642       <para>
3643        Make the <link linkend="SQL-COPY"><command>COPY</></link>
3644        command return a command tag that includes the number of
3645        rows copied (Volkan YAZICI)
3646       </para>
3647      </listitem>
3648
3649      <listitem>
3650       <para>
3651        Allow <link linkend="SQL-VACUUM"><command>VACUUM</></link>
3652        to expire rows without being affected by other concurrent
3653        <command>VACUUM</> operations (Hannu Krossing, Alvaro, Tom)
3654       </para>
3655      </listitem>
3656
3657      <listitem>
3658       <para>
3659        Make <link linkend="APP-INITDB"><application>initdb</></link>
3660        detect the operating system locale and set the default
3661        <varname>DateStyle</> accordingly (Peter)
3662       </para>
3663
3664       <para>
3665        This makes it more likely that the installed
3666        <filename>postgresql.conf</> <varname>DateStyle</> value will
3667        be as desired.
3668       </para>
3669      </listitem>
3670
3671      <listitem>
3672       <para>
3673        Reduce number of progress messages displayed by <application>initdb</> (Tom)
3674       </para>
3675      </listitem>
3676
3677     </itemizedlist>
3678
3679    </sect3>
3680
3681    <sect3>
3682     <title>Date/Time Changes</title>
3683     <itemizedlist>
3684
3685      <listitem>
3686       <para>
3687        Allow full timezone names in <link
3688        linkend="datatype-datetime"><type>timestamp</></link> input values
3689        (Joachim Wieland)
3690       </para>
3691
3692       <para>
3693        For example, <literal>'2006-05-24 21:11
3694        America/New_York'::timestamptz</>.
3695       </para>
3696      </listitem>
3697
3698      <listitem>
3699       <para>
3700        Support configurable timezone abbreviations (Joachim Wieland)
3701       </para>
3702
3703       <para>
3704        A desired set of timezone abbreviations can be chosen via the
3705        configuration parameter <link
3706        linkend="guc-timezone-abbreviations"><varname>timezone_abbreviations</></link>.
3707       </para>
3708      </listitem>
3709
3710      <listitem>
3711       <para>
3712        Add <link
3713        linkend="view-pg-timezone-abbrevs"><varname>pg_timezone_abbrevs</></link>
3714        and <link
3715        linkend="view-pg-timezone-names"><varname>pg_timezone_names</></link>
3716        views to show supported timezones (Magnus Hagander)
3717       </para>
3718      </listitem>
3719
3720      <listitem>
3721       <para>
3722        Add <link
3723        linkend="functions-datetime-table"><function>clock_timestamp()</></link>,
3724        <link
3725        linkend="functions-datetime-table"><function>statement_timestamp()</></link>,
3726        and <link
3727        linkend="functions-datetime-table"><function>transaction_timestamp()</></link>
3728        (Bruce)
3729       </para>
3730
3731       <para>
3732        <function>clock_timestamp()</> is the current wall-clock time,
3733        <function>statement_timestamp()</> is the time the current
3734        statement arrived at the server, and
3735        <function>transaction_timestamp()</> is an alias for
3736        <function>now()</>.
3737       </para>
3738      </listitem>
3739
3740      <listitem>
3741       <para>
3742        Allow <link
3743        linkend="functions-formatting"><function>to_char()</></link>
3744        to print localized month and day names (Euler Taveira de
3745        Oliveira)
3746       </para>
3747      </listitem>
3748
3749      <listitem>
3750       <para>
3751        Allow <link
3752        linkend="functions-formatting"><function>to_char(time)</></link>
3753        and <link
3754        linkend="functions-formatting"><function>to_char(interval)</></link>
3755        to output <acronym>AM</>/<acronym>PM</> specifications
3756        (Bruce)
3757       </para>
3758
3759       <para>
3760        Intervals and times are treated as 24-hour periods, e.g.
3761        <literal>25 hours</> is considered <acronym>AM</>.
3762       </para>
3763      </listitem>
3764
3765      <listitem>
3766       <para>
3767        Add new function <link
3768        linkend="functions-datetime-table"><function>justify_interval()</></link>
3769        to adjust interval units (Mark Dilger)
3770       </para>
3771      </listitem>
3772
3773      <listitem>
3774       <para>
3775        Allow timezone offsets up to 14:59 away from GMT
3776       </para>
3777
3778       <para>
3779        Kiribati uses GMT+14, so we'd better accept that.
3780       </para>
3781      </listitem>
3782
3783      <listitem>
3784       <para>
3785        Interval computation improvements (Michael Glaesemann, Bruce)
3786       </para>
3787      </listitem>
3788
3789     </itemizedlist>
3790
3791    </sect3>
3792
3793    <sect3>
3794     <title>Other Data Type and Function Changes</title>
3795     <itemizedlist>
3796
3797      <listitem>
3798       <para>
3799        Allow arrays to contain <literal>NULL</> elements (Tom)
3800       </para>
3801      </listitem>
3802
3803      <listitem>
3804       <para>
3805        Allow assignment to array elements not contiguous with the existing
3806        entries (Tom)
3807       </para>
3808
3809       <para>
3810        The intervening array positions will be filled with nulls.
3811        This is per SQL standard.
3812       </para>
3813      </listitem>
3814
3815      <listitem>
3816       <para>
3817        New built-in <link linkend="functions-array">operators</link>
3818        for array-subset comparisons (<literal>@&gt;</>,
3819        <literal>&lt;@</>, <literal>&amp;&amp;</>) (Teodor, Tom)
3820       </para>
3821
3822       <para>
3823        These operators can be indexed for many data types using
3824        <acronym>GiST</> or <acronym>GIN</> indexes.
3825       </para>
3826      </listitem>
3827
3828      <listitem>
3829       <para>
3830        Add convenient arithmetic <link
3831        linkend="cidr-inet-operators-table">operations</link> on
3832        <type>INET</>/<type>CIDR</> values (Stephen R. van den
3833        Berg)
3834       </para>
3835
3836       <para>
3837        The new operators are <literal>&amp;</> (and), <literal>|</>
3838        (or), <literal>~</> (not), <type>inet</> <literal>+</> <type>int8</>,
3839        <type>inet</> <literal>-</> <type>int8</>, and
3840        <type>inet</> <literal>-</> <type>inet</>.
3841       </para>
3842      </listitem>
3843
3844      <listitem>
3845       <para>
3846        Add new <link
3847        linkend="functions-aggregate-statistics-table">aggregate functions</link>
3848        from SQL:2003 (Neil)
3849       </para>
3850
3851       <para>
3852        The new functions are <function>var_pop()</>,
3853        <function>var_samp()</>, <function>stddev_pop()</>, and
3854        <function>stddev_samp()</>.  <function>var_samp()</> and
3855        <function>stddev_samp()</> are merely renamings of the
3856        existing aggregates <function>variance()</> and
3857        <function>stddev()</>.  The latter names remain available
3858        for backward compatibility.
3859       </para>
3860      </listitem>
3861
3862      <listitem>
3863       <para>
3864        Add SQL:2003 statistical <link
3865        linkend="functions-aggregate-statistics-table">aggregates</link>
3866        (Sergey Koposov)
3867       </para>
3868
3869       <para>
3870        New functions:  <function>regr_intercept()</>,
3871        <function>regr_slope()</>, <function>regr_r2()</>,
3872        <function>corr()</>, <function>covar_samp()</>,
3873        <function>covar_pop()</>, <function>regr_avgx()</>,
3874        <function>regr_avgy()</>, <function>regr_sxy()</>,
3875        <function>regr_sxx()</>, <function>regr_syy()</>,
3876        <function>regr_count()</>.
3877       </para>
3878      </listitem>
3879
3880      <listitem>
3881       <para>
3882        Allow <link linkend="SQL-CREATEDOMAIN">domains</link> to be
3883        based on other domains (Tom)
3884       </para>
3885      </listitem>
3886
3887      <listitem>
3888       <para>
3889        Properly enforce domain <link
3890        linkend="ddl-constraints"><literal>CHECK</></link> constraints
3891        everywhere (Neil, Tom)
3892       </para>
3893
3894       <para>
3895        For example, the result of a user-defined function that is
3896        declared to return a domain type is now checked against the
3897        domain's constraints. This closes a significant hole in the domain
3898        implementation.
3899       </para>
3900      </listitem>
3901
3902      <listitem>
3903       <para>
3904        Fix problems with dumping renamed <link
3905        linkend="datatype-serial"><type>SERIAL</></link> columns
3906        (Tom)
3907       </para>
3908
3909       <para>
3910        The fix is to dump a <type>SERIAL</> column by explicitly
3911        specifying its <literal>DEFAULT</> and sequence elements,
3912        and reconstructing the <type>SERIAL</> column on reload
3913        using a new <link linkend="SQL-ALTERSEQUENCE"><command>ALTER
3914        SEQUENCE OWNED BY</></link> command.  This also allows
3915        dropping a <type>SERIAL</> column specification.
3916       </para>
3917      </listitem>
3918
3919      <listitem>
3920       <para>
3921        Add a server-side sleep function <link
3922        linkend="functions-datetime-delay"><function>pg_sleep()</></link>
3923        (Joachim Wieland)
3924       </para>
3925      </listitem>
3926
3927      <listitem>
3928       <para>
3929        Add all comparison operators for the <link
3930        linkend="datatype-oid"><type>tid</></link> (tuple id) data
3931        type (Mark Kirkwood, Greg Stark, Tom)
3932       </para>
3933      </listitem>
3934
3935     </itemizedlist>
3936
3937    </sect3>
3938
3939    <sect3>
3940     <title>PL/PgSQL Server-Side Language Changes</title>
3941     <itemizedlist>
3942
3943      <listitem>
3944       <para>
3945        Add <literal>TG_table_name</> and <literal>TG_table_schema</> to
3946        trigger parameters (Andrew)
3947       </para>
3948
3949       <para>
3950        <literal>TG_relname</> is now deprecated.  Comparable
3951        changes have been made in the trigger parameters for the other
3952        PLs as well.
3953       </para>
3954      </listitem>
3955
3956      <listitem>
3957       <para>
3958        Allow <literal>FOR</> statements to return values to scalars
3959        as well as records and row types (Pavel Stehule)
3960       </para>
3961      </listitem>
3962
3963      <listitem>
3964       <para>
3965        Add a <literal>BY</> clause to the <literal>FOR</> loop,
3966        to control the iteration increment (Jaime Casanova)
3967       </para>
3968      </listitem>
3969
3970      <listitem>
3971       <para>
3972        Add <literal>STRICT</> to <link
3973        linkend="plpgsql-statements-sql-onerow"><command>SELECT
3974        INTO</></link> (Matt Miller)
3975       </para>
3976
3977       <para>
3978        <literal>STRICT</> mode throws an exception if more or less
3979        than one row is returned by the <command>SELECT</>, for
3980        <productname>Oracle PL/SQL</> compatibility.
3981       </para>
3982      </listitem>
3983
3984     </itemizedlist>
3985
3986    </sect3>
3987
3988    <sect3>
3989     <title>PL/Perl Server-Side Language Changes</title>
3990     <itemizedlist>
3991
3992      <listitem>
3993       <para>
3994        Add <literal>table_name</> and <literal>table_schema</> to
3995        trigger parameters (Adam Sj&oslash;gren)
3996       </para>
3997      </listitem>
3998
3999      <listitem>
4000       <para>
4001        Add prepared queries (Dmitry Karasik)
4002       </para>
4003      </listitem>
4004
4005      <listitem>
4006       <para>
4007        Make <literal>$_TD</> trigger data a global variable (Andrew)
4008       </para>
4009
4010       <para>
4011        Previously, it was lexical, which caused unexpected sharing
4012        violations.
4013       </para>
4014      </listitem>
4015
4016      <listitem>
4017       <para>
4018        Run PL/Perl and PL/PerlU in separate interpreters, for security
4019        reasons (Andrew)
4020       </para>
4021       <para>
4022        In consequence, they can no longer share data nor loaded modules.
4023        Also, if Perl has not been compiled with the requisite flags to
4024        allow multiple interpreters, only one of these languages can be used
4025        in any given backend process.
4026       </para>
4027      </listitem>
4028
4029     </itemizedlist>
4030
4031    </sect3>
4032
4033    <sect3>
4034     <title>PL/Python Server-Side Language Changes</title>
4035     <itemizedlist>
4036
4037      <listitem>
4038       <para>
4039        Named parameters are passed as ordinary variables, as well as in the
4040        <literal>args[]</> array (Sven Suursoho)
4041       </para>
4042      </listitem>
4043
4044      <listitem>
4045       <para>
4046        Add <literal>table_name</> and <literal>table_schema</> to
4047        trigger parameters (Andrew)
4048       </para>
4049      </listitem>
4050
4051      <listitem>
4052       <para>
4053        Allow returning of composite types and result sets (Sven Suursoho)
4054       </para>
4055      </listitem>
4056
4057      <listitem>
4058       <para>
4059        Return result-set as <literal>list</>, <literal>iterator</>,
4060        or <literal>generator </>(Sven Suursoho)
4061       </para>
4062      </listitem>
4063
4064      <listitem>
4065       <para>
4066        Allow functions to return <literal>void</> (Neil)
4067       </para>
4068      </listitem>
4069
4070      <listitem>
4071       <para>
4072        Python 2.5 is now supported (Tom)
4073       </para>
4074      </listitem>
4075
4076     </itemizedlist>
4077
4078    </sect3>
4079
4080    <sect3>
4081     <title><link linkend="APP-PSQL"><application>psql</></link> Changes</title>
4082     <itemizedlist>
4083
4084      <listitem>
4085       <para>
4086        Add new command <literal>\password</> for changing role
4087        password with client-side password encryption (Peter)
4088       </para>
4089      </listitem>
4090
4091      <listitem>
4092       <para>
4093        Allow <literal>\c</> to connect to a new host and port
4094        number (David, Volkan YAZICI)
4095       </para>
4096      </listitem>
4097
4098      <listitem>
4099       <para>
4100        Add tablespace display to <literal>\l+</> (Philip Yarra)
4101       </para>
4102      </listitem>
4103
4104      <listitem>
4105       <para>
4106        Improve <literal>\df</> slash command to include the argument
4107        names and modes (<literal>OUT</> or <literal>INOUT</>) of
4108        the function (David Fetter)
4109       </para>
4110      </listitem>
4111
4112      <listitem>
4113       <para>
4114        Support binary <command>COPY</> (Andreas Pflug)
4115       </para>
4116      </listitem>
4117
4118      <listitem>
4119       <para>
4120        Add option to run the entire session in a single transaction
4121        (Simon)
4122       </para>
4123
4124       <para>
4125        Use option <literal>-1</> or <literal>--single-transaction</>.
4126       </para>
4127      </listitem>
4128
4129      <listitem>
4130       <para>
4131        Support for automatically retrieving <command>SELECT</>
4132        results in batches using a cursor (Chris Mair)
4133       </para>
4134
4135       <para>
4136        This is enabled using <command>\set FETCH_COUNT
4137        <replaceable>n</></command>. This
4138        feature allows large result sets to be retrieved in
4139        <application>psql</> without attempting to buffer the entire
4140        result set in memory.
4141       </para>
4142      </listitem>
4143
4144      <listitem>
4145       <para>
4146        Make multi-line values align in the proper column
4147        (Martijn van Oosterhout)
4148       </para>
4149
4150       <para>
4151        Field values containing newlines are now displayed in a more
4152        readable fashion.
4153       </para>
4154      </listitem>
4155
4156      <listitem>
4157       <para>
4158        Save multi-line statements as a single entry, rather than
4159        one line at a time (Sergey E. Koposov)
4160       </para>
4161
4162       <para>
4163        This makes up-arrow recall of queries easier.  (This is
4164        not available on Windows, because that platform uses the native
4165        command-line editing present in the operating system.)
4166       </para>
4167      </listitem>
4168
4169      <listitem>
4170       <para>
4171        Make the line counter 64-bit so it can handle files with more
4172        than two billion lines (David Fetter)
4173       </para>
4174      </listitem>
4175
4176      <listitem>
4177       <para>
4178        Report both the returned data and the command status tag
4179        for <command>INSERT</>/<command>UPDATE</>/<command>DELETE
4180        RETURNING</> (Tom)
4181       </para>
4182      </listitem>
4183
4184     </itemizedlist>
4185
4186    </sect3>
4187
4188    <sect3>
4189     <title><link linkend="APP-PGDUMP"><application>pg_dump</></link> Changes</title>
4190     <itemizedlist>
4191
4192      <listitem>
4193       <para>
4194        Allow complex selection of objects to be included or excluded
4195        by <application>pg_dump</> (Greg Sabino Mullane)
4196       </para>
4197
4198       <para>
4199        <application>pg_dump</> now supports multiple <literal>-n</>
4200        (schema) and <literal>-t</> (table) options, and adds
4201        <literal>-N</> and <literal>-T</> options to exclude objects.
4202        Also, the arguments of these switches can now be wild-card expressions
4203        rather than single object names, for example
4204        <literal>-t 'foo*'</>, and a schema can be part of
4205        a <literal>-t</> or <literal>-T</> switch, for example
4206        <literal>-t schema1.table1</>.
4207       </para>
4208      </listitem>
4209
4210      <listitem>
4211       <para>
4212        Add <link linkend="APP-PGRESTORE"><application>pg_restore</></link>
4213        <literal>--no-data-for-failed-tables</> option to suppress
4214        loading data if table creation failed (i.e., the table already
4215        exists) (Martin Pitt)
4216       </para>
4217      </listitem>
4218
4219      <listitem>
4220       <para>
4221        Add <link linkend="APP-PGRESTORE"><application>pg_restore</></link>
4222        option to run the entire session in a single transaction
4223        (Simon)
4224       </para>
4225
4226       <para>
4227        Use option <literal>-1</> or <literal>--single-transaction</>.
4228       </para>
4229      </listitem>
4230
4231     </itemizedlist>
4232
4233    </sect3>
4234
4235    <sect3>
4236     <title><link linkend="libpq"><application>libpq</></link> Changes</title>
4237     <itemizedlist>
4238
4239      <listitem>
4240       <para>
4241        Add <link
4242        linkend="libpq-misc"><function>PQencryptPassword()</></link>
4243        to encrypt passwords (Tom)
4244       </para>
4245
4246       <para>
4247        This allows passwords to be sent pre-encrypted for commands
4248        like <link linkend="SQL-ALTERROLE"><command>ALTER ROLE ...
4249        PASSWORD</></link>.
4250       </para>
4251      </listitem>
4252
4253      <listitem>
4254       <para>
4255        Add function <link
4256        linkend="libpq-threading"><function>PQisthreadsafe()</></link>
4257        (Bruce)
4258       </para>
4259
4260       <para>
4261        This allows applications to query the thread-safety status
4262        of the library.
4263       </para>
4264      </listitem>
4265
4266      <listitem>
4267       <para>
4268        Add <link
4269        linkend="libpq-exec-main"><function>PQdescribePrepared()</></link>,
4270        <link
4271        linkend="libpq-exec-main"><function>PQdescribePortal()</></link>,
4272        and related functions to return information about previously
4273        prepared statements and open cursors (Volkan YAZICI)
4274       </para>
4275      </listitem>
4276
4277      <listitem>
4278       <para>
4279        Allow <link linkend="libpq-ldap"><acronym>LDAP</></link> lookups
4280        from <link
4281        linkend="libpq-pgservice"><filename>pg_service.conf</></link>
4282        (Laurenz Albe)
4283       </para>
4284      </listitem>
4285
4286      <listitem>
4287       <para>
4288        Allow a hostname in <link
4289        linkend="libpq-pgpass"><filename>~/.pgpass</></link>
4290        to match the default socket directory (Bruce)
4291       </para>
4292
4293       <para>
4294        A blank hostname continues to match any Unix-socket connection,
4295        but this addition allows entries that are specific to one of
4296        several postmasters on the machine.
4297       </para>
4298      </listitem>
4299
4300     </itemizedlist>
4301
4302    </sect3>
4303
4304    <sect3>
4305     <title><link linkend="ecpg"><application>ecpg</></link> Changes</title>
4306     <itemizedlist>
4307
4308      <listitem>
4309       <para>
4310        Allow <link linkend="SQL-SHOW"><command>SHOW</></link> to
4311        put its result into a variable (Joachim Wieland)
4312       </para>
4313      </listitem>
4314
4315      <listitem>
4316       <para>
4317        Add <link linkend="SQL-COPY"><command>COPY TO STDOUT</></link>
4318        (Joachim Wieland)
4319       </para>
4320      </listitem>
4321
4322      <listitem>
4323       <para>
4324        Add regression tests (Joachim Wieland, Michael)
4325       </para>
4326      </listitem>
4327
4328      <listitem>
4329       <para>
4330        Major source code cleanups (Joachim Wieland, Michael)
4331       </para>
4332      </listitem>
4333
4334     </itemizedlist>
4335
4336    </sect3>
4337
4338    <sect3>
4339     <title><application>Windows</> Port</title>
4340     <itemizedlist>
4341
4342      <listitem>
4343       <para>
4344        Allow <acronym>MSVC</> to compile the <productname>PostgreSQL</>
4345        server (Magnus, Hiroshi Saito)
4346       </para>
4347      </listitem>
4348
4349      <listitem>
4350       <para>
4351        Add <acronym>MSVC</> support for utility commands and <link
4352        linkend="APP-PGDUMP"><application>pg_dump</></link> (Hiroshi
4353        Saito)
4354       </para>
4355      </listitem>
4356
4357      <listitem>
4358       <para>
4359        Add support for Windows code pages <literal>1253</>,
4360        <literal>1254</>, <literal>1255</>, and <literal>1257</>
4361        (Kris Jurka)
4362       </para>
4363      </listitem>
4364
4365      <listitem>
4366       <para>
4367        Drop privileges on startup, so that the server can be started from
4368        an administrative account (Magnus)
4369       </para>
4370      </listitem>
4371
4372      <listitem>
4373       <para>
4374        Stability fixes (Qingqing Zhou, Magnus)
4375       </para>
4376      </listitem>
4377
4378      <listitem>
4379       <para>
4380        Add native semaphore implementation (Qingqing Zhou)
4381       </para>
4382
4383       <para>
4384        The previous code mimicked SysV semaphores.
4385       </para>
4386      </listitem>
4387
4388     </itemizedlist>
4389
4390    </sect3>
4391
4392    <sect3>
4393     <title>Source Code Changes</title>
4394     <itemizedlist>
4395
4396      <listitem>
4397       <para>
4398        Add <link linkend="GIN"><acronym>GIN</></link> (Generalized
4399        Inverted iNdex) index access method (Teodor, Oleg)
4400       </para>
4401      </listitem>
4402
4403      <listitem>
4404       <para>
4405        Remove R-tree indexing (Tom)
4406       </para>
4407
4408       <para>
4409        Rtree has been re-implemented using <link
4410        linkend="GiST"><acronym>GiST</></link>. Among other
4411        differences, this means that rtree indexes now have support
4412        for crash recovery via write-ahead logging (WAL).
4413       </para>
4414      </listitem>
4415
4416      <listitem>
4417       <para>
4418        Reduce libraries needlessly linked into the backend (Martijn
4419        van Oosterhout, Tom)
4420       </para>
4421      </listitem>
4422
4423      <listitem>
4424       <para>
4425        Add a configure flag to allow libedit to be preferred over
4426        <acronym>GNU</> readline (Bruce)
4427       </para>
4428
4429       <para>
4430        Use configure <link
4431        linkend="configure"><literal>--with-libedit-preferred</></link>.
4432       </para>
4433      </listitem>
4434
4435      <listitem>
4436       <para>
4437        Allow installation into directories containing spaces
4438        (Peter)
4439       </para>
4440      </listitem>
4441
4442      <listitem>
4443       <para>
4444        Improve ability to relocate installation directories (Tom)
4445       </para>
4446      </listitem>
4447
4448      <listitem>
4449       <para>
4450        Add support for <productname>Solaris x86_64</> using the
4451        <productname>Solaris</> compiler (Pierre Girard, Theo
4452        Schlossnagle, Bruce)
4453       </para>
4454      </listitem>
4455
4456      <listitem>
4457       <para>
4458        Add <application>DTrace</> support (Robert Lor)
4459       </para>
4460      </listitem>
4461
4462      <listitem>
4463       <para>
4464        Add <literal>PG_VERSION_NUM</> for use by third-party
4465        applications wanting to test the backend version in C using &gt;
4466        and &lt; comparisons (Bruce)
4467       </para>
4468      </listitem>
4469
4470      <listitem>
4471       <para>
4472        Add <literal>XLOG_BLCKSZ</> as independent from <literal>BLCKSZ</>
4473        (Mark Wong)
4474       </para>
4475      </listitem>
4476
4477      <listitem>
4478       <para>
4479        Add <literal>LWLOCK_STATS</> define to report locking
4480        activity (Tom)
4481       </para>
4482      </listitem>
4483
4484      <listitem>
4485       <para>
4486        Emit warnings for unknown <application>configure</> options
4487        (Martijn van Oosterhout)
4488       </para>
4489      </listitem>
4490
4491      <listitem>
4492       <para>
4493        Add server support for <quote>plugin</> libraries
4494        that can be used for add-on tasks such as debugging and performance
4495        measurement (Korry Douglas)
4496       </para>
4497
4498       <para>
4499        This consists of two features: a table of <quote>rendezvous
4500        variables</> that allows separately-loaded shared libraries to
4501        communicate, and a new configuration parameter <link
4502        linkend="guc-local-preload-libraries"><varname>local_preload_libraries</></link>
4503        that allows libraries to be loaded into specific sessions without
4504        explicit cooperation from the client application.  This allows
4505        external add-ons to implement features such as a PL/PgSQL debugger.
4506       </para>
4507      </listitem>
4508
4509      <listitem>
4510       <para>
4511        Rename existing configuration parameter
4512        <varname>preload_libraries</> to <link
4513        linkend="guc-shared-preload-libraries"><varname>shared_preload_libraries</></link>
4514        (Tom)
4515       </para>
4516
4517       <para>
4518        This was done for clarity in comparison to
4519        <varname>local_preload_libraries</>.
4520       </para>
4521      </listitem>
4522
4523      <listitem>
4524       <para>
4525        Add new configuration parameter <link
4526        linkend="guc-server-version-num"><varname>server_version_num</></link>
4527        (Greg Sabino Mullane)
4528       </para>
4529
4530       <para>
4531        This is like <varname>server_version</varname>, but is an
4532        integer, e.g.  <literal>80200</>. This allows applications to
4533        make version checks more easily.
4534       </para>
4535      </listitem>
4536
4537      <listitem>
4538       <para>
4539        Add a configuration parameter <link
4540        linkend="guc-seq-page-cost"><varname>seq_page_cost</></link>
4541        (Tom)
4542       </para>
4543      </listitem>
4544
4545      <listitem>
4546       <para>
4547        Re-implement the <link linkend="regress">regression test</link> script as a C program
4548        (Magnus, Tom)
4549       </para>
4550      </listitem>
4551
4552      <listitem>
4553       <para>
4554        Allow loadable modules to allocate shared memory and
4555        lightweight locks (Marc Munro)
4556       </para>
4557      </listitem>
4558
4559      <listitem>
4560       <para>
4561        Add automatic initialization and finalization of dynamically
4562        loaded libraries (Ralf Engelschall, Tom)
4563       </para>
4564
4565       <para>
4566        New <link linkend="xfunc-c-dynload">functions</link>
4567        <function>_PG_init()</> and <function>_PG_fini()</> are
4568        called if the library defines such symbols.  Hence we no
4569        longer need to specify an initialization function in
4570        <varname>shared_preload_libraries</>; we can assume that
4571        the library used the <function>_PG_init()</> convention
4572        instead.
4573       </para>
4574      </listitem>
4575
4576      <listitem>
4577       <para>
4578        Add <link
4579        linkend="xfunc-c-dynload"><literal>PG_MODULE_MAGIC</></link>
4580        header block to all shared object files (Martijn van
4581        Oosterhout)
4582       </para>
4583
4584       <para>
4585        The magic block prevents version mismatches between loadable object
4586        files and servers.
4587       </para>
4588      </listitem>
4589
4590      <listitem>
4591       <para>
4592         Add shared library support for AIX (Laurenz Albe)
4593       </para>
4594      </listitem>
4595
4596      <listitem>
4597       <para>
4598        New <link linkend="datatype-xml"><acronym>XML</></link>
4599        documentation section (Bruce)
4600       </para>
4601      </listitem>
4602
4603     </itemizedlist>
4604
4605    </sect3>
4606
4607    <sect3>
4608     <title>Contrib Changes</title>
4609     <itemizedlist>
4610
4611      <listitem>
4612       <para>
4613        Major tsearch2 improvements (Oleg, Teodor)
4614       </para>
4615
4616       <itemizedlist>
4617
4618        <listitem>
4619         <para>
4620          multibyte encoding support, including <acronym>UTF8</>
4621         </para>
4622        </listitem>
4623        <listitem>
4624         <para>
4625          query rewriting support
4626         </para>
4627        </listitem>
4628        <listitem>
4629         <para>
4630          improved ranking functions
4631         </para>
4632        </listitem>
4633        <listitem>
4634         <para>
4635          thesaurus dictionary support
4636         </para>
4637        </listitem>
4638        <listitem>
4639         <para>
4640          Ispell dictionaries now recognize <application>MySpell</>
4641          format, used by <application>OpenOffice</>
4642         </para>
4643        </listitem>
4644        <listitem>
4645         <para>
4646          <acronym>GIN</> support
4647         </para>
4648        </listitem>
4649
4650       </itemizedlist>
4651
4652      </listitem>
4653
4654      <listitem>
4655       <para>
4656        Add adminpack module containing <application>Pgadmin</> administration
4657        functions (Dave)
4658       </para>
4659
4660       <para>
4661        These functions provide additional file system access
4662        routines not present in the default <productname>PostgreSQL</>
4663        server.
4664       </para>
4665      </listitem>
4666
4667      <listitem>
4668       <para>
4669        Add sslinfo module (Victor Wagner)
4670       </para>
4671
4672       <para>
4673        Reports information about the current connection's <acronym>SSL</>
4674        certificate.
4675       </para>
4676      </listitem>
4677
4678      <listitem>
4679       <para>
4680        Add pgrowlocks module (Tatsuo)
4681       </para>
4682
4683       <para>
4684        This shows row locking information for a specified table.
4685       </para>
4686      </listitem>
4687
4688      <listitem>
4689       <para>
4690        Add hstore module (Oleg, Teodor)
4691       </para>
4692      </listitem>
4693
4694      <listitem>
4695       <para>
4696        Add isn module, replacing isbn_issn (Jeremy Kronuz)
4697       </para>
4698
4699       <para>
4700        This new implementation supports <acronym>EAN13</>, <acronym>UPC</>,
4701        <acronym>ISBN</> (books), <acronym>ISMN</> (music), and
4702        <acronym>ISSN</> (serials).
4703       </para>
4704      </listitem>
4705
4706      <listitem>
4707       <para>
4708        Add index information functions to pgstattuple (ITAGAKI Takahiro,
4709        Satoshi Nagayasu)
4710       </para>
4711      </listitem>
4712
4713      <listitem>
4714       <para>
4715        Add pg_freespacemap module to display free space map information
4716        (Mark Kirkwood)
4717       </para>
4718      </listitem>
4719
4720      <listitem>
4721       <para>
4722        pgcrypto now has all planned functionality (Marko Kreen)
4723       </para>
4724       <itemizedlist>
4725        <listitem>
4726         <para>
4727          Include iMath library in pgcrypto to have the public-key encryption
4728          functions always available.
4729         </para>
4730        </listitem>
4731        <listitem>
4732         <para>
4733          Add SHA224 algorithm that was missing in OpenBSD code.
4734         </para>
4735        </listitem>
4736        <listitem>
4737         <para>
4738          Activate builtin code for SHA224/256/384/512 hashes on older
4739          OpenSSL to have those algorithms always available.
4740         </para>
4741        </listitem>
4742        <listitem>
4743         <para>
4744          New function gen_random_bytes() that returns cryptographically strong
4745          randomness.  Useful for generating encryption keys.
4746         </para>
4747        </listitem>
4748        <listitem>
4749         <para>
4750          Remove digest_exists(), hmac_exists() and cipher_exists() functions.
4751         </para>
4752        </listitem>
4753       </itemizedlist>
4754      </listitem>
4755
4756      <listitem>
4757       <para>
4758        Improvements to cube module (Joshua Reich)
4759       </para>
4760
4761       <para>
4762        New functions are <function>cube(float[])</>,
4763        <function>cube(float[], float[])</>, and
4764        <function>cube_subset(cube, int4[])</>.
4765       </para>
4766      </listitem>
4767
4768      <listitem>
4769       <para>
4770        Add async query capability to dblink (Kai Londenberg,
4771        Joe Conway)
4772       </para>
4773      </listitem>
4774
4775      <listitem>
4776       <para>
4777        New operators for array-subset comparisons (<literal>@&gt;</>,
4778        <literal>&lt;@</>, <literal>&amp;&amp;</>) (Tom)
4779       </para>
4780
4781       <para>
4782        Various contrib packages already had these operators for their
4783        datatypes, but the naming wasn't consistent.  We have now added
4784        consistently named array-subset comparison operators to the core code
4785        and all the contrib packages that have such functionality.
4786        (The old names remain available, but are deprecated.)
4787       </para>
4788      </listitem>
4789
4790      <listitem>
4791       <para>
4792        Add uninstall scripts for all contrib packages that have install
4793        scripts (David, Josh Drake)
4794       </para>
4795      </listitem>
4796
4797     </itemizedlist>
4798
4799    </sect3>
4800
4801   </sect2>
4802  </sect1>