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 <sect1 id="release-8-2-14">
  <title>Release 8.2.14</title>

  <note>
  <title>Release date</title>
  <simpara>2009-09-09, AS OF 2009-08-26</simpara>
  </note>

  <para>
   This release contains a variety of fixes from 8.2.13.
   For information about new features in the 8.2 major release, see
   <xref linkend="release-8-2">.
  </para>

  <sect2>
   <title>Migration to Version 8.2.14</title>

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

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

    <listitem>
     <para>
      Treat <function>to_char(..., 'TH')</> as an uppercase ordinal
      suffix with <literal>'HH'</>/<literal>'HH12'</> (Heikki)
     </para>

     <para>
      It was previously handled as <literal>'th'</> (lowercase).
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <filename>/contrib/xml2</> <function>xslt_process()</> to
      properly handle the maximum number of parameters (twenty) (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Re-add documentation for configure flag <literal>--no-readline</> (Andrew)
     </para>
    </listitem>

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-2-13">
  <title>Release 8.2.13</title>

  <note>
  <title>Release date</title>
  <simpara>2009-03-16</simpara>
  </note>

  <para>
   This release contains a variety of fixes from 8.2.12.
   For information about new features in the 8.2 major release, see
   <xref linkend="release-8-2">.
  </para>

  <sect2>
   <title>Migration to Version 8.2.13</title>

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

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

    <listitem>
     <para>
      Prevent error recursion crashes when encoding conversion fails (Tom)
     </para>

     <para>
      This change extends fixes made in the last two minor releases for
      related failure scenarios.  The previous fixes were narrowly tailored
      for the original problem reports, but we have now recognized that
      <emphasis>any</> error thrown by an encoding conversion function could
      potentially lead to infinite recursion while trying to report the
      error.  The solution therefore is to disable translation and encoding
      conversion and report the plain-ASCII form of any error message,
      if we find we have gotten into a recursive error reporting situation.
      (CVE-2009-0922)
     </para>
    </listitem>

    <listitem>
     <para>
      Disallow <command>CREATE CONVERSION</> with the wrong encodings
      for the specified conversion function (Heikki)
     </para>

     <para>
      This prevents one possible scenario for encoding conversion failure.
      The previous change is a backstop to guard against other kinds of
      failures in the same area.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix core dump when <function>to_char()</> is given format codes that
      are inappropriate for the type of the data argument (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix possible failure in <filename>contrib/tsearch2</> when C locale is
      used with a multi-byte encoding (Teodor)
     </para>

     <para>
      Crashes were possible on platforms where <type>wchar_t</> is narrower
      than <type>int</>; Windows in particular.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix extreme inefficiency in <filename>contrib/tsearch2</> parser's
      handling of an email-like string containing multiple <literal>@</>
      characters (Heikki)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix decompilation of <literal>CASE WHEN</> with an implicit coercion
      (Tom)
     </para>

     <para>
      This mistake could lead to Assert failures in an Assert-enabled build,
      or an <quote>unexpected CASE WHEN clause</> error message in other
      cases, when trying to examine or dump a view.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix possible misassignment of the owner of a TOAST table's rowtype (Tom)
     </para>

     <para>
      If <command>CLUSTER</> or a rewriting variant of <command>ALTER TABLE</>
      were executed by someone other than the table owner, the
      <structname>pg_type</> entry for the table's TOAST table would end up
      marked as owned by that someone.  This caused no immediate problems,
      since the permissions on the TOAST rowtype aren't examined by any
      ordinary database operation.  However, it could lead to unexpected
      failures if one later tried to drop the role that issued the command
      (in 8.1 or 8.2), or <quote>owner of data type appears to be invalid</>
      warnings from <application>pg_dump</> after having done so (in 8.3).
     </para>
    </listitem>

    <listitem>
     <para>
      Fix PL/pgSQL to not treat <literal>INTO</> after <command>INSERT</> as
      an INTO-variables clause anywhere in the string, not only at the start;
      in particular, don't fail for <command>INSERT INTO</> within
      <command>CREATE RULE</> (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Clean up PL/pgSQL error status variables fully at block exit
      (Ashesh Vashi and Dave Page)
     </para>

     <para>
      This is not a problem for PL/pgSQL itself, but the omission could cause
      the PL/pgSQL Debugger to crash while examining the state of a function.
     </para>
    </listitem>

    <listitem>
     <para>
      Retry failed calls to <function>CallNamedPipe()</> on Windows
      (Steve Marshall, Magnus)
     </para>

     <para>
      It appears that this function can sometimes fail transiently;
      we previously treated any failure as a hard error, which could
      confuse <command>LISTEN</>/<command>NOTIFY</> as well as other
      operations.
     </para>
    </listitem>

    <listitem>
     <para>
      Add <literal>MUST</> (Mauritius Island Summer Time) to the default list
      of known timezone abbreviations (Xavier Bugaud)
     </para>
    </listitem>

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-2-12">
  <title>Release 8.2.12</title>

  <note>
  <title>Release date</title>
  <simpara>2009-02-02</simpara>
  </note>

  <para>
   This release contains a variety of fixes from 8.2.11.
   For information about new features in the 8.2 major release, see
   <xref linkend="release-8-2">.
  </para>

  <sect2>
   <title>Migration to Version 8.2.12</title>

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

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

    <listitem>
     <para>
      Improve handling of URLs in <function>headline()</> function (Teodor)
     </para>
    </listitem>

    <listitem>
     <para>
      Improve handling of overlength headlines in <function>headline()</>
      function (Teodor)
     </para>
    </listitem>

    <listitem>
     <para>
      Prevent possible Assert failure or misconversion if an encoding
      conversion is created with the wrong conversion function for the
      specified pair of encodings (Tom, Heikki)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix possible Assert failure if a statement executed in PL/pgSQL is
      rewritten into another kind of statement, for example if an
      <command>INSERT</> is rewritten into an <command>UPDATE</> (Heikki)
     </para>
    </listitem>

    <listitem>
     <para>
      Ensure that a snapshot is available to datatype input functions (Tom)
     </para>

     <para>
      This primarily affects domains that are declared with <literal>CHECK</>
      constraints involving user-defined stable or immutable functions.  Such
      functions typically fail if no snapshot has been set.
     </para>
    </listitem>

    <listitem>
     <para>
      Make it safer for SPI-using functions to be used within datatype I/O;
      in particular, to be used in domain check constraints (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Avoid unnecessary locking of small tables in <command>VACUUM</>
      (Heikki)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix a problem that made <literal>UPDATE RETURNING tableoid</>
      return zero instead of the correct OID (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix planner misestimation of selectivity when transitive equality
      is applied to an outer-join clause (Tom)
     </para>

     <para>
      This could result in bad plans for queries like
      <literal>... from a left join b on a.a1 = b.b1 where a.a1 = 42 ...</>
     </para>
    </listitem>

    <listitem>
     <para>
      Improve optimizer's handling of long <literal>IN</> lists (Tom)
     </para>

     <para>
      This change avoids wasting large amounts of time on such lists
      when constraint exclusion is enabled.
     </para>
    </listitem>

    <listitem>
     <para>
      Ensure that the contents of a holdable cursor don't depend on the
      contents of TOAST tables (Tom)
     </para>

     <para>
      Previously, large field values in a cursor result might be represented
      as TOAST pointers, which would fail if the referenced table got dropped
      before the cursor is read, or if the large value is deleted and then
      vacuumed away.  This cannot happen with an ordinary cursor,
      but it could with a cursor that is held past its creating transaction.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix memory leak when a set-returning function is terminated without
      reading its whole result (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <filename>contrib/dblink</>'s
      <function>dblink_get_result(text,bool)</> function (Joe)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix possible garbage output from <filename>contrib/sslinfo</> functions
      (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <application>configure</> script to properly report failure when
      unable to obtain linkage information for PL/Perl (Andrew)
     </para>
    </listitem>

    <listitem>
     <para>
      Make all documentation reference <literal>pgsql-bugs</> and/or
      <literal>pgsql-hackers</> as appropriate, instead of the
      now-decommissioned <literal>pgsql-ports</> and <literal>pgsql-patches</>
      mailing lists (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Update time zone data files to <application>tzdata</> release 2009a (for
      Kathmandu and historical DST corrections in Switzerland, Cuba)
     </para>
    </listitem>

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-2-11">
  <title>Release 8.2.11</title>

  <note>
  <title>Release date</title>
  <simpara>2008-11-03</simpara>
  </note>

  <para>
   This release contains a variety of fixes from 8.2.10.
   For information about new features in the 8.2 major release, see
   <xref linkend="release-8-2">.
  </para>

  <sect2>
   <title>Migration to Version 8.2.11</title>

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

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

    <listitem>
     <para>
      Fix GiST index corruption due to marking the wrong index entry
      <quote>dead</> after a deletion (Teodor)
     </para>

     <para>
      This would result in index searches failing to find rows they
      should have found.  Corrupted indexes can be fixed with
      <command>REINDEX</>.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix backend crash when the client encoding cannot represent a localized
      error message (Tom)
     </para>

     <para>
      We have addressed similar issues before, but it would still fail if
      the <quote>character has no equivalent</> message itself couldn't
      be converted.  The fix is to disable localization and send the plain
      ASCII error message when we detect such a situation.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix possible crash when deeply nested functions are invoked from
      a trigger (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Improve optimization of <replaceable>expression</> <literal>IN</>
      (<replaceable>expression-list</>) queries (Tom, per an idea from Robert
      Haas)
     </para>

     <para>
      Cases in which there are query variables on the right-hand side had been
      handled less efficiently in 8.2.x and 8.3.x than in prior versions.
      The fix restores 8.1 behavior for such cases.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix mis-expansion of rule queries when a sub-<literal>SELECT</> appears
      in a function call in <literal>FROM</>,  a multi-row <literal>VALUES</>
      list, or a <literal>RETURNING</> list (Tom)
     </para>

     <para>
      The usual symptom of this problem is an <quote>unrecognized node type</>
      error.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix memory leak during rescan of a hashed aggregation plan (Neil)
     </para>
    </listitem>

    <listitem>
     <para>
      Ensure an error is reported when a newly-defined PL/pgSQL trigger
      function is invoked as a normal function (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Prevent possible collision of <structfield>relfilenode</> numbers
      when moving a table to another tablespace with <command>ALTER SET
      TABLESPACE</> (Heikki)
     </para>

     <para>
      The command tried to re-use the existing filename, instead of
      picking one that is known unused in the destination directory.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix incorrect tsearch2 headline generation when single query
      item matches first word of text (Sushant Sinha)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix improper display of fractional seconds in interval values when
      using a non-ISO datestyle in an <option>--enable-integer-datetimes</>
      build (Ron Mayer)
     </para>
    </listitem>

    <listitem>
     <para>
      Ensure <function>SPI_getvalue</> and <function>SPI_getbinval</>
      behave correctly when the passed tuple and tuple descriptor have
      different numbers of columns (Tom)
     </para>

     <para>
      This situation is normal when a table has had columns added or removed,
      but these two functions didn't handle it properly.
      The only likely consequence is an incorrect error indication.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <application>ecpg</>'s parsing of <command>CREATE ROLE</> (Michael)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix recent breakage of <literal>pg_ctl restart</> (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Ensure <filename>pg_control</> is opened in binary mode
      (Itagaki Takahiro)
     </para>

     <para>
      <application>pg_controldata</> and <application>pg_resetxlog</>
      did this incorrectly, and so could fail on Windows.
     </para>
    </listitem>

    <listitem>
     <para>
      Update time zone data files to <application>tzdata</> release 2008i (for
      DST law changes in Argentina, Brazil, Mauritius, Syria)
     </para>
    </listitem>

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-2-10">
  <title>Release 8.2.10</title>

  <note>
  <title>Release date</title>
  <simpara>2008-09-22</simpara>
  </note>

  <para>
   This release contains a variety of fixes from 8.2.9.
   For information about new features in the 8.2 major release, see
   <xref linkend="release-8-2">.
  </para>

  <sect2>
   <title>Migration to Version 8.2.10</title>

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

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

    <listitem>
     <para>
      Fix bug in btree WAL recovery code (Heikki)
     </para>

     <para>
      Recovery failed if the WAL ended partway through a page split operation.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix potential miscalculation of <structfield>datfrozenxid</> (Alvaro)
     </para>

     <para>
      This error may explain some recent reports of failure to remove old
      <structname>pg_clog</> data.
     </para>
    </listitem>

    <listitem>
     <para>
      Widen local lock counters from 32 to 64 bits (Tom)
     </para>

     <para>
      This responds to reports that the counters could overflow in
      sufficiently long transactions, leading to unexpected <quote>lock is
      already held</> errors.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix possible duplicate output of tuples during a GiST index scan (Teodor)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix missed permissions checks when a view contains a simple
      <literal>UNION ALL</> construct (Heikki)
     </para>

     <para>
      Permissions for the referenced tables were checked properly, but not
      permissions for the view itself.
     </para>
    </listitem>

    <listitem>
     <para>
      Add checks in executor startup to ensure that the tuples produced by an
      <command>INSERT</> or <command>UPDATE</> will match the target table's
      current rowtype (Tom)
     </para>

     <para>
      <command>ALTER COLUMN TYPE</>, followed by re-use of a previously
      cached plan, could produce this type of situation.  The check protects
      against data corruption and/or crashes that could ensue.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix possible repeated drops during <command>DROP OWNED</> (Tom)
     </para>

     <para>
      This would typically result in strange errors such as <quote>cache
      lookup failed for relation NNN</>.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <literal>AT TIME ZONE</> to first try to interpret its timezone
      argument as a timezone abbreviation, and only try it as a full timezone
      name if that fails, rather than the other way around as formerly (Tom)
     </para>

     <para>
      The timestamp input functions have always resolved ambiguous zone names
      in this order.  Making <literal>AT TIME ZONE</> do so as well improves
      consistency, and fixes a compatibility bug introduced in 8.1:
      in ambiguous cases we now behave the same as 8.0 and before did,
      since in the older versions <literal>AT TIME ZONE</> accepted
      <emphasis>only</> abbreviations.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix datetime input functions to correctly detect integer overflow when
      running on a 64-bit platform (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Prevent integer overflows during units conversion when displaying a
      configuration parameter that has units (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Improve performance of writing very long log messages to syslog (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Allow spaces in the suffix part of an LDAP URL in
      <filename>pg_hba.conf</> (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix bug in backwards scanning of a cursor on a <literal>SELECT DISTINCT
      ON</> query (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix planner bug with nested sub-select expressions (Tom)
     </para>

     <para>
      If the outer sub-select has no direct dependency on the parent query,
      but the inner one does, the outer value might not get recalculated
      for new parent query rows.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix planner to estimate that <literal>GROUP BY</> expressions yielding
      boolean results always result in two groups, regardless of the
      expressions' contents (Tom)
     </para>

     <para>
      This is very substantially more accurate than the regular <literal>GROUP
      BY</> estimate for certain boolean tests like <replaceable>col</>
      <literal>IS NULL</>.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix PL/PgSQL to not fail when a <literal>FOR</> loop's target variable
      is a record containing composite-type fields (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix PL/Tcl to behave correctly with Tcl 8.5, and to be more careful
      about the encoding of data sent to or from Tcl (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      On Windows, work around a Microsoft bug by preventing
      <application>libpq</> from trying to send more than 64kB per system call
      (Magnus)
     </para>
    </listitem>

    <listitem>
     <para>
      Improve <application>pg_dump</> and <application>pg_restore</>'s
      error reporting after failure to send a SQL command (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <application>pg_ctl</> to properly preserve postmaster
      command-line arguments across a <literal>restart</> (Bruce)
     </para>
    </listitem>

    <listitem>
     <para>
      Update time zone data files to <application>tzdata</> release 2008f (for
      DST law changes in Argentina, Bahamas, Brazil, Mauritius, Morocco,
      Pakistan, Palestine, and Paraguay)
     </para>
    </listitem>

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-2-9">
  <title>Release 8.2.9</title>

  <note>
  <title>Release date</title>
  <simpara>2008-06-12</simpara>
  </note>

  <para>
   This release contains one serious and one minor bug fix over 8.2.8.
   For information about new features in the 8.2 major release, see
   <xref linkend="release-8-2">.
  </para>

  <sect2>
   <title>Migration to Version 8.2.9</title>

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

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

    <listitem>
     <para>
      Make <function>pg_get_ruledef()</> parenthesize negative constants (Tom)
     </para>

     <para>
      Before this fix, a negative constant in a view or rule might be dumped
      as, say, <literal>-42::integer</>, which is subtly incorrect: it should
      be <literal>(-42)::integer</> due to operator precedence rules.
      Usually this would make little difference, but it could interact with
      another recent patch to cause
      <productname>PostgreSQL</> to reject what had been a valid
      <command>SELECT DISTINCT</> view query.  Since this could result in
      <application>pg_dump</> output failing to reload, it is being treated
      as a high-priority fix.  The only released versions in which dump
      output is actually incorrect are 8.3.1 and 8.2.7.
     </para>
    </listitem>

    <listitem>
     <para>
      Make <command>ALTER AGGREGATE ... OWNER TO</> update
      <structname>pg_shdepend</> (Tom)
     </para>

     <para>
      This oversight could lead to problems if the aggregate was later
      involved in a <command>DROP OWNED</> or <command>REASSIGN OWNED</>
      operation.
     </para>
    </listitem>

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-2-8">
  <title>Release 8.2.8</title>

  <note>
  <title>Release date</title>
  <simpara>never released</simpara>
  </note>

  <para>
   This release contains a variety of fixes from 8.2.7.
   For information about new features in the 8.2 major release, see
   <xref linkend="release-8-2">.
  </para>

  <sect2>
   <title>Migration to Version 8.2.8</title>

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

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

    <listitem>
     <para>
      Fix <literal>ERRORDATA_STACK_SIZE exceeded</literal> crash that
      occurred on Windows when using UTF-8 database encoding and a different
      client encoding (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <command>ALTER TABLE ADD COLUMN ... PRIMARY KEY</> so that the new
      column is correctly checked to see if it's been initialized to all
      non-nulls (Brendan Jurd)
     </para>

     <para>
      Previous versions neglected to check this requirement at all.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix possible <command>CREATE TABLE</> failure when inheriting the
      <quote>same</> constraint from multiple parent relations that
      inherited that constraint from a common ancestor (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <function>pg_get_ruledef()</> to show the alias, if any, attached
      to the target table of an <command>UPDATE</> or <command>DELETE</>
      (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix GIN bug that could result in a <literal>too many LWLocks
      taken</literal> failure (Teodor)
     </para>
    </listitem>

    <listitem>
     <para>
      Avoid possible crash when decompressing corrupted data
      (Zdenek Kotala)
     </para>
    </listitem>

    <listitem>
     <para>
      Repair two places where SIGTERM exit of a backend could leave corrupted
      state in shared memory (Tom)
     </para>

     <para>
      Neither case is very important if SIGTERM is used to shut down the
      whole database cluster together, but there was a problem if someone
      tried to SIGTERM individual backends.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix conversions between ISO-8859-5 and other encodings to handle
      Cyrillic <quote>Yo</> characters (<literal>e</> and <literal>E</> with
      two dots) (Sergey Burladyan)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix several datatype input functions, notably <function>array_in()</>,
      that were allowing unused bytes in their results to contain
      uninitialized, unpredictable values (Tom)
     </para>

     <para>
      This could lead to failures in which two apparently identical literal
      values were not seen as equal, resulting in the parser complaining
      about unmatched <literal>ORDER BY</> and <literal>DISTINCT</>
      expressions.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix a corner case in regular-expression substring matching
      (<literal>substring(<replaceable>string</> from
      <replaceable>pattern</>)</literal>) (Tom)
     </para>

     <para>
      The problem occurs when there is a match to the pattern overall but
      the user has specified a parenthesized subexpression and that
      subexpression hasn't got a match.  An example is
      <literal>substring('foo' from 'foo(bar)?')</>.
      This should return NULL, since <literal>(bar)</> isn't matched, but
      it was mistakenly returning the whole-pattern match instead (ie,
      <literal>foo</>).
     </para>
    </listitem>

    <listitem>
     <para>
      Update time zone data files to <application>tzdata</> release 2008c (for
      DST law changes in Morocco, Iraq, Choibalsan, Pakistan, Syria, Cuba, and
      Argentina/San_Luis)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix incorrect result from <application>ecpg</>'s
      <function>PGTYPEStimestamp_sub()</> function (Michael)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix broken GiST comparison function for <filename>contrib/tsearch2</>'s
      <type>tsquery</> type (Teodor)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix possible crashes in <filename>contrib/cube</> functions (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix core dump in <filename>contrib/xml2</>'s
      <function>xpath_table()</> function when the input query returns a
      NULL value (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <filename>contrib/xml2</>'s makefile to not override
      <literal>CFLAGS</> (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <literal>DatumGetBool</> macro to not fail with <application>gcc</>
      4.3 (Tom)
     </para>

     <para>
      This problem affects <quote>old style</> (V0) C functions that
      return boolean.  The fix is already in 8.3, but the need to
      back-patch it was not realized at the time.
     </para>
    </listitem>

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-2-7">
  <title>Release 8.2.7</title>

  <note>
  <title>Release date</title>
  <simpara>2008-03-17</simpara>
  </note>

  <para>
   This release contains a variety of fixes from 8.2.6.
   For information about new features in the 8.2 major release, see
   <xref linkend="release-8-2">.
  </para>

  <sect2>
   <title>Migration to Version 8.2.7</title>

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

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

    <listitem>
     <para>
      Fix character string comparison for Windows locales that consider
      different character combinations as equal (Tom)
     </para>

     <para>
      This fix applies only on Windows and only when using UTF-8
      database encoding.  The same fix was made for all other cases
      over two years ago, but Windows with UTF-8 uses a separate code
      path that was not updated.  If you are using a locale that
      considers some non-identical strings as equal, you may need to
      <command>REINDEX</> to fix existing indexes on textual columns.
     </para>
    </listitem>

    <listitem>
     <para>
      Repair potential deadlock between concurrent <command>VACUUM FULL</>
      operations on different system catalogs (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix longstanding <command>LISTEN</>/<command>NOTIFY</>
      race condition (Tom)
     </para>

     <para>
      In rare cases a session that had just executed a
      <command>LISTEN</> might not get a notification, even though
      one would be expected because the concurrent transaction executing
      <command>NOTIFY</> was observed to commit later.
     </para>

     <para>
      A side effect of the fix is that a transaction that has executed
      a not-yet-committed <command>LISTEN</> command will not see any
      row in <structname>pg_listener</> for the <command>LISTEN</>,
      should it choose to look; formerly it would have.  This behavior
      was never documented one way or the other, but it is possible that
      some applications depend on the old behavior.
     </para>
    </listitem>

    <listitem>
     <para>
      Disallow <command>LISTEN</> and <command>UNLISTEN</> within a
      prepared transaction (Tom)
     </para>

     <para>
      This was formerly allowed but trying to do it had various unpleasant
      consequences, notably that the originating backend could not exit
      as long as an <command>UNLISTEN</> remained uncommitted.
     </para>
    </listitem>

    <listitem>
     <para>
      Disallow dropping a temporary table within a
      prepared transaction (Heikki)
     </para>

     <para>
      This was correctly disallowed by 8.1, but the check was inadvertently
      broken in 8.2.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix rare crash when an error occurs during a query using a hash index
      (Heikki)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix memory leaks in certain usages of set-returning functions (Neil)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix input of datetime values for February 29 in years BC (Tom)
     </para>

     <para>
      The former coding was mistaken about which years were leap years.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <quote>unrecognized node type</> error in some variants of
      <command>ALTER OWNER</> (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Ensure <structname>pg_stat_activity</>.<structfield>waiting</> flag
      is cleared when a lock wait is aborted (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix handling of process permissions on Windows Vista (Dave, Magnus)
     </para>

     <para>
      In particular, this fix allows starting the server as the Administrator
      user.
     </para>
    </listitem>

    <listitem>
     <para>
      Update time zone data files to <application>tzdata</> release 2008a
      (in particular, recent Chile changes); adjust timezone abbreviation
      <literal>VET</> (Venezuela) to mean UTC-4:30, not UTC-4:00 (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <application>pg_ctl</> to correctly extract the postmaster's port
      number from command-line options (Itagaki Takahiro, Tom)
     </para>

     <para>
      Previously, <literal>pg_ctl start -w</> could try to contact the
      postmaster on the wrong port, leading to bogus reports of startup
      failure.
     </para>
    </listitem>

    <listitem>
     <para>
      Use <option>-fwrapv</> to defend against possible misoptimization
      in recent <application>gcc</> versions (Tom)
     </para>

     <para>
      This is known to be necessary when building <productname>PostgreSQL</>
      with <application>gcc</> 4.3 or later.
     </para>
    </listitem>


    <listitem>
     <para>
      Correctly enforce <varname>statement_timeout</> values longer
      than <literal>INT_MAX</> microseconds (about 35 minutes) (Tom)
     </para>

     <para>
      This bug affects only builds with <option>--enable-integer-datetimes</>.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <quote>unexpected PARAM_SUBLINK ID</> planner error when
      constant-folding simplifies a sub-select (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix logical errors in constraint-exclusion handling of <literal>IS
      NULL</> and <literal>NOT</> expressions (Tom)
     </para>

     <para>
      The planner would sometimes exclude partitions that should not
      have been excluded because of the possibility of NULL results.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix another cause of <quote>failed to build any N-way joins</>
      planner errors (Tom)
     </para>

     <para>
      This could happen in cases where a clauseless join needed to be
      forced before a join clause could be exploited.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix incorrect constant propagation in outer-join planning (Tom)
     </para>

     <para>
      The planner could sometimes incorrectly conclude that a variable
      could be constrained to be equal to a constant, leading
      to wrong query results.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix display of constant expressions in <literal>ORDER BY</>
      and <literal>GROUP BY</> (Tom)
     </para>

     <para>
      An explictly casted constant would be shown incorrectly.  This could
      for example lead to corruption of a view definition during
      dump and reload.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <application>libpq</> to handle NOTICE messages correctly
      during COPY OUT (Tom)
     </para>

     <para>
      This failure has only been observed to occur when a user-defined
      datatype's output routine issues a NOTICE, but there is no
      guarantee it couldn't happen due to other causes.
     </para>
    </listitem>

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-2-6">
  <title>Release 8.2.6</title>

  <note>
  <title>Release date</title>
  <simpara>2008-01-07</simpara>
  </note>

  <para>
   This release contains a variety of fixes from 8.2.5,
   including fixes for significant security issues.
   For information about new features in the 8.2 major release, see
   <xref linkend="release-8-2">.
  </para>

  <sect2>
   <title>Migration to Version 8.2.6</title>

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

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

    <listitem>
     <para>
      Prevent functions in indexes from executing with the privileges of
      the user running <command>VACUUM</>, <command>ANALYZE</>, etc (Tom)
     </para>

     <para>
      Functions used in index expressions and partial-index
      predicates are evaluated whenever a new table entry is made.  It has
      long been understood that this poses a risk of trojan-horse code
      execution if one modifies a table owned by an untrustworthy user.
      (Note that triggers, defaults, check constraints, etc. pose the
      same type of risk.)  But functions in indexes pose extra danger
      because they will be executed by routine maintenance operations
      such as <command>VACUUM FULL</>, which are commonly performed
      automatically under a superuser account.  For example, a nefarious user
      can execute code with superuser privileges by setting up a
      trojan-horse index definition and waiting for the next routine vacuum.
      The fix arranges for standard maintenance operations
      (including <command>VACUUM</>, <command>ANALYZE</>, <command>REINDEX</>,
      and <command>CLUSTER</>) to execute as the table owner rather than
      the calling user, using the same privilege-switching mechanism already
      used for <literal>SECURITY DEFINER</> functions.  To prevent bypassing
      this security measure, execution of <command>SET SESSION
      AUTHORIZATION</> and <command>SET ROLE</> is now forbidden within a
      <literal>SECURITY DEFINER</> context.  (CVE-2007-6600)
     </para>
    </listitem>

    <listitem>
     <para>
      Repair assorted bugs in the regular-expression package (Tom, Will Drewry)
     </para>

     <para>
      Suitably crafted regular-expression patterns could cause crashes,
      infinite or near-infinite looping, and/or massive memory consumption,
      all of which pose denial-of-service hazards for applications that
      accept regex search patterns from untrustworthy sources.
      (CVE-2007-4769, CVE-2007-4772, CVE-2007-6067)
     </para>
    </listitem>

    <listitem>
     <para>
      Require non-superusers who use <filename>/contrib/dblink</> to use only
      password authentication, as a security measure (Joe)
     </para>

     <para>
      The fix that appeared for this in 8.2.5 was incomplete, as it plugged
      the hole for only some <filename>dblink</> functions.  (CVE-2007-6601,
      CVE-2007-3278)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix bugs in WAL replay for GIN indexes (Teodor)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix GIN index build to work properly when
      <varname>maintenance_work_mem</> is 4GB or more (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Update time zone data files to <application>tzdata</> release 2007k
      (in particular, recent Argentina changes) (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Improve planner's handling of LIKE/regex estimation in non-C locales
      (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix planning-speed problem for deep outer-join nests, as well as
      possible poor choice of join order (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix planner failure in some cases of <literal>WHERE false AND var IN
      (SELECT ...)</> (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Make <command>CREATE TABLE ... SERIAL</> and
      <command>ALTER SEQUENCE ... OWNED BY</> not change the
      <function>currval()</> state of the sequence (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Preserve the tablespace and storage parameters of indexes that are
      rebuilt by <command>ALTER TABLE ... ALTER COLUMN TYPE</> (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Make archive recovery always start a new WAL timeline, rather than only
      when a recovery stop time was used (Simon)
     </para>

     <para>
      This avoids a corner-case risk of trying to overwrite an existing
      archived copy of the last WAL segment, and seems simpler and cleaner
      than the original definition.
     </para>
    </listitem>

    <listitem>
     <para>
      Make <command>VACUUM</> not use all of <varname>maintenance_work_mem</>
      when the table is too small for it to be useful (Alvaro)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix potential crash in <function>translate()</> when using a multibyte
      database encoding (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Make <function>corr()</> return the correct result for negative
      correlation values (Neil)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix overflow in <literal>extract(epoch from interval)</> for intervals
      exceeding 68 years (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix PL/Perl to not fail when a UTF-8 regular expression is used
      in a trusted function (Andrew)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix PL/Perl to cope when platform's Perl defines type <literal>bool</>
      as <literal>int</> rather than <literal>char</> (Tom)
     </para>

     <para>
      While this could theoretically happen anywhere, no standard build of
      Perl did things this way ... until <productname>Mac OS X</> 10.5.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix PL/Python to work correctly with Python 2.5 on 64-bit machines
      (Marko Kreen)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix PL/Python to not crash on long exception messages (Alvaro)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <application>pg_dump</> to correctly handle inheritance child tables
      that have default expressions different from their parent's (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <application>libpq</> crash when <varname>PGPASSFILE</> refers
      to a file that is not a plain file (Martin Pitt)
     </para>
    </listitem>

    <listitem>
     <para>
      <application>ecpg</> parser fixes (Michael)
     </para>
    </listitem>

    <listitem>
     <para>
      Make <filename>contrib/pgcrypto</> defend against
      <application>OpenSSL</> libraries that fail on keys longer than 128
      bits; which is the case at least on some Solaris versions (Marko Kreen)
     </para>
    </listitem>

    <listitem>
     <para>
      Make <filename>contrib/tablefunc</>'s <function>crosstab()</> handle
      NULL rowid as a category in its own right, rather than crashing (Joe)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <type>tsvector</> and <type>tsquery</> output routines to
      escape backslashes correctly (Teodor, Bruce)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix crash of <function>to_tsvector()</> on huge input strings (Teodor)
     </para>
    </listitem>

    <listitem>
     <para>
      Require a specific version of <productname>Autoconf</> to be used
      when re-generating the <command>configure</> script (Peter)
     </para>

     <para>
      This affects developers and packagers only.  The change was made
      to prevent accidental use of untested combinations of
      <productname>Autoconf</> and <productname>PostgreSQL</> versions.
      You can remove the version check if you really want to use a
      different <productname>Autoconf</> version, but it's
      your responsibility whether the result works or not.
     </para>
    </listitem>

    <listitem>
     <para>
      Update <function>gettimeofday</> configuration check so that
      <productname>PostgreSQL</> can be built on newer versions of
      <productname>MinGW</> (Magnus)
     </para>
    </listitem>

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-2-5">
  <title>Release 8.2.5</title>

  <note>
  <title>Release date</title>
  <simpara>2007-09-17</simpara>
  </note>

  <para>
   This release contains a variety of fixes from 8.2.4.
   For information about new features in the 8.2 major release, see
   <xref linkend="release-8-2">.
  </para>

  <sect2>
   <title>Migration to Version 8.2.5</title>

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

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

    <listitem>
     <para>
      Prevent index corruption when a transaction inserts rows and
      then aborts close to the end of a concurrent <command>VACUUM</>
      on the same table (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <literal>ALTER DOMAIN ADD CONSTRAINT</> for cases involving
      domains over domains (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Make <command>CREATE DOMAIN ... DEFAULT NULL</> work properly (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix some planner problems with outer joins, notably poor
      size estimation for <literal>t1 LEFT JOIN t2 WHERE t2.col IS NULL</>
      (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Allow the <type>interval</> data type to accept input consisting only of
      milliseconds or microseconds (Neil)
     </para>
    </listitem>

    <listitem>
     <para>
      Allow timezone name to appear before the year in <type>timestamp</> input (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fixes for <acronym>GIN</> indexes used by <filename>/contrib/tsearch2</> (Teodor)
     </para>
    </listitem>

    <listitem>
     <para>
      Speed up rtree index insertion (Teodor)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix excessive logging of <acronym>SSL</> error messages (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix logging so that log messages are never interleaved when using
      the syslogger process (Andrew)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix crash when <varname>log_min_error_statement</> logging runs out
      of memory (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix incorrect handling of some foreign-key corner cases (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <function>stddev_pop(numeric)</> and <function>var_pop(numeric)</> (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Prevent <command>REINDEX</> and <command>CLUSTER</> from failing
      due to attempting to process temporary tables of other sessions (Alvaro)
     </para>
    </listitem>

    <listitem>
     <para>
      Update the time zone database rules, particularly New Zealand's upcoming changes (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Windows socket and semaphore improvements (Magnus)
     </para>
    </listitem>

    <listitem>
     <para>
      Make <command>pg_ctl -w</> work properly in Windows service mode (Dave Page)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix memory allocation bug when using <application>MIT Kerberos</> on Windows (Magnus)
     </para>
    </listitem>

    <listitem>
     <para>
      Suppress timezone name (<literal>%Z</>) in log timestamps on Windows
      because of possible encoding mismatches (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Require non-superusers who use <filename>/contrib/dblink</> to use only
      password authentication, as a security measure (Joe)
     </para>
    </listitem>

    <listitem>
     <para>
      Restrict <filename>/contrib/pgstattuple</> functions to superusers, for security reasons (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Do not let <filename>/contrib/intarray</> try to make its GIN opclass
      the default (this caused problems at dump/restore) (Tom)
     </para>
    </listitem>

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-2-4">
  <title>Release 8.2.4</title>

  <note>
  <title>Release date</title>
  <simpara>2007-04-23</simpara>
  </note>

  <para>
   This release contains a variety of fixes from 8.2.3,
   including a security fix.
   For information about new features in the 8.2 major release, see
   <xref linkend="release-8-2">.
  </para>

  <sect2>
   <title>Migration to Version 8.2.4</title>

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

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

    <listitem>
     <para>
      Support explicit placement of the temporary-table schema within
      <varname>search_path</>, and disable searching it for functions
      and operators (Tom)
     </para>

     <para>
      This is needed to allow a security-definer function to set a
      truly secure value of <varname>search_path</>.  Without it,
      an unprivileged SQL user can use temporary objects to execute code
      with the privileges of the security-definer function (CVE-2007-2138).
      See <command>CREATE FUNCTION</> for more information.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <varname>shared_preload_libraries</> for Windows
      by forcing reload in each backend (Korry Douglas)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <function>to_char()</> so it properly upper/lower cases localized day or month
      names (Pavel Stehule)
     </para>
    </listitem>

    <listitem>
     <para>
      <filename>/contrib/tsearch2</> crash fixes (Teodor)
     </para>
    </listitem>

    <listitem>
     <para>
      Require <command>COMMIT PREPARED</> to be executed in the same
      database as the transaction was prepared in (Heikki)
     </para>
    </listitem>

    <listitem>
     <para>
      Allow <command>pg_dump</> to do binary backups larger than two gigabytes
      on Windows (Magnus)
     </para>
    </listitem>

    <listitem>
     <para>
      New traditional (Taiwan) Chinese <acronym>FAQ</> (Zhou Daojing)
     </para>
    </listitem>

    <listitem>
     <para>
      Prevent the statistics collector from writing to disk too frequently (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix potential-data-corruption bug in how <command>VACUUM FULL</> handles
      <command>UPDATE</> chains (Tom, Pavan Deolasee)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix bug in domains that use array types (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <command>pg_dump</> so it can dump a serial column's sequence
      using <option>-t</> when not also dumping the owning table
      (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Planner fixes, including improving outer join and bitmap scan
      selection logic (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix possible wrong answers or crash when a PL/pgSQL function tries
      to <literal>RETURN</> from within an <literal>EXCEPTION</> block
      (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix PANIC during enlargement of a hash index (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix POSIX-style timezone specs to follow new USA DST rules (Tom)
     </para>
    </listitem>

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-2-3">
  <title>Release 8.2.3</title>

  <note>
  <title>Release date</title>
  <simpara>2007-02-07</simpara>
  </note>

  <para>
   This release contains two fixes from 8.2.2.
   For information about new features in the 8.2 major release, see
   <xref linkend="release-8-2">.
  </para>

  <sect2>
   <title>Migration to Version 8.2.3</title>

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

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

    <listitem>
     <para>
      Remove overly-restrictive check for type length in constraints and
      functional indexes(Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix optimization so MIN/MAX in subqueries can again use indexes (Tom)
     </para>
    </listitem>

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-2-2">
  <title>Release 8.2.2</title>

  <note>
  <title>Release date</title>
  <simpara>2007-02-05</simpara>
  </note>

  <para>
   This release contains a variety of fixes from 8.2.1, including
   a security fix.
   For information about new features in the 8.2 major release, see
   <xref linkend="release-8-2">.
  </para>

  <sect2>
   <title>Migration to Version 8.2.2</title>

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

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

    <listitem>
     <para>
      Remove security vulnerabilities that allowed connected users
      to read backend memory (Tom)
     </para>

     <para>
      The vulnerabilities involve suppressing the normal check that a SQL
      function returns the data type it's declared to, and changing the
      data type of a table column (CVE-2007-0555, CVE-2007-0556).  These
      errors can easily be exploited to cause a backend crash, and in
      principle might be used to read database content that the user
      should not be able to access.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix not-so-rare-anymore bug wherein btree index page splits could fail
      due to choosing an infeasible split point (Heikki Linnakangas)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix Borland C compile scripts (L Bayuk)
     </para>
    </listitem>

    <listitem>
     <para>
      Properly handle <function>to_char('CC')</> for years ending in
      <literal>00</> (Tom)
     </para>

     <para>
      Year 2000 is in the twentieth century, not the twenty-first.
     </para>
    </listitem>

    <listitem>
     <para>
      <filename>/contrib/tsearch2</> localization improvements (Tatsuo, Teodor)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix incorrect permission check in
      <literal>information_schema.key_column_usage</> view (Tom)
     </para>

     <para>
      The symptom is <quote>relation with OID nnnnn does not exist</> errors.
      To get this fix without using <command>initdb</>, use <command>CREATE OR
      REPLACE VIEW</> to install the corrected definition found in
      <filename>share/information_schema.sql</>.  Note you will need to do
      this in each database.
     </para>
    </listitem>

    <listitem>
     <para>
      Improve <command>VACUUM</> performance for databases with many tables (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix for rare Assert() crash triggered by <literal>UNION</> (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix potentially incorrect results from index searches using
      <literal>ROW</> inequality conditions (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Tighten security of multi-byte character processing for UTF8 sequences
      over three bytes long (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix bogus <quote>permission denied</> failures occurring on Windows
      due to attempts to fsync already-deleted files (Magnus, Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix bug that could cause the statistics collector
      to hang on Windows (Magnus)
     </para>

     <para>
      This would in turn lead to autovacuum not working.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix possible crashes when an already-in-use PL/pgSQL function is
      updated (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Improve PL/pgSQL handling of domain types (Sergiy Vyshnevetskiy, Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix possible errors in processing PL/pgSQL exception blocks (Tom)
     </para>
    </listitem>

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-2-1">
  <title>Release 8.2.1</title>

  <note>
  <title>Release date</title>
  <simpara>2007-01-08</simpara>
  </note>

  <para>
   This release contains a variety of fixes from 8.2.
   For information about new features in the 8.2 major release, see
   <xref linkend="release-8-2">.
  </para>

  <sect2>
   <title>Migration to Version 8.2.1</title>

   <para>
    A dump/restore is not required for those running 8.2.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

    <listitem>
     <para>
      Fix crash with <literal>SELECT</> ... <literal>LIMIT ALL</> (also
      <literal>LIMIT NULL</>) (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      <filename>Several /contrib/tsearch2</> fixes (Teodor)
     </para>
    </listitem>

    <listitem>
     <para>
      On Windows, make log messages coming from the operating system use
      <acronym>ASCII</> encoding (Hiroshi Saito)
     </para>

     <para>
      This fixes a conversion problem when there is a mismatch between
      the encoding of the operating system and database server.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix Windows linking of <application>pg_dump</> using
      <filename>win32.mak</>
      (Hiroshi Saito)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix planner mistakes for outer join queries (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix several problems in queries involving sub-SELECTs (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix potential crash in SPI during subtransaction abort (Tom)
     </para>

     <para>
      This affects all PL functions since they all use SPI.
     </para>
    </listitem>

    <listitem>
     <para>
      Improve build speed of <acronym>PDF</> documentation (Peter)
     </para>
    </listitem>

    <listitem>
     <para>
      Re-add <acronym>JST</> (Japan) timezone abbreviation (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Improve optimization decisions related to index scans (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Have <application>psql</> print multi-byte combining characters as
      before, rather than output as <literal>\u</> (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Improve index usage of regular expressions that use parentheses (Tom)
     </para>

     <para>
      This improves <application>psql</> <literal>\d</> performance also.
     </para>
    </listitem>

    <listitem>
     <para>
      Make <application>pg_dumpall</> assume that databases have public
      <literal>CONNECT</> privilege, when dumping from a pre-8.2 server (Tom)
     </para>

     <para>
      This preserves the previous behavior that anyone can connect to a
      database if allowed by <filename>pg_hba.conf</>.
     </para>
    </listitem>

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-2">
  <title>Release 8.2</title>

  <note>
   <title>Release date</title>
   <simpara>2006-12-05</simpara>
  </note>

  <sect2>
   <title>Overview</title>

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

   <itemizedlist>

     <listitem>
      <para>
       Query language enhancements including <command>INSERT/UPDATE/DELETE
       RETURNING</command>, multirow <literal>VALUES</literal> lists, and
       optional target-table alias in
       <command>UPDATE</>/<command>DELETE</command>
      </para>
     </listitem>

     <listitem>
      <para>
       Index creation without blocking concurrent
       <command>INSERT</>/<command>UPDATE</>/<command>DELETE</>
       operations
      </para>
     </listitem>

     <listitem>
      <para>
       Many query optimization improvements, including support for
       reordering outer joins
      </para>
     </listitem>

     <listitem>
      <para>
       Improved sorting performance with lower memory usage
      </para>
     </listitem>

     <listitem>
      <para>
       More efficient locking with better concurrency
      </para>
     </listitem>

     <listitem>
      <para>
       More efficient vacuuming
      </para>
     </listitem>

     <listitem>
      <para>
       Easier administration of warm standby servers
      </para>
     </listitem>

     <listitem>
      <para>
       New <literal>FILLFACTOR</literal> support for tables and indexes
      </para>
     </listitem>

     <listitem>
      <para>
       Monitoring, logging, and performance tuning additions
      </para>
     </listitem>

     <listitem>
      <para>
       More control over creating and dropping objects
      </para>
     </listitem>

     <listitem>
      <para>
       Table inheritance relationships can be defined
       for and removed from pre-existing tables
      </para>
     </listitem>

     <listitem>
      <para>
       <command>COPY TO</command> can copy the output of an arbitrary
       <command>SELECT</command> statement
      </para>
     </listitem>

     <listitem>
      <para>
       Array improvements, including nulls in arrays
      </para>
     </listitem>

     <listitem>
      <para>
       Aggregate-function improvements, including multiple-input
       aggregates and SQL:2003 statistical functions
      </para>
     </listitem>

     <listitem>
      <para>
       Many <filename>contrib/</filename> improvements
      </para>
     </listitem>

    </itemizedlist>

   </para>

  </sect2>

  <sect2>
   <title>Migration to Version 8.2</title>

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

   <para>
    Observe the following incompatibilities:
   </para>

   <itemizedlist>

     <listitem>
      <para>
       Set <link
       linkend="guc-escape-string-warning"><varname>escape_string_warning</></link>
       to <literal>on</> by default (Bruce)
      </para>

      <para>
       This issues a warning if backslash escapes are used in
       <link linkend="sql-syntax-strings">non-escape (non-<literal>E''</>)
       strings</link>.
      </para>
     </listitem>

     <listitem>
      <para>
       Change the <link linkend="sql-syntax-row-constructors">row
       constructor syntax</link> (<literal>ROW(...)</>) so that
       list elements <literal>foo.*</> will be expanded to a list
       of their member fields, rather than creating a nested
       row type field as formerly (Tom)
      </para>

      <para>
       The new behavior is substantially more useful since it
       allows, for example, triggers to check for data changes
       with <literal>IF row(new.*) IS DISTINCT FROM row(old.*)</>.
       The old behavior is still available by omitting <literal>.*</>.
      </para>
     </listitem>

     <listitem>
      <para>
       Make <link linkend="row-wise-comparison">row comparisons</link>
       follow <acronym>SQL</> standard semantics and allow them
       to be used in index scans (Tom)
      </para>

      <para>
       Previously, row = and &lt;&gt; comparisons followed the
       standard but &lt; &lt;= &gt; &gt;= did not.  A row comparison
       can now be used as an index constraint for a multicolumn
       index matching the row value.
      </para>
     </listitem>

     <listitem>
      <para>
       Make <link linkend="functions-comparison">row <literal>IS <optional>NOT</> NULL</literal></link>
       tests follow <acronym>SQL</> standard semantics (Tom)
      </para>

      <para>
       The former behavior conformed to the standard for simple cases
       with <literal>IS NULL</>, but <literal>IS NOT NULL</> would return
       true if any row field was non-null, whereas the standard says it
       should return true only when all fields are non-null.
      </para>
     </listitem>

     <listitem>
      <para>
       Make <link linkend="SQL-SET-CONSTRAINTS"><command>SET
       CONSTRAINT</></link> affect only one constraint (Kris Jurka)
      </para>

      <para>
       In previous releases, <command>SET CONSTRAINT</> modified
       all constraints with a matching name.  In this release,
       the schema search path is used to modify only the first
       matching constraint.  A schema specification is also
       supported.  This more nearly conforms to the SQL standard.
      </para>
     </listitem>

     <listitem>
      <para>
       Remove <literal>RULE</> permission for tables, for security reasons
       (Tom)
      </para>

      <para>
       As of this release, only a table's owner can create or modify
       rules for the table.  For backwards compatibility,
       <command>GRANT</>/<command>REVOKE RULE</> is still accepted,
       but it does nothing.
      </para>
     </listitem>

     <listitem>
      <para>
       Array comparison improvements (Tom)
      </para>

      <para>
       Now array dimensions are also compared.
      </para>
     </listitem>

     <listitem>
      <para>
       Change <link linkend="functions-array">array concatenation</link>
       to match documented behavior (Tom)
      </para>

      <para>
       This changes the previous behavior where concatenation
       would modify the array lower bound.
      </para>
     </listitem>

     <listitem>
      <para>
       Make command-line options of <application>postmaster</>
       and <link linkend="app-postgres"><application>postgres</></link>
       identical (Peter)
      </para>

      <para>
       This allows the postmaster to pass arguments to each backend
       without using <literal>-o</>.  Note that some options are now
       only available as long-form options, because there were conflicting
       single-letter options.
      </para>
     </listitem>

     <listitem>
      <para>
       Deprecate use of <application>postmaster</> symbolic link (Peter)
      </para>

      <para>
       <application>postmaster</> and <application>postgres</>
       commands now act identically, with the behavior determined
       by command-line options.  The <application>postmaster</> symbolic link is
       kept for compatibility, but is not really needed.
      </para>
     </listitem>

     <listitem>
      <para>
       Change <link
       linkend="guc-log-duration"><varname>log_duration</></link>
       to output even if the query is not output (Tom)
      </para>

      <para>
       In prior releases, <varname>log_duration</> only printed if
       the query appeared earlier in the log.
      </para>
     </listitem>

     <listitem>
      <para>
       Make <link
       linkend="functions-formatting"><function>to_char(time)</></link>
       and <link
       linkend="functions-formatting"><function>to_char(interval)</></link>
       treat <literal>HH</> and <literal>HH12</> as 12-hour
       intervals
      </para>

      <para>
       Most applications should use <literal>HH24</> unless they
       want a 12-hour display.
      </para>
     </listitem>

     <listitem>
      <para>
       Zero unmasked bits in conversion from <link
       linkend="datatype-inet"><type>INET</></link> to <link
       linkend="datatype-inet"><type>CIDR</></link> (Tom)
      </para>

      <para>
       This ensures that the converted value is actually valid for
       <type>CIDR</>.
      </para>
     </listitem>

     <listitem>
      <para>
       Remove <varname>australian_timezones</> configuration variable
       (Joachim Wieland)
      </para>

      <para>
       This variable has been superseded by a more general facility
       for configuring timezone abbreviations.
      </para>
     </listitem>

     <listitem>
      <para>
       Improve cost estimation for nested-loop index scans (Tom)
      </para>

      <para>
       This might eliminate the need to set unrealistically small
       values of <link
       linkend="guc-random-page-cost"><varname>random_page_cost</></link>.
       If you have been using a very small <varname>random_page_cost</>,
       please recheck your test cases.
      </para>
     </listitem>

     <listitem>
      <para>
       Change behavior of <command>pg_dump</> <literal>-n</> and
       <literal>-t</> options.  (Greg Sabino Mullane)
      </para>
      <para>
       See the <command>pg_dump</> manual page for details.
      </para>
     </listitem>

     <listitem>
      <para>
       Change <link linkend="libpq"><application>libpq</></link>
       <function>PQdsplen()</> to return a useful value (Martijn
       van Oosterhout)
      </para>
     </listitem>

     <listitem>
      <para>
       Declare <link linkend="libpq"><application>libpq</></link>
       <function>PQgetssl()</> as returning <literal>void *</>,
       rather than <literal>SSL *</> (Martijn van Oosterhout)
      </para>

      <para>
       This allows applications to use the function without including
       the OpenSSL headers.
      </para>
     </listitem>

     <listitem>
      <para>
       C-language loadable modules must now include a
       <link linkend="xfunc-c-dynload"><literal>PG_MODULE_MAGIC</></link>
       macro call for version compatibility checking
       (Martijn van Oosterhout)
      </para>
     </listitem>

     <listitem>
      <para>
       For security's sake, modules used by a PL/PerlU function are no
       longer available to PL/Perl functions (Andrew)
      </para>
      <note>
       <para>
        This also implies that data can no longer be shared between a PL/Perl
        function and a PL/PerlU function.
        Some Perl installations have not been compiled with the correct flags
        to allow multiple interpreters to exist within a single process.
        In this situation PL/Perl and PL/PerlU cannot both be used in a
        single backend. The solution is to get a Perl installation which
        supports multiple interpreters.
       </para>
      </note>
     </listitem>

     <listitem>
      <para>
       In <filename>contrib/xml2/</>, rename <function>xml_valid()</> to
       <function>xml_is_well_formed()</> (Tom)
      </para>

      <para>
       <function>xml_valid()</> will remain for backward compatibility,
       but its behavior will change to do schema checking in a future
       release.
      </para>
     </listitem>

     <listitem>
      <para>
       Remove <filename>contrib/ora2pg/</>, now at <ulink
       url="http://www.samse.fr/GPL/ora2pg"></ulink>
      </para>
     </listitem>

     <listitem>
      <para>
       Remove contrib modules that have been migrated to PgFoundry:
       <filename>adddepend</>, <filename>dbase</>, <filename>dbmirror</>,
       <filename>fulltextindex</>, <filename>mac</>, <filename>userlock</>
      </para>
     </listitem>

     <listitem>
      <para>
       Remove abandoned contrib modules:
       <filename>mSQL-interface</>, <filename>tips</>
      </para>
     </listitem>

     <listitem>
      <para>
       Remove <acronym>QNX</> and <acronym>BEOS</> ports (Bruce)
      </para>

      <para>
       These ports no longer had active maintainers.
      </para>
     </listitem>

   </itemizedlist>
  </sect2>

  <sect2>
   <title>Changes</title>

   <para>
    Below you will find a detailed account of the
    changes between <productname>PostgreSQL</productname> 8.2 and
    the previous major release.
   </para>

   <sect3>
    <title>Performance Improvements</title>
    <itemizedlist>

     <listitem>
      <para>
       Allow the planner to reorder <link linkend="queries-join">outer
       joins</link> in some circumstances (Tom)
      </para>

      <para>
       In previous releases, outer joins would always be evaluated in
       the order written in the query. This change allows the
       query optimizer to consider reordering outer joins, in cases where
       it can determine that the join order can be changed without
       altering the meaning of the query.  This can make a
       considerable performance difference for queries involving
       multiple outer joins or mixed inner and outer joins.
      </para>
     </listitem>

     <listitem>
      <para>
       Improve efficiency of <link
       linkend="functions-comparisons"><literal>IN</>
       (list-of-expressions)</link> clauses (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Improve sorting speed and reduce memory usage (Simon, Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Improve subtransaction performance (Alvaro, Itagaki Takahiro,
       Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <literal>FILLFACTOR</> to <link
       linkend="SQL-CREATETABLE">table</link> and <link
       linkend="SQL-CREATEINDEX">index</link> creation (ITAGAKI
       Takahiro)
      </para>

      <para>
       This leaves extra free space in each table or index page,
       allowing improved performance as the database grows.  This
       is particularly valuable to maintain clustering.
      </para>
     </listitem>

     <listitem>
      <para>
       Increase default values for <link
       linkend="guc-shared-buffers"><varname>shared_buffers</></link>
       and <varname>max_fsm_pages</>
       (Andrew)
      </para>
     </listitem>

     <listitem>
      <para>
       Improve locking performance by breaking the lock manager tables into
       sections
       (Tom)
      </para>

      <para>
       This allows locking to be more fine-grained, reducing
       contention.
      </para>
     </listitem>

     <listitem>
      <para>
       Reduce locking requirements of sequential scans (Qingqing
       Zhou)
      </para>
     </listitem>

     <listitem>
      <para>
       Reduce locking required for database creation and destruction
       (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Improve the optimizer's selectivity estimates for <link
       linkend="functions-like"><literal>LIKE</></link>, <link
       linkend="functions-like"><literal>ILIKE</></link>, and
       <link linkend="functions-posix-regexp">regular expression</link>
       operations (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Improve planning of joins to <link linkend="ddl-inherit">inherited
       tables</link> and <link linkend="queries-union"><literal>UNION
       ALL</></link> views (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <link linkend="guc-constraint-exclusion">constraint
       exclusion</link> to be applied to <link
       linkend="ddl-inherit">inherited</link> <command>UPDATE</> and
       <command>DELETE</> queries (Tom)
      </para>

      <para>
       <command>SELECT</> already honored constraint exclusion.
      </para>
     </listitem>

     <listitem>
      <para>
       Improve planning of constant <literal>WHERE</> clauses, such as
       a condition that depends only on variables inherited from an
       outer query level (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Protocol-level unnamed prepared statements are re-planned
       for each set of <literal>BIND</> values (Tom)
      </para>

      <para>
       This improves performance because the exact parameter values
       can be used in the plan.
      </para>
     </listitem>

     <listitem>
      <para>
       Speed up vacuuming of B-Tree indexes (Heikki Linnakangas,
       Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Avoid extra scan of tables without indexes during <link
       linkend="SQL-VACUUM"><command>VACUUM</></link> (Greg Stark)
      </para>
     </listitem>

     <listitem>
      <para>
       Improve multicolumn <link linkend="GiST"><acronym>GiST</></link>
       indexing (Oleg, Teodor)
      </para>
     </listitem>

     <listitem>
      <para>
       Remove dead index entries before B-Tree page split (Junji
       Teramoto)
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title>Server Changes</title>
    <itemizedlist>

     <listitem>
      <para>
       Allow a forced switch to a new transaction log file (Simon, Tom)
      </para>

      <para>
       This is valuable for keeping warm standby slave servers
       in sync with the master.  Transaction log file switching now also happens
       automatically during <link
       linkend="functions-admin"><function>pg_stop_backup()</></link>.
       This ensures that all
       transaction log files needed for recovery can be archived immediately.
      </para>
     </listitem>

     <listitem>
      <para>
       Add <acronym>WAL</> informational functions (Simon)
      </para>

      <para>
       Add functions for interrogating the current transaction log insertion
       point and determining <acronym>WAL</> filenames from the
       hex <acronym>WAL</> locations displayed by <link
       linkend="functions-admin"><function>pg_stop_backup()</></link>
       and related functions.
      </para>
     </listitem>

     <listitem>
      <para>
       Improve recovery from a crash during <acronym>WAL</> replay (Simon)
      </para>

      <para>
       The server now does periodic checkpoints during <acronym>WAL</>
       recovery, so if there is a crash, future <acronym>WAL</>
       recovery is shortened.  This also eliminates the need for
       warm standby servers to replay the entire log since the
       base backup if they crash.
      </para>
     </listitem>

     <listitem>
      <para>
       Improve reliability of long-term <acronym>WAL</> replay
       (Heikki, Simon, Tom)
      </para>

      <para>
       Formerly, trying to roll forward through more than 2 billion
       transactions would not work due to XID wraparound.  This meant
       warm standby servers had to be reloaded
       from fresh base backups periodically.
      </para>
     </listitem>

     <listitem>
      <para>
       Add <link
       linkend="guc-archive-timeout"><varname>archive_timeout</></link>
       to force transaction log file switches at a given interval (Simon)
      </para>

      <para>
       This enforces a maximum replication delay for warm standby servers.
      </para>
     </listitem>

     <listitem>
      <para>
       Add native <link linkend="auth-ldap"><acronym>LDAP</></link>
       authentication (Magnus Hagander)
      </para>

      <para>
       This is particularly useful for platforms that do not
       support <acronym>PAM</>, such as Windows.
      </para>
     </listitem>

     <listitem>
      <para>
       Add <link linkend="sql-grant-description-objects"><literal>GRANT
       CONNECT ON DATABASE</></link> (Gevik Babakhani)
      </para>

      <para>
       This gives SQL-level control over database access.  It works as
       an additional filter on top of the existing
       <link linkend="auth-pg-hba-conf"><filename>pg_hba.conf</></link>
       controls.
      </para>
     </listitem>

     <listitem>
      <para>
       Add support for <link linkend="ssl-tcp"><acronym>SSL</>
       Certificate Revocation List</link> (<acronym>CRL</>) files
       (Libor Hoho&scaron;)
      </para>

      <para>
       The server and <application>libpq</> both recognize <acronym>CRL</>
       files now.
      </para>
     </listitem>

     <listitem>
      <para>
       <link linkend="GiST"><acronym>GiST</></link> indexes are
       now clusterable (Teodor)
      </para>
     </listitem>

     <listitem>
      <para>
       Remove routine autovacuum server log entries (Bruce)
      </para>

      <para>
       <link
       linkend="monitoring-stats-views-table"><literal>pg_stat_activity</></link>
       now shows autovacuum activity.
      </para>
     </listitem>

     <listitem>
      <para>
       Track maximum XID age within individual tables, instead of whole databases (Alvaro)
      </para>

      <para>
       This reduces the overhead involved in preventing transaction
       ID wraparound, by avoiding unnecessary VACUUMs.
      </para>
     </listitem>

     <listitem>
      <para>
       Add last vacuum and analyze timestamp columns to the stats
       collector (Larry Rosenman)
      </para>

      <para>
       These values now appear in the <link
       linkend="monitoring-stats-views-table"><literal>pg_stat_*_tables</></link>
       system views.
      </para>
     </listitem>

     <listitem>
      <para>
       Improve performance of statistics monitoring, especially
       <varname>stats_command_string</>
       (Tom, Bruce)
      </para>

      <para>
       This release enables <varname>stats_command_string</> by
       default, now that its overhead is minimal.  This means
       <link
       linkend="monitoring-stats-views-table"><literal>pg_stat_activity</></link>
       will now show all active queries by default.
      </para>
     </listitem>

     <listitem>
      <para>
       Add a <literal>waiting</> column to <link
       linkend="monitoring-stats-views-table"><literal>pg_stat_activity</></link>
       (Tom)
      </para>

      <para>
       This allows <structname>pg_stat_activity</> to show all the
       information included in the <application>ps</> display.
      </para>
     </listitem>

     <listitem>
      <para>
       Add configuration parameter <link
       linkend="guc-update-process-title"><varname>update_process_title</></link>
       to control whether the <application>ps</> display is updated
       for every command (Bruce)
      </para>

      <para>
       On platforms where it is expensive to update the <application>ps</>
       display, it might be worthwhile to turn this off and rely solely on
       <structname>pg_stat_activity</> for status information.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow units to be specified in configuration settings
       (Peter)
      </para>

      <para>
       For example, you can now set <link
       linkend="guc-shared-buffers"><varname>shared_buffers</></link>
       to <literal>32MB</> rather than mentally converting sizes.
      </para>
     </listitem>

     <listitem>
      <para>
       Add support for <link linkend="config-setting">include
       directives</link> in <filename>postgresql.conf</> (Joachim
       Wieland)
      </para>
     </listitem>

     <listitem>
      <para>
       Improve logging of protocol-level prepare/bind/execute
       messages (Bruce, Tom)
      </para>

      <para>
       Such logging now shows statement names, bind parameter
       values, and the text of the query being executed.  Also,
       the query text is properly included in logged error messages
       when enabled by <varname>log_min_error_statement</>.
      </para>
     </listitem>

     <listitem>
      <para>
       Prevent <link
       linkend="guc-max-stack-depth"><varname>max_stack_depth</></link>
       from being set to unsafe values
      </para>

      <para>
       On platforms where we can determine the actual kernel stack depth
       limit (which is most), make sure that the initial default value of
       <varname>max_stack_depth</> is safe, and reject attempts to set it
       to unsafely large values.
      </para>
     </listitem>

     <listitem>
      <para>
       Enable highlighting of error location in query in more
       cases (Tom)
      </para>

      <para>
       The server is now able to report a specific error location for
       some semantic errors (such as unrecognized column name), rather
       than just for basic syntax errors as before.
      </para>
     </listitem>

     <listitem>
      <para>
       Fix <quote>failed to re-find parent key</> errors in
       <command>VACUUM</> (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Clean out <filename>pg_internal.init</> cache files during server
       restart (Simon)
      </para>

      <para>
       This avoids a hazard that the cache files might contain stale
       data after PITR recovery.
      </para>
     </listitem>

     <listitem>
      <para>
       Fix race condition for truncation of a large relation across a
       gigabyte boundary by <command>VACUUM</> (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Fix bug causing needless deadlock errors on row-level locks (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Fix bugs affecting multi-gigabyte hash indexes (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Each backend process is now its own process group leader (Tom)
      </para>

      <para>
       This allows query cancel to abort subprocesses invoked from a
       backend or archive/recovery process.
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title>Query Changes</title>
    <itemizedlist>

     <listitem>
      <para>
       Add <link linkend="SQL-INSERT"><command>INSERT</></link>/<link
       linkend="SQL-UPDATE"><command>UPDATE</></link>/<link
       linkend="SQL-DELETE"><command>DELETE</></link>
       <literal>RETURNING</> (Jonah Harris, Tom)
      </para>

      <para>
       This allows these commands to return values, such as the
       computed serial key for a new row.  In the <command>UPDATE</>
       case, values from the updated version of the row are returned.
      </para>
     </listitem>

     <listitem>
      <para>
       Add support for multiple-row <link
       linkend="queries-values"><literal>VALUES</></link> clauses,
       per SQL standard (Joe, Tom)
      </para>

      <para>
       This allows <command>INSERT</> to insert multiple rows of
       constants, or queries to generate result sets using constants.
       For example, <literal>INSERT ...  VALUES (...), (...),
       ....</>, and <literal>SELECT * FROM (VALUES (...), (...),
       ....) AS alias(f1, ...)</>.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <link linkend="SQL-UPDATE"><command>UPDATE</></link>
       and <link linkend="SQL-DELETE"><command>DELETE</></link>
       to use an alias for the target table (Atsushi Ogawa)
      </para>

      <para>
       The SQL standard does not permit an alias in these commands, but
       many database systems allow one anyway for notational convenience.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <link linkend="SQL-UPDATE"><command>UPDATE</></link>
       to set multiple columns with a list of values (Susanne
       Ebrecht)
      </para>

      <para>
       This is basically a short-hand for assigning the columns
       and values in pairs.  The syntax is <literal>UPDATE tab
       SET (<replaceable>column</>, ...) = (<replaceable>val</>, ...)</>.
      </para>
     </listitem>

     <listitem>
      <para>
       Make row comparisons work per standard (Tom)
      </para>

      <para>
       The forms &lt;, &lt;=, &gt;, &gt;= now compare rows lexicographically,
       that is, compare the first elements, if equal compare the second
       elements, and so on.  Formerly they expanded to an AND condition
       across all the elements, which was neither standard nor very useful.
      </para>
     </listitem>

     <listitem>
      <para>
       Add <link linkend="SQL-TRUNCATE"><literal>CASCADE</></link>
       option to <command>TRUNCATE</> (Joachim Wieland)
      </para>

      <para>
       This causes <command>TRUNCATE</> to automatically include all tables
       that reference the specified table(s) via foreign keys.  While
       convenient, this is a dangerous tool &mdash; use with caution!
      </para>
     </listitem>

     <listitem>
      <para>
       Support <literal>FOR UPDATE</> and <literal>FOR SHARE</>
       in the same <link linkend="SQL-INSERT"><literal>SELECT</></link>
       command (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <link linkend="functions-comparisons"><literal>IS NOT
       DISTINCT FROM</></link> (Pavel Stehule)
      </para>

      <para>
       This operator is similar to equality (<literal>=</>), but
       evaluates to true when both left and right operands are
       <literal>NULL</>, and to false when just one is, rather than
       yielding <literal>NULL</> in these cases.
      </para>
     </listitem>

     <listitem>
      <para>
       Improve the length output used by <link
       linkend="queries-union"><literal>UNION</></link>/<literal>INTERSECT</>/<literal>EXCEPT</>
       (Tom)
      </para>

      <para>
       When all corresponding columns are of the same defined length, that
       length is used for the result, rather than a generic length.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <link linkend="functions-like"><literal>ILIKE</></link>
       to work for multi-byte encodings (Tom)
      </para>

      <para>
       Internally, <literal>ILIKE</> now calls <function>lower()</>
       and then uses <literal>LIKE</>.  Locale-specific regular
       expression patterns still do not work in these encodings.
      </para>
     </listitem>

     <listitem>
      <para>
       Enable <link
       linkend="guc-standard-conforming-strings"><varname>standard_conforming_strings</></link>
       to be turned <literal>on</> (Kevin Grittner)
      </para>

      <para>
       This allows backslash escaping in strings to be disabled,
       making <productname>PostgreSQL</> more
       standards-compliant.  The default is <literal>off</> for backwards
       compatibility, but future releases will default this to <literal>on</>.
      </para>
     </listitem>

     <listitem>
      <para>
       Do not flatten subqueries that contain <literal>volatile</>
       functions in their target lists (Jaime Casanova)
      </para>

      <para>
       This prevents surprising behavior due to multiple evaluation
       of a <literal>volatile</> function (such as <function>random()</>
       or <function>nextval()</>).  It might cause performance
       degradation in the presence of functions that are unnecessarily
       marked as <literal>volatile</>.
      </para>
     </listitem>

     <listitem>
      <para>
       Add system views <link
       linkend="view-pg-prepared-statements"><literal>pg_prepared_statements</></link>
       and <link
       linkend="view-pg-cursors"><literal>pg_cursors</></link>
       to show prepared statements and open cursors (Joachim Wieland, Neil)
      </para>

      <para>
       These are very useful in pooled connection setups.
      </para>
     </listitem>

     <listitem>
      <para>
       Support portal parameters in <link
       linkend="SQL-EXPLAIN"><command>EXPLAIN</></link> and <link
       linkend="SQL-EXECUTE"><command>EXECUTE</></link> (Tom)
      </para>

      <para>
       This allows, for example, <acronym>JDBC</> <literal>?</> parameters to
       work in these commands.
      </para>
     </listitem>

     <listitem>
      <para>
       If <acronym>SQL</>-level <link
       linkend="SQL-PREPARE"><command>PREPARE</></link> parameters
       are unspecified, infer their types from the content of the
       query (Neil)
      </para>

      <para>
       Protocol-level <command>PREPARE</> already did this.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <literal>LIMIT</> and <literal>OFFSET</> to exceed
       two billion (Dhanaraj M)
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title>Object Manipulation Changes</title>
    <itemizedlist>

     <listitem>
      <para>
       Add <literal>TABLESPACE</> clause to <link
       linkend="SQL-CREATETABLEAS"><command>CREATE TABLE AS</></link>
       (Neil)
      </para>

      <para>
       This allows a tablespace to be specified for the new table.
      </para>
     </listitem>

     <listitem>
      <para>
       Add <literal>ON COMMIT</> clause to <link
       linkend="SQL-CREATETABLEAS"><command>CREATE TABLE AS</></link>
       (Neil)
      </para>

      <para>
       This allows temporary tables to be truncated or dropped on
       transaction commit.  The default behavior is for the table
       to remain until the session ends.
      </para>
     </listitem>

     <listitem>
      <para>
       Add <literal>INCLUDING CONSTRAINTS</> to <link
       linkend="SQL-CREATETABLE"><command>CREATE TABLE LIKE</></link>
       (Greg Stark)
      </para>

      <para>
       This allows easy copying of <literal>CHECK</> constraints to a new
       table.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow the creation of placeholder (shell) <link
       linkend="SQL-CREATETYPE">types</link> (Martijn van Oosterhout)
      </para>

      <para>
       A shell type declaration creates a type name, without specifying
       any of the details of the type.  Making a shell type is useful
       because it allows cleaner declaration of the type's input/output
       functions, which must exist before the type can be defined <quote>for
       real</>.  The syntax is <command>CREATE TYPE <replaceable
       class="parameter">typename</replaceable></>.
      </para>
     </listitem>

     <listitem>
      <para>
       <link linkend="SQL-CREATEAGGREGATE">Aggregate functions</link>
       now support multiple input parameters (Sergey Koposov, Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Add new aggregate creation <link
       linkend="SQL-CREATEAGGREGATE">syntax</link> (Tom)
      </para>

      <para>
       The new syntax is <command>CREATE AGGREGATE
       <replaceable>aggname</> (<replaceable>input_type</>)
       (<replaceable>parameter_list</>)</command>.  This more
       naturally supports the new multi-parameter aggregate
       functionality.  The previous syntax is still supported.
      </para>
     </listitem>

     <listitem>
      <para>
       Add <link
       linkend="SQL-ALTERROLE"><command>ALTER ROLE PASSWORD NULL</></link>
       to remove a previously set role password (Peter)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <command>DROP</> object <literal>IF EXISTS</> for many
       object types (Andrew)
      </para>

      <para>
       This allows <command>DROP</> operations on non-existent
       objects without generating an error.
      </para>
     </listitem>

     <listitem>
      <para>
       Add <link linkend="SQL-DROP-OWNED"><literal>DROP OWNED</></link>
       to drop all objects owned by a role (Alvaro)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <link linkend="SQL-REASSIGN-OWNED"><literal>REASSIGN
       OWNED</></link> to reassign ownership of all objects owned
       by a role (Alvaro)
      </para>

      <para>
       This, and <literal>DROP OWNED</> above, facilitate dropping
       roles.
      </para>
     </listitem>

     <listitem>
      <para>
       Add <link linkend="SQL-GRANT"><command>GRANT ON SEQUENCE</></link>
       syntax (Bruce)
      </para>

      <para>
       This was added for setting sequence-specific permissions.
       <literal>GRANT ON TABLE</> for sequences is still supported
       for backward compatibility.
      </para>
     </listitem>

     <listitem>
      <para>
       Add <link linkend="SQL-GRANT"><literal>USAGE</></link>
       permission for sequences that allows only <function>currval()</>
       and <function>nextval()</>, not <function>setval()</>
       (Bruce)
      </para>

      <para>
       <literal>USAGE</> permission allows more fine-grained
       control over sequence access.  Granting <literal>USAGE</>
       allows users to increment
       a sequence, but prevents them from setting the sequence to
       an arbitrary value using <function>setval()</>.
      </para>
     </listitem>

     <listitem>
      <para>
       Add <link linkend="SQL-ALTERTABLE"><literal>ALTER TABLE
       [ NO ] INHERIT</></link> (Greg Stark)
      </para>

      <para>
       This allows inheritance to be adjusted dynamically, rather than
       just at table creation and destruction.  This is very valuable
       when using inheritance to implement table partitioning.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <link linkend="SQL-COMMENT">comments</link> on global
       objects to be stored globally (Kris Jurka)
      </para>

      <para>
       Previously, comments attached to databases were stored in individual
       databases, making them ineffective, and there was no provision
       at all for comments on roles or tablespaces.  This change adds a new
       shared catalog <link
       linkend="catalog-pg-shdescription"><structname>pg_shdescription</structname></link>
       and stores comments on databases, roles, and tablespaces therein.
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title>Utility Command Changes</title>
    <itemizedlist>

     <listitem>
      <para>
       Add option to allow indexes to be created without blocking
       concurrent writes to the table (Greg Stark, Tom)
      </para>

      <para>
       The new syntax is <link linkend="SQL-CREATEINDEX"><command>CREATE
       INDEX CONCURRENTLY</></link>.  The default behavior is
       still to block table modification while a index is being
       created.
      </para>
     </listitem>

     <listitem>
      <para>
       Provide <link linkend="functions-advisory-locks">advisory
       locking</link> functionality (Abhijit Menon-Sen, Tom)
      </para>

      <para>
       This is a new locking API designed to replace what used to be
       in /contrib/userlock.  The userlock code is now on pgfoundry.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <link linkend="SQL-COPY"><command>COPY</></link> to
       dump a <command>SELECT</> query (Zoltan Boszormenyi, Karel
       Zak)
      </para>

      <para>
       This allows <command>COPY</> to dump arbitrary <acronym>SQL</>
       queries. The syntax is <literal>COPY (SELECT ...) TO</>.
      </para>
     </listitem>

     <listitem>
      <para>
       Make the <link linkend="SQL-COPY"><command>COPY</></link>
       command return a command tag that includes the number of
       rows copied (Volkan YAZICI)
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <link linkend="SQL-VACUUM"><command>VACUUM</></link>
       to expire rows without being affected by other concurrent
       <command>VACUUM</> operations (Hannu Krossing, Alvaro, Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Make <link linkend="APP-INITDB"><application>initdb</></link>
       detect the operating system locale and set the default
       <varname>DateStyle</> accordingly (Peter)
      </para>

      <para>
       This makes it more likely that the installed
       <filename>postgresql.conf</> <varname>DateStyle</> value will
       be as desired.
      </para>
     </listitem>

     <listitem>
      <para>
       Reduce number of progress messages displayed by <application>initdb</> (Tom)
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title>Date/Time Changes</title>
    <itemizedlist>

     <listitem>
      <para>
       Allow full timezone names in <link
       linkend="datatype-datetime"><type>timestamp</></link> input values
       (Joachim Wieland)
      </para>

      <para>
       For example, <literal>'2006-05-24 21:11
       America/New_York'::timestamptz</>.
      </para>
     </listitem>

     <listitem>
      <para>
       Support configurable timezone abbreviations (Joachim Wieland)
      </para>

      <para>
       A desired set of timezone abbreviations can be chosen via the
       configuration parameter <link
       linkend="guc-timezone-abbreviations"><varname>timezone_abbreviations</></link>.
      </para>
     </listitem>

     <listitem>
      <para>
       Add <link
       linkend="view-pg-timezone-abbrevs"><varname>pg_timezone_abbrevs</></link>
       and <link
       linkend="view-pg-timezone-names"><varname>pg_timezone_names</></link>
       views to show supported timezones (Magnus Hagander)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <link
       linkend="functions-datetime-table"><function>clock_timestamp()</></link>,
       <link
       linkend="functions-datetime-table"><function>statement_timestamp()</></link>,
       and <link
       linkend="functions-datetime-table"><function>transaction_timestamp()</></link>
       (Bruce)
      </para>

      <para>
       <function>clock_timestamp()</> is the current wall-clock time,
       <function>statement_timestamp()</> is the time the current
       statement arrived at the server, and
       <function>transaction_timestamp()</> is an alias for
       <function>now()</>.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <link
       linkend="functions-formatting"><function>to_char()</></link>
       to print localized month and day names (Euler Taveira de
       Oliveira)
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <link
       linkend="functions-formatting"><function>to_char(time)</></link>
       and <link
       linkend="functions-formatting"><function>to_char(interval)</></link>
       to output <acronym>AM</>/<acronym>PM</> specifications
       (Bruce)
      </para>

      <para>
       Intervals and times are treated as 24-hour periods, e.g.
       <literal>25 hours</> is considered <acronym>AM</>.
      </para>
     </listitem>

     <listitem>
      <para>
       Add new function <link
       linkend="functions-datetime-table"><function>justify_interval()</></link>
       to adjust interval units (Mark Dilger)
      </para>
     </listitem>

     <listitem>
      <para>
       Allow timezone offsets up to 14:59 away from GMT
      </para>

      <para>
       Kiribati uses GMT+14, so we'd better accept that.
      </para>
     </listitem>

     <listitem>
      <para>
       Interval computation improvements (Michael Glaesemann, Bruce)
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title>Other Data Type and Function Changes</title>
    <itemizedlist>

     <listitem>
      <para>
       Allow arrays to contain <literal>NULL</> elements (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Allow assignment to array elements not contiguous with the existing
       entries (Tom)
      </para>

      <para>
       The intervening array positions will be filled with nulls.
       This is per SQL standard.
      </para>
     </listitem>

     <listitem>
      <para>
       New built-in <link linkend="functions-array">operators</link>
       for array-subset comparisons (<literal>@&gt;</>,
       <literal>&lt;@</>, <literal>&amp;&amp;</>) (Teodor, Tom)
      </para>

      <para>
       These operators can be indexed for many data types using
       <acronym>GiST</> or <acronym>GIN</> indexes.
      </para>
     </listitem>

     <listitem>
      <para>
       Add convenient arithmetic <link
       linkend="cidr-inet-operators-table">operations</link> on
       <type>INET</>/<type>CIDR</> values (Stephen R. van den
       Berg)
      </para>

      <para>
       The new operators are <literal>&amp;</> (and), <literal>|</>
       (or), <literal>~</> (not), <type>inet</> <literal>+</> <type>int8</>,
       <type>inet</> <literal>-</> <type>int8</>, and
       <type>inet</> <literal>-</> <type>inet</>.
      </para>
     </listitem>

     <listitem>
      <para>
       Add new <link
       linkend="functions-aggregate-statistics-table">aggregate functions</link>
       from SQL:2003 (Neil)
      </para>

      <para>
       The new functions are <function>var_pop()</>,
       <function>var_samp()</>, <function>stddev_pop()</>, and
       <function>stddev_samp()</>.  <function>var_samp()</> and
       <function>stddev_samp()</> are merely renamings of the
       existing aggregates <function>variance()</> and
       <function>stddev()</>.  The latter names remain available
       for backward compatibility.
      </para>
     </listitem>

     <listitem>
      <para>
       Add SQL:2003 statistical <link
       linkend="functions-aggregate-statistics-table">aggregates</link>
       (Sergey Koposov)
      </para>

      <para>
       New functions:  <function>regr_intercept()</>,
       <function>regr_slope()</>, <function>regr_r2()</>,
       <function>corr()</>, <function>covar_samp()</>,
       <function>covar_pop()</>, <function>regr_avgx()</>,
       <function>regr_avgy()</>, <function>regr_sxy()</>,
       <function>regr_sxx()</>, <function>regr_syy()</>,
       <function>regr_count()</>.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <link linkend="SQL-CREATEDOMAIN">domains</link> to be
       based on other domains (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Properly enforce domain <link
       linkend="ddl-constraints"><literal>CHECK</></link> constraints
       everywhere (Neil, Tom)
      </para>

      <para>
       For example, the result of a user-defined function that is
       declared to return a domain type is now checked against the
       domain's constraints. This closes a significant hole in the domain
       implementation.
      </para>
     </listitem>

     <listitem>
      <para>
       Fix problems with dumping renamed <link
       linkend="datatype-serial"><type>SERIAL</></link> columns
       (Tom)
      </para>

      <para>
       The fix is to dump a <type>SERIAL</> column by explicitly
       specifying its <literal>DEFAULT</> and sequence elements,
       and reconstructing the <type>SERIAL</> column on reload
       using a new <link linkend="SQL-ALTERSEQUENCE"><command>ALTER
       SEQUENCE OWNED BY</></link> command.  This also allows
       dropping a <type>SERIAL</> column specification.
      </para>
     </listitem>

     <listitem>
      <para>
       Add a server-side sleep function <link
       linkend="functions-datetime-delay"><function>pg_sleep()</></link>
       (Joachim Wieland)
      </para>
     </listitem>

     <listitem>
      <para>
       Add all comparison operators for the <link
       linkend="datatype-oid"><type>tid</></link> (tuple id) data
       type (Mark Kirkwood, Greg Stark, Tom)
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title>PL/PgSQL Server-Side Language Changes</title>
    <itemizedlist>

     <listitem>
      <para>
       Add <literal>TG_table_name</> and <literal>TG_table_schema</> to
       trigger parameters (Andrew)
      </para>

      <para>
       <literal>TG_relname</> is now deprecated.  Comparable
       changes have been made in the trigger parameters for the other
       PLs as well.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <literal>FOR</> statements to return values to scalars
       as well as records and row types (Pavel Stehule)
      </para>
     </listitem>

     <listitem>
      <para>
       Add a <literal>BY</> clause to the <literal>FOR</> loop,
       to control the iteration increment (Jaime Casanova)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <literal>STRICT</> to <link
       linkend="plpgsql-statements-sql-onerow"><command>SELECT
       INTO</></link> (Matt Miller)
      </para>

      <para>
       <literal>STRICT</> mode throws an exception if more or less
       than one row is returned by the <command>SELECT</>, for
       <productname>Oracle PL/SQL</> compatibility.
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title>PL/Perl Server-Side Language Changes</title>
    <itemizedlist>

     <listitem>
      <para>
       Add <literal>table_name</> and <literal>table_schema</> to
       trigger parameters (Adam Sj&oslash;gren)
      </para>
     </listitem>

     <listitem>
      <para>
       Add prepared queries (Dmitry Karasik)
      </para>
     </listitem>

     <listitem>
      <para>
       Make <literal>$_TD</> trigger data a global variable (Andrew)
      </para>

      <para>
       Previously, it was lexical, which caused unexpected sharing
       violations.
      </para>
     </listitem>

     <listitem>
      <para>
       Run PL/Perl and PL/PerlU in separate interpreters, for security
       reasons (Andrew)
      </para>
      <para>
       In consequence, they can no longer share data nor loaded modules.
       Also, if Perl has not been compiled with the requisite flags to
       allow multiple interpreters, only one of these languages can be used
       in any given backend process.
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title>PL/Python Server-Side Language Changes</title>
    <itemizedlist>

     <listitem>
      <para>
       Named parameters are passed as ordinary variables, as well as in the
       <literal>args[]</> array (Sven Suursoho)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <literal>table_name</> and <literal>table_schema</> to
       trigger parameters (Andrew)
      </para>
     </listitem>

     <listitem>
      <para>
       Allow returning of composite types and result sets (Sven Suursoho)
      </para>
     </listitem>

     <listitem>
      <para>
       Return result-set as <literal>list</>, <literal>iterator</>,
       or <literal>generator </>(Sven Suursoho)
      </para>
     </listitem>

     <listitem>
      <para>
       Allow functions to return <literal>void</> (Neil)
      </para>
     </listitem>

     <listitem>
      <para>
       Python 2.5 is now supported (Tom)
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title><link linkend="APP-PSQL"><application>psql</></link> Changes</title>
    <itemizedlist>

     <listitem>
      <para>
       Add new command <literal>\password</> for changing role
       password with client-side password encryption (Peter)
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <literal>\c</> to connect to a new host and port
       number (David, Volkan YAZICI)
      </para>
     </listitem>

     <listitem>
      <para>
       Add tablespace display to <literal>\l+</> (Philip Yarra)
      </para>
     </listitem>

     <listitem>
      <para>
       Improve <literal>\df</> slash command to include the argument
       names and modes (<literal>OUT</> or <literal>INOUT</>) of
       the function (David Fetter)
      </para>
     </listitem>

     <listitem>
      <para>
       Support binary <command>COPY</> (Andreas Pflug)
      </para>
     </listitem>

     <listitem>
      <para>
       Add option to run the entire session in a single transaction
       (Simon)
      </para>

      <para>
       Use option <literal>-1</> or <literal>--single-transaction</>.
      </para>
     </listitem>

     <listitem>
      <para>
       Support for automatically retrieving <command>SELECT</>
       results in batches using a cursor (Chris Mair)
      </para>

      <para>
       This is enabled using <command>\set FETCH_COUNT
       <replaceable>n</></command>. This
       feature allows large result sets to be retrieved in
       <application>psql</> without attempting to buffer the entire
       result set in memory.
      </para>
     </listitem>

     <listitem>
      <para>
       Make multi-line values align in the proper column
       (Martijn van Oosterhout)
      </para>

      <para>
       Field values containing newlines are now displayed in a more
       readable fashion.
      </para>
     </listitem>

     <listitem>
      <para>
       Save multi-line statements as a single entry, rather than
       one line at a time (Sergey E. Koposov)
      </para>

      <para>
       This makes up-arrow recall of queries easier.  (This is
       not available on Windows, because that platform uses the native
       command-line editing present in the operating system.)
      </para>
     </listitem>

     <listitem>
      <para>
       Make the line counter 64-bit so it can handle files with more
       than two billion lines (David Fetter)
      </para>
     </listitem>

     <listitem>
      <para>
       Report both the returned data and the command status tag
       for <command>INSERT</>/<command>UPDATE</>/<command>DELETE
       RETURNING</> (Tom)
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title><link linkend="APP-PGDUMP"><application>pg_dump</></link> Changes</title>
    <itemizedlist>

     <listitem>
      <para>
       Allow complex selection of objects to be included or excluded
       by <application>pg_dump</> (Greg Sabino Mullane)
      </para>

      <para>
       <application>pg_dump</> now supports multiple <literal>-n</>
       (schema) and <literal>-t</> (table) options, and adds
       <literal>-N</> and <literal>-T</> options to exclude objects.
       Also, the arguments of these switches can now be wild-card expressions
       rather than single object names, for example
       <literal>-t 'foo*'</>, and a schema can be part of
       a <literal>-t</> or <literal>-T</> switch, for example
       <literal>-t schema1.table1</>.
      </para>
     </listitem>

     <listitem>
      <para>
       Add <link linkend="APP-PGRESTORE"><application>pg_restore</></link>
       <literal>--no-data-for-failed-tables</> option to suppress
       loading data if table creation failed (i.e., the table already
       exists) (Martin Pitt)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <link linkend="APP-PGRESTORE"><application>pg_restore</></link>
       option to run the entire session in a single transaction
       (Simon)
      </para>

      <para>
       Use option <literal>-1</> or <literal>--single-transaction</>.
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title><link linkend="libpq"><application>libpq</></link> Changes</title>
    <itemizedlist>

     <listitem>
      <para>
       Add <link
       linkend="libpq-misc"><function>PQencryptPassword()</></link>
       to encrypt passwords (Tom)
      </para>

      <para>
       This allows passwords to be sent pre-encrypted for commands
       like <link linkend="SQL-ALTERROLE"><command>ALTER ROLE ...
       PASSWORD</></link>.
      </para>
     </listitem>

     <listitem>
      <para>
       Add function <link
       linkend="libpq-threading"><function>PQisthreadsafe()</></link>
       (Bruce)
      </para>

      <para>
       This allows applications to query the thread-safety status
       of the library.
      </para>
     </listitem>

     <listitem>
      <para>
       Add <link
       linkend="libpq-exec-main"><function>PQdescribePrepared()</></link>,
       <link
       linkend="libpq-exec-main"><function>PQdescribePortal()</></link>,
       and related functions to return information about previously
       prepared statements and open cursors (Volkan YAZICI)
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <link linkend="libpq-ldap"><acronym>LDAP</></link> lookups
       from <link
       linkend="libpq-pgservice"><filename>pg_service.conf</></link>
       (Laurenz Albe)
      </para>
     </listitem>

     <listitem>
      <para>
       Allow a hostname in <link
       linkend="libpq-pgpass"><filename>~/.pgpass</></link>
       to match the default socket directory (Bruce)
      </para>

      <para>
       A blank hostname continues to match any Unix-socket connection,
       but this addition allows entries that are specific to one of
       several postmasters on the machine.
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title><link linkend="ecpg"><application>ecpg</></link> Changes</title>
    <itemizedlist>

     <listitem>
      <para>
       Allow <link linkend="SQL-SHOW"><command>SHOW</></link> to
       put its result into a variable (Joachim Wieland)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <link linkend="SQL-COPY"><command>COPY TO STDOUT</></link>
       (Joachim Wieland)
      </para>
     </listitem>

     <listitem>
      <para>
       Add regression tests (Joachim Wieland, Michael)
      </para>
     </listitem>

     <listitem>
      <para>
       Major source code cleanups (Joachim Wieland, Michael)
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title><application>Windows</> Port</title>
    <itemizedlist>

     <listitem>
      <para>
       Allow <acronym>MSVC</> to compile the <productname>PostgreSQL</>
       server (Magnus, Hiroshi Saito)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <acronym>MSVC</> support for utility commands and <link
       linkend="APP-PGDUMP"><application>pg_dump</></link> (Hiroshi
       Saito)
      </para>
     </listitem>

     <listitem>
      <para>
       Add support for Windows code pages <literal>1253</>,
       <literal>1254</>, <literal>1255</>, and <literal>1257</>
       (Kris Jurka)
      </para>
     </listitem>

     <listitem>
      <para>
       Drop privileges on startup, so that the server can be started from
       an administrative account (Magnus)
      </para>
     </listitem>

     <listitem>
      <para>
       Stability fixes (Qingqing Zhou, Magnus)
      </para>
     </listitem>

     <listitem>
      <para>
       Add native semaphore implementation (Qingqing Zhou)
      </para>

      <para>
       The previous code mimicked SysV semaphores.
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title>Source Code Changes</title>
    <itemizedlist>

     <listitem>
      <para>
       Add <link linkend="GIN"><acronym>GIN</></link> (Generalized
       Inverted iNdex) index access method (Teodor, Oleg)
      </para>
     </listitem>

     <listitem>
      <para>
       Remove R-tree indexing (Tom)
      </para>

      <para>
       Rtree has been re-implemented using <link
       linkend="GiST"><acronym>GiST</></link>. Among other
       differences, this means that rtree indexes now have support
       for crash recovery via write-ahead logging (WAL).
      </para>
     </listitem>

     <listitem>
      <para>
       Reduce libraries needlessly linked into the backend (Martijn
       van Oosterhout, Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Add a configure flag to allow libedit to be preferred over
       <acronym>GNU</> readline (Bruce)
      </para>

      <para>
       Use configure <link
       linkend="configure"><literal>--with-libedit-preferred</></link>.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow installation into directories containing spaces
       (Peter)
      </para>
     </listitem>

     <listitem>
      <para>
       Improve ability to relocate installation directories (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Add support for <productname>Solaris x86_64</> using the
       <productname>Solaris</> compiler (Pierre Girard, Theo
       Schlossnagle, Bruce)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <application>DTrace</> support (Robert Lor)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <literal>PG_VERSION_NUM</> for use by third-party
       applications wanting to test the backend version in C using &gt;
       and &lt; comparisons (Bruce)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <literal>XLOG_BLCKSZ</> as independent from <literal>BLCKSZ</>
       (Mark Wong)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <literal>LWLOCK_STATS</> define to report locking
       activity (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Emit warnings for unknown <application>configure</> options
       (Martijn van Oosterhout)
      </para>
     </listitem>

     <listitem>
      <para>
       Add server support for <quote>plugin</> libraries
       that can be used for add-on tasks such as debugging and performance
       measurement (Korry Douglas)
      </para>

      <para>
       This consists of two features: a table of <quote>rendezvous
       variables</> that allows separately-loaded shared libraries to
       communicate, and a new configuration parameter <link
       linkend="guc-local-preload-libraries"><varname>local_preload_libraries</></link>
       that allows libraries to be loaded into specific sessions without
       explicit cooperation from the client application.  This allows
       external add-ons to implement features such as a PL/PgSQL debugger.
      </para>
     </listitem>

     <listitem>
      <para>
       Rename existing configuration parameter
       <varname>preload_libraries</> to <link
       linkend="guc-shared-preload-libraries"><varname>shared_preload_libraries</></link>
       (Tom)
      </para>

      <para>
       This was done for clarity in comparison to
       <varname>local_preload_libraries</>.
      </para>
     </listitem>

     <listitem>
      <para>
       Add new configuration parameter <link
       linkend="guc-server-version-num"><varname>server_version_num</></link>
       (Greg Sabino Mullane)
      </para>

      <para>
       This is like <varname>server_version</varname>, but is an
       integer, e.g.  <literal>80200</>. This allows applications to
       make version checks more easily.
      </para>
     </listitem>

     <listitem>
      <para>
       Add a configuration parameter <link
       linkend="guc-seq-page-cost"><varname>seq_page_cost</></link>
       (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Re-implement the <link linkend="regress">regression test</link> script as a C program
       (Magnus, Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Allow loadable modules to allocate shared memory and
       lightweight locks (Marc Munro)
      </para>
     </listitem>

     <listitem>
      <para>
       Add automatic initialization and finalization of dynamically
       loaded libraries (Ralf Engelschall, Tom)
      </para>

      <para>
       New <link linkend="xfunc-c-dynload">functions</link>
       <function>_PG_init()</> and <function>_PG_fini()</> are
       called if the library defines such symbols.  Hence we no
       longer need to specify an initialization function in
       <varname>shared_preload_libraries</>; we can assume that
       the library used the <function>_PG_init()</> convention
       instead.
      </para>
     </listitem>

     <listitem>
      <para>
       Add <link
       linkend="xfunc-c-dynload"><literal>PG_MODULE_MAGIC</></link>
       header block to all shared object files (Martijn van
       Oosterhout)
      </para>

      <para>
       The magic block prevents version mismatches between loadable object
       files and servers.
      </para>
     </listitem>

     <listitem>
      <para>
        Add shared library support for AIX (Laurenz Albe)
      </para>
     </listitem>

     <listitem>
      <para>
       New <link linkend="datatype-xml"><acronym>XML</></link>
       documentation section (Bruce)
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title>Contrib Changes</title>
    <itemizedlist>

     <listitem>
      <para>
       Major tsearch2 improvements (Oleg, Teodor)
      </para>

      <itemizedlist>

       <listitem>
        <para>
         multibyte encoding support, including <acronym>UTF8</>
        </para>
       </listitem>
       <listitem>
        <para>
         query rewriting support
        </para>
       </listitem>
       <listitem>
        <para>
         improved ranking functions
        </para>
       </listitem>
       <listitem>
        <para>
         thesaurus dictionary support
        </para>
       </listitem>
       <listitem>
        <para>
         Ispell dictionaries now recognize <application>MySpell</>
         format, used by <application>OpenOffice</>
        </para>
       </listitem>
       <listitem>
        <para>
         <acronym>GIN</> support
        </para>
       </listitem>

      </itemizedlist>

     </listitem>

     <listitem>
      <para>
       Add adminpack module containing <application>Pgadmin</> administration
       functions (Dave)
      </para>

      <para>
       These functions provide additional file system access
       routines not present in the default <productname>PostgreSQL</>
       server.
      </para>
     </listitem>

     <listitem>
      <para>
       Add sslinfo module (Victor Wagner)
      </para>

      <para>
       Reports information about the current connection's <acronym>SSL</>
       certificate.
      </para>
     </listitem>

     <listitem>
      <para>
       Add pgrowlocks module (Tatsuo)
      </para>

      <para>
       This shows row locking information for a specified table.
      </para>
     </listitem>

     <listitem>
      <para>
       Add hstore module (Oleg, Teodor)
      </para>
     </listitem>

     <listitem>
      <para>
       Add isn module, replacing isbn_issn (Jeremy Kronuz)
      </para>

      <para>
       This new implementation supports <acronym>EAN13</>, <acronym>UPC</>,
       <acronym>ISBN</> (books), <acronym>ISMN</> (music), and
       <acronym>ISSN</> (serials).
      </para>
     </listitem>

     <listitem>
      <para>
       Add index information functions to pgstattuple (ITAGAKI Takahiro,
       Satoshi Nagayasu)
      </para>
     </listitem>

     <listitem>
      <para>
       Add pg_freespacemap module to display free space map information
       (Mark Kirkwood)
      </para>
     </listitem>

     <listitem>
      <para>
       pgcrypto now has all planned functionality (Marko Kreen)
      </para>
      <itemizedlist>
       <listitem>
        <para>
         Include iMath library in pgcrypto to have the public-key encryption
         functions always available.
        </para>
       </listitem>
       <listitem>
        <para>
         Add SHA224 algorithm that was missing in OpenBSD code.
        </para>
       </listitem>
       <listitem>
        <para>
         Activate builtin code for SHA224/256/384/512 hashes on older
         OpenSSL to have those algorithms always available.
        </para>
       </listitem>
       <listitem>
        <para>
         New function gen_random_bytes() that returns cryptographically strong
         randomness.  Useful for generating encryption keys.
        </para>
       </listitem>
       <listitem>
        <para>
         Remove digest_exists(), hmac_exists() and cipher_exists() functions.
        </para>
       </listitem>
      </itemizedlist>
     </listitem>

     <listitem>
      <para>
       Improvements to cube module (Joshua Reich)
      </para>

      <para>
       New functions are <function>cube(float[])</>,
       <function>cube(float[], float[])</>, and
       <function>cube_subset(cube, int4[])</>.
      </para>
     </listitem>

     <listitem>
      <para>
       Add async query capability to dblink (Kai Londenberg,
       Joe Conway)
      </para>
     </listitem>

     <listitem>
      <para>
       New operators for array-subset comparisons (<literal>@&gt;</>,
       <literal>&lt;@</>, <literal>&amp;&amp;</>) (Tom)
      </para>

      <para>
       Various contrib packages already had these operators for their
       datatypes, but the naming wasn't consistent.  We have now added
       consistently named array-subset comparison operators to the core code
       and all the contrib packages that have such functionality.
       (The old names remain available, but are deprecated.)
      </para>
     </listitem>

     <listitem>
      <para>
       Add uninstall scripts for all contrib packages that have install
       scripts (David, Josh Drake)
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

  </sect2>
 </sect1>
