doc/src/sgml/release-7.4.sgml

   1 <!-- $PostgreSQL$ -->
   2 <!-- See header comment in release.sgml about typical markup -->
   3
   4  <sect1 id="release-7-4-25">
   5   <title>Release 7.4.25</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 7.4.24.
  14    For information about new features in the 7.4 major release, see
  15    <xref linkend="release-7-4">.
  16   </para>
  17
  18   <sect2>
  19    <title>Migration to Version 7.4.25</title>
  20
  21    <para>
  22     A dump/restore is not required for those running 7.4.X.
  23     However, if you are upgrading from a version earlier than 7.4.11,
  24     see the release notes for 7.4.11.
  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       Add <literal>MUST</> (Mauritius Island Summer Time) to the default list
  75       of known timezone abbreviations (Xavier Bugaud)
  76      </para>
  77     </listitem>
  78
  79    </itemizedlist>
  80
  81   </sect2>
  82  </sect1>
  83
  84  <sect1 id="release-7-4-24">
  85   <title>Release 7.4.24</title>
  86
  87   <note>
  88   <title>Release date</title>
  89   <simpara>2009-02-02</simpara>
  90   </note>
  91
  92   <para>
  93    This release contains a variety of fixes from 7.4.23.
  94    For information about new features in the 7.4 major release, see
  95    <xref linkend="release-7-4">.
  96   </para>
  97
  98   <sect2>
  99    <title>Migration to Version 7.4.24</title>
 100
 101    <para>
 102     A dump/restore is not required for those running 7.4.X.
 103     However, if you are upgrading from a version earlier than 7.4.11,
 104     see the release notes for 7.4.11.
 105    </para>
 106
 107   </sect2>
 108
 109   <sect2>
 110    <title>Changes</title>
 111
 112    <itemizedlist>
 113
 114     <listitem>
 115      <para>
 116       Improve handling of URLs in <function>headline()</> function (Teodor)
 117      </para>
 118     </listitem>
 119
 120     <listitem>
 121      <para>
 122       Improve handling of overlength headlines in <function>headline()</>
 123       function (Teodor)
 124      </para>
 125     </listitem>
 126
 127     <listitem>
 128      <para>
 129       Prevent possible Assert failure or misconversion if an encoding
 130       conversion is created with the wrong conversion function for the
 131       specified pair of encodings (Tom, Heikki)
 132      </para>
 133     </listitem>
 134
 135     <listitem>
 136      <para>
 137       Avoid unnecessary locking of small tables in <command>VACUUM</>
 138       (Heikki)
 139      </para>
 140     </listitem>
 141
 142     <listitem>
 143      <para>
 144       Fix uninitialized variables in <filename>contrib/tsearch2</>'s
 145       <function>get_covers()</> function (Teodor)
 146      </para>
 147     </listitem>
 148
 149     <listitem>
 150      <para>
 151       Fix bug in <function>to_char()</>'s handling of <literal>TH</>
 152       format codes (Andreas Scherbaum)
 153      </para>
 154     </listitem>
 155
 156     <listitem>
 157      <para>
 158       Make all documentation reference <literal>pgsql-bugs</> and/or
 159       <literal>pgsql-hackers</> as appropriate, instead of the
 160       now-decommissioned <literal>pgsql-ports</> and <literal>pgsql-patches</>
 161       mailing lists (Tom)
 162      </para>
 163     </listitem>
 164
 165    </itemizedlist>
 166
 167   </sect2>
 168  </sect1>
 169
 170  <sect1 id="release-7-4-23">
 171   <title>Release 7.4.23</title>
 172
 173   <note>
 174   <title>Release date</title>
 175   <simpara>2008-11-03</simpara>
 176   </note>
 177
 178   <para>
 179    This release contains a variety of fixes from 7.4.22.
 180    For information about new features in the 7.4 major release, see
 181    <xref linkend="release-7-4">.
 182   </para>
 183
 184   <sect2>
 185    <title>Migration to Version 7.4.23</title>
 186
 187    <para>
 188     A dump/restore is not required for those running 7.4.X.
 189     However, if you are upgrading from a version earlier than 7.4.11,
 190     see the release notes for 7.4.11.
 191    </para>
 192
 193   </sect2>
 194
 195   <sect2>
 196    <title>Changes</title>
 197
 198    <itemizedlist>
 199
 200     <listitem>
 201      <para>
 202       Fix backend crash when the client encoding cannot represent a localized
 203       error message (Tom)
 204      </para>
 205
 206      <para>
 207       We have addressed similar issues before, but it would still fail if
 208       the <quote>character has no equivalent</> message itself couldn't
 209       be converted.  The fix is to disable localization and send the plain
 210       ASCII error message when we detect such a situation.
 211      </para>
 212     </listitem>
 213
 214     <listitem>
 215      <para>
 216       Fix incorrect tsearch2 headline generation when single query
 217       item matches first word of text (Sushant Sinha)
 218      </para>
 219     </listitem>
 220
 221     <listitem>
 222      <para>
 223       Fix improper display of fractional seconds in interval values when
 224       using a non-ISO datestyle in an <option>--enable-integer-datetimes</>
 225       build (Ron Mayer)
 226      </para>
 227     </listitem>
 228
 229     <listitem>
 230      <para>
 231       Ensure <function>SPI_getvalue</> and <function>SPI_getbinval</>
 232       behave correctly when the passed tuple and tuple descriptor have
 233       different numbers of columns (Tom)
 234      </para>
 235
 236      <para>
 237       This situation is normal when a table has had columns added or removed,
 238       but these two functions didn't handle it properly.
 239       The only likely consequence is an incorrect error indication.
 240      </para>
 241     </listitem>
 242
 243     <listitem>
 244      <para>
 245       Fix <application>ecpg</>'s parsing of <command>CREATE USER</> (Michael)
 246      </para>
 247     </listitem>
 248
 249    </itemizedlist>
 250
 251   </sect2>
 252  </sect1>
 253
 254  <sect1 id="release-7-4-22">
 255   <title>Release 7.4.22</title>
 256
 257   <note>
 258   <title>Release date</title>
 259   <simpara>2008-09-22</simpara>
 260   </note>
 261
 262   <para>
 263    This release contains a variety of fixes from 7.4.21.
 264    For information about new features in the 7.4 major release, see
 265    <xref linkend="release-7-4">.
 266   </para>
 267
 268   <sect2>
 269    <title>Migration to Version 7.4.22</title>
 270
 271    <para>
 272     A dump/restore is not required for those running 7.4.X.
 273     However, if you are upgrading from a version earlier than 7.4.11,
 274     see the release notes for 7.4.11.
 275    </para>
 276
 277   </sect2>
 278
 279   <sect2>
 280    <title>Changes</title>
 281
 282    <itemizedlist>
 283
 284     <listitem>
 285      <para>
 286       Fix datetime input functions to correctly detect integer overflow when
 287       running on a 64-bit platform (Tom)
 288      </para>
 289     </listitem>
 290
 291     <listitem>
 292      <para>
 293       Improve performance of writing very long log messages to syslog (Tom)
 294      </para>
 295     </listitem>
 296
 297     <listitem>
 298      <para>
 299       Fix bug in backwards scanning of a cursor on a <literal>SELECT DISTINCT
 300       ON</> query (Tom)
 301      </para>
 302     </listitem>
 303
 304     <listitem>
 305      <para>
 306       Fix planner to estimate that <literal>GROUP BY</> expressions yielding
 307       boolean results always result in two groups, regardless of the
 308       expressions' contents (Tom)
 309      </para>
 310
 311      <para>
 312       This is very substantially more accurate than the regular <literal>GROUP
 313       BY</> estimate for certain boolean tests like <replaceable>col</>
 314       <literal>IS NULL</>.
 315      </para>
 316     </listitem>
 317
 318     <listitem>
 319      <para>
 320       Improve <application>pg_dump</> and <application>pg_restore</>'s
 321       error reporting after failure to send a SQL command (Tom)
 322      </para>
 323     </listitem>
 324
 325    </itemizedlist>
 326
 327   </sect2>
 328  </sect1>
 329
 330  <sect1 id="release-7-4-21">
 331   <title>Release 7.4.21</title>
 332
 333   <note>
 334   <title>Release date</title>
 335   <simpara>2008-06-12</simpara>
 336   </note>
 337
 338   <para>
 339    This release contains one serious bug fix over 7.4.20.
 340    For information about new features in the 7.4 major release, see
 341    <xref linkend="release-7-4">.
 342   </para>
 343
 344   <sect2>
 345    <title>Migration to Version 7.4.21</title>
 346
 347    <para>
 348     A dump/restore is not required for those running 7.4.X.
 349     However, if you are upgrading from a version earlier than 7.4.11,
 350     see the release notes for 7.4.11.
 351    </para>
 352
 353   </sect2>
 354
 355   <sect2>
 356    <title>Changes</title>
 357
 358    <itemizedlist>
 359
 360     <listitem>
 361      <para>
 362       Make <function>pg_get_ruledef()</> parenthesize negative constants (Tom)
 363      </para>
 364
 365      <para>
 366       Before this fix, a negative constant in a view or rule might be dumped
 367       as, say, <literal>-42::integer</>, which is subtly incorrect: it should
 368       be <literal>(-42)::integer</> due to operator precedence rules.
 369       Usually this would make little difference, but it could interact with
 370       another recent patch to cause
 371       <productname>PostgreSQL</> to reject what had been a valid
 372       <command>SELECT DISTINCT</> view query.  Since this could result in
 373       <application>pg_dump</> output failing to reload, it is being treated
 374       as a high-priority fix.  The only released versions in which dump
 375       output is actually incorrect are 8.3.1 and 8.2.7.
 376      </para>
 377     </listitem>
 378
 379    </itemizedlist>
 380
 381   </sect2>
 382  </sect1>
 383
 384  <sect1 id="release-7-4-20">
 385   <title>Release 7.4.20</title>
 386
 387   <note>
 388   <title>Release date</title>
 389   <simpara>never released</simpara>
 390   </note>
 391
 392   <para>
 393    This release contains a variety of fixes from 7.4.19.
 394    For information about new features in the 7.4 major release, see
 395    <xref linkend="release-7-4">.
 396   </para>
 397
 398   <sect2>
 399    <title>Migration to Version 7.4.20</title>
 400
 401    <para>
 402     A dump/restore is not required for those running 7.4.X.
 403     However, if you are upgrading from a version earlier than 7.4.11,
 404     see the release notes for 7.4.11.
 405    </para>
 406
 407   </sect2>
 408
 409   <sect2>
 410    <title>Changes</title>
 411
 412    <itemizedlist>
 413
 414     <listitem>
 415      <para>
 416       Fix conversions between ISO-8859-5 and other encodings to handle
 417       Cyrillic <quote>Yo</> characters (<literal>e</> and <literal>E</> with
 418       two dots) (Sergey Burladyan)
 419      </para>
 420     </listitem>
 421
 422     <listitem>
 423      <para>
 424       Fix a few datatype input functions
 425       that were allowing unused bytes in their results to contain
 426       uninitialized, unpredictable values (Tom)
 427      </para>
 428
 429      <para>
 430       This could lead to failures in which two apparently identical literal
 431       values were not seen as equal, resulting in the parser complaining
 432       about unmatched <literal>ORDER BY</> and <literal>DISTINCT</>
 433       expressions.
 434      </para>
 435     </listitem>
 436
 437     <listitem>
 438      <para>
 439       Fix a corner case in regular-expression substring matching
 440       (<literal>substring(<replaceable>string</> from
 441       <replaceable>pattern</>)</literal>) (Tom)
 442      </para>
 443
 444      <para>
 445       The problem occurs when there is a match to the pattern overall but
 446       the user has specified a parenthesized subexpression and that
 447       subexpression hasn't got a match.  An example is
 448       <literal>substring('foo' from 'foo(bar)?')</>.
 449       This should return NULL, since <literal>(bar)</> isn't matched, but
 450       it was mistakenly returning the whole-pattern match instead (ie,
 451       <literal>foo</>).
 452      </para>
 453     </listitem>
 454
 455     <listitem>
 456      <para>
 457       Fix incorrect result from <application>ecpg</>'s
 458       <function>PGTYPEStimestamp_sub()</> function (Michael)
 459      </para>
 460     </listitem>
 461
 462     <listitem>
 463      <para>
 464       Fix <literal>DatumGetBool</> macro to not fail with <application>gcc</>
 465       4.3 (Tom)
 466      </para>
 467
 468      <para>
 469       This problem affects <quote>old style</> (V0) C functions that
 470       return boolean.  The fix is already in 8.3, but the need to
 471       back-patch it was not realized at the time.
 472      </para>
 473     </listitem>
 474
 475     <listitem>
 476      <para>
 477       Fix longstanding <command>LISTEN</>/<command>NOTIFY</>
 478       race condition (Tom)
 479      </para>
 480
 481      <para>
 482       In rare cases a session that had just executed a
 483       <command>LISTEN</> might not get a notification, even though
 484       one would be expected because the concurrent transaction executing
 485       <command>NOTIFY</> was observed to commit later.
 486      </para>
 487
 488      <para>
 489       A side effect of the fix is that a transaction that has executed
 490       a not-yet-committed <command>LISTEN</> command will not see any
 491       row in <structname>pg_listener</> for the <command>LISTEN</>,
 492       should it choose to look; formerly it would have.  This behavior
 493       was never documented one way or the other, but it is possible that
 494       some applications depend on the old behavior.
 495      </para>
 496     </listitem>
 497
 498     <listitem>
 499      <para>
 500       Fix display of constant expressions in <literal>ORDER BY</>
 501       and <literal>GROUP BY</> (Tom)
 502      </para>
 503
 504      <para>
 505       An explictly casted constant would be shown incorrectly.  This could
 506       for example lead to corruption of a view definition during
 507       dump and reload.
 508      </para>
 509     </listitem>
 510
 511     <listitem>
 512      <para>
 513       Fix <application>libpq</> to handle NOTICE messages correctly
 514       during COPY OUT (Tom)
 515      </para>
 516
 517      <para>
 518       This failure has only been observed to occur when a user-defined
 519       datatype's output routine issues a NOTICE, but there is no
 520       guarantee it couldn't happen due to other causes.
 521      </para>
 522     </listitem>
 523
 524    </itemizedlist>
 525
 526   </sect2>
 527  </sect1>
 528
 529  <sect1 id="release-7-4-19">
 530   <title>Release 7.4.19</title>
 531
 532   <note>
 533   <title>Release date</title>
 534   <simpara>2008-01-07</simpara>
 535   </note>
 536
 537   <para>
 538    This release contains a variety of fixes from 7.4.18,
 539    including fixes for significant security issues.
 540    For information about new features in the 7.4 major release, see
 541    <xref linkend="release-7-4">.
 542   </para>
 543
 544   <sect2>
 545    <title>Migration to Version 7.4.19</title>
 546
 547    <para>
 548     A dump/restore is not required for those running 7.4.X.  However,
 549     if you are upgrading from a version earlier than 7.4.11, see the release
 550     notes for 7.4.11.
 551    </para>
 552
 553   </sect2>
 554
 555   <sect2>
 556    <title>Changes</title>
 557
 558    <itemizedlist>
 559
 560     <listitem>
 561      <para>
 562       Prevent functions in indexes from executing with the privileges of
 563       the user running <command>VACUUM</>, <command>ANALYZE</>, etc (Tom)
 564      </para>
 565
 566      <para>
 567       Functions used in index expressions and partial-index
 568       predicates are evaluated whenever a new table entry is made.  It has
 569       long been understood that this poses a risk of trojan-horse code
 570       execution if one modifies a table owned by an untrustworthy user.
 571       (Note that triggers, defaults, check constraints, etc. pose the
 572       same type of risk.)  But functions in indexes pose extra danger
 573       because they will be executed by routine maintenance operations
 574       such as <command>VACUUM FULL</>, which are commonly performed
 575       automatically under a superuser account.  For example, a nefarious user
 576       can execute code with superuser privileges by setting up a
 577       trojan-horse index definition and waiting for the next routine vacuum.
 578       The fix arranges for standard maintenance operations
 579       (including <command>VACUUM</>, <command>ANALYZE</>, <command>REINDEX</>,
 580       and <command>CLUSTER</>) to execute as the table owner rather than
 581       the calling user, using the same privilege-switching mechanism already
 582       used for <literal>SECURITY DEFINER</> functions.  To prevent bypassing
 583       this security measure, execution of <command>SET SESSION
 584       AUTHORIZATION</> and <command>SET ROLE</> is now forbidden within a
 585       <literal>SECURITY DEFINER</> context.  (CVE-2007-6600)
 586      </para>
 587     </listitem>
 588
 589     <listitem>
 590      <para>
 591       Repair assorted bugs in the regular-expression package (Tom, Will Drewry)
 592      </para>
 593
 594      <para>
 595       Suitably crafted regular-expression patterns could cause crashes,
 596       infinite or near-infinite looping, and/or massive memory consumption,
 597       all of which pose denial-of-service hazards for applications that
 598       accept regex search patterns from untrustworthy sources.
 599       (CVE-2007-4769, CVE-2007-4772, CVE-2007-6067)
 600      </para>
 601     </listitem>
 602
 603     <listitem>
 604      <para>
 605       Require non-superusers who use <filename>/contrib/dblink</> to use only
 606       password authentication, as a security measure (Joe)
 607      </para>
 608
 609      <para>
 610       The fix that appeared for this in 7.4.18 was incomplete, as it plugged
 611       the hole for only some <filename>dblink</> functions.  (CVE-2007-6601,
 612       CVE-2007-3278)
 613      </para>
 614     </listitem>
 615
 616     <listitem>
 617      <para>
 618       Fix planner failure in some cases of <literal>WHERE false AND var IN
 619       (SELECT ...)</> (Tom)
 620      </para>
 621     </listitem>
 622
 623     <listitem>
 624      <para>
 625       Fix potential crash in <function>translate()</> when using a multibyte
 626       database encoding (Tom)
 627      </para>
 628     </listitem>
 629
 630     <listitem>
 631      <para>
 632       Fix PL/Python to not crash on long exception messages (Alvaro)
 633      </para>
 634     </listitem>
 635
 636     <listitem>
 637      <para>
 638       <application>ecpg</> parser fixes (Michael)
 639      </para>
 640     </listitem>
 641
 642     <listitem>
 643      <para>
 644       Make <filename>contrib/tablefunc</>'s <function>crosstab()</> handle
 645       NULL rowid as a category in its own right, rather than crashing (Joe)
 646      </para>
 647     </listitem>
 648
 649     <listitem>
 650      <para>
 651       Fix <type>tsvector</> and <type>tsquery</> output routines to
 652       escape backslashes correctly (Teodor, Bruce)
 653      </para>
 654     </listitem>
 655
 656     <listitem>
 657      <para>
 658       Fix crash of <function>to_tsvector()</> on huge input strings (Teodor)
 659      </para>
 660     </listitem>
 661
 662     <listitem>
 663      <para>
 664       Require a specific version of <productname>Autoconf</> to be used
 665       when re-generating the <command>configure</> script (Peter)
 666      </para>
 667
 668      <para>
 669       This affects developers and packagers only.  The change was made
 670       to prevent accidental use of untested combinations of
 671       <productname>Autoconf</> and <productname>PostgreSQL</> versions.
 672       You can remove the version check if you really want to use a
 673       different <productname>Autoconf</> version, but it's
 674       your responsibility whether the result works or not.
 675      </para>
 676     </listitem>
 677
 678    </itemizedlist>
 679
 680   </sect2>
 681  </sect1>
 682
 683  <sect1 id="release-7-4-18">
 684   <title>Release 7.4.18</title>
 685
 686   <note>
 687   <title>Release date</title>
 688   <simpara>2007-09-17</simpara>
 689   </note>
 690
 691   <para>
 692    This release contains fixes from 7.4.17.
 693    For information about new features in the 7.4 major release, see
 694    <xref linkend="release-7-4">.
 695   </para>
 696
 697   <sect2>
 698    <title>Migration to Version 7.4.18</title>
 699
 700    <para>
 701     A dump/restore is not required for those running 7.4.X.  However,
 702     if you are upgrading from a version earlier than 7.4.11, see the release
 703     notes for 7.4.11.
 704    </para>
 705
 706   </sect2>
 707
 708   <sect2>
 709    <title>Changes</title>
 710
 711    <itemizedlist>
 712
 713     <listitem>
 714      <para>
 715       Prevent index corruption when a transaction inserts rows and
 716       then aborts close to the end of a concurrent <command>VACUUM</>
 717       on the same table (Tom)
 718      </para>
 719     </listitem>
 720
 721     <listitem>
 722      <para>
 723       Make <command>CREATE DOMAIN ... DEFAULT NULL</> work properly (Tom)
 724      </para>
 725     </listitem>
 726
 727     <listitem>
 728      <para>
 729       Fix excessive logging of <acronym>SSL</> error messages (Tom)
 730      </para>
 731     </listitem>
 732
 733     <listitem>
 734      <para>
 735       Fix crash when <varname>log_min_error_statement</> logging runs out
 736       of memory (Tom)
 737      </para>
 738     </listitem>
 739
 740     <listitem>
 741      <para>
 742       Prevent <command>CLUSTER</> from failing
 743       due to attempting to process temporary tables of other sessions (Alvaro)
 744      </para>
 745     </listitem>
 746
 747     <listitem>
 748      <para>
 749       Require non-superusers who use <filename>/contrib/dblink</> to use only
 750       password authentication, as a security measure (Joe)
 751      </para>
 752     </listitem>
 753
 754    </itemizedlist>
 755
 756   </sect2>
 757  </sect1>
 758
 759  <sect1 id="release-7-4-17">
 760   <title>Release 7.4.17</title>
 761
 762   <note>
 763   <title>Release date</title>
 764   <simpara>2007-04-23</simpara>
 765   </note>
 766
 767   <para>
 768    This release contains fixes from 7.4.16,
 769    including a security fix.
 770    For information about new features in the 7.4 major release, see
 771    <xref linkend="release-7-4">.
 772   </para>
 773
 774   <sect2>
 775    <title>Migration to Version 7.4.17</title>
 776
 777    <para>
 778     A dump/restore is not required for those running 7.4.X.  However,
 779     if you are upgrading from a version earlier than 7.4.11, see the release
 780     notes for 7.4.11.
 781    </para>
 782
 783   </sect2>
 784
 785   <sect2>
 786    <title>Changes</title>
 787
 788    <itemizedlist>
 789
 790     <listitem>
 791     <para>
 792      Support explicit placement of the temporary-table schema within
 793      <varname>search_path</>, and disable searching it for functions
 794      and operators (Tom)
 795     </para>
 796     <para>
 797      This is needed to allow a security-definer function to set a
 798      truly secure value of <varname>search_path</>.  Without it,
 799      an unprivileged SQL user can use temporary objects to execute code
 800      with the privileges of the security-definer function (CVE-2007-2138).
 801      See <command>CREATE FUNCTION</> for more information.
 802     </para>
 803     </listitem>
 804
 805     <listitem>
 806     <para>
 807      <filename>/contrib/tsearch2</> crash fixes (Teodor)
 808     </para>
 809     </listitem>
 810
 811     <listitem>
 812     <para>
 813      Fix potential-data-corruption bug in how <command>VACUUM FULL</> handles
 814      <command>UPDATE</> chains (Tom, Pavan Deolasee)
 815     </para>
 816     </listitem>
 817
 818     <listitem>
 819     <para>
 820      Fix PANIC during enlargement of a hash index (bug introduced in 7.4.15)
 821      (Tom)
 822     </para>
 823     </listitem>
 824
 825    </itemizedlist>
 826
 827   </sect2>
 828  </sect1>
 829
 830  <sect1 id="release-7-4-16">
 831   <title>Release 7.4.16</title>
 832
 833   <note>
 834   <title>Release date</title>
 835   <simpara>2007-02-05</simpara>
 836   </note>
 837
 838   <para>
 839    This release contains a variety of fixes from 7.4.15, including
 840    a security fix.
 841    For information about new features in the 7.4 major release, see
 842    <xref linkend="release-7-4">.
 843   </para>
 844
 845   <sect2>
 846    <title>Migration to Version 7.4.16</title>
 847
 848    <para>
 849     A dump/restore is not required for those running 7.4.X.  However,
 850     if you are upgrading from a version earlier than 7.4.11, see the release
 851     notes for 7.4.11.
 852    </para>
 853
 854   </sect2>
 855
 856   <sect2>
 857    <title>Changes</title>
 858
 859    <itemizedlist>
 860
 861     <listitem>
 862     <para>
 863      Remove security vulnerability that allowed connected users
 864      to read backend memory (Tom)
 865     </para>
 866     <para>
 867      The vulnerability involves suppressing the normal check that a SQL
 868      function returns the data type it's declared to, or changing the
 869      data type of a table column used in a SQL function (CVE-2007-0555).
 870      This error can easily be exploited to cause a backend crash, and in
 871      principle might be used to read database content that the user
 872      should not be able to access.
 873     </para>
 874     </listitem>
 875
 876     <listitem>
 877     <para>
 878      Fix rare bug wherein btree index page splits could fail
 879      due to choosing an infeasible split point (Heikki Linnakangas)
 880     </para>
 881     </listitem>
 882
 883     <listitem>
 884     <para>
 885      Fix for rare Assert() crash triggered by <literal>UNION</> (Tom)
 886     </para>
 887     </listitem>
 888
 889     <listitem>
 890     <para>
 891      Tighten security of multi-byte character processing for UTF8 sequences
 892      over three bytes long (Tom)
 893     </para>
 894     </listitem>
 895
 896    </itemizedlist>
 897
 898   </sect2>
 899  </sect1>
 900
 901  <sect1 id="release-7-4-15">
 902   <title>Release 7.4.15</title>
 903
 904   <note>
 905   <title>Release date</title>
 906   <simpara>2007-01-08</simpara>
 907   </note>
 908
 909   <para>
 910    This release contains a variety of fixes from 7.4.14.
 911    For information about new features in the 7.4 major release, see
 912    <xref linkend="release-7-4">.
 913   </para>
 914
 915   <sect2>
 916    <title>Migration to Version 7.4.15</title>
 917
 918    <para>
 919     A dump/restore is not required for those running 7.4.X.  However,
 920     if you are upgrading from a version earlier than 7.4.11, see the release
 921     notes for 7.4.11.
 922    </para>
 923
 924   </sect2>
 925
 926   <sect2>
 927    <title>Changes</title>
 928
 929    <itemizedlist>
 930
 931     <listitem>
 932      <para>
 933       Improve handling of <function>getaddrinfo()</> on AIX (Tom)
 934      </para>
 935
 936      <para>
 937       This fixes a problem with starting the statistics collector,
 938       among other things.
 939      </para>
 940     </listitem>
 941
 942      <listitem>
 943       <para>
 944        Fix <quote>failed to re-find parent key</> errors in
 945        <command>VACUUM</> (Tom)
 946       </para>
 947      </listitem>
 948
 949      <listitem>
 950       <para>
 951        Fix bugs affecting multi-gigabyte hash indexes (Tom)
 952       </para>
 953      </listitem>
 954
 955     <listitem>
 956      <para>
 957       Fix error when constructing an <literal>ARRAY[]</> made up of multiple
 958       empty elements (Tom)
 959      </para>
 960     </listitem>
 961
 962     <listitem>
 963      <para>
 964       <function>to_number()</> and <function>to_char(numeric)</>
 965       are now <literal>STABLE</>, not <literal>IMMUTABLE</>, for
 966       new <application>initdb</> installs (Tom)
 967      </para>
 968
 969      <para>
 970       This is because <varname>lc_numeric</> can potentially
 971       change the output of these functions.
 972      </para>
 973     </listitem>
 974
 975     <listitem>
 976      <para>
 977       Improve index usage of regular expressions that use parentheses (Tom)
 978      </para>
 979
 980      <para>
 981       This improves <application>psql</> <literal>\d</> performance also.
 982      </para>
 983     </listitem>
 984
 985    </itemizedlist>
 986
 987   </sect2>
 988  </sect1>
 989
 990  <sect1 id="release-7-4-14">
 991   <title>Release 7.4.14</title>
 992
 993   <note>
 994   <title>Release date</title>
 995   <simpara>2006-10-16</simpara>
 996   </note>
 997
 998   <para>
 999    This release contains a variety of fixes from 7.4.13.
1000    For information about new features in the 7.4 major release, see
1001    <xref linkend="release-7-4">.
1002   </para>
1003
1004   <sect2>
1005    <title>Migration to Version 7.4.14</title>
1006
1007    <para>
1008     A dump/restore is not required for those running 7.4.X.  However,
1009     if you are upgrading from a version earlier than 7.4.11, see the release
1010     notes for 7.4.11.
1011    </para>
1012
1013   </sect2>
1014
1015   <sect2>
1016    <title>Changes</title>
1017
1018 <itemizedlist>
1019 <listitem><para>Fix core dump when an untyped literal is taken as
1020 ANYARRAY</para></listitem>
1021 <listitem><para>Fix <function>string_to_array()</> to handle overlapping
1022  matches for the separator string</para>
1023 <para>For example, <literal>string_to_array('123xx456xxx789', 'xx')</>.
1024 </para></listitem>
1025 <listitem><para>Fix corner cases in pattern matching for
1026  <application>psql</>'s <literal>\d</> commands</para></listitem>
1027 <listitem><para>Fix index-corrupting bugs in /contrib/ltree
1028  (Teodor)</para></listitem>
1029 <listitem><para>Fix backslash escaping in /contrib/dbmirror</para></listitem>
1030 <listitem><para>Adjust regression tests for recent changes in US DST laws
1031 </para> </listitem>
1032 </itemizedlist>
1033
1034   </sect2>
1035  </sect1>
1036
1037  <sect1 id="release-7-4-13">
1038   <title>Release 7.4.13</title>
1039
1040   <note>
1041   <title>Release date</title>
1042   <simpara>2006-05-23</simpara>
1043   </note>
1044
1045   <para>
1046    This release contains a variety of fixes from 7.4.12,
1047    including patches for extremely serious security issues.
1048    For information about new features in the 7.4 major release, see
1049    <xref linkend="release-7-4">.
1050   </para>
1051
1052   <sect2>
1053    <title>Migration to Version 7.4.13</title>
1054
1055    <para>
1056     A dump/restore is not required for those running 7.4.X.  However,
1057     if you are upgrading from a version earlier than 7.4.11, see the release
1058     notes for 7.4.11.
1059    </para>
1060
1061    <para>
1062     Full security against the SQL-injection attacks described in
1063     CVE-2006-2313 and CVE-2006-2314 might require changes in application
1064     code.  If you have applications that embed untrustworthy strings
1065     into SQL commands, you should examine them as soon as possible to
1066     ensure that they are using recommended escaping techniques.  In
1067     most cases, applications should be using subroutines provided by
1068     libraries or drivers (such as <application>libpq</>'s
1069     <function>PQescapeStringConn()</>) to perform string escaping,
1070     rather than relying on <foreignphrase>ad hoc</> code to do it.
1071    </para>
1072   </sect2>
1073
1074   <sect2>
1075    <title>Changes</title>
1076
1077 <itemizedlist>
1078 <listitem><para>Change the server to reject invalidly-encoded multibyte
1079 characters in all cases (Tatsuo, Tom)</para>
1080 <para>While <productname>PostgreSQL</> has been moving in this direction for
1081 some time, the checks are now applied uniformly to all encodings and all
1082 textual input, and are now always errors not merely warnings.  This change
1083 defends against SQL-injection attacks of the type described in CVE-2006-2313.
1084 </para></listitem>
1085
1086 <listitem><para>Reject unsafe uses of <literal>\'</> in string literals</para>
1087 <para>As a server-side defense against SQL-injection attacks of the type
1088 described in CVE-2006-2314, the server now only accepts <literal>''</> and not
1089 <literal>\'</> as a representation of ASCII single quote in SQL string
1090 literals.  By default, <literal>\'</> is rejected only when
1091 <varname>client_encoding</> is set to a client-only encoding (SJIS, BIG5, GBK,
1092 GB18030, or UHC), which is the scenario in which SQL injection is possible.
1093 A new configuration parameter <varname>backslash_quote</> is available to
1094 adjust this behavior when needed.  Note that full security against
1095 CVE-2006-2314 might require client-side changes; the purpose of
1096 <varname>backslash_quote</> is in part to make it obvious that insecure
1097 clients are insecure.
1098 </para></listitem>
1099
1100 <listitem><para>Modify <application>libpq</>'s string-escaping routines to be
1101 aware of encoding considerations and
1102 <varname>standard_conforming_strings</></para>
1103 <para>This fixes <application>libpq</>-using applications for the security
1104 issues described in CVE-2006-2313 and CVE-2006-2314, and also future-proofs
1105 them against the planned changeover to SQL-standard string literal syntax.
1106 Applications that use multiple <productname>PostgreSQL</> connections
1107 concurrently should migrate to <function>PQescapeStringConn()</> and
1108 <function>PQescapeByteaConn()</> to ensure that escaping is done correctly
1109 for the settings in use in each database connection.  Applications that
1110 do string escaping <quote>by hand</> should be modified to rely on library
1111 routines instead.
1112 </para></listitem>
1113
1114 <listitem><para>Fix some incorrect encoding conversion functions</para>
1115 <para><function>win1251_to_iso</>, <function>alt_to_iso</>,
1116 <function>euc_tw_to_big5</>, <function>euc_tw_to_mic</>,
1117 <function>mic_to_euc_tw</> were all broken to varying
1118 extents.
1119 </para></listitem>
1120
1121 <listitem><para>Clean up stray remaining uses of <literal>\'</> in strings
1122 (Bruce, Jan)</para></listitem>
1123
1124 <listitem><para>Fix bug that sometimes caused OR'd index scans to
1125 miss rows they should have returned</para></listitem>
1126
1127 <listitem><para>Fix WAL replay for case where a btree index has been
1128 truncated</para></listitem>
1129
1130 <listitem><para>Fix <literal>SIMILAR TO</> for patterns involving
1131 <literal>|</> (Tom)</para></listitem>
1132
1133 <listitem><para>Fix server to use custom DH SSL parameters correctly (Michael
1134 Fuhr)</para></listitem>
1135
1136 <listitem><para>Fix for Bonjour on Intel Macs (Ashley Clark)</para></listitem>
1137
1138 <listitem><para>Fix various minor memory leaks</para></listitem>
1139 </itemizedlist>
1140
1141   </sect2>
1142  </sect1>
1143
1144  <sect1 id="release-7-4-12">
1145   <title>Release 7.4.12</title>
1146
1147   <note>
1148   <title>Release date</title>
1149   <simpara>2006-02-14</simpara>
1150   </note>
1151
1152   <para>
1153    This release contains a variety of fixes from 7.4.11.
1154    For information about new features in the 7.4 major release, see
1155    <xref linkend="release-7-4">.
1156   </para>
1157
1158   <sect2>
1159    <title>Migration to Version 7.4.12</title>
1160
1161    <para>
1162     A dump/restore is not required for those running 7.4.X.  However,
1163     if you are upgrading from a version earlier than 7.4.11, see the release
1164     notes for 7.4.11.
1165    </para>
1166   </sect2>
1167
1168   <sect2>
1169    <title>Changes</title>
1170
1171 <itemizedlist>
1172
1173 <listitem><para>Fix potential crash in <command>SET
1174 SESSION AUTHORIZATION</> (CVE-2006-0553)</para>
1175 <para>An unprivileged user could crash the server process, resulting in
1176 momentary denial of service to other users, if the server has been compiled
1177 with Asserts enabled (which is not the default).
1178 Thanks to Akio Ishida for reporting this problem.
1179 </para></listitem>
1180
1181 <listitem><para>Fix bug with row visibility logic in self-inserted
1182 rows (Tom)</para>
1183 <para>Under rare circumstances a row inserted by the current command
1184 could be seen as already valid, when it should not be.  Repairs bug
1185 created in 7.4.9 and 7.3.11 releases.
1186 </para></listitem>
1187
1188 <listitem><para>Fix race condition that could lead to <quote>file already
1189 exists</> errors during pg_clog file creation
1190 (Tom)</para></listitem>
1191
1192 <listitem><para>Properly check <literal>DOMAIN</> constraints for
1193 <literal>UNKNOWN</> parameters in prepared statements
1194 (Neil)</para></listitem>
1195
1196 <listitem><para>Fix to allow restoring dumps that have cross-schema
1197 references to custom operators (Tom)</para></listitem>
1198
1199 <listitem><para>Portability fix for testing presence of <function>finite</>
1200 and <function>isinf</> during configure (Tom)</para></listitem>
1201
1202 </itemizedlist>
1203
1204   </sect2>
1205  </sect1>
1206
1207  <sect1 id="release-7-4-11">
1208   <title>Release 7.4.11</title>
1209
1210   <note>
1211   <title>Release date</title>
1212   <simpara>2006-01-09</simpara>
1213   </note>
1214
1215   <para>
1216    This release contains a variety of fixes from 7.4.10.
1217    For information about new features in the 7.4 major release, see
1218    <xref linkend="release-7-4">.
1219   </para>
1220
1221   <sect2>
1222    <title>Migration to Version 7.4.11</title>
1223
1224    <para>
1225     A dump/restore is not required for those running 7.4.X.  However,
1226     if you are upgrading from a version earlier than 7.4.8, see the release
1227     notes for 7.4.8.
1228     Also, you might need to <command>REINDEX</> indexes on textual
1229     columns after updating, if you are affected by the locale or
1230     <application>plperl</> issues described below.
1231    </para>
1232   </sect2>
1233
1234   <sect2>
1235    <title>Changes</title>
1236
1237 <itemizedlist>
1238
1239 <listitem><para>Fix for protocol-level Describe messages issued
1240 outside a transaction or in a failed transaction (Tom)</para></listitem>
1241
1242 <listitem><para>Fix character string comparison for locales that consider
1243 different character combinations as equal, such as Hungarian (Tom)</para>
1244 <para>This might require <command>REINDEX</> to fix existing indexes on
1245 textual columns.</para></listitem>
1246
1247 <listitem><para>Set locale environment variables during postmaster startup
1248 to ensure that <application>plperl</> won't change the locale later</para>
1249 <para>This fixes a problem that occurred if the <application>postmaster</> was
1250 started with environment variables specifying a different locale than what
1251 <application>initdb</> had been told.  Under these conditions, any use of
1252 <application>plperl</> was likely to lead to corrupt indexes.  You might need
1253 <command>REINDEX</> to fix existing indexes on
1254 textual columns if this has happened to you.</para></listitem>
1255
1256 <listitem><para>Fix longstanding bug in strpos() and regular expression
1257 handling in certain rarely used Asian multi-byte character sets (Tatsuo)
1258 </para></listitem>
1259
1260 <listitem><para>Fix bug in <filename>/contrib/pgcrypto</> gen_salt,
1261 which caused it not to use all available salt space for MD5 and
1262 XDES algorithms (Marko Kreen, Solar Designer)</para>
1263 <para>Salts for Blowfish and standard DES are unaffected.</para></listitem>
1264
1265 <listitem><para>Fix <filename>/contrib/dblink</> to throw an error,
1266 rather than crashing, when the number of columns specified is different from
1267 what's actually returned by the query (Joe)</para></listitem>
1268
1269 </itemizedlist>
1270
1271   </sect2>
1272  </sect1>
1273
1274  <sect1 id="release-7-4-10">
1275   <title>Release 7.4.10</title>
1276
1277   <note>
1278   <title>Release date</title>
1279   <simpara>2005-12-12</simpara>
1280   </note>
1281
1282   <para>
1283    This release contains a variety of fixes from 7.4.9.
1284    For information about new features in the 7.4 major release, see
1285    <xref linkend="release-7-4">.
1286   </para>
1287
1288   <sect2>
1289    <title>Migration to Version 7.4.10</title>
1290
1291    <para>
1292     A dump/restore is not required for those running 7.4.X.  However,
1293     if you are upgrading from a version earlier than 7.4.8, see the release
1294     notes for 7.4.8.
1295    </para>
1296   </sect2>
1297
1298   <sect2>
1299    <title>Changes</title>
1300
1301 <itemizedlist>
1302
1303 <listitem><para>Fix race condition in transaction log management</para>
1304 <para>There was a narrow window in which an I/O operation could be initiated
1305 for the wrong page, leading to an Assert failure or data
1306 corruption.</para>
1307 </listitem>
1308
1309 <listitem><para>Prevent failure if client sends Bind protocol message
1310 when current transaction is already aborted</para></listitem>
1311
1312 <listitem><para><filename>/contrib/ltree</> fixes (Teodor)</para></listitem>
1313
1314 <listitem><para>AIX and HPUX compile fixes (Tom)</para></listitem>
1315
1316 <listitem><para>Fix longstanding planning error for outer joins</para>
1317 <para>This bug sometimes caused a bogus error <quote>RIGHT JOIN is
1318 only supported with merge-joinable join conditions</>.</para></listitem>
1319
1320 <listitem><para>Prevent core dump in <application>pg_autovacuum</> when a
1321 table has been dropped</para></listitem>
1322 </itemizedlist>
1323
1324   </sect2>
1325  </sect1>
1326
1327  <sect1 id="release-7-4-9">
1328   <title>Release 7.4.9</title>
1329
1330   <note>
1331   <title>Release date</title>
1332   <simpara>2005-10-04</simpara>
1333   </note>
1334
1335   <para>
1336    This release contains a variety of fixes from 7.4.8.
1337    For information about new features in the 7.4 major release, see
1338    <xref linkend="release-7-4">.
1339   </para>
1340
1341   <sect2>
1342    <title>Migration to Version 7.4.9</title>
1343
1344    <para>
1345     A dump/restore is not required for those running 7.4.X.  However,
1346     if you are upgrading from a version earlier than 7.4.8, see the release
1347     notes for 7.4.8.
1348    </para>
1349   </sect2>
1350
1351   <sect2>
1352    <title>Changes</title>
1353
1354 <itemizedlist>
1355 <listitem><para>Fix error that allowed <command>VACUUM</> to remove
1356 <literal>ctid</> chains too soon, and add more checking in code that follows
1357 <literal>ctid</> links</para>
1358 <para>This fixes a long-standing problem that could cause crashes in very rare
1359 circumstances.</para></listitem>
1360 <listitem><para>Fix <type>CHAR()</> to properly pad spaces to the specified
1361 length when using a multiple-byte character set (Yoshiyuki Asaba)</para>
1362 <para>In prior releases, the padding of <type>CHAR()</> was incorrect
1363 because it only padded to the specified number of bytes without
1364 considering how many characters were stored.</para></listitem>
1365 <listitem><para>Fix the sense of the test for read-only transaction
1366 in <command>COPY</></para>
1367 <para>The code formerly prohibited <command>COPY TO</>, where it should
1368 prohibit <command>COPY FROM</>.
1369 </para></listitem>
1370 <listitem><para>Fix planning problem with outer-join ON clauses that reference
1371 only the inner-side relation</para></listitem>
1372 <listitem><para>Further fixes for <literal>x FULL JOIN y ON true</> corner
1373 cases</para></listitem>
1374 <listitem><para>Make <function>array_in</> and <function>array_recv</> more
1375 paranoid about validating their OID parameter</para></listitem>
1376 <listitem><para>Fix missing rows in queries like <literal>UPDATE a=... WHERE
1377 a...</> with GiST index on column <literal>a</></para></listitem>
1378 <listitem><para>Improve robustness of datetime parsing</para></listitem>
1379 <listitem><para>Improve checking for partially-written WAL
1380 pages</para></listitem>
1381 <listitem><para>Improve robustness of signal handling when SSL is
1382 enabled</para></listitem>
1383 <listitem><para>Don't try to open more than <literal>max_files_per_process</>
1384 files during postmaster startup</para></listitem>
1385 <listitem><para>Various memory leakage fixes</para></listitem>
1386 <listitem><para>Various portability improvements</para></listitem>
1387 <listitem><para>Fix PL/PgSQL to handle <literal>var := var</> correctly when
1388 the variable is of pass-by-reference type</para></listitem>
1389 <listitem><para>Update <filename>contrib/tsearch2</> to use current Snowball
1390 code</para></listitem>
1391 </itemizedlist>
1392
1393   </sect2>
1394  </sect1>
1395
1396  <sect1 id="release-7-4-8">
1397   <title>Release 7.4.8</title>
1398
1399   <note>
1400   <title>Release date</title>
1401   <simpara>2005-05-09</simpara>
1402   </note>
1403
1404   <para>
1405    This release contains a variety of fixes from 7.4.7, including several
1406    security-related issues.
1407    For information about new features in the 7.4 major release, see
1408    <xref linkend="release-7-4">.
1409   </para>
1410
1411   <sect2>
1412    <title>Migration to Version 7.4.8</title>
1413
1414    <para>
1415     A dump/restore is not required for those running 7.4.X.  However,
1416     it is one possible way of handling two significant security problems
1417     that have been found in the initial contents of 7.4.X system
1418     catalogs.  A dump/initdb/reload sequence using 7.4.8's initdb will
1419     automatically correct these problems.
1420    </para>
1421
1422    <para>
1423     The larger security problem is that the built-in character set encoding
1424     conversion functions can be invoked from SQL commands by unprivileged
1425     users, but the functions were not designed for such use and are not
1426     secure against malicious choices of arguments.  The fix involves changing
1427     the declared parameter list of these functions so that they can no longer
1428     be invoked from SQL commands.  (This does not affect their normal use
1429     by the encoding conversion machinery.)
1430    </para>
1431
1432    <para>
1433     The lesser problem is that the <filename>contrib/tsearch2</> module
1434     creates several functions that are misdeclared to return
1435     <type>internal</> when they do not accept <type>internal</> arguments.
1436     This breaks type safety for all functions using <type>internal</>
1437     arguments.
1438    </para>
1439
1440    <para>
1441     It is strongly recommended that all installations repair these errors,
1442     either by initdb or by following the manual repair procedures given
1443     below.  The errors at least allow unprivileged database users to crash
1444     their server process, and might allow unprivileged users to gain the
1445     privileges of a database superuser.
1446    </para>
1447
1448    <para>
1449     If you wish not to do an initdb, perform the following procedures instead.
1450     As the database superuser, do:
1451
1452 <programlisting>
1453 BEGIN;
1454 UPDATE pg_proc SET proargtypes[3] = 'internal'::regtype
1455 WHERE pronamespace = 11 AND pronargs = 5
1456      AND proargtypes[2] = 'cstring'::regtype;
1457 -- The command should report having updated 90 rows;
1458 -- if not, rollback and investigate instead of committing!
1459 COMMIT;
1460 </programlisting>
1461
1462     Next, if you have installed <filename>contrib/tsearch2</>, do:
1463
1464 <programlisting>
1465 BEGIN;
1466 UPDATE pg_proc SET proargtypes[0] = 'internal'::regtype
1467 WHERE oid IN (
1468    'dex_init(text)'::regprocedure,
1469    'snb_en_init(text)'::regprocedure,
1470    'snb_ru_init(text)'::regprocedure,
1471    'spell_init(text)'::regprocedure,
1472    'syn_init(text)'::regprocedure
1473 );
1474 -- The command should report having updated 5 rows;
1475 -- if not, rollback and investigate instead of committing!
1476 COMMIT;
1477 </programlisting>
1478
1479     If this command fails with a message like <quote>function
1480     "dex_init(text)" does not exist</>, then either <filename>tsearch2</>
1481     is not installed in this database, or you already did the update.
1482    </para>
1483
1484    <para>
1485     The above procedures must be carried out in <emphasis>each</> database
1486     of an installation, including <literal>template1</>, and ideally
1487     including <literal>template0</> as well.  If you do not fix the
1488     template databases then any subsequently created databases will contain
1489     the same errors.  <literal>template1</> can be fixed in the same way
1490     as any other database, but fixing <literal>template0</> requires
1491     additional steps.  First, from any database issue:
1492 <programlisting>
1493 UPDATE pg_database SET datallowconn = true WHERE datname = 'template0';
1494 </programlisting>
1495      Next connect to <literal>template0</> and perform the above repair
1496      procedures.  Finally, do:
1497 <programlisting>
1498 -- re-freeze template0:
1499 VACUUM FREEZE;
1500 -- and protect it against future alterations:
1501 UPDATE pg_database SET datallowconn = false WHERE datname = 'template0';
1502 </programlisting>
1503    </para>
1504   </sect2>
1505
1506   <sect2>
1507    <title>Changes</title>
1508
1509 <itemizedlist>
1510 <listitem><para>Change encoding function signature to prevent
1511 misuse</para></listitem>
1512 <listitem><para>Change <filename>contrib/tsearch2</> to avoid unsafe use of
1513 <type>INTERNAL</> function results</para></listitem>
1514 <listitem><para>Repair ancient race condition that allowed a transaction to be
1515 seen as committed for some purposes (eg SELECT FOR UPDATE) slightly sooner
1516 than for other purposes</para>
1517 <para>This is an extremely serious bug since it could lead to apparent
1518 data inconsistencies being briefly visible to applications.</para></listitem>
1519 <listitem><para>Repair race condition between relation extension and
1520 VACUUM</para>
1521 <para>This could theoretically have caused loss of a page's worth of
1522 freshly-inserted data, although the scenario seems of very low probability.
1523 There are no known cases of it having caused more than an Assert failure.
1524 </para></listitem>
1525 <listitem><para>Fix comparisons of <type>TIME WITH TIME ZONE</> values</para>
1526 <para>
1527 The comparison code was wrong in the case where the
1528 <literal>--enable-integer-datetimes</> configuration switch had been used.
1529 NOTE: if you have an index on a <type>TIME WITH TIME ZONE</> column,
1530 it will need to be <command>REINDEX</>ed after installing this update, because
1531 the fix corrects the sort order of column values.
1532 </para></listitem>
1533 <listitem><para>Fix <function>EXTRACT(EPOCH)</> for
1534 <type>TIME WITH TIME ZONE</> values</para></listitem>
1535 <listitem><para>Fix mis-display of negative fractional seconds in
1536 <type>INTERVAL</> values</para>
1537 <para>
1538 This error only occurred when the
1539 <literal>--enable-integer-datetimes</> configuration switch had been used.
1540 </para></listitem>
1541 <listitem><para>Ensure operations done during backend shutdown are counted by
1542 statistics collector</para>
1543 <para>
1544 This is expected to resolve reports of <application>pg_autovacuum</>
1545 not vacuuming the system catalogs often enough &mdash; it was not being
1546 told about catalog deletions caused by temporary table removal during
1547 backend exit.
1548 </para></listitem>
1549 <listitem><para>Additional buffer overrun checks in plpgsql
1550 (Neil)</para></listitem>
1551 <listitem><para>Fix pg_dump to dump trigger names containing <literal>%</>
1552 correctly (Neil)</para></listitem>
1553 <listitem><para>Fix <filename>contrib/pgcrypto</> for newer OpenSSL builds
1554 (Marko Kreen)</para></listitem>
1555 <listitem><para>Still more 64-bit fixes for
1556 <filename>contrib/intagg</></para></listitem>
1557 <listitem><para>Prevent incorrect optimization of functions returning
1558 <type>RECORD</></para></listitem>
1559 <listitem><para>Prevent <function>to_char(interval)</> from dumping core for
1560 month-related formats</para></listitem>
1561 <listitem><para>Prevent crash on <literal>COALESCE(NULL,NULL)</></para></listitem>
1562 <listitem><para>Fix <function>array_map</> to call PL functions correctly</para></listitem>
1563 <listitem><para>Fix permission checking in <command>ALTER DATABASE RENAME</></para></listitem>
1564 <listitem><para>Fix <command>ALTER LANGUAGE RENAME</></para></listitem>
1565 <listitem><para>Make <function>RemoveFromWaitQueue</> clean up after itself</para>
1566 <para>
1567 This fixes a lock management error that would only be visible if a transaction
1568 was kicked out of a wait for a lock (typically by query cancel) and then the
1569 holder of the lock released it within a very narrow window.
1570 </para></listitem>
1571 <listitem><para>Fix problem with untyped parameter appearing in
1572 <command>INSERT ... SELECT</></para></listitem>
1573 <listitem><para>Fix <command>CLUSTER</> failure after
1574 <command>ALTER TABLE SET WITHOUT OIDS</></para></listitem>
1575 </itemizedlist>
1576
1577   </sect2>
1578  </sect1>
1579
1580  <sect1 id="release-7-4-7">
1581   <title>Release 7.4.7</title>
1582
1583   <note>
1584   <title>Release date</title>
1585   <simpara>2005-01-31</simpara>
1586   </note>
1587
1588   <para>
1589    This release contains a variety of fixes from 7.4.6, including several
1590    security-related issues.
1591    For information about new features in the 7.4 major release, see
1592    <xref linkend="release-7-4">.
1593   </para>
1594
1595   <sect2>
1596    <title>Migration to Version 7.4.7</title>
1597
1598    <para>
1599     A dump/restore is not required for those running 7.4.X.
1600    </para>
1601   </sect2>
1602
1603   <sect2>
1604    <title>Changes</title>
1605
1606 <itemizedlist>
1607 <listitem><para>Disallow <command>LOAD</> to non-superusers</para>
1608 <para>
1609 On platforms that will automatically execute initialization functions of a
1610 shared library (this includes at least Windows and ELF-based Unixen),
1611 <command>LOAD</> can be used to make the server execute arbitrary code.
1612 Thanks to NGS Software for reporting this.</para></listitem>
1613 <listitem><para>Check that creator of an aggregate function has the right to
1614 execute the specified transition functions</para>
1615 <para>
1616 This oversight made it possible to bypass denial of EXECUTE
1617 permission on a function.</para></listitem>
1618 <listitem><para>Fix security and 64-bit issues in
1619 contrib/intagg</para></listitem>
1620 <listitem><para>Add needed STRICT marking to some contrib functions (Kris
1621 Jurka)</para></listitem>
1622 <listitem><para>Avoid buffer overrun when plpgsql cursor declaration has too
1623 many parameters (Neil)</para></listitem>
1624 <listitem><para>Fix planning error for FULL and RIGHT outer joins</para>
1625 <para>
1626 The result of the join was mistakenly supposed to be sorted the same as the
1627 left input.  This could not only deliver mis-sorted output to the user, but
1628 in case of nested merge joins could give outright wrong answers.
1629 </para></listitem>
1630 <listitem><para>Fix plperl for quote marks in tuple fields</para></listitem>
1631 <listitem><para>Fix display of negative intervals in SQL and GERMAN
1632 datestyles</para></listitem>
1633 <listitem><para>Make age(timestamptz) do calculation in local timezone not
1634 GMT</para></listitem>
1635 </itemizedlist>
1636
1637   </sect2>
1638  </sect1>
1639
1640  <sect1 id="release-7-4-6">
1641   <title>Release 7.4.6</title>
1642
1643   <note>
1644   <title>Release date</title>
1645   <simpara>2004-10-22</simpara>
1646   </note>
1647
1648   <para>
1649    This release contains a variety of fixes from 7.4.5.
1650    For information about new features in the 7.4 major release, see
1651    <xref linkend="release-7-4">.
1652   </para>
1653
1654
1655   <sect2>
1656    <title>Migration to Version 7.4.6</title>
1657
1658    <para>
1659     A dump/restore is not required for those running 7.4.X.
1660    </para>
1661   </sect2>
1662
1663   <sect2>
1664    <title>Changes</title>
1665
1666 <itemizedlist>
1667 <listitem><para>Repair possible failure to update hint bits on disk</para>
1668 <para>
1669 Under rare circumstances this oversight could lead to
1670 <quote>could not access transaction status</> failures, which qualifies
1671 it as a potential-data-loss bug.
1672 </para></listitem>
1673 <listitem><para>Ensure that hashed outer join does not miss tuples</para>
1674 <para>
1675 Very large left joins using a hash join plan could fail to output unmatched
1676 left-side rows given just the right data distribution.
1677 </para></listitem>
1678 <listitem><para>Disallow running <application>pg_ctl</> as root</para>
1679 <para>
1680 This is to guard against any possible security issues.
1681 </para></listitem>
1682 <listitem><para>Avoid using temp files in <filename>/tmp</> in <command>make_oidjoins_check</command></para>
1683 <para>
1684 This has been reported as a security issue, though it's hardly worthy of
1685 concern since there is no reason for non-developers to use this script anyway.
1686 </para></listitem>
1687 <listitem><para>Prevent forced backend shutdown from re-emitting prior command
1688 result</para>
1689 <para>
1690 In rare cases, a client might think that its last command had succeeded when
1691 it really had been aborted by forced database shutdown.
1692 </para></listitem>
1693 <listitem><para>Repair bug in <function>pg_stat_get_backend_idset</function></para>
1694 <para>
1695 This could lead to misbehavior in some of the system-statistics views.
1696 </para></listitem>
1697 <listitem><para>Fix small memory leak in postmaster</para></listitem>
1698 <listitem><para>Fix <quote>expected both swapped tables to have TOAST
1699 tables</> bug</para>
1700 <para>
1701 This could arise in cases such as CLUSTER after ALTER TABLE DROP COLUMN.
1702 </para></listitem>
1703 <listitem><para>Prevent <literal>pg_ctl restart</> from adding <literal>-D</> multiple times</para></listitem>
1704 <listitem><para>Fix problem with NULL values in GiST indexes</para></listitem>
1705 <listitem><para><literal>::</> is no longer interpreted as a variable in an
1706 ECPG prepare statement</para></listitem>
1707 </itemizedlist>
1708
1709   </sect2>
1710  </sect1>
1711
1712  <sect1 id="release-7-4-5">
1713   <title>Release 7.4.5</title>
1714
1715   <note>
1716   <title>Release date</title>
1717   <simpara>2004-08-18</simpara>
1718   </note>
1719
1720   <para>
1721    This release contains one serious bug fix over 7.4.4.
1722    For information about new features in the 7.4 major release, see
1723    <xref linkend="release-7-4">.
1724   </para>
1725
1726
1727   <sect2>
1728    <title>Migration to Version 7.4.5</title>
1729
1730    <para>
1731     A dump/restore is not required for those running 7.4.X.
1732    </para>
1733   </sect2>
1734
1735   <sect2>
1736    <title>Changes</title>
1737
1738 <itemizedlist>
1739 <listitem><para>Repair possible crash during concurrent B-tree index insertions</para>
1740 <para>
1741 This patch fixes a rare case in which concurrent insertions into a B-tree index
1742 could result in a server panic.  No permanent damage would result, but it's
1743 still worth a re-release.  The bug does not exist in pre-7.4 releases.
1744 </para></listitem>
1745 </itemizedlist>
1746
1747   </sect2>
1748  </sect1>
1749
1750  <sect1 id="release-7-4-4">
1751   <title>Release 7.4.4</title>
1752
1753   <note>
1754   <title>Release date</title>
1755   <simpara>2004-08-16</simpara>
1756   </note>
1757
1758   <para>
1759    This release contains a variety of fixes from 7.4.3.
1760    For information about new features in the 7.4 major release, see
1761    <xref linkend="release-7-4">.
1762   </para>
1763
1764
1765   <sect2>
1766    <title>Migration to Version 7.4.4</title>
1767
1768    <para>
1769     A dump/restore is not required for those running 7.4.X.
1770    </para>
1771   </sect2>
1772
1773   <sect2>
1774    <title>Changes</title>
1775
1776 <itemizedlist>
1777 <listitem><para>Prevent possible loss of committed transactions during crash</para>
1778 <para>
1779 Due to insufficient interlocking between transaction commit and checkpointing,
1780 it was possible for transactions committed just before the most recent
1781 checkpoint to be lost, in whole or in part, following a database crash and
1782 restart.  This is a serious bug that has existed
1783 since <productname>PostgreSQL</productname> 7.1.
1784 </para></listitem>
1785 <listitem><para>Check HAVING restriction before evaluating result list of an
1786 aggregate plan</para></listitem>
1787 <listitem><para>Avoid crash when session's current user ID is deleted</para></listitem>
1788 <listitem><para>Fix hashed crosstab for zero-rows case (Joe)</para></listitem>
1789 <listitem><para>Force cache update after renaming a column in a foreign key</para></listitem>
1790 <listitem><para>Pretty-print UNION queries correctly</para></listitem>
1791 <listitem><para>Make psql handle <literal>\r\n</> newlines properly in COPY IN</para></listitem>
1792 <listitem><para><application>pg_dump</> handled ACLs with grant options incorrectly</para></listitem>
1793 <listitem><para>Fix thread support for OS X and Solaris</para></listitem>
1794 <listitem><para>Updated JDBC driver (build 215) with various fixes</para></listitem>
1795 <listitem><para>ECPG fixes</para></listitem>
1796 <listitem><para>Translation updates (various contributors)</para></listitem>
1797 </itemizedlist>
1798
1799   </sect2>
1800  </sect1>
1801
1802  <sect1 id="release-7-4-3">
1803   <title>Release 7.4.3</title>
1804
1805   <note>
1806   <title>Release date</title>
1807   <simpara>2004-06-14</simpara>
1808   </note>
1809
1810   <para>
1811    This release contains a variety of fixes from 7.4.2.
1812    For information about new features in the 7.4 major release, see
1813    <xref linkend="release-7-4">.
1814   </para>
1815
1816
1817   <sect2>
1818    <title>Migration to Version 7.4.3</title>
1819
1820    <para>
1821     A dump/restore is not required for those running 7.4.X.
1822    </para>
1823   </sect2>
1824
1825   <sect2>
1826    <title>Changes</title>
1827
1828 <itemizedlist>
1829 <listitem><para>Fix temporary memory leak when using non-hashed aggregates (Tom)</para></listitem>
1830 <listitem><para>ECPG fixes, including some for Informix compatibility (Michael)</para></listitem>
1831 <listitem><para>Fixes for compiling with thread-safety, particularly Solaris (Bruce)</para></listitem>
1832 <listitem><para>Fix error in COPY IN termination when using the old network protocol (ljb)</para></listitem>
1833 <listitem><para>Several important fixes in pg_autovacuum, including fixes for
1834 large tables, unsigned oids, stability, temp tables, and debug mode
1835 (Matthew T. O'Connor)</para></listitem>
1836 <listitem><para>Fix problem with reading tar-format dumps on NetBSD and BSD/OS (Bruce)</para></listitem>
1837 <listitem><para>Several JDBC fixes</para></listitem>
1838 <listitem><para>Fix ALTER SEQUENCE RESTART where last_value equals the restart value (Tom)</para></listitem>
1839 <listitem><para>Repair failure to recalculate nested sub-selects (Tom)</para></listitem>
1840 <listitem><para>Fix problems with non-constant expressions in LIMIT/OFFSET</para></listitem>
1841 <listitem><para>Support FULL JOIN with no join clause, such as X FULL JOIN Y ON TRUE (Tom)</para></listitem>
1842 <listitem><para>Fix another zero-column table bug (Tom)</para></listitem>
1843 <listitem><para>Improve handling of non-qualified identifiers in GROUP BY clauses in sub-selects (Tom)</para>
1844 <para>
1845 Select-list aliases within the sub-select will now take precedence over
1846 names from outer query levels.
1847 </para></listitem>
1848 <listitem><para>Do not generate <quote>NATURAL CROSS JOIN</> when decompiling rules (Tom)</para></listitem>
1849 <listitem><para>Add checks for invalid field length in binary COPY (Tom)</para>
1850 <para>
1851  This fixes a difficult-to-exploit security hole.
1852 </para></listitem>
1853 <listitem><para>Avoid locking conflict between <command>ANALYZE</command> and <command>LISTEN</command>/<command>NOTIFY</command></para></listitem>
1854 <listitem><para>Numerous translation updates (various contributors)</para></listitem>
1855 </itemizedlist>
1856
1857   </sect2>
1858  </sect1>
1859
1860  <sect1 id="release-7-4-2">
1861   <title>Release 7.4.2</title>
1862
1863   <note>
1864   <title>Release date</title>
1865   <simpara>2004-03-08</simpara>
1866   </note>
1867
1868   <para>
1869    This release contains a variety of fixes from 7.4.1.
1870    For information about new features in the 7.4 major release, see
1871    <xref linkend="release-7-4">.
1872   </para>
1873
1874
1875   <sect2>
1876    <title>Migration to Version 7.4.2</title>
1877
1878    <para>
1879     A dump/restore is not required for those running 7.4.X.  However,
1880     it might be advisable as the easiest method of incorporating fixes for
1881     two errors that have been found in the initial contents of 7.4.X system
1882     catalogs.  A dump/initdb/reload sequence using 7.4.2's initdb will
1883     automatically correct these problems.
1884    </para>
1885
1886    <para>
1887     The more severe of the two errors is that data type <type>anyarray</>
1888     has the wrong alignment label; this is a problem because the
1889     <structname>pg_statistic</> system catalog uses <type>anyarray</>
1890     columns.  The mislabeling can cause planner misestimations and even
1891     crashes when planning queries that involve <literal>WHERE</> clauses on
1892     double-aligned columns (such as <type>float8</> and <type>timestamp</>).
1893     It is strongly recommended that all installations repair this error,
1894     either by initdb or by following the manual repair procedure given
1895     below.
1896    </para>
1897
1898    <para>
1899     The lesser error is that the system view <structname>pg_settings</>
1900     ought to be marked as having public update access, to allow
1901     <literal>UPDATE pg_settings</> to be used as a substitute for
1902     <command>SET</>.  This can also be fixed either by initdb or manually,
1903     but it is not necessary to fix unless you want to use <literal>UPDATE
1904     pg_settings</>.
1905    </para>
1906
1907    <para>
1908     If you wish not to do an initdb, the following procedure will work
1909     for fixing <structname>pg_statistic</>.  As the database superuser,
1910     do:
1911
1912 <programlisting>
1913 -- clear out old data in pg_statistic:
1914 DELETE FROM pg_statistic;
1915 VACUUM pg_statistic;
1916 -- this should update 1 row:
1917 UPDATE pg_type SET typalign = 'd' WHERE oid = 2277;
1918 -- this should update 6 rows:
1919 UPDATE pg_attribute SET attalign = 'd' WHERE atttypid = 2277;
1920 --
1921 -- At this point you MUST start a fresh backend to avoid a crash!
1922 --
1923 -- repopulate pg_statistic:
1924 ANALYZE;
1925 </programlisting>
1926
1927     This can be done in a live database, but beware that all backends
1928     running in the altered database must be restarted before it is safe to
1929     repopulate <structname>pg_statistic</>.
1930    </para>
1931
1932    <para>
1933     To repair the <structname>pg_settings</> error, simply do:
1934 <programlisting>
1935 GRANT SELECT, UPDATE ON pg_settings TO PUBLIC;
1936 </programlisting>
1937    </para>
1938
1939    <para>
1940     The above procedures must be carried out in <emphasis>each</> database
1941     of an installation, including <literal>template1</>, and ideally
1942     including <literal>template0</> as well.  If you do not fix the
1943     template databases then any subsequently created databases will contain
1944     the same errors.  <literal>template1</> can be fixed in the same way
1945     as any other database, but fixing <literal>template0</> requires
1946     additional steps.  First, from any database issue:
1947 <programlisting>
1948 UPDATE pg_database SET datallowconn = true WHERE datname = 'template0';
1949 </programlisting>
1950      Next connect to <literal>template0</> and perform the above repair
1951      procedures.  Finally, do:
1952 <programlisting>
1953 -- re-freeze template0:
1954 VACUUM FREEZE;
1955 -- and protect it against future alterations:
1956 UPDATE pg_database SET datallowconn = false WHERE datname = 'template0';
1957 </programlisting>
1958    </para>
1959   </sect2>
1960
1961   <sect2>
1962    <title>Changes</title>
1963
1964 <para>
1965    Release 7.4.2 incorporates all the fixes included in release 7.3.6,
1966    plus the following fixes:
1967 </para>
1968
1969 <itemizedlist>
1970 <listitem><para>Fix <structname>pg_statistics</> alignment bug that could crash optimizer</para>
1971 <para>See above for details about this problem.</para></listitem>
1972 <listitem><para>Allow non-super users to update <structname>pg_settings</></para></listitem>
1973 <listitem><para>Fix several optimizer bugs, most of which led to
1974 <quote>variable not found in subplan target lists</> errors</para></listitem>
1975 <listitem><para>Avoid out-of-memory failure during startup of large multiple
1976 index scan</para></listitem>
1977 <listitem><para>Fix multibyte problem that could lead to <quote>out of
1978 memory</> error during <command>COPY IN</></para></listitem>
1979 <listitem><para>Fix problems with <command>SELECT INTO</> / <command>CREATE
1980 TABLE AS</> from tables without OIDs</para></listitem>
1981 <listitem><para>Fix problems with <filename>alter_table</> regression test
1982 during parallel testing</para></listitem>
1983 <listitem><para>Fix problems with hitting open file limit, especially on OS X (Tom)</para></listitem>
1984 <listitem><para>Partial fix for Turkish-locale issues</para>
1985 <para>initdb will succeed now in Turkish locale, but there are still some
1986 inconveniences associated with the <literal>i/I</> problem.</para></listitem>
1987 <listitem><para>Make pg_dump set client encoding on restore</para></listitem>
1988 <listitem><para>Other minor pg_dump fixes</para></listitem>
1989 <listitem><para>Allow ecpg to again use C keywords as column names (Michael)</para></listitem>
1990 <listitem><para>Added ecpg <literal>WHENEVER NOT_FOUND</> to
1991 <literal>SELECT/INSERT/UPDATE/DELETE</> (Michael)</para></listitem>
1992 <listitem><para>Fix ecpg crash for queries calling set-returning functions (Michael)</para></listitem>
1993 <listitem><para>Various other ecpg fixes (Michael)</para></listitem>
1994 <listitem><para>Fixes for Borland compiler</para></listitem>
1995 <listitem><para>Thread build improvements (Bruce)</para></listitem>
1996 <listitem><para>Various other build fixes</para></listitem>
1997 <listitem><para>Various JDBC fixes</para></listitem>
1998 </itemizedlist>
1999
2000   </sect2>
2001  </sect1>
2002
2003  <sect1 id="release-7-4-1">
2004   <title>Release 7.4.1</title>
2005
2006   <note>
2007   <title>Release date</title>
2008   <simpara>2003-12-22</simpara>
2009   </note>
2010
2011   <para>
2012    This release contains a variety of fixes from 7.4.
2013    For information about new features in the 7.4 major release, see
2014    <xref linkend="release-7-4">.
2015   </para>
2016
2017
2018   <sect2>
2019    <title>Migration to Version 7.4.1</title>
2020
2021    <para>
2022     A dump/restore is <emphasis>not</emphasis> required for those
2023     running 7.4.
2024    </para>
2025
2026    <para>
2027     If you want to install the fixes in the information schema
2028     you need to reload it into the database.
2029     This is either accomplished by initializing a new cluster
2030     by running <command>initdb</command>, or by running the following
2031     sequence of SQL commands in each database (ideally including
2032     <literal>template1</literal>) as a superuser in
2033     <application>psql</application>, after installing the new release:
2034 <programlisting>
2035 DROP SCHEMA information_schema CASCADE;
2036 \i /usr/local/pgsql/share/information_schema.sql
2037 </programlisting>
2038     Substitute your installation path in the second command.
2039    </para>
2040
2041   </sect2>
2042
2043   <sect2>
2044    <title>Changes</title>
2045
2046 <itemizedlist>
2047 <listitem><para>Fixed bug in <command>CREATE SCHEMA</command> parsing in ECPG (Michael)</para></listitem>
2048 <listitem><para>Fix compile error when <option>--enable-thread-safety</option> and <option>--with-perl</option> are used together (Peter)</para></listitem>
2049 <listitem><para>Fix for subqueries that used hash joins (Tom)</para>
2050 <para>
2051    Certain subqueries that used hash joins would crash because of
2052    improperly shared structures.
2053 </para></listitem>
2054 <listitem><para>Fix free space map compaction bug (Tom)</para>
2055 <para>
2056    This fixes a bug where compaction of the free space map could lead
2057    to a database server shutdown.
2058 </para>
2059 </listitem>
2060 <listitem><para>Fix for Borland compiler build of libpq (Bruce)</para></listitem>
2061 <listitem><para>Fix <function>netmask()</function> and <function>hostmask()</function> to return the maximum-length masklen (Tom)</para>
2062 <para>
2063    Fix these functions to return values consistent with pre-7.4
2064    releases.
2065 </para>
2066 </listitem>
2067 <listitem><para>Several <filename>contrib/pg_autovacuum</filename> fixes</para>
2068 <para>
2069    Fixes include improper variable initialization, missing vacuum after
2070    <command>TRUNCATE</command>, and duration computation overflow for long vacuums.
2071 </para>
2072 </listitem>
2073 <listitem><para>Allow compile of <filename>contrib/cube</filename> under Cygwin (Jason Tishler)</para></listitem>
2074 <listitem><para>Fix Solaris use of password file when no passwords are defined (Tom)</para>
2075 <para>
2076    Fix crash on Solaris caused by use of any type of password
2077    authentication when no passwords were defined.
2078 </para>
2079 </listitem>
2080 <listitem><para>JDBC fix for thread problems, other fixes</para></listitem>
2081 <listitem><para>Fix for <type>bytea</type> index lookups (Joe)</para></listitem>
2082 <listitem><para>Fix information schema for bit data types (Peter)</para></listitem>
2083 <listitem><para>Force zero_damaged_pages to be on during recovery from WAL</para></listitem>
2084 <listitem><para>Prevent some obscure cases of <quote>variable not in subplan target lists</quote></para></listitem>
2085 <listitem><para>Make <function>PQescapeBytea</function> and <function>byteaout</function> consistent with each other (Joe)</para></listitem>
2086 <listitem><para>Escape <type>bytea</type> output for bytes &gt; 0x7e(Joe)</para>
2087 <para>
2088  If different client encodings are used for <type>bytea</type> output and input, it
2089  is possible for <type>bytea</type> values to be corrupted by the differing
2090  encodings.  This fix escapes all bytes that might be affected.
2091 </para>
2092 </listitem>
2093 <listitem><para>Added missing <function>SPI_finish()</function> calls to dblink's <function>get_tuple_of_interest()</function> (Joe)</para></listitem>
2094 <listitem><para>New Czech FAQ</para></listitem>
2095 <listitem><para>Fix information schema view <literal>constraint_column_usage</literal> for foreign keys (Peter)</para></listitem>
2096 <listitem><para>ECPG fixes (Michael)</para></listitem>
2097 <listitem><para>Fix bug with multiple <literal>IN</literal> subqueries and joins in the subqueries (Tom)</para></listitem>
2098 <listitem><para>Allow <literal>COUNT('x')</literal> to work (Tom)</para></listitem>
2099 <listitem><para>Install ECPG include files for Informix compatibility into separate directory (Peter)</para>
2100 <para>
2101  Some names of ECPG include files for Informix compatibility conflicted with operating system include files.
2102  By installing them in their own directory, name conflicts have been reduced.
2103 </para>
2104 </listitem>
2105 <listitem><para>Fix SSL memory leak (Neil)</para>
2106 <para>
2107  This release fixes a bug in 7.4 where SSL didn't free all memory it allocated.
2108 </para>
2109 </listitem>
2110 <listitem><para>Prevent <filename>pg_service.conf</filename> from using service name as default dbname (Bruce)</para></listitem>
2111 <listitem><para>Fix local ident authentication on FreeBSD (Tom)</para></listitem>
2112 </itemizedlist>
2113
2114  </sect2>
2115 </sect1>
2116
2117 <sect1 id="release-7-4">
2118  <title>Release 7.4</title>
2119
2120  <note>
2121   <title>Release date</title>
2122   <simpara>2003-11-17</simpara>
2123  </note>
2124
2125  <sect2>
2126   <title>Overview</title>
2127
2128   <para>
2129    Major changes in this release:
2130   </para>
2131
2132   <variablelist>
2133    <varlistentry>
2134     <term>
2135      <literal>IN</literal> / <literal>NOT IN</literal> subqueries are
2136      now much more efficient
2137     </term>
2138
2139     <listitem>
2140      <para>
2141       In previous releases, <literal>IN</literal>/<literal>NOT
2142       IN</literal> subqueries were joined to the upper query by
2143       sequentially scanning the subquery looking for a match.  The
2144       7.4 code uses the same sophisticated techniques used by
2145       ordinary joins and so is much faster.  An
2146       <literal>IN</literal> will now usually be as fast as or faster
2147       than an equivalent <literal>EXISTS</literal> subquery; this
2148       reverses the conventional wisdom that applied to previous
2149       releases.
2150      </para>
2151     </listitem>
2152    </varlistentry>
2153
2154    <varlistentry>
2155     <term>
2156      Improved <literal>GROUP BY</literal> processing by using hash buckets
2157     </term>
2158
2159     <listitem>
2160      <para>
2161       In previous releases, rows to be grouped had to be sorted
2162       first.  The 7.4 code can do <literal>GROUP BY</literal>
2163       without sorting, by accumulating results into a hash table
2164       with one entry per group.  It will still use the sort
2165       technique, however, if the hash table is estimated to be too
2166       large to fit in <varname>sort_mem</>.
2167      </para>
2168     </listitem>
2169    </varlistentry>
2170
2171    <varlistentry>
2172     <term>
2173      New multikey hash join capability
2174     </term>
2175
2176     <listitem>
2177      <para>
2178       In previous releases, hash joins could only occur on single
2179       keys.  This release allows multicolumn hash joins.
2180      </para>
2181     </listitem>
2182    </varlistentry>
2183
2184    <varlistentry>
2185     <term>
2186      Queries using the explicit <literal>JOIN</literal> syntax are
2187      now better optimized
2188     </term>
2189
2190     <listitem>
2191      <para>
2192       Prior releases evaluated queries using the explicit
2193       <literal>JOIN</literal> syntax only in the order implied by
2194       the syntax. 7.4 allows full optimization of these queries,
2195       meaning the optimizer considers all possible join orderings
2196       and chooses the most efficient.  Outer joins, however, must
2197       still follow the declared ordering.
2198      </para>
2199     </listitem>
2200    </varlistentry>
2201
2202    <varlistentry>
2203     <term>
2204      Faster and more powerful regular expression code
2205     </term>
2206
2207     <listitem>
2208      <para>
2209       The entire regular expression module has been replaced with a
2210       new version by Henry Spencer, originally written for Tcl.  The
2211       code greatly improves performance and supports several flavors
2212       of regular expressions.
2213      </para>
2214     </listitem>
2215    </varlistentry>
2216
2217    <varlistentry>
2218     <term>
2219      Function-inlining for simple SQL functions
2220     </term>
2221
2222     <listitem>
2223      <para>
2224       Simple SQL functions can now be inlined by including their SQL
2225       in the main query.  This improves performance by eliminating
2226       per-call overhead.  That means simple SQL functions now
2227       behave like macros.
2228      </para>
2229     </listitem>
2230    </varlistentry>
2231
2232    <varlistentry>
2233     <term>
2234      Full support for IPv6 connections and IPv6 address data types
2235     </term>
2236
2237     <listitem>
2238      <para>
2239       Previous releases allowed only IPv4 connections, and the IP
2240       data types only supported IPv4 addresses. This release adds
2241       full IPv6 support in both of these areas.
2242      </para>
2243     </listitem>
2244    </varlistentry>
2245
2246    <varlistentry>
2247     <term>
2248      Major improvements in SSL performance and reliability
2249     </term>
2250
2251     <listitem>
2252      <para>
2253       Several people very familiar with the SSL API have overhauled
2254       our SSL code to improve SSL key negotiation and error
2255       recovery.
2256      </para>
2257     </listitem>
2258    </varlistentry>
2259
2260    <varlistentry>
2261     <term>
2262      Make free space map efficiently reuse empty index pages,
2263      and other free space management improvements
2264     </term>
2265
2266     <listitem>
2267      <para>
2268       In previous releases, B-tree index pages that were left empty
2269       because of deleted rows could only be reused by rows with
2270       index values similar to the rows originally indexed on that
2271       page. In 7.4, <command>VACUUM</command> records empty index
2272       pages and allows them to be reused for any future index rows.
2273      </para>
2274     </listitem>
2275    </varlistentry>
2276
2277    <varlistentry>
2278     <term>
2279      SQL-standard information schema
2280     </term>
2281
2282     <listitem>
2283      <para>
2284       The information schema provides a standardized and stable way
2285       to access information about the schema objects defined in a
2286       database.
2287      </para>
2288     </listitem>
2289    </varlistentry>
2290
2291    <varlistentry>
2292     <term>
2293      Cursors conform more closely to the SQL standard
2294     </term>
2295
2296     <listitem>
2297      <para>
2298       The commands <command>FETCH</command> and
2299       <command>MOVE</command> have been overhauled to conform more
2300       closely to the SQL standard.
2301      </para>
2302     </listitem>
2303    </varlistentry>
2304
2305    <varlistentry>
2306     <term>
2307      Cursors can exist outside transactions
2308     </term>
2309
2310     <listitem>
2311      <para>
2312       These cursors are also called holdable cursors.
2313      </para>
2314     </listitem>
2315    </varlistentry>
2316
2317    <varlistentry>
2318     <term>
2319      New client-to-server protocol
2320     </term>
2321
2322     <listitem>
2323      <para>
2324       The new protocol adds error codes, more status information,
2325       faster startup, better support for binary data transmission,
2326       parameter values separated from SQL commands, prepared
2327       statements available at the protocol level, and cleaner
2328       recovery from <command>COPY</command> failures.  The older
2329       protocol is still supported by both server and clients.
2330      </para>
2331     </listitem>
2332    </varlistentry>
2333
2334    <varlistentry>
2335     <term>
2336      <application>libpq</application> and
2337      <application>ECPG</application> applications are now fully
2338      thread-safe
2339     </term>
2340
2341     <listitem>
2342      <para>
2343       While previous <application>libpq</application> releases
2344       already supported threads, this release improves thread safety
2345       by fixing some non-thread-safe code that was used during
2346       database connection startup.  The <command>configure</command>
2347       option <option>--enable-thread-safety</option> must be used to
2348       enable this feature.
2349      </para>
2350     </listitem>
2351    </varlistentry>
2352
2353    <varlistentry>
2354     <term>
2355      New version of full-text indexing
2356     </term>
2357
2358     <listitem>
2359      <para>
2360       A new full-text indexing suite is available in
2361       <filename>contrib/tsearch2</filename>.
2362      </para>
2363     </listitem>
2364    </varlistentry>
2365
2366    <varlistentry>
2367     <term>
2368      New autovacuum tool
2369     </term>
2370
2371     <listitem>
2372      <para>
2373       The new autovacuum tool in
2374       <filename>contrib/autovacuum</filename> monitors the database
2375       statistics tables for
2376       <command>INSERT</command>/<command>UPDATE</command>/<command>DELETE</command>
2377       activity and automatically vacuums tables when needed.
2378      </para>
2379     </listitem>
2380    </varlistentry>
2381
2382    <varlistentry>
2383     <term>
2384      Array handling has been improved and moved into the server core
2385     </term>
2386
2387     <listitem>
2388      <para>
2389       Many array limitations have been removed, and arrays behave
2390       more like fully-supported data types.
2391      </para>
2392     </listitem>
2393    </varlistentry>
2394
2395   </variablelist>
2396  </sect2>
2397
2398  <sect2>
2399   <title>Migration to Version 7.4</title>
2400
2401   <para>
2402    A dump/restore using <application>pg_dump</application> is
2403    required for those wishing to migrate data from any previous
2404    release.
2405   </para>
2406
2407   <para>
2408    Observe the following incompatibilities:
2409   </para>
2410
2411   <itemizedlist>
2412    <listitem>
2413     <para>
2414      The server-side autocommit setting was removed and
2415      reimplemented in client applications and languages.
2416      Server-side autocommit was causing too many problems with
2417      languages and applications that wanted to control their own
2418      autocommit behavior, so autocommit was removed from the server
2419      and added to individual client APIs as appropriate.
2420     </para>
2421    </listitem>
2422
2423    <listitem>
2424     <para>
2425      Error message wording has changed substantially in this
2426      release.  Significant effort was invested to make the messages
2427      more consistent and user-oriented.  If your applications try to
2428      detect different error conditions by parsing the error message,
2429      you are strongly encouraged to use the new error code facility instead.
2430     </para>
2431    </listitem>
2432
2433    <listitem>
2434     <para>
2435      Inner joins using the explicit <literal>JOIN</literal> syntax
2436      might behave differently because they are now better
2437      optimized.
2438     </para>
2439    </listitem>
2440
2441    <listitem>
2442     <para>
2443      A number of server configuration parameters have been renamed
2444      for clarity, primarily those related to
2445      logging.
2446     </para>
2447    </listitem>
2448
2449    <listitem>
2450     <para>
2451      <literal>FETCH 0</literal> or <literal>MOVE 0</literal> now
2452      does nothing.  In prior releases, <literal>FETCH 0</literal>
2453      would fetch all remaining rows, and <literal>MOVE 0</literal>
2454      would move to the end of the cursor.
2455     </para>
2456    </listitem>
2457
2458    <listitem>
2459     <para>
2460      <command>FETCH</command> and <command>MOVE</command> now return
2461      the actual number of rows fetched/moved, or zero if at the
2462      beginning/end of the cursor.  Prior releases would return the
2463      row count passed to the command, not the number of rows
2464      actually fetched or moved.
2465     </para>
2466    </listitem>
2467
2468    <listitem>
2469     <para>
2470      <command>COPY</command> now can process files that use
2471      carriage-return or carriage-return/line-feed end-of-line
2472      sequences. Literal carriage-returns and line-feeds are no
2473      longer accepted in data values; use <literal>\r</literal> and
2474      <literal>\n</literal> instead.
2475     </para>
2476    </listitem>
2477
2478    <listitem>
2479     <para>
2480      Trailing spaces are now trimmed when converting from type
2481      <type>char(<replaceable>n</>)</type> to
2482      <type>varchar(<replaceable>n</>)</type> or <type>text</type>.
2483      This is what most people always expected to happen anyway.
2484     </para>
2485    </listitem>
2486
2487    <listitem>
2488     <para>
2489      The data type <type>float(<replaceable>p</>)</type> now
2490      measures <replaceable>p</> in binary digits, not decimal
2491      digits.  The new behavior follows the SQL standard.
2492     </para>
2493    </listitem>
2494
2495    <listitem>
2496     <para>
2497      Ambiguous date values now must match the ordering specified by
2498      the <varname>datestyle</varname> setting.  In prior releases, a
2499      date specification of <literal>10/20/03</> was interpreted as a
2500      date in October even if <varname>datestyle</> specified that
2501      the day should be first.  7.4 will throw an error if a date
2502      specification is invalid for the current setting of
2503      <varname>datestyle</>.
2504     </para>
2505    </listitem>
2506
2507    <listitem>
2508     <para>
2509      The functions <function>oidrand</function>,
2510      <function>oidsrand</function>, and
2511      <function>userfntest</function> have been removed.  These
2512      functions were determined to be no longer useful.
2513     </para>
2514    </listitem>
2515
2516    <listitem>
2517     <para>
2518      String literals specifying time-varying date/time values, such
2519      as <literal>'now'</literal> or <literal>'today'</literal> will
2520      no longer work as expected in column default expressions; they
2521      now cause the time of the table creation to be the default, not
2522      the time of the insertion.  Functions such as
2523      <function>now()</>, <function>current_timestamp</>, or
2524      <function>current_date</function> should be used instead.
2525     </para>
2526
2527     <para>
2528      In previous releases, there was special code so that strings
2529      such as <literal>'now'</literal> were interpreted at
2530      <command>INSERT</> time and not at table creation time, but
2531      this work around didn't cover all cases.  Release 7.4 now
2532      requires that defaults be defined properly using functions such
2533      as <function>now()</> or <function>current_timestamp</>. These
2534      will work in all situations.
2535     </para>
2536    </listitem>
2537
2538    <listitem>
2539     <para>
2540      The dollar sign (<literal>$</>) is no longer allowed in
2541      operator names.  It can instead be a non-first character in
2542      identifiers.  This was done to improve compatibility with other
2543      database systems, and to avoid syntax problems when parameter
2544      placeholders (<literal>$<replaceable>n</></>) are written
2545      adjacent to operators.
2546     </para>
2547    </listitem>
2548
2549   </itemizedlist>
2550  </sect2>
2551
2552  <sect2>
2553   <title>Changes</title>
2554
2555   <para>
2556    Below you will find a detailed account of the changes between
2557    release 7.4 and the previous major release.
2558   </para>
2559
2560  <sect3>
2561   <title>Server Operation Changes</title>
2562
2563   <itemizedlist>
2564    <listitem>
2565     <para>
2566      Allow IPv6 server connections (Nigel Kukard, Johan Jordaan,
2567      Bruce, Tom, Kurt Roeckx, Andrew Dunstan)
2568     </para>
2569    </listitem>
2570
2571    <listitem>
2572     <para>
2573      Fix SSL to handle errors cleanly (Nathan Mueller)
2574     </para>
2575     <para>
2576      In prior releases, certain SSL API error reports were not
2577      handled correctly.  This release fixes those problems.
2578     </para>
2579    </listitem>
2580
2581    <listitem>
2582     <para>
2583      SSL protocol security and performance improvements (Sean Chittenden)
2584     </para>
2585     <para>
2586      SSL key renegotiation was happening too frequently, causing poor
2587      SSL performance.  Also, initial key handling was improved.
2588     </para>
2589    </listitem>
2590
2591    <listitem>
2592     <para>
2593      Print lock information when a deadlock is detected (Tom)
2594     </para>
2595     <para>
2596      This allows easier debugging of deadlock situations.
2597     </para>
2598    </listitem>
2599
2600    <listitem>
2601     <para>
2602      Update <filename>/tmp</filename> socket modification times
2603      regularly to avoid their removal (Tom)
2604     </para>
2605     <para>
2606      This should help prevent <filename>/tmp</filename> directory
2607      cleaner administration scripts from removing server socket
2608      files.
2609     </para>
2610    </listitem>
2611
2612    <listitem><para>Enable PAM for Mac OS X (Aaron Hillegass)</para></listitem>
2613
2614    <listitem>
2615     <para>Make B-tree indexes fully WAL-safe (Tom)</para>
2616     <para>
2617      In prior releases, under certain rare cases, a server crash
2618      could cause B-tree indexes to become corrupt. This release
2619      removes those last few rare cases.
2620     </para>
2621    </listitem>
2622
2623    <listitem><para>Allow B-tree index compaction and empty page reuse (Tom)</para></listitem>
2624
2625    <listitem>
2626     <para>
2627      Fix inconsistent index lookups during split of first root page (Tom)
2628     </para>
2629     <para>
2630      In prior releases, when a single-page index split into two
2631      pages, there was a brief period when another database session
2632      could miss seeing an index entry.  This release fixes that rare
2633      failure case.
2634     </para>
2635    </listitem>
2636
2637    <listitem><para>Improve free space map allocation logic (Tom)</para></listitem>
2638
2639    <listitem>
2640     <para>Preserve free space information between server restarts (Tom)</para>
2641     <para>
2642      In prior releases, the free space map was not saved when the
2643      postmaster was stopped, so newly started servers had no free
2644      space information. This release saves the free space map, and
2645      reloads it when the server is restarted.
2646     </para>
2647    </listitem>
2648
2649    <listitem><para>Add start time to <literal>pg_stat_activity</literal> (Neil)</para></listitem>
2650    <listitem><para>New code to detect corrupt disk pages; erase with <varname>zero_damaged_pages</varname> (Tom)</para></listitem>
2651    <listitem><para>New client/server protocol: faster, no username length limit, allow clean exit from <command>COPY</command> (Tom)</para></listitem>
2652    <listitem><para>Add transaction status, table ID, column ID to client/server protocol (Tom)</para></listitem>
2653    <listitem><para>Add binary I/O to client/server protocol (Tom)</para></listitem>
2654    <listitem><para>Remove autocommit server setting; move to client applications (Tom)</para></listitem>
2655    <listitem><para>New error message wording, error codes, and three levels of error detail (Tom, Joe, Peter)</para></listitem>
2656   </itemizedlist>
2657  </sect3>
2658
2659  <sect3>
2660   <title>Performance Improvements</title>
2661
2662   <itemizedlist>
2663    <listitem><para>Add hashing for <literal>GROUP BY</literal> aggregates (Tom)</para></listitem>
2664    <listitem><para>Make nested-loop joins be smarter about multicolumn indexes (Tom)</para></listitem>
2665    <listitem><para>Allow multikey hash joins (Tom)</para></listitem>
2666    <listitem><para>Improve constant folding (Tom)</para></listitem>
2667    <listitem><para>Add ability to inline simple SQL functions (Tom)</para></listitem>
2668
2669    <listitem>
2670     <para>Reduce memory usage for queries using complex functions (Tom)</para>
2671     <para>
2672      In prior releases, functions returning allocated memory would
2673      not free it until the query completed. This release allows the
2674      freeing of function-allocated memory when the function call
2675      completes, reducing the total memory used by functions.
2676     </para>
2677    </listitem>
2678
2679    <listitem>
2680     <para>Improve GEQO optimizer performance (Tom)</para>
2681     <para>
2682      This release fixes several inefficiencies in the way the GEQO optimizer
2683      manages potential query paths.
2684     </para>
2685    </listitem>
2686
2687    <listitem>
2688     <para>
2689      Allow <literal>IN</>/<literal>NOT IN</> to be handled via hash
2690      tables (Tom)
2691     </para>
2692    </listitem>
2693
2694    <listitem>
2695     <para>
2696      Improve <literal>NOT IN (<replaceable>subquery</>)</literal>
2697      performance (Tom)
2698     </para>
2699    </listitem>
2700
2701    <listitem>
2702     <para>
2703      Allow most <literal>IN</literal> subqueries to be processed as
2704      joins (Tom)
2705     </para>
2706    </listitem>
2707
2708    <listitem>
2709     <para>
2710      Pattern matching operations can use indexes regardless of
2711      locale (Peter)
2712     </para>
2713     <para>
2714      There is no way for non-ASCII locales to use the standard
2715      indexes for <literal>LIKE</literal> comparisons. This release
2716      adds a way to create a special index for
2717      <literal>LIKE</literal>.
2718     </para>
2719    </listitem>
2720
2721    <listitem>
2722     <para>Allow the postmaster to preload libraries using <varname>preload_libraries</varname> (Joe)</para>
2723     <para>
2724      For shared libraries that require a long time to load, this
2725      option is available so the library can be preloaded in the
2726      postmaster and inherited by all database sessions.
2727     </para>
2728    </listitem>
2729
2730    <listitem>
2731     <para>
2732      Improve optimizer cost computations, particularly for subqueries (Tom)
2733     </para>
2734    </listitem>
2735
2736    <listitem>
2737     <para>
2738      Avoid sort when subquery <literal>ORDER BY</literal> matches upper query (Tom)
2739     </para>
2740    </listitem>
2741
2742    <listitem>
2743     <para>
2744      Deduce that <literal>WHERE a.x = b.y AND b.y = 42</literal> also
2745      means <literal>a.x = 42</literal> (Tom)
2746     </para>
2747    </listitem>
2748
2749    <listitem>
2750     <para>
2751      Allow hash/merge joins on complex joins (Tom)
2752     </para>
2753    </listitem>
2754
2755    <listitem>
2756     <para>
2757      Allow hash joins for more data types (Tom)
2758     </para>
2759    </listitem>
2760
2761    <listitem>
2762     <para>
2763      Allow join optimization of explicit inner joins, disable with
2764      <varname>join_collapse_limit</varname> (Tom)
2765     </para>
2766    </listitem>
2767
2768    <listitem>
2769     <para>
2770      Add parameter <varname>from_collapse_limit</varname> to control
2771      conversion of subqueries to joins (Tom)
2772     </para>
2773    </listitem>
2774
2775    <listitem>
2776     <para>
2777      Use faster and more powerful regular expression code from Tcl
2778      (Henry Spencer, Tom)
2779     </para>
2780    </listitem>
2781
2782    <listitem>
2783     <para>
2784      Use bit-mapped relation sets in the optimizer (Tom)
2785     </para>
2786    </listitem>
2787
2788    <listitem>
2789     <para>Improve connection startup time (Tom)</para>
2790     <para>
2791      The new client/server protocol requires fewer network packets to
2792      start a database session.
2793     </para>
2794    </listitem>
2795
2796    <listitem>
2797     <para>
2798      Improve trigger/constraint performance (Stephan)
2799     </para>
2800    </listitem>
2801
2802    <listitem>
2803     <para>
2804      Improve speed of <literal>col IN (const, const, const, ...)</literal> (Tom)
2805     </para>
2806    </listitem>
2807
2808    <listitem>
2809     <para>
2810      Fix hash indexes which were broken in rare cases (Tom)
2811     </para>
2812    </listitem>
2813
2814    <listitem><para>Improve hash index concurrency and speed (Tom)</para>
2815     <para>
2816      Prior releases suffered from poor hash index performance,
2817      particularly for high concurrency situations. This release fixes
2818      that, and the development group is interested in reports
2819      comparing B-tree and hash index performance.
2820     </para>
2821    </listitem>
2822
2823    <listitem>
2824     <para>Align shared buffers on 32-byte boundary for copy speed improvement (Manfred Spraul)</para>
2825     <para>
2826      Certain CPU's perform faster data copies when addresses are
2827      32-byte aligned.
2828     </para>
2829    </listitem>
2830
2831    <listitem>
2832     <para>Data type <type>numeric</type> reimplemented for better performance (Tom)</para>
2833     <para>
2834      <type>numeric</type> used to be stored in base 100. The new code
2835      uses base 10000, for significantly better performance.
2836     </para>
2837    </listitem>
2838   </itemizedlist>
2839  </sect3>
2840
2841  <sect3>
2842   <title>Server Configuration Changes</title>
2843
2844   <itemizedlist>
2845    <listitem>
2846     <para>Rename server parameter <varname>server_min_messages</> to <varname>log_min_messages</> (Bruce)</para>
2847     <para>
2848      This was done so most parameters that control the server logs
2849      begin with <literal>log_</>.
2850     </para>
2851    </listitem>
2852
2853    <listitem><para>Rename <varname>show_*_stats</> to <varname>log_*_stats</> (Bruce)</para></listitem>
2854    <listitem><para>Rename <varname>show_source_port</> to <varname>log_source_port</> (Bruce)</para></listitem>
2855    <listitem><para>Rename <varname>hostname_lookup</> to <varname>log_hostname</> (Bruce)</para></listitem>
2856
2857    <listitem>
2858     <para>Add <varname>checkpoint_warning</> to warn of excessive checkpointing (Bruce)</para>
2859     <para>
2860      In prior releases, it was difficult to determine if checkpoint
2861      was happening too frequently. This feature adds a warning to the
2862      server logs when excessive checkpointing happens.
2863     </para>
2864    </listitem>
2865
2866    <listitem><para>New read-only server parameters for localization (Tom)</para></listitem>
2867
2868    <listitem>
2869     <para>
2870      Change debug server log messages to output as <literal>DEBUG</>
2871      rather than <literal>LOG</> (Bruce)
2872     </para>
2873    </listitem>
2874
2875    <listitem>
2876     <para>Prevent server log variables from being turned off by non-superusers (Bruce)</para>
2877     <para>
2878      This is a security feature so non-superusers cannot disable
2879      logging that was enabled by the administrator.
2880     </para>
2881    </listitem>
2882
2883    <listitem>
2884     <para>
2885      <varname>log_min_messages</>/<varname>client_min_messages</> now
2886      controls <varname>debug_*</> output (Bruce)
2887     </para>
2888     <para>
2889      This centralizes client debug information so all debug output
2890      can be sent to either the client or server logs.
2891     </para>
2892    </listitem>
2893
2894    <listitem>
2895     <para>Add Mac OS X Rendezvous server support (Chris Campbell)</para>
2896     <para>
2897      This allows Mac OS X hosts to query the network for available
2898      <productname>PostgreSQL</productname> servers.
2899     </para>
2900    </listitem>
2901
2902    <listitem>
2903     <para>
2904      Add ability to print only slow statements using
2905      <varname>log_min_duration_statement</varname>
2906      (Christopher)
2907     </para>
2908     <para>
2909      This is an often requested debugging feature that allows
2910      administrators to see only slow queries in their server logs.
2911     </para>
2912    </listitem>
2913
2914    <listitem>
2915     <para>Allow <filename>pg_hba.conf</filename> to accept netmasks in CIDR format (Andrew Dunstan)</para>
2916     <para>
2917      This allows administrators to merge the host IP address and
2918      netmask fields into a single CIDR field in <filename>pg_hba.conf</filename>.
2919     </para>
2920    </listitem>
2921
2922    <listitem><para>New read-only parameter <varname>is_superuser</varname> (Tom)</para></listitem>
2923
2924    <listitem>
2925     <para>New parameter <varname>log_error_verbosity</varname> to control error detail (Tom)</para>
2926     <para>
2927      This works with the new error reporting feature to supply
2928      additional error information like hints, file names and line
2929      numbers.
2930     </para>
2931    </listitem>
2932
2933    <listitem>
2934     <para><literal>postgres --describe-config</literal> now dumps server config variables (Aizaz Ahmed, Peter)</para>
2935     <para>
2936      This option is useful for administration tools that need to know
2937      the configuration variable names and their minimums, maximums,
2938      defaults, and descriptions.
2939     </para>
2940    </listitem>
2941
2942    <listitem>
2943     <para>
2944      Add new columns in <literal>pg_settings</literal>:
2945      <literal>context</>, <literal>type</>, <literal>source</>,
2946      <literal>min_val</>, <literal>max_val</> (Joe)
2947     </para>
2948    </listitem>
2949
2950    <listitem>
2951     <para>
2952      Make default <varname>shared_buffers</> 1000 and
2953      <varname>max_connections</> 100, if possible (Tom)
2954     </para>
2955     <para>
2956      Prior versions defaulted to 64 shared buffers so <productname>PostgreSQL</productname>
2957      would start on even very old systems. This release tests the
2958      amount of shared memory allowed by the platform and selects more
2959      reasonable default values if possible.  Of course, users are
2960      still encouraged to evaluate their resource load and size
2961      <varname>shared_buffers</varname> accordingly.
2962     </para>
2963    </listitem>
2964
2965    <listitem>
2966     <para>
2967      New <filename>pg_hba.conf</filename> record type
2968      <literal>hostnossl</> to prevent SSL connections (Jon
2969      Jensen)
2970     </para>
2971     <para>
2972      In prior releases, there was no way to prevent SSL connections
2973      if both the client and server supported SSL. This option allows
2974      that capability.
2975     </para>
2976    </listitem>
2977
2978    <listitem>
2979     <para>
2980      Remove parameter <varname>geqo_random_seed</varname>
2981      (Tom)
2982     </para>
2983    </listitem>
2984
2985    <listitem>
2986     <para>
2987      Add server parameter <varname>regex_flavor</varname> to control regular expression processing (Tom)
2988     </para>
2989    </listitem>
2990
2991    <listitem>
2992     <para>
2993      Make <command>pg_ctl</command> better handle nonstandard ports (Greg)
2994     </para>
2995    </listitem>
2996   </itemizedlist>
2997  </sect3>
2998
2999  <sect3>
3000   <title>Query Changes</title>
3001
3002   <itemizedlist>
3003    <listitem><para>New SQL-standard information schema (Peter)</para></listitem>
3004    <listitem><para>Add read-only transactions (Peter)</para></listitem>
3005    <listitem><para>Print key name and value in foreign-key violation messages (Dmitry Tkach)</para></listitem>
3006
3007    <listitem>
3008     <para>Allow users to see their own queries in <literal>pg_stat_activity</literal> (Kevin Brown)</para>
3009     <para>
3010      In prior releases, only the superuser could see query strings
3011      using <literal>pg_stat_activity</literal>. Now ordinary users
3012      can see their own query strings.
3013     </para>
3014    </listitem>
3015
3016    <listitem>
3017     <para>Fix aggregates in subqueries to match SQL standard (Tom)</para>
3018     <para>
3019      The SQL standard says that an aggregate function appearing
3020      within a nested subquery belongs to the outer query if its
3021      argument contains only outer-query variables.  Prior
3022      <productname>PostgreSQL</productname> releases did not handle
3023      this fine point correctly.
3024     </para>
3025    </listitem>
3026
3027    <listitem>
3028     <para>Add option to prevent auto-addition of tables referenced in query (Nigel J. Andrews)</para>
3029     <para>
3030      By default, tables mentioned in the query are automatically
3031      added to the <literal>FROM</> clause if they are not already
3032      there.  This is compatible with historic
3033      <productname>POSTGRES</productname> behavior but is contrary to
3034      the SQL standard.  This option allows selecting
3035      standard-compatible behavior.
3036     </para>
3037    </listitem>
3038
3039    <listitem>
3040     <para>Allow <literal>UPDATE ... SET col = DEFAULT</literal> (Rod)</para>
3041     <para>
3042      This allows <command>UPDATE</command> to set a column to its
3043      declared default value.
3044     </para>
3045    </listitem>
3046
3047    <listitem>
3048     <para>Allow expressions to be used in <literal>LIMIT</>/<literal>OFFSET</> (Tom)</para>
3049     <para>
3050      In prior releases, <literal>LIMIT</>/<literal>OFFSET</> could
3051      only use constants, not expressions.
3052     </para>
3053    </listitem>
3054
3055    <listitem>
3056     <para>Implement <literal>CREATE TABLE AS EXECUTE</literal> (Neil, Peter)</para>
3057    </listitem>
3058   </itemizedlist>
3059  </sect3>
3060
3061  <sect3>
3062   <title>Object Manipulation Changes</title>
3063
3064   <itemizedlist>
3065    <listitem>
3066     <para>Make <command>CREATE SEQUENCE</command> grammar more conforming to SQL:2003 (Neil)</para>
3067    </listitem>
3068
3069    <listitem>
3070     <para>Add statement-level triggers (Neil)</para>
3071     <para>
3072      While this allows a trigger to fire at the end of a statement,
3073      it does not allow the trigger to access all rows modified by the
3074      statement.  This capability is planned for a future release.
3075     </para>
3076    </listitem>
3077
3078    <listitem>
3079     <para>Add check constraints for domains (Rod)</para>
3080     <para>
3081      This greatly increases the usefulness of domains by allowing
3082      them to use check constraints.
3083     </para>
3084    </listitem>
3085
3086    <listitem>
3087     <para>Add <command>ALTER DOMAIN</command> (Rod)</para>
3088     <para>
3089      This allows manipulation of existing domains.
3090     </para>
3091    </listitem>
3092
3093    <listitem>
3094     <para>Fix several zero-column table bugs (Tom)</para>
3095     <para>
3096      <productname>PostgreSQL</productname> supports zero-column tables. This fixes various bugs
3097      that occur when using such tables.
3098     </para>
3099    </listitem>
3100
3101    <listitem>
3102     <para>Have <literal>ALTER TABLE ... ADD PRIMARY KEY</literal> add not-null constraint (Rod)</para>
3103     <para>
3104      In prior releases, <literal>ALTER TABLE ... ADD
3105      PRIMARY</literal> would add a unique index, but not a not-null
3106      constraint.  That is fixed in this release.
3107     </para>
3108    </listitem>
3109
3110    <listitem><para>Add <literal>ALTER TABLE ... WITHOUT OIDS</literal> (Rod)</para>
3111     <para>
3112      This allows control over whether new and updated rows will have
3113      an OID column.  This is most useful for saving storage space.
3114     </para>
3115    </listitem>
3116
3117    <listitem>
3118     <para>
3119      Add <literal>ALTER SEQUENCE</literal> to modify minimum, maximum,
3120      increment, cache, cycle values (Rod)
3121     </para>
3122    </listitem>
3123
3124    <listitem>
3125     <para>Add <literal>ALTER TABLE ... CLUSTER ON</literal> (Alvaro Herrera)</para>
3126     <para>
3127      This command is used by <command>pg_dump</command> to record the
3128      cluster column for each table previously clustered. This
3129      information is used by database-wide cluster to cluster all
3130      previously clustered tables.
3131     </para>
3132    </listitem>
3133
3134    <listitem><para>Improve automatic type casting for domains (Rod, Tom)</para></listitem>
3135    <listitem><para>Allow dollar signs in identifiers, except as first character (Tom)</para></listitem>
3136    <listitem><para>Disallow dollar signs in operator names, so <literal>x=$1</> works (Tom)</para></listitem>
3137
3138    <listitem>
3139     <para>
3140      Allow copying table schema using <literal>LIKE
3141      <replaceable>subtable</replaceable></literal>, also SQL:2003
3142      feature <literal>INCLUDING DEFAULTS</literal> (Rod)
3143     </para>
3144    </listitem>
3145
3146    <listitem>
3147     <para>
3148      Add <literal>WITH GRANT OPTION</literal> clause to
3149      <command>GRANT</command> (Peter)
3150     </para>
3151     <para>
3152      This enabled <command>GRANT</command> to give other users the
3153      ability to grant privileges on a object.
3154     </para>
3155    </listitem>
3156   </itemizedlist>
3157  </sect3>
3158
3159  <sect3>
3160   <title>Utility Command Changes</title>
3161
3162   <itemizedlist>
3163    <listitem>
3164     <para>Add <literal>ON COMMIT</literal> clause to <command>CREATE TABLE</command> for temporary tables (Gavin)</para>
3165     <para>
3166      This adds the ability for a table to be dropped or all rows
3167      deleted on transaction commit.
3168     </para>
3169    </listitem>
3170
3171    <listitem>
3172     <para>Allow cursors outside transactions using <literal>WITH HOLD</literal> (Neil)</para>
3173     <para>
3174      In previous releases, cursors were removed at the end of the
3175      transaction that created them. Cursors can now be created with
3176      the <literal>WITH HOLD</literal> option, which allows them to
3177      continue to be accessed after the creating transaction has
3178      committed.
3179     </para>
3180    </listitem>
3181
3182    <listitem>
3183     <para><literal>FETCH 0</literal> and <literal>MOVE 0 </literal> now do nothing (Bruce)</para>
3184     <para>
3185      In previous releases, <literal>FETCH 0</literal> fetched all
3186      remaining rows, and <literal>MOVE 0</literal> moved to the end
3187      of the cursor.
3188     </para>
3189    </listitem>
3190
3191    <listitem>
3192     <para>
3193      Cause <command>FETCH</command> and <command>MOVE</command> to
3194      return the number of rows fetched/moved, or zero if at the
3195      beginning/end of cursor, per SQL standard (Bruce)
3196     </para>
3197     <para>
3198      In prior releases, the row count returned by
3199      <command>FETCH</command> and <command>MOVE</command> did not
3200      accurately reflect the number of rows processed.
3201     </para>
3202    </listitem>
3203
3204    <listitem>
3205     <para>Properly handle <literal>SCROLL</literal> with cursors, or
3206     report an error (Neil)</para>
3207     <para>
3208      Allowing random access (both forward and backward scrolling) to
3209      some kinds of queries cannot be done without some additional
3210      work. If <literal>SCROLL</literal> is specified when the cursor
3211      is created, this additional work will be performed. Furthermore,
3212      if the cursor has been created with <literal>NO SCROLL</literal>,
3213      no random access is allowed.
3214     </para>
3215    </listitem>
3216
3217    <listitem>
3218     <para>
3219      Implement SQL-compatible options <literal>FIRST</>,
3220      <literal>LAST</>, <literal>ABSOLUTE <replaceable>n</></>,
3221      <literal>RELATIVE <replaceable>n</></> for
3222      <command>FETCH</command> and <command>MOVE</command> (Tom)
3223     </para>
3224    </listitem>
3225
3226    <listitem>
3227     <para>Allow <command>EXPLAIN</command> on <command>DECLARE CURSOR</command> (Tom)</para>
3228    </listitem>
3229
3230    <listitem>
3231     <para>Allow <command>CLUSTER</command> to use index marked as pre-clustered by default (Alvaro Herrera)</para>
3232    </listitem>
3233
3234    <listitem>
3235     <para>Allow <command>CLUSTER</command> to cluster all tables (Alvaro Herrera)</para>
3236     <para>
3237      This allows all previously clustered tables in a database to be
3238      reclustered with a single command.
3239     </para>
3240    </listitem>
3241
3242    <listitem><para>Prevent <command>CLUSTER</command> on partial indexes (Tom)</para></listitem>
3243
3244    <listitem><para>Allow DOS and Mac line-endings in <command>COPY</> files (Bruce)</para></listitem>
3245
3246    <listitem>
3247     <para>
3248      Disallow literal carriage return as a data value,
3249      backslash-carriage-return and <literal>\r</> are still allowed
3250      (Bruce)
3251     </para>
3252    </listitem>
3253
3254    <listitem>
3255     <para><command>COPY</> changes (binary, <literal>\.</>) (Tom)</para>
3256    </listitem>
3257
3258    <listitem>
3259     <para>Recover from <command>COPY</command> failure cleanly (Tom)</para>
3260    </listitem>
3261
3262    <listitem>
3263     <para>Prevent possible memory leaks in <command>COPY</command> (Tom)</para>
3264    </listitem>
3265
3266    <listitem>
3267     <para>Make <command>TRUNCATE</command> transaction-safe (Rod)</para>
3268     <para>
3269      <command>TRUNCATE</command> can now be used inside a
3270      transaction. If the transaction aborts, the changes made by the
3271      <command>TRUNCATE</command> are automatically rolled back.
3272     </para>
3273    </listitem>
3274
3275    <listitem>
3276     <para>
3277      Allow prepare/bind of utility commands like
3278      <command>FETCH</command> and <command>EXPLAIN</command> (Tom)
3279     </para>
3280    </listitem>
3281
3282    <listitem>
3283     <para>Add <command>EXPLAIN EXECUTE</command> (Neil)</para>
3284    </listitem>
3285
3286    <listitem>
3287     <para>Improve <command>VACUUM</command> performance on indexes by reducing WAL traffic (Tom)</para>
3288    </listitem>
3289
3290    <listitem>
3291     <para>Functional indexes have been generalized into indexes on expressions (Tom)</para>
3292     <para>
3293      In prior releases, functional indexes only supported a simple
3294      function applied to one or more column names.  This release
3295      allows any type of scalar expression.
3296     </para>
3297    </listitem>
3298
3299    <listitem>
3300     <para>
3301      Have <command>SHOW TRANSACTION ISOLATION</command> match input
3302      to <command>SET TRANSACTION ISOLATION</command>
3303      (Tom)
3304     </para>
3305    </listitem>
3306
3307    <listitem>
3308     <para>
3309       Have <command>COMMENT ON DATABASE</command> on nonlocal
3310       database generate a warning, rather than an error (Rod)
3311      </para>
3312
3313     <para>
3314      Database comments are stored in database-local tables so
3315      comments on a database have to be stored in each database.
3316     </para>
3317    </listitem>
3318
3319    <listitem>
3320     <para>
3321      Improve reliability of <command>LISTEN</>/<command>NOTIFY</> (Tom)
3322     </para>
3323    </listitem>
3324
3325    <listitem>
3326     <para>Allow <command>REINDEX</command> to reliably reindex nonshared system catalog indexes (Tom)</para>
3327     <para>
3328      This allows system tables to be reindexed without the
3329      requirement of a standalone session, which was necessary in
3330      previous releases. The only tables that now require a standalone
3331      session for reindexing are the global system tables
3332      <literal>pg_database</>, <literal>pg_shadow</>, and
3333      <literal>pg_group</>.
3334     </para>
3335    </listitem>
3336   </itemizedlist>
3337  </sect3>
3338
3339  <sect3>
3340   <title>Data Type and Function Changes</title>
3341
3342   <itemizedlist>
3343    <listitem>
3344     <para>
3345      New server parameter <varname>extra_float_digits</varname> to
3346      control precision display of floating-point numbers (Pedro
3347      Ferreira, Tom)
3348     </para>
3349     <para>
3350      This controls output precision which was causing regression
3351      testing problems.
3352     </para>
3353    </listitem>
3354
3355    <listitem><para>Allow <literal>+1300</literal> as a numeric time-zone specifier, for FJST (Tom)</para></listitem>
3356
3357    <listitem>
3358     <para>
3359      Remove rarely used functions <function>oidrand</>,
3360      <function>oidsrand</>, and <function>userfntest</> functions
3361      (Neil)
3362     </para>
3363    </listitem>
3364
3365    <listitem>
3366     <para>Add <function>md5()</> function to main server, already in <filename>contrib/pgcrypto</filename> (Joe)</para>
3367     <para>
3368      An MD5 function was frequently requested. For more complex
3369      encryption capabilities, use
3370      <filename>contrib/pgcrypto</filename>.
3371     </para>
3372    </listitem>
3373
3374    <listitem><para>Increase date range of <type>timestamp</type> (John Cochran)</para></listitem>
3375
3376    <listitem>
3377     <para>
3378      Change <literal>EXTRACT(EPOCH FROM timestamp)</literal> so
3379      <type>timestamp without time zone</type> is assumed to be in
3380      local time, not GMT (Tom)
3381     </para>
3382    </listitem>
3383
3384    <listitem><para>Trap division by zero in case the operating system doesn't prevent it (Tom)</para></listitem>
3385    <listitem><para>Change the <type>numeric</type> data type internally to base 10000 (Tom)</para></listitem>
3386    <listitem><para>New <function>hostmask()</function> function (Greg Wickham)</para></listitem>
3387    <listitem><para>Fixes for <function>to_char()</function> and <function>to_timestamp()</function> (Karel)</para></listitem>
3388
3389    <listitem>
3390     <para>
3391      Allow functions that can take any argument data type and return
3392      any data type, using <type>anyelement</type> and
3393      <type>anyarray</type> (Joe)
3394     </para>
3395     <para>
3396      This allows the creation of functions that can work with any
3397      data type.
3398     </para>
3399    </listitem>
3400
3401    <listitem>
3402     <para>
3403      Arrays can now be specified as <literal>ARRAY[1,2,3]</literal>,
3404      <literal>ARRAY[['a','b'],['c','d']]</literal>, or
3405      <literal>ARRAY[ARRAY[ARRAY[2]]]</literal> (Joe)
3406     </para>
3407    </listitem>
3408
3409    <listitem>
3410     <para>
3411      Allow proper comparisons for arrays, including <literal>ORDER
3412      BY</literal> and <literal>DISTINCT</literal> support
3413      (Joe)
3414     </para>
3415    </listitem>
3416
3417    <listitem><para>Allow indexes on array columns (Joe)</para></listitem>
3418    <listitem><para>Allow array concatenation with <literal>||</literal> (Joe)</para></listitem>
3419
3420    <listitem>
3421     <para>
3422      Allow <literal>WHERE</literal> qualification
3423      <literal><replaceable>expr</> <replaceable>op</> ANY/SOME/ALL
3424      (<replaceable>array_expr</>)</literal> (Joe)
3425     </para>
3426     <para>
3427      This allows arrays to behave like a list of values, for purposes
3428      like <literal>SELECT * FROM tab WHERE col IN
3429      (array_val)</literal>.
3430     </para>
3431    </listitem>
3432
3433    <listitem>
3434     <para>
3435      New array functions <function>array_append</>,
3436      <function>array_cat</>, <function>array_lower</>,
3437      <function>array_prepend</>, <function>array_to_string</>,
3438      <function>array_upper</>, <function>string_to_array</> (Joe)
3439     </para>
3440    </listitem>
3441
3442    <listitem><para>Allow user defined aggregates to use polymorphic functions (Joe)</para></listitem>
3443    <listitem><para>Allow assignments to empty arrays (Joe)</para></listitem>
3444
3445    <listitem>
3446     <para>
3447      Allow 60 in seconds fields of <type>time</type>,
3448      <type>timestamp</type>, and <type>interval</type> input values
3449      (Tom)
3450     </para>
3451     <para>
3452      Sixty-second values are needed for leap seconds.
3453     </para>
3454    </listitem>
3455
3456    <listitem><para>Allow <type>cidr</type> data type to be cast to <type>text</type> (Tom)</para></listitem>
3457
3458    <listitem><para>Disallow invalid time zone names in SET TIMEZONE</para></listitem>
3459
3460    <listitem>
3461     <para>
3462      Trim trailing spaces when <type>char</type> is cast to
3463      <type>varchar</> or <type>text</> (Tom)
3464     </para>
3465    </listitem>
3466
3467    <listitem>
3468     <para>
3469      Make <type>float(<replaceable>p</>)</> measure the precision
3470      <replaceable>p</> in binary digits, not decimal digits
3471      (Tom)
3472     </para>
3473    </listitem>
3474
3475    <listitem>
3476     <para>Add IPv6 support to the <type>inet</type> and <type>cidr</type> data types (Michael Graff)</para>
3477    </listitem>
3478
3479    <listitem>
3480     <para>Add <function>family()</function> function to report whether address is IPv4 or IPv6 (Michael Graff)</para>
3481    </listitem>
3482
3483    <listitem>
3484     <para>
3485      Have <literal>SHOW datestyle</literal> generate output similar
3486      to that used by <literal>SET datestyle</literal> (Tom)
3487     </para>
3488    </listitem>
3489
3490    <listitem>
3491     <para>
3492      Make <literal>EXTRACT(TIMEZONE)</literal> and <literal>SET/SHOW
3493      TIME ZONE</literal> follow the SQL convention for the sign of
3494      time zone offsets, i.e., positive is east from UTC (Tom)
3495     </para>
3496    </listitem>
3497
3498    <listitem>
3499     <para>Fix <literal>date_trunc('quarter', ...)</literal> (Böjthe Zoltán)</para>
3500     <para>
3501      Prior releases returned an incorrect value for this function call.
3502     </para>
3503    </listitem>
3504
3505    <listitem>
3506     <para>Make <function>initcap()</function> more compatible with Oracle (Mike Nolan)</para>
3507     <para>
3508      <function>initcap()</function> now uppercases a letter appearing
3509      after any non-alphanumeric character, rather than only after
3510      whitespace.
3511     </para>
3512    </listitem>
3513
3514    <listitem>
3515     <para>Allow only <varname>datestyle</varname> field order for date values not in ISO-8601 format (Greg)</para>
3516    </listitem>
3517
3518    <listitem>
3519     <para>
3520      Add new <varname>datestyle</varname> values <literal>MDY</>,
3521      <literal>DMY</>, and <literal>YMD</> to set input field order;
3522      honor <literal>US</> and <literal>European</> for backward
3523      compatibility (Tom)
3524     </para>
3525    </listitem>
3526
3527    <listitem>
3528     <para>
3529      String literals like <literal>'now'</literal> or
3530      <literal>'today'</literal> will no longer work as a column
3531      default. Use functions such as <function>now()</function>,
3532      <function>current_timestamp</function> instead.  (change
3533      required for prepared statements) (Tom)
3534     </para>
3535    </listitem>
3536
3537    <listitem>
3538     <para>Treat NaN as larger than any other value in <function>min()</>/<function>max()</> (Tom)</para>
3539     <para>
3540      NaN was already sorted after ordinary numeric values for most
3541      purposes, but <function>min()</> and <function>max()</> didn't
3542      get this right.
3543     </para>
3544    </listitem>
3545
3546    <listitem>
3547     <para>Prevent interval from suppressing <literal>:00</literal>
3548     seconds display</para>
3549    </listitem>
3550
3551    <listitem>
3552     <para>
3553      New functions <function>pg_get_triggerdef(prettyprint)</function>
3554      and <function>pg_conversion_is_visible()</function> (Christopher)
3555     </para>
3556    </listitem>
3557
3558    <listitem>
3559     <para>Allow time to be specified as <literal>040506</> or <literal>0405</> (Tom)</para>
3560    </listitem>
3561
3562    <listitem>
3563     <para>
3564      Input date order must now be <literal>YYYY-MM-DD</literal> (with 4-digit year) or
3565      match <varname>datestyle</varname>
3566     </para>
3567    </listitem>
3568
3569    <listitem>
3570     <para>
3571      Make <function>pg_get_constraintdef</function> support
3572      unique, primary-key, and check constraints (Christopher)
3573     </para>
3574    </listitem>
3575   </itemizedlist>
3576  </sect3>
3577
3578  <sect3>
3579   <title>Server-Side Language Changes</title>
3580
3581   <itemizedlist>
3582    <listitem>
3583     <para>
3584      Prevent PL/pgSQL crash when <literal>RETURN NEXT</literal> is
3585      used on a zero-row record variable (Tom)
3586     </para>
3587    </listitem>
3588
3589    <listitem>
3590     <para>
3591      Make PL/Python's <function>spi_execute</function> interface
3592      handle null values properly (Andrew Bosma)
3593     </para>
3594    </listitem>
3595
3596    <listitem>
3597     <para>Allow PL/pgSQL to declare variables of composite types without <literal>%ROWTYPE</literal> (Tom)</para>
3598    </listitem>
3599
3600    <listitem>
3601     <para>Fix PL/Python's <function>_quote()</function> function to handle big integers</para>
3602    </listitem>
3603
3604    <listitem>
3605     <para>Make PL/Python an untrusted language, now called <literal>plpythonu</literal> (Kevin Jacobs, Tom)</para>
3606     <para>
3607      The Python language no longer supports a restricted execution
3608      environment, so the trusted version of PL/Python was removed. If
3609      this situation changes, a version of PL/Python that can be used
3610      by non-superusers will be readded.
3611     </para>
3612    </listitem>
3613
3614    <listitem>
3615     <para>Allow polymorphic PL/pgSQL functions (Joe, Tom)</para>
3616    </listitem>
3617
3618    <listitem>
3619     <para>Allow polymorphic SQL functions (Joe)</para>
3620    </listitem>
3621
3622    <listitem>
3623     <para>
3624      Improved compiled function caching mechanism in PL/pgSQL with
3625      full support for polymorphism (Joe)
3626     </para>
3627    </listitem>
3628
3629    <listitem>
3630     <para>
3631      Add new parameter <literal>$0</> in PL/pgSQL representing the
3632      function's actual return type (Joe)
3633     </para>
3634    </listitem>
3635
3636    <listitem>
3637     <para>
3638      Allow PL/Tcl and PL/Python to use the same trigger on multiple tables (Tom)
3639     </para>
3640    </listitem>
3641
3642    <listitem>
3643     <para>
3644      Fixed PL/Tcl's <function>spi_prepare</function> to accept fully
3645      qualified type names in the parameter type list
3646      (Jan)
3647     </para>
3648    </listitem>
3649   </itemizedlist>
3650  </sect3>
3651
3652  <sect3>
3653   <title>psql Changes</title>
3654
3655   <itemizedlist>
3656    <listitem>
3657     <para>Add <literal>\pset pager always</literal> to always use pager (Greg)</para>
3658     <para>
3659      This forces the pager to be used even if the number of rows is
3660      less than the screen height.  This is valuable for rows that
3661      wrap across several screen rows.
3662     </para>
3663    </listitem>
3664
3665    <listitem><para>Improve tab completion (Rod, Ross Reedstrom, Ian Barwick)</para></listitem>
3666    <listitem><para>Reorder <literal>\?</> help into groupings (Harald Armin Massa, Bruce)</para></listitem>
3667    <listitem><para>Add backslash commands for listing schemas, casts, and conversions (Christopher)</para></listitem>
3668
3669    <listitem>
3670     <para>
3671      <command>\encoding</> now changes based on the server parameter
3672      <varname>client_encoding</varname> (Tom)
3673     </para>
3674     <para>
3675      In previous versions, <command>\encoding</command> was not aware
3676      of encoding changes made using <literal>SET
3677      client_encoding</literal>.
3678     </para>
3679    </listitem>
3680
3681    <listitem>
3682     <para>Save editor buffer into readline history (Ross)</para>
3683     <para>
3684      When <command>\e</> is used to edit a query, the result is saved
3685      in the readline history for retrieval using the up arrow.
3686     </para>
3687    </listitem>
3688
3689    <listitem><para>Improve <command>\d</command> display (Christopher)</para></listitem>
3690    <listitem><para>Enhance HTML mode to be more standards-conforming (Greg)</para></listitem>
3691
3692    <listitem>
3693     <para>New <command>\set AUTOCOMMIT off</command> capability (Tom)</para>
3694     <para>
3695      This takes the place of the removed server parameter <varname>autocommit</varname>.
3696     </para>
3697    </listitem>
3698
3699    <listitem>
3700     <para>New <command>\set VERBOSITY</command> to control error detail (Tom)</para>
3701     <para>
3702      This controls the new error reporting details.
3703     </para>
3704    </listitem>
3705
3706    <listitem><para>New prompt escape sequence <literal>%x</literal> to show transaction status (Tom)</para></listitem>
3707    <listitem><para>Long options for <application>psql</application> are now available on all platforms</para></listitem>
3708   </itemizedlist>
3709  </sect3>
3710
3711  <sect3>
3712   <title>pg_dump Changes</title>
3713
3714   <itemizedlist>
3715    <listitem><para>Multiple pg_dump fixes, including tar format and large objects</para></listitem>
3716    <listitem><para>Allow pg_dump to dump specific schemas (Neil)</para></listitem>
3717
3718    <listitem>
3719     <para>Make pg_dump preserve column storage characteristics (Christopher)</para>
3720     <para>
3721      This preserves <literal>ALTER TABLE ... SET STORAGE</literal> information.
3722     </para>
3723    </listitem>
3724
3725    <listitem><para>Make pg_dump preserve <command>CLUSTER</command> characteristics (Christopher)</para></listitem>
3726
3727    <listitem>
3728     <para>
3729      Have pg_dumpall use <command>GRANT</>/<command>REVOKE</> to dump database-level privileges (Tom)
3730     </para>
3731    </listitem>
3732
3733    <listitem>
3734     <para>
3735      Allow pg_dumpall to support the options <option>-a</>,
3736      <option>-s</>, <option>-x</> of pg_dump (Tom)
3737     </para>
3738    </listitem>
3739
3740    <listitem><para>Prevent pg_dump from lowercasing identifiers specified on the command line (Tom)</para></listitem>
3741
3742    <listitem>
3743     <para>
3744      pg_dump options <option>--use-set-session-authorization</option>
3745      and <option>--no-reconnect</option> now do nothing, all dumps
3746      use <command>SET SESSION AUTHORIZATION</command>
3747     </para>
3748     <para>
3749      pg_dump no longer reconnects to switch users, but instead always
3750      uses <command>SET SESSION AUTHORIZATION</command>. This will
3751      reduce password prompting during restores.
3752     </para>
3753    </listitem>
3754
3755    <listitem>
3756     <para>Long options for <application>pg_dump</application> are now available on all platforms</para>
3757     <para>
3758      <productname>PostgreSQL</productname> now includes its own
3759      long-option processing routines.
3760     </para>
3761    </listitem>
3762   </itemizedlist>
3763  </sect3>
3764
3765  <sect3>
3766   <title>libpq Changes</title>
3767
3768   <itemizedlist>
3769    <listitem>
3770     <para>
3771      Add function <function>PQfreemem</function> for freeing memory on
3772      Windows, suggested for <command>NOTIFY</command> (Bruce)
3773     </para>
3774     <para>
3775      Windows requires that memory allocated in a library be freed by
3776      a function in the same library, hence
3777      <function>free()</function> doesn't work for freeing memory
3778      allocated by libpq. <function>PQfreemem</function> is the proper
3779      way to free libpq memory, especially on Windows, and is
3780      recommended for other platforms as well.
3781     </para>
3782    </listitem>
3783
3784    <listitem>
3785     <para>Document service capability, and add sample file (Bruce)</para>
3786     <para>
3787      This allows clients to look up connection information in a
3788      central file on the client machine.
3789     </para>
3790    </listitem>
3791
3792    <listitem>
3793     <para>
3794      Make <function>PQsetdbLogin</function> have the same defaults as
3795      <function>PQconnectdb</function> (Tom)
3796     </para>
3797    </listitem>
3798
3799    <listitem><para>Allow libpq to cleanly fail when result sets are too large (Tom)</para></listitem>
3800
3801    <listitem>
3802     <para>
3803      Improve performance of function <function>PQunescapeBytea</function> (Ben Lamb)
3804     </para>
3805    </listitem>
3806
3807    <listitem>
3808     <para>
3809      Allow thread-safe libpq with <filename>configure</filename>
3810      option <option>--enable-thread-safety</option> (Lee Kindness,
3811      Philip Yarra)
3812     </para>
3813    </listitem>
3814
3815    <listitem>
3816     <para>
3817      Allow function <function>pqInternalNotice</function> to accept a
3818      format string and arguments instead of just a preformatted
3819      message (Tom, Sean Chittenden)
3820     </para>
3821    </listitem>
3822
3823    <listitem>
3824     <para>
3825      Control SSL negotiation with <literal>sslmode</literal> values
3826      <literal>disable</literal>, <literal>allow</literal>,
3827      <literal>prefer</literal>, and <literal>require</literal> (Jon
3828      Jensen)
3829     </para>
3830    </listitem>
3831
3832    <listitem>
3833     <para>Allow new error codes and levels of text (Tom)</para>
3834    </listitem>
3835
3836    <listitem>
3837     <para>Allow access to the underlying table and column of a query result (Tom)</para>
3838     <para>
3839      This is helpful for query-builder applications that want to know
3840      the underlying table and column names associated with a specific
3841      result set.
3842     </para>
3843    </listitem>
3844
3845    <listitem><para>Allow access to the current transaction status (Tom)</para></listitem>
3846    <listitem><para>Add ability to pass binary data directly to the server (Tom)</para></listitem>
3847
3848    <listitem>
3849     <para>
3850      Add function <function>PQexecPrepared</function> and
3851      <function>PQsendQueryPrepared</function> functions which perform
3852      bind/execute of previously prepared statements (Tom)
3853      </para>
3854     </listitem>
3855   </itemizedlist>
3856  </sect3>
3857
3858  <sect3>
3859   <title>JDBC Changes</title>
3860
3861   <itemizedlist>
3862    <listitem><para>Allow <function>setNull</function> on updateable result sets</para></listitem>
3863    <listitem><para>Allow <function>executeBatch</function> on a prepared statement (Barry)</para></listitem>
3864    <listitem><para>Support SSL connections (Barry)</para></listitem>
3865    <listitem><para>Handle schema names in result sets (Paul Sorenson)</para></listitem>
3866    <listitem><para>Add refcursor support (Nic Ferrier)</para></listitem>
3867   </itemizedlist>
3868  </sect3>
3869
3870  <sect3>
3871   <title>Miscellaneous Interface Changes</title>
3872
3873   <itemizedlist>
3874    <listitem>
3875     <para>Prevent possible memory leak or core dump during libpgtcl shutdown (Tom)</para>
3876    </listitem>
3877    <listitem>
3878     <para>Add Informix compatibility to ECPG (Michael)</para>
3879     <para>
3880      This allows ECPG to process embedded C programs that were
3881      written using certain Informix extensions.
3882     </para>
3883    </listitem>
3884
3885    <listitem>
3886     <para>Add type <type>decimal</type> to ECPG that is fixed length, for Informix (Michael)</para>
3887    </listitem>
3888
3889    <listitem>
3890     <para>
3891      Allow thread-safe embedded SQL programs with
3892      <filename>configure</filename> option
3893      <option>--enable-thread-safety</option> (Lee Kindness, Bruce)
3894     </para>
3895     <para>
3896      This allows multiple threads to access the database at the same
3897      time.
3898     </para>
3899    </listitem>
3900
3901    <listitem>
3902     <para>Moved Python client PyGreSQL to <ulink url="http://www.pygresql.org"></ulink> (Marc)</para>
3903    </listitem>
3904   </itemizedlist>
3905  </sect3>
3906
3907  <sect3>
3908   <title>Source Code Changes</title>
3909
3910   <itemizedlist>
3911    <listitem><para>Prevent need for separate platform geometry regression result files (Tom)</para></listitem>
3912    <listitem><para>Improved PPC locking primitive (Reinhard Max)</para></listitem>
3913    <listitem><para>New function <function>palloc0</function> to allocate and clear memory (Bruce)</para></listitem>
3914    <listitem><para>Fix locking code for s390x CPU (64-bit) (Tom)</para></listitem>
3915    <listitem><para>Allow OpenBSD to use local ident credentials (William Ahern)</para></listitem>
3916    <listitem><para>Make query plan trees read-only to executor (Tom)</para></listitem>
3917    <listitem><para>Add Darwin startup scripts (David Wheeler)</para></listitem>
3918    <listitem><para>Allow libpq to compile with Borland C++ compiler (Lester Godwin, Karl Waclawek)</para></listitem>
3919    <listitem><para>Use our own version of <function>getopt_long()</function> if needed (Peter)</para></listitem>
3920    <listitem><para>Convert administration scripts to C (Peter)</para></listitem>
3921    <listitem><para> Bison &gt;= 1.85 is now required to build the <productname>PostgreSQL</> grammar, if building from CVS</para></listitem>
3922    <listitem><para>Merge documentation into one book (Peter)</para></listitem>
3923    <listitem><para>Add Windows compatibility functions (Bruce)</para></listitem>
3924    <listitem><para>Allow client interfaces to compile under MinGW (Bruce)</para></listitem>
3925    <listitem><para>New <function>ereport()</function> function for error reporting (Tom)</para></listitem>
3926    <listitem><para>Support Intel compiler on Linux (Peter)</para></listitem>
3927    <listitem><para>Improve Linux startup scripts (Slawomir Sudnik, Darko Prenosil)</para></listitem>
3928    <listitem><para>Add support for AMD Opteron and Itanium (Jeffrey W. Baker, Bruce)</para></listitem>
3929    <listitem>
3930     <para>Remove <option>--enable-recode</option> option from <command>configure</command></para>
3931     <para>
3932      This was no longer needed now that we have <command>CREATE CONVERSION</command>.
3933     </para>
3934    </listitem>
3935    <listitem>
3936     <para>Generate a compile error if spinlock code is not found (Bruce)</para>
3937     <para>
3938      Platforms without spinlock code will now fail to compile, rather
3939      than silently using semaphores. This failure can be disabled
3940      with a new <command>configure</command> option.
3941     </para>
3942    </listitem>
3943   </itemizedlist>
3944  </sect3>
3945
3946  <sect3>
3947   <title>Contrib Changes</title>
3948
3949   <itemizedlist>
3950    <listitem><para>Change dbmirror license to BSD</para></listitem>
3951    <listitem><para>Improve earthdistance (Bruno Wolff III)</para></listitem>
3952    <listitem><para>Portability improvements to pgcrypto (Marko Kreen)</para></listitem>
3953    <listitem><para>Prevent crash in xml (John Gray, Michael Richards)</para></listitem>
3954    <listitem><para>Update oracle</para></listitem>
3955    <listitem><para>Update mysql</para></listitem>
3956    <listitem><para>Update cube (Bruno Wolff III)</para></listitem>
3957    <listitem><para>Update earthdistance to use cube (Bruno Wolff III)</para></listitem>
3958    <listitem><para>Update btree_gist (Oleg)</para></listitem>
3959    <listitem><para>New tsearch2 full-text search module (Oleg, Teodor)</para></listitem>
3960    <listitem><para>Add hash-based crosstab function to tablefuncs (Joe)</para></listitem>
3961    <listitem><para>Add serial column to order <function>connectby()</> siblings in tablefuncs (Nabil Sayegh,Joe)</para></listitem>
3962    <listitem><para>Add named persistent connections to dblink (Shridhar Daithanka)</para></listitem>
3963    <listitem><para>New pg_autovacuum allows automatic <command>VACUUM</command> (Matthew T. O'Connor)</para></listitem>
3964    <listitem><para>Make pgbench honor environment variables <envar>PGHOST</>, <envar>PGPORT</>, <envar>PGUSER</> (Tatsuo)</para></listitem>
3965    <listitem><para>Improve intarray (Teodor Sigaev)</para></listitem>
3966    <listitem><para>Improve pgstattuple (Rod)</para></listitem>
3967    <listitem><para>Fix bug in <function>metaphone()</function> in fuzzystrmatch</para></listitem>
3968    <listitem><para>Improve adddepend (Rod)</para></listitem>
3969    <listitem><para>Update spi/timetravel (Böjthe Zoltán)</para></listitem>
3970    <listitem><para>Fix dbase <option>-s</> option and improve non-ASCII handling (Thomas Behr, Márcio Smiderle)</para></listitem>
3971    <listitem><para>Remove array module because features now included by default (Joe)</para></listitem>
3972   </itemizedlist>
3973  </sect3>
3974  </sect2>
3975 </sect1>