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 <sect1 id="release-8-3-23">
  <title>Release 8.3.23</title>

  <formalpara>
  <title>Release date:</title>
  <para>2013-02-07</para>
  </formalpara>

  <para>
   This release contains a variety of fixes from 8.3.22.
   For information about new features in the 8.3 major release, see
   <xref linkend="release-8-3"/>.
  </para>

  <para>
   This is expected to be the last <productname>PostgreSQL</productname> release
   in the 8.3.X series.  Users are encouraged to update to a newer
   release branch soon.
  </para>

  <sect2>
   <title>Migration to Version 8.3.23</title>

   <para>
    A dump/restore is not required for those running 8.3.X.
   </para>

   <para>
    However, if you are upgrading from a version earlier than 8.3.17,
    see <xref linkend="release-8-3-17"/>.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

    <listitem>
     <para>
      Prevent execution of <function>enum_recv</function> from SQL (Tom Lane)
     </para>

     <para>
      The function was misdeclared, allowing a simple SQL command to crash the
      server.  In principle an attacker might be able to use it to examine the
      contents of server memory.  Our thanks to Sumit Soni (via Secunia SVCRP)
      for reporting this issue.  (CVE-2013-0255)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix SQL grammar to allow subscripting or field selection from a
      sub-SELECT result (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Protect against race conditions when scanning
      <structname>pg_tablespace</structname> (Stephen Frost, Tom Lane)
     </para>

     <para>
      <command>CREATE DATABASE</command> and <command>DROP DATABASE</command> could
      misbehave if there were concurrent updates of
      <structname>pg_tablespace</structname> entries.
     </para>
    </listitem>

    <listitem>
     <para>
      Prevent <command>DROP OWNED</command> from trying to drop whole databases or
      tablespaces (&Aacute;lvaro Herrera)
     </para>

     <para>
      For safety, ownership of these objects must be reassigned, not dropped.
     </para>
    </listitem>

    <listitem>
     <para>
      Prevent misbehavior when a <symbol>RowExpr</symbol> or <symbol>XmlExpr</symbol>
      is parse-analyzed twice (Andres Freund, Tom Lane)
     </para>

     <para>
      This mistake could be user-visible in contexts such as
      <literal>CREATE TABLE LIKE INCLUDING INDEXES</literal>.
     </para>
    </listitem>

    <listitem>
     <para>
      Improve defenses against integer overflow in hashtable sizing
      calculations (Jeff Davis)
     </para>
    </listitem>

    <listitem>
     <para>
      Ensure that non-ASCII prompt strings are translated to the correct
      code page on Windows (Alexander Law, Noah Misch)
     </para>

     <para>
      This bug affected <application>psql</application> and some other client programs.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix possible crash in <application>psql</application>'s <command>\?</command> command
      when not connected to a database (Meng Qingzhong)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix one-byte buffer overrun in <application>libpq</application>'s
      <function>PQprintTuples</function> (Xi Wang)
     </para>

     <para>
      This ancient function is not used anywhere by
      <productname>PostgreSQL</productname> itself, but it might still be used by some
      client code.
     </para>
    </listitem>

    <listitem>
     <para>
      Rearrange configure's tests for supplied functions so it is not
      fooled by bogus exports from libedit/libreadline (Christoph Berg)
     </para>
    </listitem>

    <listitem>
     <para>
      Ensure Windows build number increases over time (Magnus Hagander)
     </para>
    </listitem>

    <listitem>
     <para>
      Make <application>pgxs</application> build executables with the right
      <literal>.exe</literal> suffix when cross-compiling for Windows
      (Zoltan Boszormenyi)
     </para>
    </listitem>

    <listitem>
     <para>
      Add new timezone abbreviation <literal>FET</literal> (Tom Lane)
     </para>

     <para>
      This is now used in some eastern-European time zones.
     </para>
    </listitem>

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-3-22">
  <title>Release 8.3.22</title>

  <formalpara>
  <title>Release date:</title>
  <para>2012-12-06</para>
  </formalpara>

  <para>
   This release contains a variety of fixes from 8.3.21.
   For information about new features in the 8.3 major release, see
   <xref linkend="release-8-3"/>.
  </para>

  <para>
   The <productname>PostgreSQL</productname> community will stop releasing updates
   for the 8.3.X release series in February 2013.
   Users are encouraged to update to a newer release branch soon.
  </para>

  <sect2>
   <title>Migration to Version 8.3.22</title>

   <para>
    A dump/restore is not required for those running 8.3.X.
   </para>

   <para>
    However, if you are upgrading from a version earlier than 8.3.17,
    see <xref linkend="release-8-3-17"/>.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

    <listitem>
     <para>
      Fix multiple bugs associated with <command>CREATE INDEX
      CONCURRENTLY</command> (Andres Freund, Tom Lane)
     </para>

     <para>
      Fix <command>CREATE INDEX CONCURRENTLY</command> to use
      in-place updates when changing the state of an index's
      <structname>pg_index</structname> row.  This prevents race conditions that could
      cause concurrent sessions to miss updating the target index, thus
      resulting in corrupt concurrently-created indexes.
     </para>

     <para>
      Also, fix various other operations to ensure that they ignore
      invalid indexes resulting from a failed <command>CREATE INDEX
      CONCURRENTLY</command> command.  The most important of these is
      <command>VACUUM</command>, because an auto-vacuum could easily be launched
      on the table before corrective action can be taken to fix or remove
      the invalid index.
     </para>
    </listitem>

    <listitem>
     <para>
      Avoid corruption of internal hash tables when out of memory
      (Hitoshi Harada)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix planning of non-strict equivalence clauses above outer joins
      (Tom Lane)
     </para>

     <para>
      The planner could derive incorrect constraints from a clause equating
      a non-strict construct to something else, for example
      <literal>WHERE COALESCE(foo, 0) = 0</literal>
      when <literal>foo</literal> is coming from the nullable side of an outer join.
     </para>
    </listitem>

    <listitem>
     <para>
      Improve planner's ability to prove exclusion constraints from
      equivalence classes (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix partial-row matching in hashed subplans to handle cross-type cases
      correctly (Tom Lane)
     </para>

     <para>
      This affects multicolumn <literal>NOT IN</literal> subplans, such as
      <literal>WHERE (a, b) NOT IN (SELECT x, y FROM ...)</literal>
      when for instance <literal>b</literal> and <literal>y</literal> are <type>int4</type>
      and <type>int8</type> respectively.  This mistake led to wrong answers
      or crashes depending on the specific datatypes involved.
     </para>
    </listitem>

    <listitem>
     <para>
      Acquire buffer lock when re-fetching the old tuple for an
      <literal>AFTER ROW UPDATE/DELETE</literal> trigger (Andres Freund)
     </para>

     <para>
      In very unusual circumstances, this oversight could result in passing
      incorrect data to the precheck logic for a foreign-key enforcement
      trigger.  That could result in a crash, or in an incorrect decision
      about whether to fire the trigger.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <command>REASSIGN OWNED</command> to handle grants on tablespaces
      (&Aacute;lvaro Herrera)
     </para>
    </listitem>

    <listitem>
     <para>
      Ignore incorrect <structname>pg_attribute</structname> entries for system
      columns for views (Tom Lane)
     </para>

     <para>
      Views do not have any system columns.  However, we forgot to
      remove such entries when converting a table to a view.  That's fixed
      properly for 9.3 and later, but in previous branches we need to defend
      against existing mis-converted views.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix rule printing to dump <literal>INSERT INTO <replaceable>table</replaceable>
      DEFAULT VALUES</literal> correctly (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Guard against stack overflow when there are too many
      <literal>UNION</literal>/<literal>INTERSECT</literal>/<literal>EXCEPT</literal> clauses
      in a query (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Prevent platform-dependent failures when dividing the minimum possible
      integer value by -1 (Xi Wang, Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix possible access past end of string in date parsing
      (Hitoshi Harada)
     </para>
    </listitem>

    <listitem>
     <para>
      Produce an understandable error message if the length of the path name
      for a Unix-domain socket exceeds the platform-specific limit
      (Tom Lane, Andrew Dunstan)
     </para>

     <para>
      Formerly, this would result in something quite unhelpful, such as
      <quote>Non-recoverable failure in name resolution</quote>.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix memory leaks when sending composite column values to the client
      (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Make <application>pg_ctl</application> more robust about reading the
      <filename>postmaster.pid</filename> file (Heikki Linnakangas)
     </para>

     <para>
      Fix race conditions and possible file descriptor leakage.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix possible crash in <application>psql</application> if incorrectly-encoded data
      is presented and the <varname>client_encoding</varname> setting is a
      client-only encoding, such as SJIS (Jiang Guiqing)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix bugs in the <filename>restore.sql</filename> script emitted by
      <application>pg_dump</application> in <literal>tar</literal> output format (Tom Lane)
     </para>

     <para>
      The script would fail outright on tables whose names include
      upper-case characters.  Also, make the script capable of restoring
      data in <option>--inserts</option> mode as well as the regular COPY mode.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <application>pg_restore</application> to accept POSIX-conformant
      <literal>tar</literal> files (Brian Weaver, Tom Lane)
     </para>

     <para>
      The original coding of <application>pg_dump</application>'s <literal>tar</literal>
      output mode produced files that are not fully conformant with the
      POSIX standard.  This has been corrected for version 9.3.  This
      patch updates previous branches so that they will accept both the
      incorrect and the corrected formats, in hopes of avoiding
      compatibility problems when 9.3 comes out.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <application>pg_resetxlog</application> to locate <filename>postmaster.pid</filename>
      correctly when given a relative path to the data directory (Tom Lane)
     </para>

     <para>
      This mistake could lead to <application>pg_resetxlog</application> not noticing
      that there is an active postmaster using the data directory.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <application>libpq</application>'s <function>lo_import()</function> and
      <function>lo_export()</function> functions to report file I/O errors properly
      (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <application>ecpg</application>'s processing of nested structure pointer
      variables (Muhammad Usama)
     </para>
    </listitem>

    <listitem>
     <para>
      Make <filename>contrib/pageinspect</filename>'s btree page inspection
      functions take buffer locks while examining pages (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <application>pgxs</application> support for building loadable modules on AIX
      (Tom Lane)
     </para>

     <para>
      Building modules outside the original source tree didn't work on AIX.
     </para>
    </listitem>

    <listitem>
     <para>
      Update time zone data files to <application>tzdata</application> release 2012j
      for DST law changes in Cuba, Israel, Jordan, Libya, Palestine, Western
      Samoa, and portions of Brazil.
     </para>
    </listitem>

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-3-21">
  <title>Release 8.3.21</title>

  <formalpara>
  <title>Release date:</title>
  <para>2012-09-24</para>
  </formalpara>

  <para>
   This release contains a variety of fixes from 8.3.20.
   For information about new features in the 8.3 major release, see
   <xref linkend="release-8-3"/>.
  </para>

  <para>
   The <productname>PostgreSQL</productname> community will stop releasing updates
   for the 8.3.X release series in February 2013.
   Users are encouraged to update to a newer release branch soon.
  </para>

  <sect2>
   <title>Migration to Version 8.3.21</title>

   <para>
    A dump/restore is not required for those running 8.3.X.
   </para>

   <para>
    However, if you are upgrading from a version earlier than 8.3.17,
    see <xref linkend="release-8-3-17"/>.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

    <listitem>
     <para>
      Improve page-splitting decisions in GiST indexes (Alexander Korotkov,
      Robert Haas, Tom Lane)
     </para>

     <para>
      Multi-column GiST indexes might suffer unexpected bloat due to this
      error.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix cascading privilege revoke to stop if privileges are still held
      (Tom Lane)
     </para>

     <para>
      If we revoke a grant option from some role <replaceable>X</replaceable>, but
      <replaceable>X</replaceable> still holds that option via a grant from someone
      else, we should not recursively revoke the corresponding privilege
      from role(s) <replaceable>Y</replaceable> that <replaceable>X</replaceable> had granted it
      to.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix handling of <literal>SIGFPE</literal> when PL/Perl is in use (Andres Freund)
     </para>

     <para>
      Perl resets the process's <literal>SIGFPE</literal> handler to
      <literal>SIG_IGN</literal>, which could result in crashes later on.  Restore
      the normal Postgres signal handler after initializing PL/Perl.
     </para>
    </listitem>

    <listitem>
     <para>
      Prevent PL/Perl from crashing if a recursive PL/Perl function is
      redefined while being executed (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Work around possible misoptimization in PL/Perl (Tom Lane)
     </para>

     <para>
      Some Linux distributions contain an incorrect version of
      <filename>pthread.h</filename> that results in incorrect compiled code in
      PL/Perl, leading to crashes if a PL/Perl function calls another one
      that throws an error.
     </para>
    </listitem>

    <listitem>
     <para>
      Update time zone data files to <application>tzdata</application> release 2012f
      for DST law changes in Fiji
     </para>
    </listitem>

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-3-20">
  <title>Release 8.3.20</title>

  <formalpara>
  <title>Release date:</title>
  <para>2012-08-17</para>
  </formalpara>

  <para>
   This release contains a variety of fixes from 8.3.19.
   For information about new features in the 8.3 major release, see
   <xref linkend="release-8-3"/>.
  </para>

  <para>
   The <productname>PostgreSQL</productname> community will stop releasing updates
   for the 8.3.X release series in February 2013.
   Users are encouraged to update to a newer release branch soon.
  </para>

  <sect2>
   <title>Migration to Version 8.3.20</title>

   <para>
    A dump/restore is not required for those running 8.3.X.
   </para>

   <para>
    However, if you are upgrading from a version earlier than 8.3.17,
    see <xref linkend="release-8-3-17"/>.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

    <listitem>
     <para>
      Prevent access to external files/URLs via XML entity references
      (Noah Misch, Tom Lane)
     </para>

     <para>
      <function>xml_parse()</function> would attempt to fetch external files or
      URLs as needed to resolve DTD and entity references in an XML value,
      thus allowing unprivileged database users to attempt to fetch data
      with the privileges of the database server.  While the external data
      wouldn't get returned directly to the user, portions of it could be
      exposed in error messages if the data didn't parse as valid XML; and
      in any case the mere ability to check existence of a file might be
      useful to an attacker.  (CVE-2012-3489)
     </para>
    </listitem>

    <listitem>
     <para>
      Prevent access to external files/URLs via <filename>contrib/xml2</filename>'s
      <function>xslt_process()</function> (Peter Eisentraut)
     </para>

     <para>
      <application>libxslt</application> offers the ability to read and write both
      files and URLs through stylesheet commands, thus allowing
      unprivileged database users to both read and write data with the
      privileges of the database server.  Disable that through proper use
      of <application>libxslt</application>'s security options.  (CVE-2012-3488)
     </para>

     <para>
      Also, remove <function>xslt_process()</function>'s ability to fetch documents
      and stylesheets from external files/URLs.  While this was a
      documented <quote>feature</quote>, it was long regarded as a bad idea.
      The fix for CVE-2012-3489 broke that capability, and rather than
      expend effort on trying to fix it, we're just going to summarily
      remove it.
     </para>
    </listitem>

    <listitem>
     <para>
      Prevent too-early recycling of btree index pages (Noah Misch)
     </para>

     <para>
      When we allowed read-only transactions to skip assigning XIDs, we
      introduced the possibility that a deleted btree page could be
      recycled while a read-only transaction was still in flight to it.
      This would result in incorrect index search results.  The probability
      of such an error occurring in the field seems very low because of the
      timing requirements, but nonetheless it should be fixed.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix crash-safety bug with newly-created-or-reset sequences (Tom Lane)
     </para>

     <para>
      If <command>ALTER SEQUENCE</command> was executed on a freshly created or
      reset sequence, and then precisely one <function>nextval()</function> call
      was made on it, and then the server crashed, WAL replay would restore
      the sequence to a state in which it appeared that no
      <function>nextval()</function> had been done, thus allowing the first
      sequence value to be returned again by the next
      <function>nextval()</function> call.  In particular this could manifest for
      <type>serial</type> columns, since creation of a serial column's sequence
      includes an <command>ALTER SEQUENCE OWNED BY</command> step.
     </para>
    </listitem>

    <listitem>
     <para>
      Ensure the <filename>backup_label</filename> file is fsync'd after
      <function>pg_start_backup()</function> (Dave Kerr)
     </para>
    </listitem>

    <listitem>
     <para>
      Back-patch 9.1 improvement to compress the fsync request queue
      (Robert Haas)
     </para>

     <para>
      This improves performance during checkpoints.  The 9.1 change
      has now seen enough field testing to seem safe to back-patch.
     </para>
    </listitem>

    <listitem>
     <para>
      Only allow autovacuum to be auto-canceled by a directly blocked
      process (Tom Lane)
     </para>

     <para>
      The original coding could allow inconsistent behavior in some cases;
      in particular, an autovacuum could get canceled after less than
      <literal>deadlock_timeout</literal> grace period.
     </para>
    </listitem>

    <listitem>
     <para>
      Improve logging of autovacuum cancels (Robert Haas)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix log collector so that <literal>log_truncate_on_rotation</literal> works
      during the very first log rotation after server start (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Ensure that a whole-row reference to a subquery doesn't include any
      extra <literal>GROUP BY</literal> or <literal>ORDER BY</literal> columns (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Disallow copying whole-row references in <literal>CHECK</literal>
      constraints and index definitions during <command>CREATE TABLE</command>
      (Tom Lane)
     </para>

     <para>
      This situation can arise in <command>CREATE TABLE</command> with
      <literal>LIKE</literal> or <literal>INHERITS</literal>.  The copied whole-row
      variable was incorrectly labeled with the row type of the original
      table not the new one.  Rejecting the case seems reasonable for
      <literal>LIKE</literal>, since the row types might well diverge later.  For
      <literal>INHERITS</literal> we should ideally allow it, with an implicit
      coercion to the parent table's row type; but that will require more
      work than seems safe to back-patch.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix memory leak in <literal>ARRAY(SELECT ...)</literal> subqueries (Heikki
      Linnakangas, Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix extraction of common prefixes from regular expressions (Tom Lane)
     </para>

     <para>
      The code could get confused by quantified parenthesized
      subexpressions, such as <literal>^(foo)?bar</literal>.  This would lead to
      incorrect index optimization of searches for such patterns.
     </para>
    </listitem>

    <listitem>
     <para>
      Report errors properly in <filename>contrib/xml2</filename>'s
      <function>xslt_process()</function> (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Update time zone data files to <application>tzdata</application> release 2012e
      for DST law changes in Morocco and Tokelau
     </para>
    </listitem>

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-3-19">
  <title>Release 8.3.19</title>

  <formalpara>
  <title>Release date:</title>
  <para>2012-06-04</para>
  </formalpara>

  <para>
   This release contains a variety of fixes from 8.3.18.
   For information about new features in the 8.3 major release, see
   <xref linkend="release-8-3"/>.
  </para>

  <sect2>
   <title>Migration to Version 8.3.19</title>

   <para>
    A dump/restore is not required for those running 8.3.X.
   </para>

   <para>
    However, if you are upgrading from a version earlier than 8.3.17,
    see <xref linkend="release-8-3-17"/>.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

    <listitem>
     <para>
      Fix incorrect password transformation in
      <filename>contrib/pgcrypto</filename>'s DES <function>crypt()</function> function
      (Solar Designer)
     </para>

     <para>
      If a password string contained the byte value <literal>0x80</literal>, the
      remainder of the password was ignored, causing the password to be much
      weaker than it appeared.  With this fix, the rest of the string is
      properly included in the DES hash.  Any stored password values that are
      affected by this bug will thus no longer match, so the stored values may
      need to be updated.  (CVE-2012-2143)
     </para>
    </listitem>

    <listitem>
     <para>
      Ignore <literal>SECURITY DEFINER</literal> and <literal>SET</literal> attributes for
      a procedural language's call handler (Tom Lane)
     </para>

     <para>
      Applying such attributes to a call handler could crash the server.
      (CVE-2012-2655)
     </para>
    </listitem>

    <listitem>
     <para>
      Allow numeric timezone offsets in <type>timestamp</type> input to be up to
      16 hours away from UTC (Tom Lane)
     </para>

     <para>
      Some historical time zones have offsets larger than 15 hours, the
      previous limit.  This could result in dumped data values being rejected
      during reload.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix timestamp conversion to cope when the given time is exactly the
      last DST transition time for the current timezone (Tom Lane)
     </para>

     <para>
      This oversight has been there a long time, but was not noticed
      previously because most DST-using zones are presumed to have an
      indefinite sequence of future DST transitions.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <type>text</type> to <type>name</type> and <type>char</type> to <type>name</type>
      casts to perform string truncation correctly in multibyte encodings
      (Karl Schnaitter)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix memory copying bug in <function>to_tsquery()</function> (Heikki Linnakangas)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix slow session startup when <structname>pg_attribute</structname> is very large
      (Tom Lane)
     </para>

     <para>
      If <structname>pg_attribute</structname> exceeds one-fourth of
      <varname>shared_buffers</varname>, cache rebuilding code that is sometimes
      needed during session start would trigger the synchronized-scan logic,
      causing it to take many times longer than normal.  The problem was
      particularly acute if many new sessions were starting at once.
     </para>
    </listitem>

    <listitem>
     <para>
      Ensure sequential scans check for query cancel reasonably often (Merlin
      Moncure)
     </para>

     <para>
      A scan encountering many consecutive pages that contain no live tuples
      would not respond to interrupts meanwhile.
     </para>
    </listitem>

    <listitem>
     <para>
      Ensure the Windows implementation of <function>PGSemaphoreLock()</function>
      clears <varname>ImmediateInterruptOK</varname> before returning (Tom Lane)
     </para>

     <para>
      This oversight meant that a query-cancel interrupt received later
      in the same query could be accepted at an unsafe time, with
      unpredictable but not good consequences.
     </para>
    </listitem>

    <listitem>
     <para>
      Show whole-row variables safely when printing views or rules
      (Abbas Butt, Tom Lane)
     </para>

     <para>
      Corner cases involving ambiguous names (that is, the name could be
      either a table or column name of the query) were printed in an
      ambiguous way, risking that the view or rule would be interpreted
      differently after dump and reload.  Avoid the ambiguous case by
      attaching a no-op cast.
     </para>
    </listitem>

    <listitem>
     <para>
      Ensure autovacuum worker processes perform stack depth checking
      properly (Heikki Linnakangas)
     </para>

     <para>
      Previously, infinite recursion in a function invoked by
      auto-<command>ANALYZE</command> could crash worker processes.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix logging collector to not lose log coherency under high load (Andrew
      Dunstan)
     </para>

     <para>
      The collector previously could fail to reassemble large messages if it
      got too busy.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix logging collector to ensure it will restart file rotation
      after receiving <systemitem>SIGHUP</systemitem> (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix PL/pgSQL's <command>GET DIAGNOSTICS</command> command when the target
      is the function's first variable (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix several performance problems in <application>pg_dump</application> when
      the database contains many objects (Jeff Janes, Tom Lane)
     </para>

     <para>
      <application>pg_dump</application> could get very slow if the database contained
      many schemas, or if many objects are in dependency loops, or if there
      are many owned sequences.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <filename>contrib/dblink</filename>'s <function>dblink_exec()</function> to not leak
      temporary database connections upon error (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Update time zone data files to <application>tzdata</application> release 2012c
      for DST law changes in Antarctica, Armenia, Chile, Cuba, Falkland
      Islands, Gaza, Haiti, Hebron, Morocco, Syria, and Tokelau Islands;
      also historical corrections for Canada.
     </para>
    </listitem>

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-3-18">
  <title>Release 8.3.18</title>

  <formalpara>
  <title>Release date:</title>
  <para>2012-02-27</para>
  </formalpara>

  <para>
   This release contains a variety of fixes from 8.3.17.
   For information about new features in the 8.3 major release, see
   <xref linkend="release-8-3"/>.
  </para>

  <sect2>
   <title>Migration to Version 8.3.18</title>

   <para>
    A dump/restore is not required for those running 8.3.X.
   </para>

   <para>
    However, if you are upgrading from a version earlier than 8.3.17,
    see <xref linkend="release-8-3-17"/>.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

    <listitem>
     <para>
      Require execute permission on the trigger function for
      <command>CREATE TRIGGER</command> (Robert Haas)
     </para>

     <para>
      This missing check could allow another user to execute a trigger
      function with forged input data, by installing it on a table he owns.
      This is only of significance for trigger functions marked
      <literal>SECURITY DEFINER</literal>, since otherwise trigger functions run
      as the table owner anyway.  (CVE-2012-0866)
     </para>
    </listitem>

    <listitem>
     <para>
      Convert newlines to spaces in names written in <application>pg_dump</application>
      comments (Robert Haas)
     </para>

     <para>
      <application>pg_dump</application> was incautious about sanitizing object names
      that are emitted within SQL comments in its output script.  A name
      containing a newline would at least render the script syntactically
      incorrect.  Maliciously crafted object names could present a SQL
      injection risk when the script is reloaded.  (CVE-2012-0868)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix btree index corruption from insertions concurrent with vacuuming
      (Tom Lane)
     </para>

     <para>
      An index page split caused by an insertion could sometimes cause a
      concurrently-running <command>VACUUM</command> to miss removing index entries
      that it should remove.  After the corresponding table rows are removed,
      the dangling index entries would cause errors (such as <quote>could not
      read block N in file ...</quote>) or worse, silently wrong query results
      after unrelated rows are re-inserted at the now-free table locations.
      This bug has been present since release 8.2, but occurs so infrequently
      that it was not diagnosed until now.  If you have reason to suspect
      that it has happened in your database, reindexing the affected index
      will fix things.
     </para>
    </listitem>

    <listitem>
     <para>
      Allow non-existent values for some settings in <command>ALTER
      USER/DATABASE SET</command> (Heikki Linnakangas)
     </para>

     <para>
      Allow <varname>default_text_search_config</varname>,
      <varname>default_tablespace</varname>, and <varname>temp_tablespaces</varname> to be
      set to names that are not known.  This is because they might be known
      in another database where the setting is intended to be used, or for the
      tablespace cases because the tablespace might not be created yet.  The
      same issue was previously recognized for <varname>search_path</varname>, and
      these settings now act like that one.
     </para>
    </listitem>

    <listitem>
     <para>
      Track the OID counter correctly during WAL replay, even when it wraps
      around (Tom Lane)
     </para>

     <para>
      Previously the OID counter would remain stuck at a high value until the
      system exited replay mode.  The practical consequences of that are
      usually nil, but there are scenarios wherein a standby server that's
      been promoted to master might take a long time to advance the OID
      counter to a reasonable value once values are needed.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix regular expression back-references with <literal>*</literal> attached
      (Tom Lane)
     </para>

     <para>
      Rather than enforcing an exact string match, the code would effectively
      accept any string that satisfies the pattern sub-expression referenced
      by the back-reference symbol.
     </para>

     <para>
      A similar problem still afflicts back-references that are embedded in a
      larger quantified expression, rather than being the immediate subject
      of the quantifier.  This will be addressed in a future
      <productname>PostgreSQL</productname> release.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix recently-introduced memory leak in processing of
      <type>inet</type>/<type>cidr</type> values (Heikki Linnakangas)
     </para>

     <para>
      A patch in the December 2011 releases of <productname>PostgreSQL</productname>
      caused memory leakage in these operations, which could be significant
      in scenarios such as building a btree index on such a column.
     </para>
    </listitem>

    <listitem>
     <para>
      Avoid double close of file handle in syslogger on Windows (MauMau)
     </para>

     <para>
      Ordinarily this error was invisible, but it would cause an exception
      when running on a debug version of Windows.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix I/O-conversion-related memory leaks in plpgsql
      (Andres Freund, Jan Urbanski, Tom Lane)
     </para>

     <para>
      Certain operations would leak memory until the end of the current
      function.
     </para>
    </listitem>

    <listitem>
     <para>
      Improve <application>pg_dump</application>'s handling of inherited table columns
      (Tom Lane)
     </para>

     <para>
      <application>pg_dump</application> mishandled situations where a child column has
      a different default expression than its parent column.  If the default
      is textually identical to the parent's default, but not actually the
      same (for instance, because of schema search path differences) it would
      not be recognized as different, so that after dump and restore the
      child would be allowed to inherit the parent's default.  Child columns
      that are <literal>NOT NULL</literal> where their parent is not could also be
      restored subtly incorrectly.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <application>pg_restore</application>'s direct-to-database mode for
      INSERT-style table data (Tom Lane)
     </para>

     <para>
      Direct-to-database restores from archive files made with
      <option>--inserts</option> or <option>--column-inserts</option> options fail when
      using <application>pg_restore</application> from a release dated September or
      December 2011, as a result of an oversight in a fix for another
      problem.  The archive file itself is not at fault, and text-mode
      output is okay.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix error in <filename>contrib/intarray</filename>'s <literal>int[] &amp;
      int[]</literal> operator (Guillaume Lelarge)
     </para>

     <para>
      If the smallest integer the two input arrays have in common is 1,
      and there are smaller values in either array, then 1 would be
      incorrectly omitted from the result.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix error detection in <filename>contrib/pgcrypto</filename>'s
      <function>encrypt_iv()</function> and <function>decrypt_iv()</function>
      (Marko Kreen)
     </para>

     <para>
      These functions failed to report certain types of invalid-input errors,
      and would instead return random garbage values for incorrect input.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix one-byte buffer overrun in <filename>contrib/test_parser</filename>
      (Paul Guyot)
     </para>

     <para>
      The code would try to read one more byte than it should, which would
      crash in corner cases.
      Since <filename>contrib/test_parser</filename> is only example code, this is
      not a security issue in itself, but bad example code is still bad.
     </para>
    </listitem>

    <listitem>
     <para>
      Use <function>__sync_lock_test_and_set()</function> for spinlocks on ARM, if
      available (Martin Pitt)
     </para>

     <para>
      This function replaces our previous use of the <literal>SWPB</literal>
      instruction, which is deprecated and not available on ARMv6 and later.
      Reports suggest that the old code doesn't fail in an obvious way on
      recent ARM boards, but simply doesn't interlock concurrent accesses,
      leading to bizarre failures in multiprocess operation.
     </para>
    </listitem>

    <listitem>
     <para>
      Use <option>-fexcess-precision=standard</option> option when building with
      gcc versions that accept it (Andrew Dunstan)
     </para>

     <para>
      This prevents assorted scenarios wherein recent versions of gcc will
      produce creative results.
     </para>
    </listitem>

    <listitem>
     <para>
      Allow use of threaded Python on FreeBSD (Chris Rees)
     </para>

     <para>
      Our configure script previously believed that this combination wouldn't
      work; but FreeBSD fixed the problem, so remove that error check.
     </para>
    </listitem>

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-3-17">
  <title>Release 8.3.17</title>

  <formalpara>
  <title>Release date:</title>
  <para>2011-12-05</para>
  </formalpara>

  <para>
   This release contains a variety of fixes from 8.3.16.
   For information about new features in the 8.3 major release, see
   <xref linkend="release-8-3"/>.
  </para>

  <sect2>
   <title>Migration to Version 8.3.17</title>

   <para>
    A dump/restore is not required for those running 8.3.X.
   </para>

   <para>
    However, a longstanding error was discovered in the definition of the
    <literal>information_schema.referential_constraints</literal> view.  If you
    rely on correct results from that view, you should replace its
    definition as explained in the first changelog item below.
   </para>

   <para>
    Also, if you are upgrading from a version earlier than 8.3.8,
    see <xref linkend="release-8-3-8"/>.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

    <listitem>
     <para>
      Fix bugs in <literal>information_schema.referential_constraints</literal> view
      (Tom Lane)
     </para>

     <para>
      This view was being insufficiently careful about matching the
      foreign-key constraint to the depended-on primary or unique key
      constraint.  That could result in failure to show a foreign key
      constraint at all, or showing it multiple times, or claiming that it
      depends on a different constraint than the one it really does.
     </para>

     <para>
      Since the view definition is installed by <application>initdb</application>,
      merely upgrading will not fix the problem.  If you need to fix this
      in an existing installation, you can (as a superuser) drop the
      <literal>information_schema</literal> schema then re-create it by sourcing
      <filename><replaceable>SHAREDIR</replaceable>/information_schema.sql</filename>.
      (Run <literal>pg_config --sharedir</literal> if you're uncertain where
      <replaceable>SHAREDIR</replaceable> is.)  This must be repeated in each database
      to be fixed.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix TOAST-related data corruption during <literal>CREATE TABLE dest AS
      SELECT * FROM src</literal> or <literal>INSERT INTO dest SELECT * FROM src</literal>
      (Tom Lane)
     </para>

     <para>
      If a table has been modified by <command>ALTER TABLE ADD COLUMN</command>,
      attempts to copy its data verbatim to another table could produce
      corrupt results in certain corner cases.
      The problem can only manifest in this precise form in 8.4 and later,
      but we patched earlier versions as well in case there are other code
      paths that could trigger the same bug.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix race condition during toast table access from stale syscache entries
      (Tom Lane)
     </para>

     <para>
      The typical symptom was transient errors like <quote>missing chunk
      number 0 for toast value NNNNN in pg_toast_2619</quote>, where the cited
      toast table would always belong to a system catalog.
     </para>
    </listitem>

    <listitem>
     <para>
      Make <function>DatumGetInetP()</function> unpack inet datums that have a 1-byte
      header, and add a new macro, <function>DatumGetInetPP()</function>, that does
      not (Heikki Linnakangas)
     </para>

     <para>
      This change affects no core code, but might prevent crashes in add-on
      code that expects <function>DatumGetInetP()</function> to produce an unpacked
      datum as per usual convention.
     </para>
    </listitem>

    <listitem>
     <para>
      Improve locale support in <type>money</type> type's input and output
      (Tom Lane)
     </para>

     <para>
      Aside from not supporting all standard
      <link linkend="guc-lc-monetary"><varname>lc_monetary</varname></link>
      formatting options, the input and output functions were inconsistent,
      meaning there were locales in which dumped <type>money</type> values could
      not be re-read.
     </para>
    </listitem>

    <listitem>
     <para>
      Don't let <link
      linkend="guc-transform-null-equals"><varname>transform_null_equals</varname></link>
      affect <literal>CASE foo WHEN NULL ...</literal> constructs
      (Heikki Linnakangas)
     </para>

     <para>
      <varname>transform_null_equals</varname> is only supposed to affect
      <literal>foo = NULL</literal> expressions written directly by the user, not
      equality checks generated internally by this form of <literal>CASE</literal>.
     </para>
    </listitem>

    <listitem>
     <para>
      Change foreign-key trigger creation order to better support
      self-referential foreign keys (Tom Lane)
     </para>

     <para>
      For a cascading foreign key that references its own table, a row update
      will fire both the <literal>ON UPDATE</literal> trigger and the
      <literal>CHECK</literal> trigger as one event.  The <literal>ON UPDATE</literal>
      trigger must execute first, else the <literal>CHECK</literal> will check a
      non-final state of the row and possibly throw an inappropriate error.
      However, the firing order of these triggers is determined by their
      names, which generally sort in creation order since the triggers have
      auto-generated names following the convention
      <quote>RI_ConstraintTrigger_NNNN</quote>.  A proper fix would require
      modifying that convention, which we will do in 9.2, but it seems risky
      to change it in existing releases.  So this patch just changes the
      creation order of the triggers.  Users encountering this type of error
      should drop and re-create the foreign key constraint to get its
      triggers into the right order.
     </para>
    </listitem>

    <listitem>
     <para>
      Avoid floating-point underflow while tracking buffer allocation rate
      (Greg Matthews)
     </para>

     <para>
      While harmless in itself, on certain platforms this would result in
      annoying kernel log messages.
     </para>
    </listitem>

    <listitem>
     <para>
      Preserve blank lines within commands in <application>psql</application>'s command
      history (Robert Haas)
     </para>

     <para>
      The former behavior could cause problems if an empty line was removed
      from within a string literal, for example.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <application>pg_dump</application> to dump user-defined casts between
      auto-generated types, such as table rowtypes (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Use the preferred version of <application>xsubpp</application> to build PL/Perl,
      not necessarily the operating system's main copy
      (David Wheeler and Alex Hunsaker)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix incorrect coding in <filename>contrib/dict_int</filename> and
      <filename>contrib/dict_xsyn</filename> (Tom Lane)
     </para>

     <para>
      Some functions incorrectly assumed that memory returned by
      <function>palloc()</function> is guaranteed zeroed.
     </para>
    </listitem>

    <listitem>
     <para>
      Honor query cancel interrupts promptly in <function>pgstatindex()</function>
      (Robert Haas)
     </para>
    </listitem>

    <listitem>
     <para>
      Ensure VPATH builds properly install all server header files
      (Peter Eisentraut)
     </para>
    </listitem>

    <listitem>
     <para>
      Shorten file names reported in verbose error messages (Peter Eisentraut)
     </para>

     <para>
      Regular builds have always reported just the name of the C file
      containing the error message call, but VPATH builds formerly
      reported an absolute path name.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix interpretation of Windows timezone names for Central America
      (Tom Lane)
     </para>

     <para>
      Map <quote>Central America Standard Time</quote> to <literal>CST6</literal>, not
      <literal>CST6CDT</literal>, because DST is generally not observed anywhere in
      Central America.
     </para>
    </listitem>

    <listitem>
     <para>
      Update time zone data files to <application>tzdata</application> release 2011n
      for DST law changes in Brazil, Cuba, Fiji, Palestine, Russia, and Samoa;
      also historical corrections for Alaska and British East Africa.
     </para>
    </listitem>

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-3-16">
  <title>Release 8.3.16</title>

  <formalpara>
  <title>Release date:</title>
  <para>2011-09-26</para>
  </formalpara>

  <para>
   This release contains a variety of fixes from 8.3.15.
   For information about new features in the 8.3 major release, see
   <xref linkend="release-8-3"/>.
  </para>

  <sect2>
   <title>Migration to Version 8.3.16</title>

   <para>
    A dump/restore is not required for those running 8.3.X.
    However, if you are upgrading from a version earlier than 8.3.8,
    see <xref linkend="release-8-3-8"/>.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

    <listitem>
     <para>
      Fix bugs in indexing of in-doubt HOT-updated tuples (Tom Lane)
     </para>

     <para>
      These bugs could result in index corruption after reindexing a system
      catalog.  They are not believed to affect user indexes.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix multiple bugs in GiST index page split processing (Heikki
      Linnakangas)
     </para>

     <para>
      The probability of occurrence was low, but these could lead to index
      corruption.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix possible buffer overrun in <function>tsvector_concat()</function>
      (Tom Lane)
     </para>

     <para>
      The function could underestimate the amount of memory needed for its
      result, leading to server crashes.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix crash in <function>xml_recv</function> when processing a
      <quote>standalone</quote> parameter (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Avoid possibly accessing off the end of memory in <command>ANALYZE</command>
      and in SJIS-2004 encoding conversion (Noah Misch)
     </para>

     <para>
      This fixes some very-low-probability server crash scenarios.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix race condition in relcache init file invalidation (Tom Lane)
     </para>

     <para>
      There was a window wherein a new backend process could read a stale init
      file but miss the inval messages that would tell it the data is stale.
      The result would be bizarre failures in catalog accesses, typically
      <quote>could not read block 0 in file ...</quote> later during startup.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix memory leak at end of a GiST index scan (Tom Lane)
     </para>

     <para>
      Commands that perform many separate GiST index scans, such as
      verification of a new GiST-based exclusion constraint on a table
      already containing many rows, could transiently require large amounts of
      memory due to this leak.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix performance problem when constructing a large, lossy bitmap
      (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix array- and path-creating functions to ensure padding bytes are
      zeroes (Tom Lane)
     </para>

     <para>
      This avoids some situations where the planner will think that
      semantically-equal constants are not equal, resulting in poor
      optimization.
     </para>
    </listitem>

    <listitem>
     <para>
      Work around gcc 4.6.0 bug that breaks WAL replay (Tom Lane)
     </para>

     <para>
      This could lead to loss of committed transactions after a server crash.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix dump bug for <literal>VALUES</literal> in a view (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Disallow <literal>SELECT FOR UPDATE/SHARE</literal> on sequences (Tom Lane)
     </para>

     <para>
      This operation doesn't work as expected and can lead to failures.
     </para>
    </listitem>

    <listitem>
     <para>
      Defend against integer overflow when computing size of a hash table (Tom
      Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix cases where <command>CLUSTER</command> might attempt to access
      already-removed TOAST data (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix portability bugs in use of credentials control messages for
      <quote>peer</quote> authentication (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix SSPI login when multiple roundtrips are required (Ahmed Shinwari,
      Magnus Hagander)
     </para>

     <para>
      The typical symptom of this problem was <quote>The function requested is
      not supported</quote> errors during SSPI login.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix typo in <function>pg_srand48</function> seed initialization (Andres Freund)
     </para>

     <para>
      This led to failure to use all bits of the provided seed.  This function
      is not used on most platforms (only those without <function>srandom</function>),
      and the potential security exposure from a less-random-than-expected
      seed seems minimal in any case.
     </para>
    </listitem>

    <listitem>
     <para>
      Avoid integer overflow when the sum of <literal>LIMIT</literal> and
      <literal>OFFSET</literal> values exceeds 2^63 (Heikki Linnakangas)
     </para>
    </listitem>

    <listitem>
     <para>
      Add overflow checks to <type>int4</type> and <type>int8</type> versions of
      <function>generate_series()</function> (Robert Haas)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix trailing-zero removal in <function>to_char()</function> (Marti Raudsepp)
     </para>

     <para>
      In a format with <literal>FM</literal> and no digit positions
      after the decimal point, zeroes to the left of the decimal point could
      be removed incorrectly.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <function>pg_size_pretty()</function> to avoid overflow for inputs close to
      2^63 (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      In <application>pg_ctl</application>, support silent mode for service registrations
      on Windows (MauMau)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <application>psql</application>'s counting of script file line numbers during
      <literal>COPY</literal> from a different file (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <application>pg_restore</application>'s direct-to-database mode for
      <varname>standard_conforming_strings</varname> (Tom Lane)
     </para>

     <para>
      <application>pg_restore</application> could emit incorrect commands when restoring
      directly to a database server from an archive file that had been made
      with <varname>standard_conforming_strings</varname> set to <literal>on</literal>.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix write-past-buffer-end and memory leak in <application>libpq</application>'s
      LDAP service lookup code (Albe Laurenz)
     </para>
    </listitem>

    <listitem>
     <para>
      In <application>libpq</application>, avoid failures when using nonblocking I/O
      and an SSL connection (Martin Pihlak, Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Improve libpq's handling of failures during connection startup
      (Tom Lane)
     </para>

     <para>
      In particular, the response to a server report of <function>fork()</function>
      failure during SSL connection startup is now saner.
     </para>
    </listitem>

    <listitem>
     <para>
      Improve <application>libpq</application>'s error reporting for SSL failures (Tom
      Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Make <application>ecpglib</application> write <type>double</type> values with 15 digits
      precision (Akira Kurosawa)
     </para>
    </listitem>

    <listitem>
     <para>
      In <application>ecpglib</application>, be sure <literal>LC_NUMERIC</literal> setting is
      restored after an error (Michael Meskes)
     </para>
    </listitem>

    <listitem>
     <para>
      Apply upstream fix for blowfish signed-character bug (CVE-2011-2483)
      (Tom Lane)
     </para>

     <para>
      <filename>contrib/pg_crypto</filename>'s blowfish encryption code could give
      wrong results on platforms where char is signed (which is most),
      leading to encrypted passwords being weaker than they should be.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix memory leak in <filename>contrib/seg</filename> (Heikki Linnakangas)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <function>pgstatindex()</function> to give consistent results for empty
      indexes (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Allow building with perl 5.14 (Alex Hunsaker)
     </para>
    </listitem>

    <listitem>
     <para>
      Update configure script's method for probing existence of system
      functions (Tom Lane)
     </para>

     <para>
      The version of autoconf we used in 8.3 and 8.2 could be fooled by
      compilers that perform link-time optimization.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix assorted issues with build and install file paths containing spaces
      (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Update time zone data files to <application>tzdata</application> release 2011i
      for DST law changes in Canada, Egypt, Russia, Samoa, and South Sudan.
     </para>
    </listitem>

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-3-15">
  <title>Release 8.3.15</title>

  <formalpara>
  <title>Release date:</title>
  <para>2011-04-18</para>
  </formalpara>

  <para>
   This release contains a variety of fixes from 8.3.14.
   For information about new features in the 8.3 major release, see
   <xref linkend="release-8-3"/>.
  </para>

  <sect2>
   <title>Migration to Version 8.3.15</title>

   <para>
    A dump/restore is not required for those running 8.3.X.
    However, if you are upgrading from a version earlier than 8.3.8,
    see <xref linkend="release-8-3-8"/>.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

    <listitem>
     <para>
      Disallow including a composite type in itself (Tom Lane)
     </para>

     <para>
      This prevents scenarios wherein the server could recurse infinitely
      while processing the composite type.  While there are some possible
      uses for such a structure, they don't seem compelling enough to
      justify the effort required to make sure it always works safely.
     </para>
    </listitem>

    <listitem>
     <para>
      Avoid potential deadlock during catalog cache initialization
      (Nikhil Sontakke)
     </para>

     <para>
      In some cases the cache loading code would acquire share lock on a
      system index before locking the index's catalog.  This could deadlock
      against processes trying to acquire exclusive locks in the other,
      more standard order.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix dangling-pointer problem in <literal>BEFORE ROW UPDATE</literal> trigger
      handling when there was a concurrent update to the target tuple
      (Tom Lane)
     </para>

     <para>
      This bug has been observed to result in intermittent <quote>cannot
      extract system attribute from virtual tuple</quote> failures while trying to
      do <literal>UPDATE RETURNING ctid</literal>.  There is a very small probability
      of more serious errors, such as generating incorrect index entries for
      the updated tuple.
     </para>
    </listitem>

    <listitem>
     <para>
      Disallow <command>DROP TABLE</command> when there are pending deferred trigger
      events for the table (Tom Lane)
     </para>

     <para>
      Formerly the <command>DROP</command> would go through, leading to
      <quote>could not open relation with OID nnn</quote> errors when the
      triggers were eventually fired.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix PL/Python memory leak involving array slices (Daniel Popowich)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <application>pg_restore</application> to cope with long lines (over 1KB) in
      TOC files (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Put in more safeguards against crashing due to division-by-zero
      with overly enthusiastic compiler optimization (Aurelien Jarno)
     </para>
    </listitem>

    <listitem>
     <para>
      Support use of dlopen() in FreeBSD and OpenBSD on MIPS (Tom Lane)
     </para>

     <para>
      There was a hard-wired assumption that this system function was not
      available on MIPS hardware on these systems.  Use a compile-time test
      instead, since more recent versions have it.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix compilation failures on HP-UX (Heikki Linnakangas)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix version-incompatibility problem with <application>libintl</application> on
      Windows (Hiroshi Inoue)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix usage of <application>xcopy</application> in Windows build scripts to
      work correctly under Windows 7 (Andrew Dunstan)
     </para>

     <para>
      This affects the build scripts only, not installation or usage.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix path separator used by <application>pg_regress</application> on Cygwin
      (Andrew Dunstan)
     </para>
    </listitem>

    <listitem>
     <para>
      Update time zone data files to <application>tzdata</application> release 2011f
      for DST law changes in Chile, Cuba, Falkland Islands, Morocco, Samoa,
      and Turkey; also historical corrections for South Australia, Alaska,
      and Hawaii.
     </para>
    </listitem>

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-3-14">
  <title>Release 8.3.14</title>

  <formalpara>
  <title>Release date:</title>
  <para>2011-01-31</para>
  </formalpara>

  <para>
   This release contains a variety of fixes from 8.3.13.
   For information about new features in the 8.3 major release, see
   <xref linkend="release-8-3"/>.
  </para>

  <sect2>
   <title>Migration to Version 8.3.14</title>

   <para>
    A dump/restore is not required for those running 8.3.X.
    However, if you are upgrading from a version earlier than 8.3.8,
    see <xref linkend="release-8-3-8"/>.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

    <listitem>
     <para>
      Avoid failures when <command>EXPLAIN</command> tries to display a simple-form
      <literal>CASE</literal> expression (Tom Lane)
     </para>

     <para>
      If the <literal>CASE</literal>'s test expression was a constant, the planner
      could simplify the <literal>CASE</literal> into a form that confused the
      expression-display code, resulting in <quote>unexpected CASE WHEN
      clause</quote> errors.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix assignment to an array slice that is before the existing range
      of subscripts (Tom Lane)
     </para>

     <para>
      If there was a gap between the newly added subscripts and the first
      pre-existing subscript, the code miscalculated how many entries needed
      to be copied from the old array's null bitmap, potentially leading to
      data corruption or crash.
     </para>
    </listitem>

    <listitem>
     <para>
      Avoid unexpected conversion overflow in planner for very distant date
      values (Tom Lane)
     </para>

     <para>
      The <type>date</type> type supports a wider range of dates than can be
      represented by the <type>timestamp</type> types, but the planner assumed it
      could always convert a date to timestamp with impunity.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <application>pg_restore</application>'s text output for large objects (BLOBs)
      when <varname>standard_conforming_strings</varname> is on (Tom Lane)
     </para>

     <para>
      Although restoring directly to a database worked correctly, string
      escaping was incorrect if <application>pg_restore</application> was asked for
      SQL text output and <varname>standard_conforming_strings</varname> had been
      enabled in the source database.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix erroneous parsing of <type>tsquery</type> values containing
      <literal>... &amp; !(subexpression) | ...</literal> (Tom Lane)
     </para>

     <para>
      Queries containing this combination of operators were not executed
      correctly.  The same error existed in <filename>contrib/intarray</filename>'s
      <type>query_int</type> type and <filename>contrib/ltree</filename>'s
      <type>ltxtquery</type> type.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix buffer overrun in <filename>contrib/intarray</filename>'s input function
      for the <type>query_int</type> type (Apple)
     </para>

     <para>
      This bug is a security risk since the function's return address could
      be overwritten.  Thanks to Apple Inc's security team for reporting this
      issue and supplying the fix.  (CVE-2010-4015)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix bug in <filename>contrib/seg</filename>'s GiST picksplit algorithm
      (Alexander Korotkov)
     </para>

     <para>
      This could result in considerable inefficiency, though not actually
      incorrect answers, in a GiST index on a <type>seg</type> column.
      If you have such an index, consider <command>REINDEX</command>ing it after
      installing this update.  (This is identical to the bug that was fixed in
      <filename>contrib/cube</filename> in the previous update.)
     </para>
    </listitem>

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-3-13">
  <title>Release 8.3.13</title>

  <formalpara>
  <title>Release date:</title>
  <para>2010-12-16</para>
  </formalpara>

  <para>
   This release contains a variety of fixes from 8.3.12.
   For information about new features in the 8.3 major release, see
   <xref linkend="release-8-3"/>.
  </para>

  <sect2>
   <title>Migration to Version 8.3.13</title>

   <para>
    A dump/restore is not required for those running 8.3.X.
    However, if you are upgrading from a version earlier than 8.3.8,
    see <xref linkend="release-8-3-8"/>.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

    <listitem>
     <para>
      Force the default
      <link linkend="guc-wal-sync-method"><varname>wal_sync_method</varname></link>
      to be <literal>fdatasync</literal> on Linux (Tom Lane, Marti Raudsepp)
     </para>

     <para>
      The default on Linux has actually been <literal>fdatasync</literal> for many
      years, but recent kernel changes caused <productname>PostgreSQL</productname> to
      choose <literal>open_datasync</literal> instead.  This choice did not result
      in any performance improvement, and caused outright failures on
      certain filesystems, notably <literal>ext4</literal> with the
      <literal>data=journal</literal> mount option.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix assorted bugs in WAL replay logic for GIN indexes (Tom Lane)
     </para>

     <para>
      This could result in <quote>bad buffer id: 0</quote> failures or
      corruption of index contents during replication.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix recovery from base backup when the starting checkpoint WAL record
      is not in the same WAL segment as its redo point (Jeff Davis)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix persistent slowdown of autovacuum workers when multiple workers
      remain active for a long time (Tom Lane)
     </para>

     <para>
      The effective <varname>vacuum_cost_limit</varname> for an autovacuum worker
      could drop to nearly zero if it processed enough tables, causing it
      to run extremely slowly.
     </para>
    </listitem>

    <listitem>
     <para>
      Add support for detecting register-stack overrun on <literal>IA64</literal>
      (Tom Lane)
     </para>

     <para>
      The <literal>IA64</literal> architecture has two hardware stacks.  Full
      prevention of stack-overrun failures requires checking both.
     </para>
    </listitem>

    <listitem>
     <para>
      Add a check for stack overflow in <function>copyObject()</function> (Tom Lane)
     </para>

     <para>
      Certain code paths could crash due to stack overflow given a
      sufficiently complex query.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix detection of page splits in temporary GiST indexes (Heikki
      Linnakangas)
     </para>

     <para>
      It is possible to have a <quote>concurrent</quote> page split in a
      temporary index, if for example there is an open cursor scanning the
      index when an insertion is done.  GiST failed to detect this case and
      hence could deliver wrong results when execution of the cursor
      continued.
     </para>
    </listitem>

    <listitem>
     <para>
      Avoid memory leakage while <command>ANALYZE</command>'ing complex index
      expressions (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Ensure an index that uses a whole-row Var still depends on its table
      (Tom Lane)
     </para>

     <para>
      An index declared like <literal>create index i on t (foo(t.*))</literal>
      would not automatically get dropped when its table was dropped.
     </para>
    </listitem>

    <listitem>
     <para>
      Do not <quote>inline</quote> a SQL function with multiple <literal>OUT</literal>
      parameters (Tom Lane)
     </para>

     <para>
      This avoids a possible crash due to loss of information about the
      expected result rowtype.
     </para>
    </listitem>

    <listitem>
     <para>
      Behave correctly if <literal>ORDER BY</literal>, <literal>LIMIT</literal>,
      <literal>FOR UPDATE</literal>, or <literal>WITH</literal> is attached to the
      <literal>VALUES</literal> part of <literal>INSERT ... VALUES</literal> (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix constant-folding of <literal>COALESCE()</literal> expressions (Tom Lane)
     </para>

     <para>
      The planner would sometimes attempt to evaluate sub-expressions that
      in fact could never be reached, possibly leading to unexpected errors.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix postmaster crash when connection acceptance
      (<function>accept()</function> or one of the calls made immediately after it)
      fails, and the postmaster was compiled with GSSAPI support (Alexander
      Chernikov)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix missed unlink of temporary files when <varname>log_temp_files</varname>
      is active (Tom Lane)
     </para>

     <para>
      If an error occurred while attempting to emit the log message, the
      unlink was not done, resulting in accumulation of temp files.
     </para>
    </listitem>

    <listitem>
     <para>
      Add print functionality for <structname>InhRelation</structname> nodes (Tom Lane)
     </para>

     <para>
      This avoids a failure when <varname>debug_print_parse</varname> is enabled
      and certain types of query are executed.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix incorrect calculation of distance from a point to a horizontal
      line segment (Tom Lane)
     </para>

     <para>
      This bug affected several different geometric distance-measurement
      operators.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <application>PL/pgSQL</application>'s handling of <quote>simple</quote>
      expressions to not fail in recursion or error-recovery cases (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <application>PL/Python</application>'s handling of set-returning functions
      (Jan Urbanski)
     </para>

     <para>
      Attempts to call SPI functions within the iterator generating a set
      result would fail.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix bug in <filename>contrib/cube</filename>'s GiST picksplit algorithm
      (Alexander Korotkov)
     </para>

     <para>
      This could result in considerable inefficiency, though not actually
      incorrect answers, in a GiST index on a <type>cube</type> column.
      If you have such an index, consider <command>REINDEX</command>ing it after
      installing this update.
     </para>
    </listitem>

    <listitem>
     <para>
      Don't emit <quote>identifier will be truncated</quote> notices in
      <filename>contrib/dblink</filename> except when creating new connections
      (Itagaki Takahiro)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix potential coredump on missing public key in
      <filename>contrib/pgcrypto</filename> (Marti Raudsepp)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix memory leak in <filename>contrib/xml2</filename>'s XPath query functions
      (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Update time zone data files to <application>tzdata</application> release 2010o
      for DST law changes in Fiji and Samoa;
      also historical corrections for Hong Kong.
     </para>
    </listitem>

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-3-12">
  <title>Release 8.3.12</title>

  <formalpara>
  <title>Release date:</title>
  <para>2010-10-04</para>
  </formalpara>

  <para>
   This release contains a variety of fixes from 8.3.11.
   For information about new features in the 8.3 major release, see
   <xref linkend="release-8-3"/>.
  </para>

  <sect2>
   <title>Migration to Version 8.3.12</title>

   <para>
    A dump/restore is not required for those running 8.3.X.
    However, if you are upgrading from a version earlier than 8.3.8,
    see <xref linkend="release-8-3-8"/>.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

    <listitem>
     <para>
      Use a separate interpreter for each calling SQL userid in PL/Perl and
      PL/Tcl (Tom Lane)
     </para>

     <para>
      This change prevents security problems that can be caused by subverting
      Perl or Tcl code that will be executed later in the same session under
      another SQL user identity (for example, within a <literal>SECURITY
      DEFINER</literal> function).  Most scripting languages offer numerous ways that
      that might be done, such as redefining standard functions or operators
      called by the target function.  Without this change, any SQL user with
      Perl or Tcl language usage rights can do essentially anything with the
      SQL privileges of the target function's owner.
     </para>

     <para>
      The cost of this change is that intentional communication among Perl
      and Tcl functions becomes more difficult.  To provide an escape hatch,
      PL/PerlU and PL/TclU functions continue to use only one interpreter
      per session.  This is not considered a security issue since all such
      functions execute at the trust level of a database superuser already.
     </para>

     <para>
      It is likely that third-party procedural languages that claim to offer
      trusted execution have similar security issues.  We advise contacting
      the authors of any PL you are depending on for security-critical
      purposes.
     </para>

     <para>
      Our thanks to Tim Bunce for pointing out this issue (CVE-2010-3433).
     </para>
    </listitem>

    <listitem>
     <para>
      Prevent possible crashes in <function>pg_get_expr()</function> by disallowing
      it from being called with an argument that is not one of the system
      catalog columns it's intended to be used with
      (Heikki Linnakangas, Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Treat exit code 128 (<literal>ERROR_WAIT_NO_CHILDREN</literal>) as non-fatal on
      Windows (Magnus Hagander)
     </para>

     <para>
      Under high load, Windows processes will sometimes fail at startup with
      this error code.  Formerly the postmaster treated this as a panic
      condition and restarted the whole database, but that seems to be
      an overreaction.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix incorrect usage of non-strict OR joinclauses in Append indexscans
      (Tom Lane)
     </para>

     <para>
      This is a back-patch of an 8.4 fix that was missed in the 8.3 branch.
      This corrects an error introduced in 8.3.8 that could cause incorrect
      results for outer joins when the inner relation is an inheritance tree
      or <literal>UNION ALL</literal> subquery.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix possible duplicate scans of <literal>UNION ALL</literal> member relations
      (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <quote>cannot handle unplanned sub-select</quote> error (Tom Lane)
     </para>

     <para>
      This occurred when a sub-select contains a join alias reference that
      expands into an expression containing another sub-select.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix failure to mark cached plans as transient (Tom Lane)
     </para>

     <para>
      If a plan is prepared while <command>CREATE INDEX CONCURRENTLY</command> is
      in progress for one of the referenced tables, it is supposed to be
      re-planned once the index is ready for use.  This was not happening
      reliably.
     </para>
    </listitem>

    <listitem>
     <para>
      Reduce PANIC to ERROR in some occasionally-reported btree failure cases,
      and provide additional detail in the resulting error messages
      (Tom Lane)
     </para>

     <para>
      This should improve the system's robustness with corrupted indexes.
     </para>
    </listitem>

    <listitem>
     <para>
      Prevent show_session_authorization() from crashing within autovacuum
      processes (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Defend against functions returning setof record where not all the
      returned rows are actually of the same rowtype (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix possible failure when hashing a pass-by-reference function result
      (Tao Ma, Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Improve merge join's handling of NULLs in the join columns (Tom Lane)
     </para>

     <para>
      A merge join can now stop entirely upon reaching the first NULL,
      if the sort order is such that NULLs sort high.
     </para>
    </listitem>

    <listitem>
     <para>
      Take care to fsync the contents of lockfiles (both
      <filename>postmaster.pid</filename> and the socket lockfile) while writing them
      (Tom Lane)
     </para>

     <para>
      This omission could result in corrupted lockfile contents if the
      machine crashes shortly after postmaster start.  That could in turn
      prevent subsequent attempts to start the postmaster from succeeding,
      until the lockfile is manually removed.
     </para>
    </listitem>

    <listitem>
     <para>
      Avoid recursion while assigning XIDs to heavily-nested
      subtransactions (Andres Freund, Robert Haas)
     </para>

     <para>
      The original coding could result in a crash if there was limited
      stack space.
     </para>
    </listitem>

    <listitem>
     <para>
      Avoid holding open old WAL segments in the walwriter process
      (Magnus Hagander, Heikki Linnakangas)
     </para>

     <para>
      The previous coding would prevent removal of no-longer-needed segments.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <varname>log_line_prefix</varname>'s <literal>%i</literal> escape,
      which could produce junk early in backend startup (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix possible data corruption in <command>ALTER TABLE ... SET
      TABLESPACE</command> when archiving is enabled (Jeff Davis)
     </para>
    </listitem>

    <listitem>
     <para>
      Allow <command>CREATE DATABASE</command> and <command>ALTER DATABASE ... SET
      TABLESPACE</command> to be interrupted by query-cancel (Guillaume Lelarge)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <command>REASSIGN OWNED</command> to handle operator classes and families
      (Asko Tiidumaa)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix possible core dump when comparing two empty <type>tsquery</type> values
      (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <literal>LIKE</literal>'s handling of patterns containing <literal>%</literal>
      followed by <literal>_</literal> (Tom Lane)
     </para>

     <para>
      We've fixed this before, but there were still some incorrectly-handled
      cases.
     </para>
    </listitem>

    <listitem>
     <para>
      In PL/Python, defend against null pointer results from
      <function>PyCObject_AsVoidPtr</function> and <function>PyCObject_FromVoidPtr</function>
      (Peter Eisentraut)
     </para>
    </listitem>

    <listitem>
     <para>
      Make psql recognize <command>DISCARD ALL</command> as a command that should
      not be encased in a transaction block in autocommit-off mode
      (Itagaki Takahiro)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <application>ecpg</application> to process data from <literal>RETURNING</literal>
      clauses correctly (Michael Meskes)
     </para>
    </listitem>

    <listitem>
     <para>
      Improve <filename>contrib/dblink</filename>'s handling of tables containing
      dropped columns (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix connection leak after <quote>duplicate connection name</quote>
      errors in <filename>contrib/dblink</filename> (Itagaki Takahiro)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <filename>contrib/dblink</filename> to handle connection names longer than
      62 bytes correctly (Itagaki Takahiro)
     </para>
    </listitem>

    <listitem>
     <para>
      Add <function>hstore(text, text)</function>
      function to <filename>contrib/hstore</filename> (Robert Haas)
     </para>

     <para>
      This function is the recommended substitute for the now-deprecated
      <literal>=&gt;</literal> operator.  It was back-patched so that future-proofed
      code can be used with older server versions.  Note that the patch will
      be effective only after <filename>contrib/hstore</filename> is installed or
      reinstalled in a particular database.  Users might prefer to execute
      the <command>CREATE FUNCTION</command> command by hand, instead.
     </para>
    </listitem>

    <listitem>
     <para>
      Update build infrastructure and documentation to reflect the source code
      repository's move from CVS to Git (Magnus Hagander and others)
     </para>
    </listitem>

    <listitem>
     <para>
      Update time zone data files to <application>tzdata</application> release 2010l
      for DST law changes in Egypt and Palestine; also historical corrections
      for Finland.
     </para>

     <para>
      This change also adds new names for two Micronesian timezones:
      Pacific/Chuuk is now preferred over Pacific/Truk (and the preferred
      abbreviation is CHUT not TRUT) and Pacific/Pohnpei is preferred over
      Pacific/Ponape.
     </para>
    </listitem>

    <listitem>
     <para>
      Make Windows' <quote>N. Central Asia Standard Time</quote> timezone map to
      Asia/Novosibirsk, not Asia/Almaty (Magnus Hagander)
     </para>

     <para>
      Microsoft changed the DST behavior of this zone in the timezone update
      from KB976098. Asia/Novosibirsk is a better match to its new behavior.
     </para>
    </listitem>

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-3-11">
  <title>Release 8.3.11</title>

  <formalpara>
  <title>Release date:</title>
  <para>2010-05-17</para>
  </formalpara>

  <para>
   This release contains a variety of fixes from 8.3.10.
   For information about new features in the 8.3 major release, see
   <xref linkend="release-8-3"/>.
  </para>

  <sect2>
   <title>Migration to Version 8.3.11</title>

   <para>
    A dump/restore is not required for those running 8.3.X.
    However, if you are upgrading from a version earlier than 8.3.8,
    see <xref linkend="release-8-3-8"/>.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

    <listitem>
     <para>
      Enforce restrictions in <literal>plperl</literal> using an opmask applied to
      the whole interpreter, instead of using <filename>Safe.pm</filename>
      (Tim Bunce, Andrew Dunstan)
     </para>

     <para>
      Recent developments have convinced us that <filename>Safe.pm</filename> is too
      insecure to rely on for making <literal>plperl</literal> trustable.  This
      change removes use of <filename>Safe.pm</filename> altogether, in favor of using
      a separate interpreter with an opcode mask that is always applied.
      Pleasant side effects of the change include that it is now possible to
      use Perl's <literal>strict</literal> pragma in a natural way in
      <literal>plperl</literal>, and that Perl's <literal>$a</literal> and <literal>$b</literal>
      variables work as expected in sort routines, and that function
      compilation is significantly faster.  (CVE-2010-1169)
     </para>
    </listitem>

    <listitem>
     <para>
      Prevent PL/Tcl from executing untrustworthy code from
      <structname>pltcl_modules</structname> (Tom)
     </para>

     <para>
      PL/Tcl's feature for autoloading Tcl code from a database table
      could be exploited for trojan-horse attacks, because there was no
      restriction on who could create or insert into that table.  This change
      disables the feature unless <structname>pltcl_modules</structname> is owned by a
      superuser.  (However, the permissions on the table are not checked, so
      installations that really need a less-than-secure modules table can
      still grant suitable privileges to trusted non-superusers.)  Also,
      prevent loading code into the unrestricted <quote>normal</quote> Tcl
      interpreter unless we are really going to execute a <literal>pltclu</literal>
      function.  (CVE-2010-1170)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix possible crash if a cache reset message is received during
      rebuild of a relcache entry (Heikki)
     </para>

     <para>
      This error was introduced in 8.3.10 while fixing a related failure.
     </para>
    </listitem>

    <listitem>
     <para>
      Apply per-function GUC settings while running the language validator
      for the function (Itagaki Takahiro)
     </para>

     <para>
      This avoids failures if the function's code is invalid without the
      setting; an example is that SQL functions may not parse if the
      <varname>search_path</varname> is not correct.
     </para>
    </listitem>

    <listitem>
     <para>
      Do not allow an unprivileged user to reset superuser-only parameter
      settings (Alvaro)
     </para>

     <para>
      Previously, if an unprivileged user ran <literal>ALTER USER ... RESET
      ALL</literal> for himself, or <literal>ALTER DATABASE ... RESET ALL</literal> for
      a database he owns, this would remove all special parameter settings
      for the user or database, even ones that are only supposed to be
      changeable by a superuser.  Now, the <command>ALTER</command> will only
      remove the parameters that the user has permission to change.
     </para>
    </listitem>

    <listitem>
     <para>
      Avoid possible crash during backend shutdown if shutdown occurs
      when a <literal>CONTEXT</literal> addition would be made to log entries (Tom)
     </para>

     <para>
      In some cases the context-printing function would fail because the
      current transaction had already been rolled back when it came time
      to print a log message.
     </para>
    </listitem>

    <listitem>
     <para>
      Ensure the archiver process responds to changes in
      <varname>archive_command</varname> as soon as possible (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Update PL/Perl's <filename>ppport.h</filename> for modern Perl versions
      (Andrew)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix assorted memory leaks in PL/Python (Andreas Freund, Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Prevent infinite recursion in <application>psql</application> when expanding
      a variable that refers to itself (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <application>psql</application>'s <literal>\copy</literal> to not add spaces around
      a dot within <literal>\copy (select ...)</literal> (Tom)
     </para>

     <para>
      Addition of spaces around the decimal point in a numeric literal would
      result in a syntax error.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix unnecessary <quote>GIN indexes do not support whole-index scans</quote>
      errors for unsatisfiable queries using <filename>contrib/intarray</filename>
      operators (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Ensure that <filename>contrib/pgstattuple</filename> functions respond to cancel
      interrupts promptly (Tatsuhito Kasahara)
     </para>
    </listitem>

    <listitem>
     <para>
      Make server startup deal properly with the case that
      <function>shmget()</function> returns <literal>EINVAL</literal> for an existing
      shared memory segment (Tom)
     </para>

     <para>
      This behavior has been observed on BSD-derived kernels including macOS.
      It resulted in an entirely-misleading startup failure complaining that
      the shared memory request size was too large.
     </para>
    </listitem>

    <listitem>
     <para>
      Avoid possible crashes in syslogger process on Windows (Heikki)
     </para>
    </listitem>

    <listitem>
     <para>
      Deal more robustly with incomplete time zone information in the
      Windows registry (Magnus)
     </para>
    </listitem>

    <listitem>
     <para>
      Update the set of known Windows time zone names (Magnus)
     </para>
    </listitem>

    <listitem>
     <para>
      Update time zone data files to <application>tzdata</application> release 2010j
      for DST law changes in Argentina, Australian Antarctic, Bangladesh,
      Mexico, Morocco, Pakistan, Palestine, Russia, Syria, Tunisia;
      also historical corrections for Taiwan.
     </para>

     <para>
      Also, add <literal>PKST</literal> (Pakistan Summer Time) to the default set of
      timezone abbreviations.
     </para>
    </listitem>

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-3-10">
  <title>Release 8.3.10</title>

  <formalpara>
  <title>Release date:</title>
  <para>2010-03-15</para>
  </formalpara>

  <para>
   This release contains a variety of fixes from 8.3.9.
   For information about new features in the 8.3 major release, see
   <xref linkend="release-8-3"/>.
  </para>

  <sect2>
   <title>Migration to Version 8.3.10</title>

   <para>
    A dump/restore is not required for those running 8.3.X.
    However, if you are upgrading from a version earlier than 8.3.8,
    see <xref linkend="release-8-3-8"/>.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

    <listitem>
     <para>
      Add new configuration parameter <varname>ssl_renegotiation_limit</varname> to
      control how often we do session key renegotiation for an SSL connection
      (Magnus)
     </para>

     <para>
      This can be set to zero to disable renegotiation completely, which may
      be required if a broken SSL library is used.  In particular, some
      vendors are shipping stopgap patches for CVE-2009-3555 that cause
      renegotiation attempts to fail.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix possible deadlock during backend startup (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix possible crashes due to not handling errors during relcache reload
      cleanly (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix possible crash due to use of dangling pointer to a cached plan
      (Tatsuo)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix possible crashes when trying to recover from a failure in
      subtransaction start (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix server memory leak associated with use of savepoints and a client
      encoding different from server's encoding (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix incorrect WAL data emitted during end-of-recovery cleanup of a GIST
      index page split (Yoichi Hirai)
     </para>

     <para>
      This would result in index corruption, or even more likely an error
      during WAL replay, if we were unlucky enough to crash during
      end-of-recovery cleanup after having completed an incomplete GIST
      insertion.
     </para>
    </listitem>

    <listitem>
     <para>
      Make <function>substring()</function> for <type>bit</type> types treat any negative
      length as meaning <quote>all the rest of the string</quote> (Tom)
     </para>

     <para>
      The previous coding treated only -1 that way, and would produce an
      invalid result value for other negative values, possibly leading to
      a crash (CVE-2010-0442).
     </para>
    </listitem>

    <listitem>
     <para>
      Fix integer-to-bit-string conversions to handle the first fractional
      byte correctly when the output bit width is wider than the given
      integer by something other than a multiple of 8 bits (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix some cases of pathologically slow regular expression matching (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix assorted crashes in <type>xml</type> processing caused by sloppy
      memory management (Tom)
     </para>

     <para>
      This is a back-patch of changes first applied in 8.4.  The 8.3 code
      was known buggy, but the new code was sufficiently different to not
      want to back-patch it until it had gotten some field testing.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix bug with trying to update a field of an element of a
      composite-type array column (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix the <literal>STOP WAL LOCATION</literal> entry in backup history files to
      report the next WAL segment's name when the end location is exactly at a
      segment boundary (Itagaki Takahiro)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix some more cases of temporary-file leakage (Heikki)
     </para>

     <para>
      This corrects a problem introduced in the previous minor release.
      One case that failed is when a plpgsql function returning set is
      called within another function's exception handler.
     </para>
    </listitem>

    <listitem>
     <para>
      Improve constraint exclusion processing of boolean-variable cases,
      in particular make it possible to exclude a partition that has a
      <quote>bool_column = false</quote> constraint (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      When reading <filename>pg_hba.conf</filename> and related files, do not treat
      <literal>@something</literal> as a file inclusion request if the <literal>@</literal>
      appears inside quote marks; also, never treat <literal>@</literal> by itself
      as a file inclusion request (Tom)
     </para>

     <para>
      This prevents erratic behavior if a role or database name starts with
      <literal>@</literal>.  If you need to include a file whose path name
      contains spaces, you can still do so, but you must write
      <literal>@"/path to/file"</literal> rather than putting the quotes around
      the whole construct.
     </para>
    </listitem>

    <listitem>
     <para>
      Prevent infinite loop on some platforms if a directory is named as
      an inclusion target in <filename>pg_hba.conf</filename> and related files
      (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix possible infinite loop if <function>SSL_read</function> or
      <function>SSL_write</function> fails without setting <varname>errno</varname> (Tom)
     </para>

     <para>
      This is reportedly possible with some Windows versions of
      <application>OpenSSL</application>.
     </para>
    </listitem>

    <listitem>
     <para>
      Disallow <acronym>GSSAPI</acronym> authentication on local connections,
      since it requires a hostname to function correctly (Magnus)
     </para>
    </listitem>

    <listitem>
     <para>
      Make <application>ecpg</application> report the proper SQLSTATE if the connection
      disappears (Michael)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <application>psql</application>'s <literal>numericlocale</literal> option to not
      format strings it shouldn't in latex and troff output formats (Heikki)
     </para>
    </listitem>

    <listitem>
     <para>
      Make <application>psql</application> return the correct exit status (3) when
      <literal>ON_ERROR_STOP</literal> and <literal>--single-transaction</literal> are
      both specified and an error occurs during the implied <command>COMMIT</command>
      (Bruce)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix plpgsql failure in one case where a composite column is set to NULL
      (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix possible failure when calling PL/Perl functions from PL/PerlU
      or vice versa (Tim Bunce)
     </para>
    </listitem>

    <listitem>
     <para>
      Add <literal>volatile</literal> markings in PL/Python to avoid possible
      compiler-specific misbehavior (Zdenek Kotala)
     </para>
    </listitem>

    <listitem>
     <para>
      Ensure PL/Tcl initializes the Tcl interpreter fully (Tom)
     </para>

     <para>
      The only known symptom of this oversight is that the Tcl
      <literal>clock</literal> command misbehaves if using Tcl 8.5 or later.
     </para>
    </listitem>

    <listitem>
     <para>
      Prevent crash in <filename>contrib/dblink</filename> when too many key
      columns are specified to a <function>dblink_build_sql_*</function> function
      (Rushabh Lathia, Joe Conway)
     </para>
    </listitem>

    <listitem>
     <para>
      Allow zero-dimensional arrays in <filename>contrib/ltree</filename> operations
      (Tom)
     </para>

     <para>
      This case was formerly rejected as an error, but it's more convenient to
      treat it the same as a zero-element array.  In particular this avoids
      unnecessary failures when an <type>ltree</type> operation is applied to the
      result of <literal>ARRAY(SELECT ...)</literal> and the sub-select returns no
      rows.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix assorted crashes in <filename>contrib/xml2</filename> caused by sloppy
      memory management (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Make building of <filename>contrib/xml2</filename> more robust on Windows
      (Andrew)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix race condition in Windows signal handling (Radu Ilie)
     </para>

     <para>
      One known symptom of this bug is that rows in <structname>pg_listener</structname>
      could be dropped under heavy load.
     </para>
    </listitem>

    <listitem>
     <para>
      Update time zone data files to <application>tzdata</application> release 2010e
      for DST law changes in Bangladesh, Chile, Fiji, Mexico, Paraguay, Samoa.
     </para>
    </listitem>

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-3-9">
  <title>Release 8.3.9</title>

  <formalpara>
  <title>Release date:</title>
  <para>2009-12-14</para>
  </formalpara>

  <para>
   This release contains a variety of fixes from 8.3.8.
   For information about new features in the 8.3 major release, see
   <xref linkend="release-8-3"/>.
  </para>

  <sect2>
   <title>Migration to Version 8.3.9</title>

   <para>
    A dump/restore is not required for those running 8.3.X.
    However, if you are upgrading from a version earlier than 8.3.8,
    see <xref linkend="release-8-3-8"/>.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

    <listitem>
     <para>
      Protect against indirect security threats caused by index functions
      changing session-local state (Gurjeet Singh, Tom)
     </para>

     <para>
      This change prevents allegedly-immutable index functions from possibly
      subverting a superuser's session (CVE-2009-4136).
     </para>
    </listitem>

    <listitem>
     <para>
      Reject SSL certificates containing an embedded null byte in the common
      name (CN) field (Magnus)
     </para>

     <para>
      This prevents unintended matching of a certificate to a server or client
      name during SSL validation (CVE-2009-4034).
     </para>
    </listitem>

    <listitem>
     <para>
      Fix possible crash during backend-startup-time cache initialization (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Avoid crash on empty thesaurus dictionary (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Prevent signals from interrupting <literal>VACUUM</literal> at unsafe times
      (Alvaro)
     </para>

     <para>
      This fix prevents a PANIC if a <literal>VACUUM FULL</literal> is canceled
      after it's already committed its tuple movements, as well as transient
      errors if a plain <literal>VACUUM</literal> is interrupted after having
      truncated the table.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix possible crash due to integer overflow in hash table size
      calculation (Tom)
     </para>

     <para>
      This could occur with extremely large planner estimates for the size of
      a hashjoin's result.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix very rare crash in <type>inet</type>/<type>cidr</type> comparisons (Chris
      Mikkelson)
     </para>
    </listitem>

    <listitem>
     <para>
      Ensure that shared tuple-level locks held by prepared transactions are
      not ignored (Heikki)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix premature drop of temporary files used for a cursor that is accessed
      within a subtransaction (Heikki)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix memory leak in syslogger process when rotating to a new CSV logfile
      (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix Windows permission-downgrade logic (Jesse Morris)
     </para>

     <para>
      This fixes some cases where the database failed to start on Windows,
      often with misleading error messages such as <quote>could not locate
      matching postgres executable</quote>.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix incorrect logic for GiST index page splits, when the split depends
      on a non-first column of the index (Paul Ramsey)
     </para>
    </listitem>

    <listitem>
     <para>
      Don't error out if recycling or removing an old WAL file fails at the
      end of checkpoint (Heikki)
     </para>

     <para>
      It's better to treat the problem as non-fatal and allow the checkpoint
      to complete.  Future checkpoints will retry the removal.  Such problems
      are not expected in normal operation, but have been seen to be
      caused by misdesigned Windows anti-virus and backup software.
     </para>
    </listitem>

    <listitem>
     <para>
      Ensure WAL files aren't repeatedly archived on Windows (Heikki)
     </para>

     <para>
      This is another symptom that could happen if some other process
      interfered with deletion of a no-longer-needed file.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix PAM password processing to be more robust (Tom)
     </para>

     <para>
      The previous code is known to fail with the combination of the Linux
      <literal>pam_krb5</literal> PAM module with Microsoft Active Directory as the
      domain controller.  It might have problems elsewhere too, since it was
      making unjustified assumptions about what arguments the PAM stack would
      pass to it.
     </para>
    </listitem>

    <listitem>
     <para>
      Raise the maximum authentication token (Kerberos ticket) size in GSSAPI
      and SSPI authentication methods (Ian Turner)
     </para>

     <para>
      While the old 2000-byte limit was more than enough for Unix Kerberos
      implementations, tickets issued by Windows Domain Controllers can be
      much larger.
     </para>
    </listitem>

    <listitem>
     <para>
      Re-enable collection of access statistics for sequences (Akira Kurosawa)
     </para>

     <para>
      This used to work but was broken in 8.3.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix processing of ownership dependencies during <literal>CREATE OR
      REPLACE FUNCTION</literal> (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix incorrect handling of <literal>WHERE</literal>
      <replaceable>x</replaceable>=<replaceable>x</replaceable> conditions (Tom)
     </para>

     <para>
      In some cases these could get ignored as redundant, but they aren't
      &mdash; they're equivalent to <replaceable>x</replaceable> <literal>IS NOT NULL</literal>.
     </para>
    </listitem>

    <listitem>
     <para>
      Make text search parser accept underscores in XML attributes (Peter)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix encoding handling in <type>xml</type> binary input (Heikki)
     </para>

     <para>
      If the XML header doesn't specify an encoding, we now assume UTF-8 by
      default; the previous handling was inconsistent.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix bug with calling <literal>plperl</literal> from <literal>plperlu</literal> or vice
      versa (Tom)
     </para>

     <para>
      An error exit from the inner function could result in crashes due to
      failure to re-select the correct Perl interpreter for the outer function.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix session-lifespan memory leak when a PL/Perl function is redefined
      (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Ensure that Perl arrays are properly converted to
      <productname>PostgreSQL</productname> arrays when returned by a set-returning
      PL/Perl function (Andrew Dunstan, Abhijit Menon-Sen)
     </para>

     <para>
      This worked correctly already for non-set-returning functions.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix rare crash in exception processing in PL/Python (Peter)
     </para>
    </listitem>

    <listitem>
     <para>
      In <filename>contrib/pg_standby</filename>, disable triggering failover with a
      signal on Windows (Fujii Masao)
     </para>

     <para>
      This never did anything useful, because Windows doesn't have Unix-style
      signals, but recent changes made it actually crash.
     </para>
    </listitem>

    <listitem>
     <para>
      Ensure <application>psql</application>'s flex module is compiled with the correct
      system header definitions (Tom)
     </para>

     <para>
      This fixes build failures on platforms where
      <literal>--enable-largefile</literal> causes incompatible changes in the
      generated code.
     </para>
    </listitem>

    <listitem>
     <para>
      Make the postmaster ignore any <literal>application_name</literal> parameter in
      connection request packets, to improve compatibility with future libpq
      versions (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Update the timezone abbreviation files to match current reality (Joachim
      Wieland)
     </para>

     <para>
      This includes adding <literal>IDT</literal> and <literal>SGT</literal> to the default
      timezone abbreviation set.
     </para>
    </listitem>

    <listitem>
     <para>
      Update time zone data files to <application>tzdata</application> release 2009s
      for DST law changes in Antarctica, Argentina, Bangladesh, Fiji,
      Novokuznetsk, Pakistan, Palestine, Samoa, Syria; also historical
      corrections for Hong Kong.
     </para>
    </listitem>

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-3-8">
  <title>Release 8.3.8</title>

  <formalpara>
  <title>Release date:</title>
  <para>2009-09-09</para>
  </formalpara>

  <para>
   This release contains a variety of fixes from 8.3.7.
   For information about new features in the 8.3 major release, see
   <xref linkend="release-8-3"/>.
  </para>

  <sect2>
   <title>Migration to Version 8.3.8</title>

   <para>
    A dump/restore is not required for those running 8.3.X.
    However, if you have any hash indexes on <type>interval</type> columns,
    you must <command>REINDEX</command> them after updating to 8.3.8.
    Also, if you are upgrading from a version earlier than 8.3.5,
    see <xref linkend="release-8-3-5"/>.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

    <listitem>
     <para>
      Fix Windows shared-memory allocation code (Tsutomu Yamada, Magnus)
     </para>

     <para>
      This bug led to the often-reported <quote>could not reattach
      to shared memory</quote> error message.
     </para>
    </listitem>

    <listitem>
     <para>
      Force WAL segment switch during <function>pg_start_backup()</function>
      (Heikki)
     </para>

     <para>
      This avoids corner cases that could render a base backup unusable.
     </para>
    </listitem>

    <listitem>
     <para>
      Disallow <command>RESET ROLE</command> and <command>RESET SESSION
      AUTHORIZATION</command> inside security-definer functions (Tom, Heikki)
     </para>

     <para>
      This covers a case that was missed in the previous patch that
      disallowed <command>SET ROLE</command> and <command>SET SESSION
      AUTHORIZATION</command> inside security-definer functions.
      (See CVE-2007-6600)
     </para>
    </listitem>

    <listitem>
     <para>
      Make <command>LOAD</command> of an already-loaded loadable module
      into a no-op (Tom)
     </para>

     <para>
      Formerly, <command>LOAD</command> would attempt to unload and re-load the
      module, but this is unsafe and not all that useful.
     </para>
    </listitem>

    <listitem>
     <para>
      Disallow empty passwords during LDAP authentication (Magnus)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix handling of sub-SELECTs appearing in the arguments of
      an outer-level aggregate function (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix bugs associated with fetching a whole-row value from the
      output of a Sort or Materialize plan node (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Prevent <varname>synchronize_seqscans</varname> from changing the results of
      scrollable and <literal>WITH HOLD</literal> cursors (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Revert planner change that disabled partial-index and constraint
      exclusion optimizations when there were more than 100 clauses in
      an AND or OR list (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix hash calculation for data type <type>interval</type> (Tom)
     </para>

     <para>
      This corrects wrong results for hash joins on interval values.
      It also changes the contents of hash indexes on interval columns.
      If you have any such indexes, you must <command>REINDEX</command> them
      after updating.
     </para>
    </listitem>

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

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

    <listitem>
     <para>
      Fix overflow for <literal>INTERVAL '<replaceable>x</replaceable> ms'</literal>
      when <replaceable>x</replaceable> is more than 2 million and integer
      datetimes are in use (Alex Hunsaker)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix calculation of distance between a point and a line segment (Tom)
     </para>

     <para>
      This led to incorrect results from a number of geometric operators.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <type>money</type> data type to work in locales where currency
      amounts have no fractional digits, e.g. Japan (Itagaki Takahiro)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <literal>LIKE</literal> for case where pattern contains <literal>%_</literal>
      (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Properly round datetime input like
      <literal>00:12:57.9999999999999999999999999999</literal> (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix memory leaks in XML operations (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix poor choice of page split point in GiST R-tree operator classes
      (Teodor)
     </para>
    </listitem>

    <listitem>
     <para>
      Ensure that a <quote>fast shutdown</quote> request will forcibly terminate
      open sessions, even if a <quote>smart shutdown</quote> was already in progress
      (Fujii Masao)
     </para>
    </listitem>

    <listitem>
     <para>
      Avoid performance degradation in bulk inserts into GIN indexes
      when the input values are (nearly) in sorted order (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Correctly enforce NOT NULL domain constraints in some contexts in
      PL/pgSQL (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix portability issues in plperl initialization (Andrew Dunstan)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <application>pg_ctl</application> to not go into an infinite loop if
      <filename>postgresql.conf</filename> is empty (Jeff Davis)
     </para>
    </listitem>

    <listitem>
     <para>
      Improve <application>pg_dump</application>'s efficiency when there are
      many large objects (Tamas Vincze)
     </para>
    </listitem>

    <listitem>
     <para>
      Use <literal>SIGUSR1</literal>, not <literal>SIGQUIT</literal>, as the
      failover signal for <application>pg_standby</application> (Heikki)
     </para>
    </listitem>

    <listitem>
     <para>
      Make <application>pg_standby</application>'s <literal>maxretries</literal> option
      behave as documented (Fujii Masao)
     </para>
    </listitem>

    <listitem>
     <para>
      Make <filename>contrib/hstore</filename> throw an error when a key or
      value is too long to fit in its data structure, rather than
      silently truncating it (Andrew Gierth)
     </para>
    </listitem>

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

    <listitem>
     <para>
      Improve robustness of <application>libpq</application>'s code to recover
      from errors during <command>COPY FROM STDIN</command> (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Avoid including conflicting readline and editline header files
      when both libraries are installed (Zdenek Kotala)
     </para>
    </listitem>

    <listitem>
     <para>
      Update time zone data files to <application>tzdata</application> release 2009l
      for DST law changes in Bangladesh, Egypt, Jordan, Pakistan,
      Argentina/San_Luis, Cuba, Jordan (historical correction only),
      Mauritius, Morocco, Palestine, Syria, Tunisia.
     </para>
    </listitem>

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-3-7">
  <title>Release 8.3.7</title>

  <formalpara>
  <title>Release date:</title>
  <para>2009-03-16</para>
  </formalpara>

  <para>
   This release contains a variety of fixes from 8.3.6.
   For information about new features in the 8.3 major release, see
   <xref linkend="release-8-3"/>.
  </para>

  <sect2>
   <title>Migration to Version 8.3.7</title>

   <para>
    A dump/restore is not required for those running 8.3.X.
    However, if you are upgrading from a version earlier than 8.3.5,
    see <xref linkend="release-8-3-5"/>.
   </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</emphasis> 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</command> 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 <function>xpath()</function> to not modify the path expression unless
      necessary, and to make a saner attempt at it when necessary (Andrew)
     </para>

     <para>
      The SQL standard suggests that <function>xpath</function> should work on data
      that is a document fragment, but <application>libxml</application> doesn't support
      that, and indeed it's not clear that this is sensible according to the
      XPath standard.  <function>xpath</function> attempted to work around this
      mismatch by modifying both the data and the path expression, but the
      modification was buggy and could cause valid searches to fail.  Now,
      <function>xpath</function> checks whether the data is in fact a well-formed
      document, and if so invokes <application>libxml</application> with no change to the
      data or path expression.  Otherwise, a different modification method
      that is somewhat less likely to fail is used.
     </para>

     <note>
      <para>
       The new modification method is still not 100% satisfactory, and it
       seems likely that no real solution is possible.  This patch should
       therefore be viewed as a band-aid to keep from breaking existing
       applications unnecessarily.  It is likely that
       <productname>PostgreSQL</productname> 8.4 will simply reject use of
       <function>xpath</function> on data that is not a well-formed document.
      </para>
     </note>
    </listitem>

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

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

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

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

    <listitem>
     <para>
      Fix planner problem with sub-<command>SELECT</command> in the output list
      of a larger subquery (Tom)
     </para>

     <para>
      The known symptom of this bug is a <quote>failed to locate grouping
      columns</quote> error that is dependent on the datatype involved;
      but there could be other issues as well.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix decompilation of <literal>CASE WHEN</literal> 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</quote> 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</command> or a rewriting variant of <command>ALTER TABLE</command>
      were executed by someone other than the table owner, the
      <structname>pg_type</structname> 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</quote>
      warnings from <application>pg_dump</application> after having done so (in 8.3).
     </para>
    </listitem>

    <listitem>
     <para>
      Change <command>UNLISTEN</command> to exit quickly if the current session has
      never executed any <command>LISTEN</command> command (Tom)
     </para>

     <para>
      Most of the time this is not a particularly useful optimization, but
      since <command>DISCARD ALL</command> invokes <command>UNLISTEN</command>, the previous
      coding caused a substantial performance problem for applications that
      made heavy use of <command>DISCARD ALL</command>.
     </para>
    </listitem>

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

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

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-3-6">
  <title>Release 8.3.6</title>

  <formalpara>
  <title>Release date:</title>
  <para>2009-02-02</para>
  </formalpara>

  <para>
   This release contains a variety of fixes from 8.3.5.
   For information about new features in the 8.3 major release, see
   <xref linkend="release-8-3"/>.
  </para>

  <sect2>
   <title>Migration to Version 8.3.6</title>

   <para>
    A dump/restore is not required for those running 8.3.X.
    However, if you are upgrading from a version earlier than 8.3.5,
    see <xref linkend="release-8-3-5"/>.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

    <listitem>
     <para>
      Make <command>DISCARD ALL</command> release advisory locks, in addition
      to everything it already did (Tom)
     </para>

     <para>
      This was decided to be the most appropriate behavior.  This could
      affect existing applications, however.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix whole-index GiST scans to work correctly (Teodor)
     </para>

     <para>
      This error could cause rows to be lost if a table is clustered
      on a GiST index.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix crash of <literal>xmlconcat(NULL)</literal> (Peter)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix possible crash in <literal>ispell</literal> dictionary if high-bit-set
      characters are used as flags (Teodor)
     </para>

     <para>
      This is known to be done by one widely available Norwegian dictionary,
      and the same condition may exist in others.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix misordering of <application>pg_dump</application> output for composite types
      (Tom)
     </para>

     <para>
      The most likely problem was for user-defined operator classes to
      be dumped after indexes or views that needed them.
     </para>
    </listitem>

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

    <listitem>
     <para>
      Improve handling of overlength headlines in <function>headline()</function>
      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</command> is rewritten into an <command>UPDATE</command> (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</literal>
      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</command>
      (Heikki)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix a problem that sometimes kept <command>ALTER TABLE ENABLE/DISABLE
      RULE</command> from being recognized by active sessions (Tom)
     </para>
    </listitem>

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

    <listitem>
     <para>
      Allow functions declared as taking <type>ANYARRAY</type> to work on
      the <structname>pg_statistic</structname> columns of that type (Tom)
     </para>

     <para>
      This used to work, but was unintentionally broken in 8.3.
     </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 ...</literal>
     </para>
    </listitem>

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

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

    <listitem>
     <para>
      Prevent synchronous scan during GIN index build (Tom)
     </para>

     <para>
      Because GIN is optimized for inserting tuples in increasing TID order,
      choosing to use a synchronous scan could slow the build by a factor of
      three or more.
     </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 encoding conversion problems in XML functions when the database
      encoding isn't UTF-8 (Tom)
     </para>
    </listitem>

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

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

    <listitem>
     <para>
      Fix incorrect behavior of <filename>contrib/tsearch2</filename> compatibility
      trigger when it's fired more than once in a command (Teodor)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix possible mis-signaling in autovacuum (Heikki)
     </para>
    </listitem>

    <listitem>
     <para>
      Support running as a service on Windows 7 beta (Dave and Magnus)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <application>ecpg</application>'s handling of varchar structs (Michael)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <application>configure</application> 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</literal> and/or
      <literal>pgsql-hackers</literal> as appropriate, instead of the
      now-decommissioned <literal>pgsql-ports</literal> and <literal>pgsql-patches</literal>
      mailing lists (Tom)
     </para>
    </listitem>

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

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-3-5">
  <title>Release 8.3.5</title>

  <formalpara>
  <title>Release date:</title>
  <para>2008-11-03</para>
  </formalpara>

  <para>
   This release contains a variety of fixes from 8.3.4.
   For information about new features in the 8.3 major release, see
   <xref linkend="release-8-3"/>.
  </para>

  <sect2>
   <title>Migration to Version 8.3.5</title>

   <para>
    A dump/restore is not required for those running 8.3.X.
    However, if you are upgrading from a version earlier than 8.3.1,
    see <xref linkend="release-8-3-1"/>.  Also, if you were running a previous
    8.3.X release, it is recommended to <command>REINDEX</command> 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</quote> 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</command>.
     </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</quote> 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 in <type>bytea</type>-to-XML mapping (Michael McMaster)
     </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</replaceable> <literal>IN</literal>
      (<replaceable>expression-list</replaceable>) 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</literal> appears
      in a function call in <literal>FROM</literal>,  a multi-row <literal>VALUES</literal>
      list, or a <literal>RETURNING</literal> list (Tom)
     </para>

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

    <listitem>
     <para>
      Fix Assert failure during rescan of an <literal>IS NULL</literal>
      search of a GiST index (Teodor)
     </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>
      Force a checkpoint before <command>CREATE DATABASE</command> starts to copy
      files (Heikki)
     </para>

     <para>
      This prevents a possible failure if files had recently been deleted
      in the source database.
     </para>
    </listitem>

    <listitem>
     <para>
      Prevent possible collision of <structfield>relfilenode</structfield> numbers
      when moving a table to another tablespace with <command>ALTER SET
      TABLESPACE</command> (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 text search 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</option>
      build (Ron Mayer)
     </para>
    </listitem>

    <listitem>
     <para>
      Make <literal>ILIKE</literal> compare characters case-insensitively
      even when they're escaped (Andrew)
     </para>
    </listitem>

    <listitem>
     <para>
      Ensure <command>DISCARD</command> is handled properly by statement logging (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix incorrect logging of last-completed-transaction time during
      PITR recovery (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Ensure <function>SPI_getvalue</function> and <function>SPI_getbinval</function>
      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>
      Mark <varname>SessionReplicationRole</varname> as <literal>PGDLLIMPORT</literal>
      so it can be used by <application>Slony</application> on Windows (Magnus)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix small memory leak when using <application>libpq</application>'s
      <literal>gsslib</literal> parameter (Magnus)
     </para>

     <para>
      The space used by the parameter string was not freed at connection
      close.
     </para>
    </listitem>

    <listitem>
     <para>
      Ensure <application>libgssapi</application> is linked into <application>libpq</application>
      if needed (Markus Schaaf)
     </para>
    </listitem>

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

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

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

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

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

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-3-4">
  <title>Release 8.3.4</title>

  <formalpara>
  <title>Release date:</title>
  <para>2008-09-22</para>
  </formalpara>

  <para>
   This release contains a variety of fixes from 8.3.3.
   For information about new features in the 8.3 major release, see
   <xref linkend="release-8-3"/>.
  </para>

  <sect2>
   <title>Migration to Version 8.3.4</title>

   <para>
    A dump/restore is not required for those running 8.3.X.
    However, if you are upgrading from a version earlier than 8.3.1,
    see <xref linkend="release-8-3-1"/>.
   </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 use of wrong cutoff XID for HOT page pruning (Alvaro)
     </para>

     <para>
      This error created a risk of corruption in system
      catalogs that are consulted by <command>VACUUM</command>: dead tuple versions
      might be removed too soon.  The impact of this on actual database
      operations would be minimal, since the system doesn't follow MVCC
      rules while examining catalogs, but it might result in transiently
      wrong output from <application>pg_dump</application> or other client programs.
     </para>
    </listitem>

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

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

    <listitem>
     <para>
      Fix incorrect HOT updates after <structname>pg_class</structname> is reindexed
      (Tom)
     </para>

     <para>
      Corruption of <structname>pg_class</structname> could occur if <literal>REINDEX
      TABLE pg_class</literal> was followed in the same session by an <literal>ALTER
      TABLE RENAME</literal> or <literal>ALTER TABLE SET SCHEMA</literal> command.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix missed <quote>combo cid</quote> case (Karl Schnaitter)
     </para>

     <para>
      This error made rows incorrectly invisible to a transaction in which they
      had been deleted by multiple subtransactions that all aborted.
     </para>
    </listitem>

    <listitem>
     <para>
      Prevent autovacuum from crashing if the table it's currently
      checking is deleted at just the wrong time (Alvaro)
     </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</quote> errors.
     </para>
    </listitem>

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

    <listitem>
     <para>
      Regenerate foreign key checking queries from scratch when either
      table is modified (Tom)
     </para>

     <para>
      Previously, 8.3 would attempt to replan the query, but would work from
      previously generated query text.  This led to failures if a
      table or column was renamed.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix missed permissions checks when a view contains a simple
      <literal>UNION ALL</literal> 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</command> or <command>UPDATE</command> will match the target table's
      current rowtype (Tom)
     </para>

     <para>
      This situation is believed to be impossible in 8.3, but it can happen in
      prior releases, so a check seems prudent.
     </para>
    </listitem>

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

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

    <listitem>
     <para>
      Fix several memory leaks in XML operations (Kris Jurka, Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <function>xmlserialize()</function> to raise error properly for
      unacceptable target data type (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix a couple of places that mis-handled multibyte characters in text
      search configuration file parsing (Tom)
     </para>

     <para>
      Certain characters occurring in configuration files would always cause
      <quote>invalid byte sequence for encoding</quote> failures.
     </para>
    </listitem>

    <listitem>
     <para>
      Provide file name and line number location for all errors reported
      in text search configuration files (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <literal>AT TIME ZONE</literal> 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</literal> 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</literal> accepted
      <emphasis>only</emphasis> 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</filename> (Tom)
     </para>
    </listitem>

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

    <listitem>
     <para>
      Fix planner bug that could improperly push down <literal>IS NULL</literal>
      tests below an outer join (Tom)
     </para>

     <para>
      This was triggered by occurrence of <literal>IS NULL</literal> tests for
      the same relation in all arms of an upper <literal>OR</literal> clause.
     </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</literal> 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</literal> estimate for certain boolean tests like <replaceable>col</replaceable>
      <literal>IS NULL</literal>.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix PL/pgSQL to not fail when a <literal>FOR</literal> 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>
      Improve performance of <function>PQescapeBytea()</function> (Rudolf Leitgeb)
     </para>
    </listitem>

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

    <listitem>
     <para>
      Fix <application>ecpg</application> to handle variables properly in <command>SET</command>
      commands (Michael)
     </para>
    </listitem>

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

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

    <listitem>
     <para>
      Fix erroneous WAL file cutoff point calculation in
      <application>pg_standby</application> (Simon)
     </para>
    </listitem>

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

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-3-3">
  <title>Release 8.3.3</title>

  <formalpara>
  <title>Release date:</title>
  <para>2008-06-12</para>
  </formalpara>

  <para>
   This release contains one serious and one minor bug fix over 8.3.2.
   For information about new features in the 8.3 major release, see
   <xref linkend="release-8-3"/>.
  </para>

  <sect2>
   <title>Migration to Version 8.3.3</title>

   <para>
    A dump/restore is not required for those running 8.3.X.
    However, if you are upgrading from a version earlier than 8.3.1,
    see <xref linkend="release-8-3-1"/>.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

    <listitem>
     <para>
      Make <function>pg_get_ruledef()</function> 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</literal>, which is subtly incorrect: it should
      be <literal>(-42)::integer</literal> due to operator precedence rules.
      Usually this would make little difference, but it could interact with
      another recent patch to cause
      <productname>PostgreSQL</productname> to reject what had been a valid
      <command>SELECT DISTINCT</command> view query.  Since this could result in
      <application>pg_dump</application> 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</command> update
      <structname>pg_shdepend</structname> (Tom)
     </para>

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

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-3-2">
  <title>Release 8.3.2</title>

  <formalpara>
  <title>Release date:</title>
  <para>never released</para>
  </formalpara>

  <para>
   This release contains a variety of fixes from 8.3.1.
   For information about new features in the 8.3 major release, see
   <xref linkend="release-8-3"/>.
  </para>

  <sect2>
   <title>Migration to Version 8.3.2</title>

   <para>
    A dump/restore is not required for those running 8.3.X.
    However, if you are upgrading from a version earlier than 8.3.1,
    see <xref linkend="release-8-3-1"/>.
   </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 incorrect archive truncation point calculation for the
      <literal>%r</literal> macro in <varname>restore_command</varname> parameters
      (Simon)
     </para>

     <para>
      This could lead to data loss if a warm-standby script relied on
      <literal>%r</literal> to decide when to throw away WAL segment files.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <command>ALTER TABLE ADD COLUMN ... PRIMARY KEY</command> 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 <command>REASSIGN OWNED</command> so that it works on procedural
      languages too (Alvaro)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix problems with <command>SELECT FOR UPDATE/SHARE</command> occurring as a
      subquery in a query with a non-<command>SELECT</command> top-level operation
      (Tom)
     </para>
    </listitem>

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

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

    <listitem>
     <para>
      Restore the pre-8.3 behavior that an out-of-range block number in a
      TID being used in a TidScan plan results in silently not matching any
      rows (Tom)
     </para>

     <para>
      8.3.0 and 8.3.1 threw an error instead.
     </para>
    </listitem>

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

    <listitem>
     <para>
      Fix broken GiST comparison function for <type>tsquery</type> (Teodor)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <function>tsvector_update_trigger()</function> and <function>ts_stat()</function>
      to accept domains over the types they expect to work with (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix failure to support enum data types as foreign keys (Tom)
     </para>
    </listitem>

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

    <listitem>
     <para>
      Fix race conditions between delayed unlinks and <command>DROP
      DATABASE</command> (Heikki)
     </para>

     <para>
      In the worst case this could result in deleting a newly created table
      in a new database that happened to get the same OID as the
      recently-dropped one; but of course that is an extremely
      low-probability scenario.
     </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 possible crash due to incorrect plan generated for an
      <literal><replaceable>x</replaceable> IN (SELECT <replaceable>y</replaceable>
      FROM ...)</literal> clause when <replaceable>x</replaceable> and <replaceable>y</replaceable>
      have different data types; and make sure the behavior is semantically
      correct when the conversion from <replaceable>y</replaceable>'s type to
      <replaceable>x</replaceable>'s type is lossy (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix oversight that prevented the planner from substituting known Param
      values as if they were constants (Tom)
     </para>

     <para>
      This mistake partially disabled optimization of unnamed
      extended-Query statements in 8.3.0 and 8.3.1: in particular the
      LIKE-to-indexscan optimization would never be applied if the LIKE
      pattern was passed as a parameter, and constraint exclusion
      depending on a parameter value didn't work either.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix planner failure when an indexable <function>MIN</function> or
      <function>MAX</function> aggregate is used with <literal>DISTINCT</literal> or
      <literal>ORDER BY</literal> (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix planner to ensure it never uses a <quote>physical tlist</quote> for a
      plan node that is feeding a Sort node (Tom)
     </para>

     <para>
      This led to the sort having to push around more data than it really
      needed to, since unused column values were included in the sorted
      data.
     </para>
    </listitem>

    <listitem>
     <para>
      Avoid unnecessary copying of query strings (Tom)
     </para>

     <para>
      This fixes a performance problem introduced in 8.3.0 when a very large
      number of commands are submitted as a single query string.
     </para>
    </listitem>

    <listitem>
     <para>
      Make <function>TransactionIdIsCurrentTransactionId()</function> use binary
      search instead of linear search when checking child-transaction XIDs
      (Heikki)
     </para>

     <para>
      This fixes some cases in which 8.3.0 was significantly
      slower than earlier releases.
     </para>
    </listitem>

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

    <listitem>
     <para>
      Fix several datatype input functions, notably <function>array_in()</function>,
      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</literal> and <literal>DISTINCT</literal>
      expressions.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix a corner case in regular-expression substring matching
      (<literal>substring(<replaceable>string</replaceable> from
      <replaceable>pattern</replaceable>)</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)?')</literal>.
      This should return NULL, since <literal>(bar)</literal> isn't matched, but
      it was mistakenly returning the whole-pattern match instead (ie,
      <literal>foo</literal>).
     </para>
    </listitem>

    <listitem>
     <para>
      Prevent cancellation of an auto-vacuum that was launched to prevent
      XID wraparound (Alvaro)
     </para>
    </listitem>

    <listitem>
     <para>
      Improve <command>ANALYZE</command>'s handling of in-doubt tuples (those
      inserted or deleted by a not-yet-committed transaction) so that the
      counts it reports to the stats collector are more likely to be correct
      (Pavan Deolasee)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <application>initdb</application> to reject a relative path for its
      <literal>--xlogdir</literal> (<literal>-X</literal>) option (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Make <application>psql</application> print tab characters as an appropriate
      number of spaces, rather than <literal>\x09</literal> as was done in
      8.3.0 and 8.3.1 (Bruce)
     </para>
    </listitem>

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

    <listitem>
     <para>
      Add <function>ECPGget_PGconn()</function> function to
      <application>ecpglib</application> (Michael)
     </para>
    </listitem>

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

    <listitem>
     <para>
      Fix handling of continuation line markers in <application>ecpg</application>
      (Michael)
     </para>
    </listitem>

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

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

    <listitem>
     <para>
      Fix <filename>contrib/xml2</filename>'s makefile to not override
      <literal>CFLAGS</literal>, and make it auto-configure properly for
      <application>libxslt</application> present or not (Tom)
     </para>
    </listitem>

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-3-1">
  <title>Release 8.3.1</title>

  <formalpara>
  <title>Release date:</title>
  <para>2008-03-17</para>
  </formalpara>

  <para>
   This release contains a variety of fixes from 8.3.0.
   For information about new features in the 8.3 major release, see
   <xref linkend="release-8-3"/>.
  </para>

  <sect2>
   <title>Migration to Version 8.3.1</title>

   <para>
    A dump/restore is not required for those running 8.3.X.
    However, you might need to <command>REINDEX</command> 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</command> to fix existing indexes on textual columns.
     </para>
    </listitem>

    <listitem>
     <para>
      Repair corner-case bugs in <command>VACUUM FULL</command> (Tom)
     </para>

     <para>
      A potential deadlock between concurrent <command>VACUUM FULL</command>
      operations on different system catalogs was introduced in 8.2.
      This has now been corrected.  8.3 made this worse because the
      deadlock could occur within a critical code section, making it
      a PANIC rather than just ERROR condition.
     </para>

     <para>
      Also, a <command>VACUUM FULL</command> that failed partway through
      vacuuming a system catalog could result in cache corruption in
      concurrent database sessions.
     </para>

     <para>
      Another <command>VACUUM FULL</command> bug introduced in 8.3 could
      result in a crash or out-of-memory report when dealing with
      pages containing no live tuples.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix misbehavior of foreign key checks involving <type>character</type>
      or <type>bit</type> columns (Tom)
     </para>

     <para>
      If the referencing column were of a different but compatible type
      (for instance <type>varchar</type>), the constraint was enforced incorrectly.
     </para>
    </listitem>

    <listitem>
     <para>
      Avoid needless deadlock failures in no-op foreign-key checks (Stephan
      Szabo, Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix possible core dump when re-planning a prepared query (Tom)
     </para>

     <para>
      This bug affected only protocol-level prepare operations, not
      SQL <command>PREPARE</command>, and so tended to be seen only with
      JDBC, DBI, and other client-side drivers that use prepared
      statements heavily.
     </para>
    </listitem>

    <listitem>
     <para>
      Fix possible failure when re-planning a query that calls an SPI-using
      function (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix failure in row-wise comparisons involving columns of different
      datatypes (Tom)
     </para>
    </listitem>

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

     <para>
      In rare cases a session that had just executed a
      <command>LISTEN</command> might not get a notification, even though
      one would be expected because the concurrent transaction executing
      <command>NOTIFY</command> 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> command will not see any
      row in <structname>pg_listener</structname> for the <command>LISTEN</command>,
      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</command> and <command>UNLISTEN</command> 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</command> 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 and 8.3.
     </para>
    </listitem>

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

    <listitem>
     <para>
      Fix incorrect comparison of <type>tsquery</type> values (Teodor)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix incorrect behavior of <literal>LIKE</literal> with non-ASCII characters
      in single-byte encodings (Rolf Jentsch)
     </para>
    </listitem>

    <listitem>
     <para>
      Disable <function>xmlvalidate</function> (Tom)
     </para>

     <para>
      This function should have been removed before 8.3 release, but
      was inadvertently left in the source code.  It poses a small
      security risk since unprivileged users could use it to read the
      first few characters of any file accessible to the server.
     </para>
    </listitem>

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

    <listitem>
     <para>
      Make <function>encode(<replaceable>bytea</replaceable>, 'escape')</function> convert all
      high-bit-set byte values into <literal>\</literal><replaceable>nnn</replaceable> octal
      escape sequences (Tom)
     </para>

     <para>
      This is necessary to avoid encoding problems when the database
      encoding is multi-byte.  This change could pose compatibility issues
      for applications that are expecting specific results from
      <function>encode</function>.
     </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</quote> error in some variants of
      <command>ALTER OWNER</command> (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Avoid tablespace permissions errors in <command>CREATE TABLE LIKE
      INCLUDING INDEXES</command> (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Ensure <structname>pg_stat_activity</structname>.<structfield>waiting</structfield> 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</application> release 2008a
      (in particular, recent Chile changes); adjust timezone abbreviation
      <literal>VET</literal> (Venezuela) to mean UTC-4:30, not UTC-4:00 (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix <application>ecpg</application> problems with arrays (Michael)
     </para>
    </listitem>

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

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

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

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

    <listitem>
     <para>
      Enable building <filename>contrib/uuid-ossp</filename> with MSVC (Hiroshi Saito)
     </para>
    </listitem>

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-3">
  <title>Release 8.3</title>

  <formalpara>
   <title>Release date:</title>
   <para>2008-02-04</para>
  </formalpara>

  <sect2>
   <title>Overview</title>

   <para>
    With significant new functionality and performance enhancements,
    this release represents a major leap forward for
    <productname>PostgreSQL</productname>. This was made possible by a growing
    community that has dramatically accelerated the pace of
    development. This release adds the following major features:
   </para>

   <itemizedlist>

    <listitem>
     <para>
      Full text search is integrated into the core database system
     </para>
    </listitem>

    <listitem>
     <para>
      Support for the SQL/XML standard, including new operators and an
      <type>XML</type> data type
     </para>
    </listitem>

    <listitem>
     <para>
      Enumerated data types (<type>ENUM</type>)
     </para>
    </listitem>

    <listitem>
     <para>
      Arrays of composite types
     </para>
    </listitem>

    <listitem>
     <para>
      Universally Unique Identifier (<type>UUID</type>) data type
     </para>
    </listitem>

    <listitem>
     <para>
      Add control over whether <literal>NULL</literal>s sort first or last
     </para>
    </listitem>

    <listitem>
     <para>
      Updatable cursors
     </para>
    </listitem>

    <listitem>
     <para>
      Server configuration parameters can now be set on a per-function
      basis
     </para>
    </listitem>

    <listitem>
     <para>
      User-defined types can now have type modifiers
     </para>
    </listitem>

    <listitem>
     <para>
      Automatically re-plan cached queries when table
      definitions change or statistics are updated
     </para>
    </listitem>

    <listitem>
     <para>
      Numerous improvements in logging and statistics collection
     </para>
    </listitem>

    <listitem>
     <para>
      Support Security Service Provider Interface (<acronym>SSPI</acronym>) for
      authentication on Windows
     </para>
    </listitem>

    <listitem>
     <para>
      Support multiple concurrent autovacuum processes, and other
      autovacuum improvements
     </para>
    </listitem>

    <listitem>
     <para>
      Allow the whole <productname>PostgreSQL</productname> distribution to be compiled
      with <productname>Microsoft Visual C++</productname>
     </para>
    </listitem>

   </itemizedlist>

   <para>
    Major performance improvements are listed below.  Most of
    these enhancements are automatic and do not require user changes or
    tuning:
   </para>

  <itemizedlist>

    <listitem>
     <para>
      Asynchronous commit delays writes to WAL during transaction commit
     </para>
    </listitem>

    <listitem>
     <para>
      Checkpoint writes can be spread over a longer time period to smooth
      the I/O spike during each checkpoint
     </para>
    </listitem>

    <listitem>
     <para>
      Heap-Only Tuples (<acronym>HOT</acronym>) accelerate space reuse for
      most <command>UPDATE</command>s and <command>DELETE</command>s
     </para>
    </listitem>

    <listitem>
     <para>
      Just-in-time background writer strategy improves disk write
      efficiency
     </para>
    </listitem>

    <listitem>
     <para>
      Using non-persistent transaction IDs for read-only transactions
      reduces overhead and <command>VACUUM</command> requirements
     </para>
    </listitem>

    <listitem>
     <para>
      Per-field and per-row storage overhead has been reduced
     </para>
    </listitem>

    <listitem>
     <para>
      Large sequential scans no longer force out frequently used
      cached pages
     </para>
    </listitem>

    <listitem>
     <para>
      Concurrent large sequential scans can now share disk reads
     </para>
    </listitem>

    <listitem>
     <para>
      <literal>ORDER BY ... LIMIT</literal> can be done without sorting
     </para>
    </listitem>

   </itemizedlist>

   <para>
    The above items are explained in more detail in the sections below.
   </para>

  </sect2>

  <sect2>
   <title>Migration to Version 8.3</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>

   <sect3>
    <title>General</title>
    <itemizedlist>

     <listitem>
      <para>
       Non-character data types are no longer automatically cast to
       <type>TEXT</type> (Peter, Tom)
      </para>

      <para>
       Previously, if a non-character value was supplied to an operator or
       function that requires <type>text</type> input, it was automatically
       cast to <type>text</type>, for most (though not all) built-in data types.
       This no longer happens: an explicit cast to <type>text</type> is now
       required for all non-character-string types.  For example, these
       expressions formerly worked:

<programlisting>
substr(current_date, 1, 4)
23 LIKE '2%'
</programlisting>

       but will now draw <quote>function does not exist</quote> and <quote>operator
       does not exist</quote> errors respectively.  Use an explicit cast instead:

<programlisting>
substr(current_date::text, 1, 4)
23::text LIKE '2%'
</programlisting>

       (Of course, you can use the more verbose <literal>CAST()</literal> syntax too.)
       The reason for the change is that these automatic casts too often caused
       surprising behavior.  An example is that in previous releases, this
       expression was accepted but did not do what was expected:

<programlisting>
current_date &lt; 2017-11-17
</programlisting>

       This is actually comparing a date to an integer, which should be
       (and now is) rejected &mdash; but in the presence of automatic
       casts both sides were cast to <type>text</type> and a textual comparison
       was done, because the <literal>text &lt; text</literal> operator was able
       to match the expression when no other <literal>&lt;</literal> operator could.
      </para>

      <para>
       Types <type>char(<replaceable>n</replaceable>)</type> and
       <type>varchar(<replaceable>n</replaceable>)</type> still cast to <type>text</type>
       automatically.  Also, automatic casting to <type>text</type> still works for
       inputs to the concatenation (<literal>||</literal>) operator, so long as least
       one input is a character-string type.
      </para>
     </listitem>

     <listitem>
      <para>
        Full text search features from <filename>contrib/tsearch2</filename> have
        been moved into the core server, with some minor syntax changes
      </para>

      <para>
       <filename>contrib/tsearch2</filename> now contains a compatibility
       interface.
      </para>
     </listitem>

     <listitem>
      <para>
       <literal>ARRAY(SELECT ...)</literal>, where the <command>SELECT</command>
       returns no rows, now returns an empty array, rather than NULL
       (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       The array type name for a base data type is no longer always the base
       type's name with an underscore prefix
      </para>

      <para>
       The old naming convention is still honored when possible, but
       application code should no longer depend on it. Instead
       use the new <literal>pg_type.typarray</literal> column to
       identify the array data type associated with a given type.
      </para>
     </listitem>

     <listitem>
      <para>
       <literal>ORDER BY ... USING</literal> <replaceable>operator</replaceable> must now
       use a less-than or greater-than <replaceable>operator</replaceable> that is
       defined in a btree operator class
      </para>

      <para>
       This restriction was added to prevent inconsistent results.
      </para>
     </listitem>

     <listitem>
      <para>
       <command>SET LOCAL</command> changes now persist until
       the end of the outermost transaction, unless rolled back (Tom)
      </para>

      <para>
       Previously <command>SET LOCAL</command>'s effects were lost
       after subtransaction commit (<command>RELEASE SAVEPOINT</command>
       or exit from a PL/pgSQL exception block).
      </para>
     </listitem>

     <listitem>
      <para>
       Commands rejected in transaction blocks are now also rejected in
       multiple-statement query strings (Tom)
      </para>

      <para>
       For example, <literal>"BEGIN; DROP DATABASE; COMMIT"</literal> will now be
       rejected even if submitted as a single query message.
      </para>
     </listitem>

     <listitem>
      <para>
       <command>ROLLBACK</command> outside a transaction block now
       issues <literal>NOTICE</literal> instead of <literal>WARNING</literal> (Bruce)
      </para>
     </listitem>

     <listitem>
      <para>
       Prevent <command>NOTIFY</command>/<command>LISTEN</command>/<command>UNLISTEN</command>
       from accepting schema-qualified names (Bruce)
      </para>

      <para>
       Formerly, these commands accepted <literal>schema.relation</literal> but
       ignored the schema part, which was confusing.
      </para>
     </listitem>

     <listitem>
      <para>
       <command>ALTER SEQUENCE</command> no longer affects the sequence's
       <function>currval()</function> state (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Foreign keys now must match indexable conditions for
       cross-data-type references (Tom)
      </para>

      <para>
       This improves semantic consistency and helps avoid
       performance problems.
      </para>
     </listitem>

     <listitem>
      <para>
       Restrict object size functions to users who have reasonable
       permissions to view such information (Tom)
      </para>

      <para>
       For example, <function>pg_database_size()</function> now requires
       <literal>CONNECT</literal> permission, which is granted to everyone by
       default. <function>pg_tablespace_size()</function> requires
       <literal>CREATE</literal> permission in the tablespace, or is allowed if
       the tablespace is the default tablespace for the database.
      </para>
     </listitem>

     <listitem>
      <para>
       Remove the undocumented <literal>!!=</literal> (not in) operator (Tom)
      </para>

      <para>
       <literal>NOT IN (SELECT ...)</literal> is the proper way to
       perform this operation.
      </para>
     </listitem>

     <listitem>
      <para>
       Internal hashing functions are now more uniformly-distributed (Tom)
      </para>

      <para>
       If application code was computing and storing hash values using
       internal <productname>PostgreSQL</productname> hashing functions, the hash
       values must be regenerated.
      </para>
     </listitem>

     <listitem>
      <para>
       C-code conventions for handling variable-length data values
       have changed (Greg Stark, Tom)
      </para>

      <para>
       The new <function>SET_VARSIZE()</function> macro <emphasis>must</emphasis> be used
       to set the length of generated <type>varlena</type> values. Also, it
       might be necessary to expand (<quote>de-TOAST</quote>) input values
       in more cases.
      </para>
     </listitem>

     <listitem>
      <para>
       Continuous archiving no longer reports each successful archive
       operation to the server logs unless <literal>DEBUG</literal> level is used
       (Simon)
      </para>
     </listitem>

    </itemizedlist>

    </sect3>

    <sect3>
     <title>Configuration Parameters</title>

    <itemizedlist>

     <listitem>
      <para>
       Numerous changes in administrative server parameters
      </para>

      <para>
       <varname>bgwriter_lru_percent</varname>,
       <varname>bgwriter_all_percent</varname>,
       <varname>bgwriter_all_maxpages</varname>,
       <varname>stats_start_collector</varname>, and
       <varname>stats_reset_on_server_start</varname> are removed.
       <varname>redirect_stderr</varname> is renamed to
       <varname>logging_collector</varname>.
       <varname>stats_command_string</varname> is renamed to
       <varname>track_activities</varname>.
       <varname>stats_block_level</varname> and <varname>stats_row_level</varname>
       are merged into <varname>track_counts</varname>.
       A new boolean configuration parameter, <varname>archive_mode</varname>,
       controls archiving. Autovacuum's default settings have changed.
      </para>
     </listitem>

     <listitem>
      <para>
       Remove <varname>stats_start_collector</varname> parameter (Tom)
      </para>

      <para>
       We now always start the collector process, unless <acronym>UDP</acronym>
       socket creation fails.
      </para>
     </listitem>

     <listitem>
      <para>
       Remove <varname>stats_reset_on_server_start</varname> parameter (Tom)
      </para>

      <para>
       This was removed because <function>pg_stat_reset()</function>
       can be used for this purpose.
      </para>
     </listitem>

     <listitem>
      <para>
       Commenting out a parameter in <filename>postgresql.conf</filename> now
       causes it to revert to its default value (Joachim Wieland)
      </para>

      <para>
       Previously, commenting out an entry left the parameter's value unchanged
       until the next server restart.
      </para>
     </listitem>

    </itemizedlist>

    </sect3>


    <sect3>
     <title>Character Encodings</title>

    <itemizedlist>

     <listitem>
      <para>
       Add more checks for invalidly-encoded data (Andrew)
      </para>

      <para>
       This change plugs some holes that existed in literal backslash
       escape string processing and <command>COPY</command> escape
       processing. Now the de-escaped string is rechecked to see if the
       result created an invalid multi-byte character.
      </para>
     </listitem>

     <listitem>
      <para>
       Disallow database encodings that are inconsistent with the server's
       locale setting (Tom)
      </para>

      <para>
       On most platforms, <literal>C</literal> locale is the only locale that
       will work with any database encoding.  Other locale settings imply
       a specific encoding and will misbehave if the database encoding
       is something different.  (Typical symptoms include bogus textual
       sort order and wrong results from <function>upper()</function> or
       <function>lower()</function>.)  The server now rejects attempts to create
       databases that have an incompatible encoding.
      </para>
     </listitem>

     <listitem>
      <para>
       Ensure that <function>chr()</function> cannot create
       invalidly-encoded values (Andrew)
      </para>

      <para>
       In UTF8-encoded databases the argument of <function>chr()</function> is
       now treated as a Unicode code point. In other multi-byte encodings
       <function>chr()</function>'s argument must designate a 7-bit ASCII
       character.  Zero is no longer accepted.
       <function>ascii()</function> has been adjusted to match.
      </para>
     </listitem>

     <listitem>
      <para>
       Adjust <function>convert()</function> behavior to ensure encoding
       validity (Andrew)
      </para>

      <para>
       The two argument form of <function>convert()</function> has been
       removed. The three argument form now takes a <type>bytea</type>
       first argument and returns a <type>bytea</type>. To cover the
       loss of functionality, three new functions have been added:
      </para>

      <itemizedlist>
       <listitem>
        <para>
         <function>convert_from(bytea, name)</function> returns
         <type>text</type> &mdash; converts the first argument from the named
         encoding to the database encoding
        </para>
       </listitem>

       <listitem>
        <para>
         <function>convert_to(text, name)</function> returns
         <type>bytea</type> &mdash; converts the first argument from the
         database encoding to the named encoding
        </para>
       </listitem>

       <listitem>
        <para>
         <function>length(bytea, name)</function> returns
         <type>integer</type> &mdash; gives the length of the first
         argument in characters in the named encoding
        </para>
       </listitem>
      </itemizedlist>
     </listitem>

     <listitem>
      <para>
       Remove <literal>convert(argument USING conversion_name)</literal>
       (Andrew)
      </para>

      <para>
       Its behavior did not match the SQL standard.
      </para>
     </listitem>

     <listitem>
      <para>
       Make JOHAB encoding client-only (Tatsuo)
      </para>

      <para>
       JOHAB is not safe as a server-side encoding.
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

  </sect2>

  <sect2>
   <title>Changes</title>

   <para>
    Below you will find a detailed account of the
    changes between <productname>PostgreSQL</productname> 8.3 and
    the previous major release.
   </para>

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

     <listitem>
      <para>
       Asynchronous commit delays writes to WAL during transaction commit
       (Simon)
      </para>

      <para>
       This feature dramatically increases performance for short data-modifying
       transactions.  The disadvantage is that because disk writes are delayed,
       if the database or operating system crashes before data is written to
       the disk, committed data will be lost.  This feature is useful for
       applications that can accept some data loss.  Unlike turning off
       <varname>fsync</varname>, using asynchronous commit does not put
       database consistency at risk; the worst case is that after a crash the
       last few reportedly-committed transactions might not be committed after
       all.
       This feature is enabled by turning off <varname>synchronous_commit</varname>
       (which can be done per-session or per-transaction, if some transactions
       are critical and others are not).
       <varname>wal_writer_delay</varname> can be adjusted to control the maximum
       delay before transactions actually reach disk.
      </para>
     </listitem>

     <listitem>
      <para>
       Checkpoint writes can be spread over a longer time period to smooth
       the I/O spike during each checkpoint (Itagaki Takahiro and Heikki
       Linnakangas)
      </para>

      <para>
       Previously all modified buffers were forced to disk as quickly as
       possible during a
       checkpoint, causing an I/O spike that decreased server performance.
       This new approach spreads out disk writes during checkpoints,
       reducing peak I/O usage. (User-requested and shutdown checkpoints
       are still written as quickly as possible.)
      </para>
     </listitem>

     <listitem>
      <para>
       Heap-Only Tuples (<acronym>HOT</acronym>) accelerate space reuse for most
       <command>UPDATE</command>s and <command>DELETE</command>s (Pavan Deolasee, with
       ideas from many others)
      </para>

      <para>
       <command>UPDATE</command>s and <command>DELETE</command>s leave dead tuples
       behind, as do failed <command>INSERT</command>s.  Previously only
       <command>VACUUM</command> could reclaim space taken by dead tuples. With
       <acronym>HOT</acronym> dead tuple space can be automatically reclaimed at
       the time of <command>INSERT</command> or <command>UPDATE</command> if no changes
       are made to indexed columns.  This allows for more consistent
       performance.  Also, <acronym>HOT</acronym> avoids adding duplicate index
       entries.
      </para>
     </listitem>

     <listitem>
      <para>
       Just-in-time background writer strategy improves disk write
       efficiency (Greg Smith, Itagaki Takahiro)
      </para>

      <para>
       This greatly reduces the need for manual tuning of the background
       writer.
      </para>
     </listitem>

     <listitem>
      <para>
       Per-field and per-row storage overhead have been reduced
       (Greg Stark, Heikki Linnakangas)
      </para>

      <para>
       Variable-length data types with data values less than 128 bytes long
       will see a storage decrease of 3 to 6 bytes. For example, two adjacent
       <type>char(1)</type> fields now use 4 bytes instead of 16. Row headers
       are also 4 bytes shorter than before.
      </para>
     </listitem>

     <listitem>
      <para>
       Using non-persistent transaction IDs for read-only transactions
       reduces overhead and <command>VACUUM</command> requirements (Florian Pflug)
      </para>

      <para>
       Non-persistent transaction IDs do not increment the global
       transaction counter. Therefore, they reduce the load on
       <structname>pg_clog</structname> and increase the time between forced
       vacuums to prevent transaction ID wraparound.
       Other performance
       improvements were also made that should improve concurrency.
      </para>
     </listitem>

     <listitem>
      <para>
       Avoid incrementing the command counter after a read-only command (Tom)
      </para>

      <para>
       There was formerly a hard limit of 2<superscript>32</superscript>
       (4 billion) commands per transaction.  Now only commands that
       actually changed the database count, so while this limit still
       exists, it should be significantly less annoying.
      </para>
     </listitem>

     <listitem>
      <para>
       Create a dedicated <acronym>WAL</acronym> writer process to off-load
       work from backends (Simon)
      </para>
     </listitem>

     <listitem>
      <para>
       Skip unnecessary WAL writes for <command>CLUSTER</command> and
       <command>COPY</command> (Simon)
      </para>

      <para>
       Unless WAL archiving is enabled, the system now avoids WAL writes
       for <command>CLUSTER</command> and just <function>fsync()</function>s the
       table at the end of the command.  It also does the same for
       <command>COPY</command> if the table was created in the same
       transaction.
      </para>
     </listitem>

     <listitem>
      <para>
       Large sequential scans no longer force out frequently used
       cached pages (Simon, Heikki, Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Concurrent large sequential scans can now share disk reads (Jeff Davis)
      </para>

      <para>
       This is accomplished by starting the new sequential scan in the
       middle of the table (where another sequential scan is already
       in-progress) and wrapping around to the beginning to finish.  This
       can affect the order of returned rows in a query that does not
       specify <literal>ORDER BY</literal>.  The <varname>synchronize_seqscans</varname>
       configuration parameter can be used to disable this if necessary.
      </para>
     </listitem>

     <listitem>
      <para>
       <literal>ORDER BY ... LIMIT</literal> can be done without sorting
       (Greg Stark)
      </para>

      <para>
       This is done by sequentially scanning the table and tracking just
       the <quote>top N</quote> candidate rows, rather than performing a
       full sort of the entire table.  This is useful when there is no
       matching index and the <literal>LIMIT</literal> is not large.
      </para>
     </listitem>

     <listitem>
      <para>
       Put a rate limit on messages sent to the statistics
       collector by backends
       (Tom)
      </para>

      <para>
       This reduces overhead for short transactions, but might sometimes
       increase the delay before statistics are tallied.
      </para>
     </listitem>

     <listitem>
      <para>
       Improve hash join performance for cases with many NULLs (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Speed up operator lookup for cases with non-exact datatype matches (Tom)
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

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

     <listitem>
      <para>
       Autovacuum is now enabled by default (Alvaro)
      </para>

      <para>
       Several changes were made to eliminate disadvantages of having
       autovacuum enabled, thereby justifying the change in default.
       Several other autovacuum parameter defaults were also modified.
      </para>
     </listitem>

     <listitem>
      <para>
       Support multiple concurrent autovacuum processes (Alvaro, Itagaki
       Takahiro)
      </para>

      <para>
       This allows multiple vacuums to run concurrently.  This prevents
       vacuuming of a large table from delaying vacuuming of smaller tables.
      </para>
     </listitem>

     <listitem>
      <para>
       Automatically re-plan cached queries when table
       definitions change or statistics are updated (Tom)
      </para>

      <para>
       Previously PL/pgSQL functions that referenced temporary tables
       would fail if the temporary table was dropped and recreated
       between function invocations, unless <literal>EXECUTE</literal> was
       used.  This improvement fixes that problem and many related issues.
      </para>
     </listitem>

     <listitem>
      <para>
       Add a <varname>temp_tablespaces</varname> parameter to control
       the tablespaces for temporary tables and files (Jaime Casanova,
       Albert Cervera, Bernd Helmle)
      </para>

      <para>
       This parameter defines a list of tablespaces to be used.  This
       enables spreading the I/O load across multiple tablespaces. A random
       tablespace is chosen each time a temporary object is created.
       Temporary files are no longer stored in per-database
       <filename>pgsql_tmp/</filename> directories but in per-tablespace
       directories.
      </para>
     </listitem>

     <listitem>
      <para>
       Place temporary tables' TOAST tables in special schemas named
       <literal>pg_toast_temp_<replaceable>nnn</replaceable></literal> (Tom)
      </para>

      <para>
       This allows low-level code to recognize these tables as temporary,
       which enables various optimizations such as not WAL-logging changes
       and using local rather than shared buffers for access. This also
       fixes a bug wherein backends unexpectedly held open file references
       to temporary TOAST tables.
      </para>
     </listitem>

     <listitem>
      <para>
       Fix problem that a constant flow of new connection requests could
       indefinitely delay the postmaster from completing a shutdown or
       a crash restart (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Guard against a very-low-probability data loss scenario by preventing
       re-use of a deleted table's relfilenode until after the next
       checkpoint (Heikki)
      </para>
     </listitem>

     <listitem>
      <para>
       Fix <command>CREATE CONSTRAINT TRIGGER</command>
       to convert old-style foreign key trigger definitions into regular
       foreign key constraints (Tom)
      </para>

      <para>
       This will ease porting of foreign key constraints carried forward from
       pre-7.3 databases, if they were never converted using
       <filename>contrib/adddepend</filename>.
      </para>
     </listitem>

     <listitem>
      <para>
       Fix <literal>DEFAULT NULL</literal> to override inherited defaults (Tom)
      </para>

      <para>
       <literal>DEFAULT NULL</literal> was formerly considered a noise phrase, but it
       should (and now does) override non-null defaults that would otherwise
       be inherited from a parent table or domain.
      </para>
     </listitem>

     <listitem>
      <para>
       Add new encodings EUC_JIS_2004 and SHIFT_JIS_2004 (Tatsuo)
      </para>

      <para>
       These new encodings can be converted to and from UTF-8.
      </para>
     </listitem>

     <listitem>
      <para>
       Change server startup log message from <quote>database system is
       ready</quote> to <quote>database system is ready to accept
       connections</quote>, and adjust its timing
      </para>

      <para>
       The message now appears only when the postmaster is really ready
       to accept connections.
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title>Monitoring</title>
    <itemizedlist>

     <listitem>
      <para>
       Add <varname>log_autovacuum_min_duration</varname> parameter to
       support configurable logging of autovacuum activity (Simon, Alvaro)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <varname>log_lock_waits</varname> parameter to log lock waiting
       (Simon)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <varname>log_temp_files</varname> parameter to log temporary
       file usage (Bill Moran)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <varname>log_checkpoints</varname> parameter to improve logging
       of checkpoints (Greg Smith, Heikki)
      </para>
     </listitem>

     <listitem>
      <para>
       <varname>log_line_prefix</varname> now supports
       <literal>%s</literal> and <literal>%c</literal> escapes in all
       processes (Andrew)
      </para>

      <para>
       Previously these escapes worked only for user sessions, not for
       background database processes.
      </para>
     </listitem>

     <listitem>
      <para>
       Add <varname>log_restartpoints</varname> to control logging of
       point-in-time recovery restart points (Simon)
      </para>
     </listitem>

     <listitem>
      <para>
       Last transaction end time is now logged at end of recovery and at
       each logged restart point (Simon)
      </para>
     </listitem>

     <listitem>
      <para>
       Autovacuum now reports its activity start time in
       <literal>pg_stat_activity</literal> (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Allow server log output in comma-separated value (CSV) format (Arul
       Shaji, Greg Smith, Andrew Dunstan)
      </para>

      <para>
       CSV-format log files can easily be loaded into a database table for
       subsequent analysis.
      </para>
     </listitem>

     <listitem>
      <para>
       Use PostgreSQL-supplied timezone support for formatting timestamps
       displayed in the server log (Tom)
      </para>

      <para>
       This avoids Windows-specific problems with localized time zone
       names that are in the wrong encoding. There is a new
       <varname>log_timezone</varname> parameter that controls the timezone
       used in log messages, independently of the client-visible
       <varname>timezone</varname> parameter.
      </para>
     </listitem>

     <listitem>
      <para>
       New system view <literal>pg_stat_bgwriter</literal> displays
       statistics about background writer activity (Magnus)
      </para>
     </listitem>

     <listitem>
      <para>
       Add new columns for database-wide tuple statistics to
       <literal>pg_stat_database</literal> (Magnus)
      </para>
     </listitem>

     <listitem>
      <para>
       Add an <literal>xact_start</literal> (transaction start time) column to
       <literal>pg_stat_activity</literal> (Neil)
      </para>

      <para>
       This makes it easier to identify long-running transactions.
      </para>
     </listitem>

     <listitem>
      <para>
       Add <literal>n_live_tuples</literal> and <literal>n_dead_tuples</literal> columns
       to <literal>pg_stat_all_tables</literal> and related views (Glen
       Parker)
      </para>
     </listitem>

     <listitem>
      <para>
       Merge <varname>stats_block_level</varname> and <varname>stats_row_level</varname>
       parameters into a single parameter <varname>track_counts</varname>, which
       controls all messages sent to the statistics collector process
       (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Rename <varname>stats_command_string</varname> parameter to
       <varname>track_activities</varname> (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Fix statistical counting of live and dead tuples to recognize that
       committed and aborted transactions have different effects (Tom)
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title>Authentication</title>
    <itemizedlist>

     <listitem>
      <para>
       Support Security Service Provider Interface (<acronym>SSPI</acronym>) for
       authentication on Windows (Magnus)
      </para>
     </listitem>

     <listitem>
      <para>
       Support GSSAPI authentication (Henry Hotz, Magnus)
      </para>

      <para>
       This should be preferred to native Kerberos authentication because
       GSSAPI is an industry standard.
      </para>
     </listitem>

     <listitem>
      <para>
       Support a global SSL configuration file (Victor Wagner)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <varname>ssl_ciphers</varname> parameter to control accepted SSL ciphers
       (Victor Wagner)
      </para>
     </listitem>

     <listitem>
      <para>
       Add a Kerberos realm parameter, <varname>krb_realm</varname> (Magnus)
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title>Write-Ahead Log (<acronym>WAL</acronym>) and Continuous Archiving</title>
    <itemizedlist>

     <listitem>
      <para>
       Change the timestamps recorded in transaction WAL records from
       time_t to TimestampTz representation (Tom)
      </para>

      <para>
       This provides sub-second resolution in WAL, which can be useful for
       point-in-time recovery.
      </para>
     </listitem>

     <listitem>
      <para>
       Reduce WAL disk space needed by warm standby servers (Simon)
      </para>

      <para>
       This change allows a warm standby server to pass the name of the earliest
       still-needed WAL file to the recovery script, allowing automatic removal
       of no-longer-needed WAL files.  This is done using <literal>%r</literal> in
       the <varname>restore_command</varname> parameter of
       <filename>recovery.conf</filename>.
      </para>
     </listitem>

     <listitem>
      <para>
       New boolean configuration parameter, <varname>archive_mode</varname>,
       controls archiving (Simon)
      </para>

      <para>
       Previously setting <varname>archive_command</varname> to an empty string
       turned off archiving. Now <varname>archive_mode</varname> turns archiving
       on and off, independently of <varname>archive_command</varname>. This is
       useful for stopping archiving temporarily.
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title>Queries</title>
    <itemizedlist>

     <listitem>
      <para>
       Full text search is integrated into the core database
       system (Teodor, Oleg)
      </para>

      <para>
       Text search has been improved, moved into the core code, and is now
       installed by default.  <filename>contrib/tsearch2</filename> now contains
       a compatibility interface.
      </para>
     </listitem>

     <listitem>
      <para>
       Add control over whether <literal>NULL</literal>s sort first or last (Teodor, Tom)
      </para>

      <para>
       The syntax is <literal>ORDER BY ... NULLS FIRST/LAST</literal>.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow per-column ascending/descending (<literal>ASC</literal>/<literal>DESC</literal>)
       ordering options for indexes (Teodor, Tom)
      </para>

      <para>
       Previously a query using <literal>ORDER BY</literal> with mixed
       <literal>ASC</literal>/<literal>DESC</literal> specifiers could not fully use
       an index. Now an index can be fully used in such cases if the
       index was created with matching
       <literal>ASC</literal>/<literal>DESC</literal> specifications.
       <literal>NULL</literal> sort order within an index can be controlled, too.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <literal>col IS NULL</literal> to use an index (Teodor)
      </para>
     </listitem>

     <listitem>
      <para>
       Updatable cursors (Arul Shaji, Tom)
      </para>

      <para>
       This eliminates the need to reference a primary key to
       <command>UPDATE</command> or <command>DELETE</command> rows returned by a cursor.
       The syntax is <literal>UPDATE/DELETE WHERE CURRENT OF</literal>.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <literal>FOR UPDATE</literal> in cursors (Arul Shaji, Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Create a general mechanism that supports casts to and from the
       standard string types (<type>TEXT</type>, <type>VARCHAR</type>,
       <type>CHAR</type>) for <emphasis>every</emphasis> datatype, by
       invoking the datatype's I/O functions (Tom)
      </para>

      <para>
       Previously, such casts were available only for types that had
       specialized function(s) for the purpose.
       These new casts are assignment-only in the to-string direction,
       explicit-only in the other direction, and therefore should create no
       surprising behavior.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <literal>UNION</literal> and related constructs to return a domain
       type, when all inputs are of that domain type (Tom)
      </para>

      <para>
       Formerly, the output would be considered to be of the domain's base
       type.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow limited hashing when using two different data types (Tom)
      </para>

      <para>
       This allows hash joins, hash indexes, hashed subplans, and hash
       aggregation to be used in situations involving cross-data-type
       comparisons, if the data types have compatible hash functions.
       Currently, cross-data-type hashing support exists for
       <type>smallint</type>/<type>integer</type>/<type>bigint</type>,
       and for <type>float4</type>/<type>float8</type>.
      </para>
     </listitem>

     <listitem>
      <para>
       Improve optimizer logic for detecting when variables are equal
       in a <literal>WHERE</literal> clause (Tom)
      </para>

      <para>
       This allows mergejoins to work with descending sort orders, and
       improves recognition of redundant sort columns.
      </para>
     </listitem>

     <listitem>
      <para>
       Improve performance when planning large inheritance trees in
       cases where most tables are excluded by constraints (Tom)
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

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

     <listitem>

      <para>
       Arrays of composite types (David Fetter, Andrew, Tom)
      </para>

      <para>
       In addition to arrays of explicitly-declared composite types,
       arrays of the rowtypes of regular tables and views are now
       supported, except for rowtypes of system catalogs, sequences, and TOAST
       tables.
      </para>

     </listitem>

     <listitem>
      <para>
       Server configuration parameters can now be set on a per-function
       basis (Tom)
      </para>

      <para>
       For example, functions can now set their own
       <varname>search_path</varname> to prevent unexpected behavior if a
       different <varname>search_path</varname> exists at run-time.  Security
       definer functions should set <varname>search_path</varname> to
       avoid security loopholes.
      </para>
     </listitem>

     <listitem>
      <para>
       <command>CREATE/ALTER FUNCTION</command> now supports
       <literal>COST</literal> and <literal>ROWS</literal> options (Tom)
      </para>

      <para>
       <literal>COST</literal> allows specification of the cost of a
       function call.  <literal>ROWS</literal> allows specification of
       the average number or rows returned by a set-returning function.
       These values are used by the optimizer in choosing the best plan.
      </para>
     </listitem>

     <listitem>
      <para>
       Implement <command>CREATE TABLE LIKE ...  INCLUDING
       INDEXES</command> (Trevor Hardcastle, Nikhil Sontakke, Neil)
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <command>CREATE INDEX CONCURRENTLY</command> to ignore
       transactions in other databases (Simon)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <command>ALTER VIEW ... RENAME TO</command> and <command>ALTER
       SEQUENCE ... RENAME TO</command> (David Fetter, Neil)
      </para>

      <para>
       Previously this could only be done via <command>ALTER TABLE ...
       RENAME TO</command>.
      </para>
     </listitem>

     <listitem>
      <para>
       Make <command>CREATE/DROP/RENAME DATABASE</command> wait briefly for
       conflicting backends to exit before failing (Tom)
      </para>

      <para>
       This increases the likelihood that these commands will succeed.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow triggers and rules to be deactivated in groups using a
       configuration parameter, for replication purposes (Jan)
      </para>

      <para>
       This allows replication systems to disable triggers and rewrite
       rules as a group without modifying the system catalogs directly.
       The behavior is controlled by <command>ALTER TABLE</command> and a new
       parameter <varname>session_replication_role</varname>.
      </para>
     </listitem>

     <listitem>
      <para>
       User-defined types can now have type modifiers (Teodor, Tom)
      </para>

      <para>
       This allows a user-defined type to take a modifier, like
       <type>ssnum(7)</type>.  Previously only built-in
       data types could have modifiers.
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

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

     <listitem>
      <para>
       Non-superuser database owners now are able to add trusted procedural
       languages to their databases by default (Jeremy Drake)
      </para>

      <para>
       While this is reasonably safe, some administrators might wish to
       revoke the privilege. It is controlled by
       <structname>pg_pltemplate</structname>.<structfield>tmpldbacreate</structfield>.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow a session's current parameter setting to be used as the
       default for future sessions (Tom)
      </para>

      <para>
       This is done with <literal>SET ... FROM CURRENT</literal> in
       <command>CREATE/ALTER FUNCTION</command>, <command>ALTER
       DATABASE</command>, or <command>ALTER ROLE</command>.
      </para>
     </listitem>

     <listitem>
      <para>
       Implement new commands <command>DISCARD ALL</command>,
       <command>DISCARD PLANS</command>, <command>DISCARD
       TEMPORARY</command>, <command>CLOSE ALL</command>, and
       <command>DEALLOCATE ALL</command> (Marko Kreen, Neil)
      </para>

      <para>
       These commands simplify resetting a database session to its initial
       state, and are particularly useful for connection-pooling software.
      </para>
     </listitem>

     <listitem>
      <para>
       Make <command>CLUSTER</command> MVCC-safe (Heikki Linnakangas)
      </para>

      <para>
       Formerly, <command>CLUSTER</command> would discard all tuples
       that were committed dead, even if there were still transactions
       that should be able to see them under MVCC visibility rules.
      </para>
     </listitem>

     <listitem>
      <para>
       Add new <command>CLUSTER</command> syntax: <literal>CLUSTER
       <replaceable>table</replaceable> USING <replaceable>index</replaceable></literal>
       (Holger Schurig)
     </para>

      <para>
       The old <command>CLUSTER</command> syntax is still supported, but
       the new form is considered more logical.
      </para>
     </listitem>

     <listitem>
      <para>
       Fix <command>EXPLAIN</command> so it can show complex plans
       more accurately (Tom)
      </para>

      <para>
       References to subplan outputs are now always shown correctly,
       instead of using <literal>?column<replaceable>N</replaceable>?</literal>
       for complicated cases.
      </para>
     </listitem>

     <listitem>
      <para>
       Limit the amount of information reported when a user is dropped
       (Alvaro)
      </para>

      <para>
       Previously, dropping (or attempting to drop) a user who owned many
       objects could result in large <literal>NOTICE</literal> or
       <literal>ERROR</literal> messages listing all these objects; this
       caused problems for some client applications.  The length of the
       message is now limited, although a full list is still sent to the
       server log.
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

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

     <listitem>
      <para>
       Support for the SQL/XML standard, including new operators and an
       <type>XML</type> data type (Nikolay Samokhvalov, Pavel Stehule, Peter)
      </para>
     </listitem>

     <listitem>
      <para>
       Enumerated data types (<type>ENUM</type>) (Tom Dunstan)
      </para>

      <para>
       This feature provides convenient support for fields that have a
       small, fixed set of allowed values.  An example of creating an
       <literal>ENUM</literal> type is
       <literal>CREATE TYPE mood AS ENUM ('sad', 'ok', 'happy')</literal>.
      </para>
     </listitem>

     <listitem>
      <para>
       Universally Unique Identifier (<type>UUID</type>) data type (Gevik
       Babakhani, Neil)
      </para>

      <para>
       This closely matches <acronym>RFC</acronym> 4122.
      </para>
     </listitem>

     <listitem>
      <para>
       Widen the <type>MONEY</type> data type to 64 bits (D'Arcy Cain)
      </para>

      <para>
       This greatly increases the range of supported <type>MONEY</type>
       values.
      </para>
     </listitem>

     <listitem>
      <para>
       Fix <type>float4</type>/<type>float8</type> to handle
       <literal>Infinity</literal> and <literal>NAN</literal> (Not A Number)
       consistently (Bruce)
      </para>

      <para>
       The code formerly was not consistent about distinguishing
       <literal>Infinity</literal> from overflow conditions.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow leading and trailing whitespace during input of
       <type>boolean</type> values (Neil)
      </para>
     </listitem>

     <listitem>
      <para>
       Prevent <command>COPY</command> from using digits and lowercase letters as
       delimiters (Tom)
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title>Functions</title>
    <itemizedlist>

     <listitem>
      <para>
       Add new regular expression functions
       <function>regexp_matches()</function>,
       <function>regexp_split_to_array()</function>, and
       <function>regexp_split_to_table()</function> (Jeremy Drake, Neil)
      </para>

      <para>
       These functions provide extraction of regular expression
       subexpressions and allow splitting a string using a POSIX regular
       expression.
      </para>
     </listitem>

     <listitem>
      <para>
       Add <function>lo_truncate()</function> for large object truncation
       (Kris Jurka)
      </para>
     </listitem>

     <listitem>
      <para>
       Implement <function>width_bucket()</function> for the <type>float8</type>
       data type (Neil)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <function>pg_stat_clear_snapshot()</function> to discard
       statistics snapshots collected during the current transaction
       (Tom)
      </para>

      <para>
       The first request for statistics in a transaction takes a statistics
       snapshot that does not change during the transaction.  This function
       allows the snapshot to be discarded and a new snapshot loaded during
       the next statistics query. This is particularly useful for PL/pgSQL
       functions, which are confined to a single transaction.
      </para>
     </listitem>

     <listitem>
      <para>
       Add <literal>isodow</literal> option to <function>EXTRACT()</function> and
       <function>date_part()</function> (Bruce)
      </para>

      <para>
       This returns the day of the week, with Sunday as seven.
       (<literal>dow</literal> returns Sunday as zero.)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <literal>ID</literal> (ISO day of week) and <literal>IDDD</literal> (ISO
       day of year) format codes for <function>to_char()</function>,
       <function>to_date()</function>, and <function>to_timestamp()</function> (Brendan
       Jurd)
      </para>
     </listitem>

     <listitem>
      <para>
       Make <function>to_timestamp()</function> and <function>to_date()</function>
       assume <literal>TM</literal> (trim) option for potentially
       variable-width fields (Bruce)
      </para>

      <para>
       This matches <productname>Oracle</productname>'s behavior.
      </para>
     </listitem>

     <listitem>
      <para>
       Fix off-by-one conversion error in
       <function>to_date()</function>/<function>to_timestamp()</function>
       <literal>D</literal> (non-ISO day of week) fields (Bruce)
      </para>
     </listitem>

     <listitem>
      <para>
       Make <function>setseed()</function> return void, rather than a
       useless integer value (Neil)
      </para>
     </listitem>

     <listitem>
      <para>
       Add a hash function for <type>NUMERIC</type> (Neil)
      </para>

      <para>
       This allows hash indexes and hash-based plans to be used with
       <type>NUMERIC</type> columns.
      </para>
     </listitem>

     <listitem>
      <para>
       Improve efficiency of
       <literal>LIKE</literal>/<literal>ILIKE</literal>, especially for
       multi-byte character sets like UTF-8 (Andrew, Itagaki Takahiro)
      </para>
     </listitem>

     <listitem>
      <para>
       Make <function>currtid()</function> functions require
       <literal>SELECT</literal> privileges on the target table (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Add several <function>txid_*()</function> functions to query
       active transaction IDs (Jan)
      </para>

      <para>
       This is useful for various replication solutions.
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title>PL/pgSQL Server-Side Language</title>
    <itemizedlist>

     <listitem>
      <para>
       Add scrollable cursor support, including directional control in
       <command>FETCH</command> (Pavel Stehule)
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <literal>IN</literal> as an alternative to
       <literal>FROM</literal> in PL/pgSQL's <command>FETCH</command>
       statement, for consistency with the backend's
       <command>FETCH</command> command (Pavel Stehule)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <command>MOVE</command> to PL/pgSQL (Magnus, Pavel Stehule,
       Neil)
      </para>
     </listitem>

     <listitem>
      <para>
       Implement <command>RETURN QUERY</command> (Pavel Stehule, Neil)
      </para>

      <para>
       This adds convenient syntax for PL/pgSQL set-returning functions
       that want to return the result of a query.  <command>RETURN QUERY</command>
       is easier and more efficient than a loop
       around <command>RETURN NEXT</command>.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow function parameter names to be qualified with the
       function's name (Tom)
      </para>

      <para>
       For example, <literal>myfunc.myvar</literal>. This is particularly
       useful for specifying variables in a query where the variable
       name might match a column name.
      </para>
     </listitem>

     <listitem>
      <para>
       Make qualification of variables with block labels work properly (Tom)
      </para>

      <para>
       Formerly, outer-level block labels could unexpectedly interfere with
       recognition of inner-level record or row references.
      </para>
     </listitem>

     <listitem>
      <para>
       Tighten requirements for <literal>FOR</literal> loop
       <literal>STEP</literal> values (Tom)
      </para>

      <para>
       Prevent non-positive <literal>STEP</literal> values, and handle
       loop overflows.
      </para>
     </listitem>

     <listitem>
      <para>
       Improve accuracy when reporting syntax error locations (Tom)
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title>Other Server-Side Languages</title>
    <itemizedlist>

     <listitem>
      <para>
       Allow type-name arguments to PL/Perl
       <function>spi_prepare()</function> to be data type aliases in
       addition to names found in <literal>pg_type</literal> (Andrew)
      </para>
     </listitem>

     <listitem>
      <para>
       Allow type-name arguments to PL/Python
       <function>plpy.prepare()</function> to be data type aliases in
       addition to names found in <literal>pg_type</literal> (Andrew)
      </para>
     </listitem>

     <listitem>
      <para>
       Allow type-name arguments to PL/Tcl <function>spi_prepare</function> to
       be data type aliases in addition to names found in
       <literal>pg_type</literal> (Andrew)
      </para>
     </listitem>

     <listitem>
      <para>
       Enable PL/PythonU to compile on Python 2.5 (Marko Kreen)
      </para>
     </listitem>

     <listitem>
      <para>
       Support a true PL/Python boolean type in compatible Python versions
       (Python 2.3 and later) (Marko Kreen)
      </para>
     </listitem>

     <listitem>
      <para>
       Fix PL/Tcl problems with thread-enabled <filename>libtcl</filename> spawning
       multiple threads within the backend (Steve Marshall, Paul Bayer,
       Doug Knight)
      </para>

      <para>
       This caused all sorts of unpleasantness.
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title><link linkend="app-psql"><application>psql</application></link></title>
    <itemizedlist>

     <listitem>
      <para>
       List disabled triggers separately in <literal>\d</literal> output
       (Brendan Jurd)
      </para>
     </listitem>

     <listitem>
      <para>
       In <literal>\d</literal> patterns, always match <literal>$</literal>
       literally (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Show aggregate return types in <literal>\da</literal> output
       (Greg Sabino Mullane)
      </para>
     </listitem>

     <listitem>
      <para>
       Add the function's volatility status to the output of
       <literal>\df+</literal> (Neil)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <literal>\prompt</literal> capability (Chad Wagner)
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <literal>\pset</literal>, <literal>\t</literal>, and
       <literal>\x</literal> to specify <literal>on</literal> or <literal>off</literal>,
       rather than just toggling (Chad Wagner)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <literal>\sleep</literal> capability (Jan)
      </para>
     </listitem>

     <listitem>
      <para>
       Enable <literal>\timing</literal> output for <literal>\copy</literal> (Andrew)
      </para>
     </listitem>

     <listitem>
      <para>
       Improve <literal>\timing</literal> resolution on Windows
       (Itagaki Takahiro)
      </para>
     </listitem>

     <listitem>
      <para>
       Flush <literal>\o</literal> output after each backslash command (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Correctly detect and report errors while reading a <literal>-f</literal>
       input file (Peter)
      </para>
     </listitem>

     <listitem>
      <para>
       Remove <literal>-u</literal> option (this option has long been deprecated)
       (Tom)
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title><link linkend="app-pgdump"><application>pg_dump</application></link></title>
    <itemizedlist>

     <listitem>
      <para>
       Add <literal>--tablespaces-only</literal> and <literal>--roles-only</literal>
       options to <application>pg_dumpall</application> (Dave Page)
      </para>
     </listitem>

     <listitem>
      <para>
       Add an output file option to
       <application>pg_dumpall</application> (Dave Page)
      </para>

      <para>
       This is primarily useful on Windows, where output redirection of
       child <application>pg_dump</application> processes does not work.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <application>pg_dumpall</application> to accept an initial-connection
       database name rather than the default
       <literal>template1</literal> (Dave Page)
      </para>
     </listitem>

     <listitem>
      <para>
       In <literal>-n</literal> and <literal>-t</literal> switches, always match
       <literal>$</literal> literally (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Improve performance when a database has thousands of objects (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Remove <literal>-u</literal> option (this option has long been deprecated)
       (Tom)
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title>Other Client Applications</title>
    <itemizedlist>

     <listitem>
      <para>
       In <application>initdb</application>, allow the location of the
       <filename>pg_xlog</filename> directory to be specified
       (Euler Taveira de Oliveira)
      </para>
     </listitem>

     <listitem>
      <para>
       Enable server core dump generation in <application>pg_regress</application>
       on supported operating systems (Andrew)
      </para>
     </listitem>

     <listitem>
      <para>
       Add a <literal>-t</literal> (timeout) parameter to <application>pg_ctl</application>
       (Bruce)
      </para>

      <para>
       This controls how long <application>pg_ctl</application> will wait when waiting
       for server startup or shutdown.  Formerly the timeout was hard-wired
       as 60 seconds.
      </para>
     </listitem>

     <listitem>
      <para>
       Add a <application>pg_ctl</application> option to control generation
       of server core dumps (Andrew)
      </para>
     </listitem>

     <listitem>
      <para>
       Allow Control-C to cancel <application>clusterdb</application>,
       <application>reindexdb</application>, and <application>vacuumdb</application> (Itagaki
       Takahiro, Magnus)
      </para>
     </listitem>

     <listitem>
      <para>
       Suppress command tag output for <application>createdb</application>,
       <application>createuser</application>, <application>dropdb</application>, and
       <application>dropuser</application> (Peter)
      </para>

      <para>
       The <literal>--quiet</literal> option is ignored and will be removed in 8.4.
       Progress messages when acting on all databases now go to stdout
       instead of stderr because they are not actually errors.
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

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

     <listitem>
      <para>
       Interpret the <literal>dbName</literal> parameter of
       <function>PQsetdbLogin()</function> as a <literal>conninfo</literal> string if
       it contains an equals sign (Andrew)
      </para>

      <para>
       This allows use of <literal>conninfo</literal> strings in client
       programs that still use <literal>PQsetdbLogin()</literal>.
      </para>
     </listitem>

     <listitem>
      <para>
       Support a global <acronym>SSL</acronym> configuration file (Victor
       Wagner)
      </para>
     </listitem>

     <listitem>
      <para>
       Add environment variable <varname>PGSSLKEY</varname> to control
       <acronym>SSL</acronym> hardware keys (Victor Wagner)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <function>lo_truncate()</function> for large object
       truncation (Kris Jurka)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <function>PQconnectionNeedsPassword()</function> that returns
       true if the server required a password but none was supplied
       (Joe Conway, Tom)
      </para>

      <para>
       If this returns true after a failed connection attempt, a client
       application should prompt the user for a password.  In the past
       applications have had to check for a specific error message string to
       decide whether a password is needed; that approach is now
       deprecated.
      </para>
     </listitem>

     <listitem>
      <para>
       Add <function>PQconnectionUsedPassword()</function> that returns
       true if the supplied password was actually used
       (Joe Conway, Tom)
      </para>

      <para>
       This is useful in some security contexts where it is important
       to know whether a user-supplied password is actually valid.
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

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

     <listitem>
      <para>
       Use V3 frontend/backend protocol (Michael)
      </para>

      <para>
       This adds support for server-side prepared statements.
      </para>
     </listitem>

     <listitem>
      <para>
       Use native threads, instead of pthreads, on Windows (Magnus)
      </para>
     </listitem>

     <listitem>
      <para>
       Improve thread-safety of ecpglib (Itagaki Takahiro)
      </para>
     </listitem>

     <listitem>
      <para>
       Make the ecpg libraries export only necessary API symbols (Michael)
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

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

     <listitem>
      <para>
       Allow the whole <productname>PostgreSQL</productname> distribution to be compiled
       with <productname>Microsoft Visual C++</productname> (Magnus and others)
      </para>

      <para>
       This allows Windows-based developers to use familiar development
       and debugging tools.
       Windows executables made with Visual C++ might also have better
       stability and performance than those made with other tool sets.
       The client-only Visual C++ build scripts have been removed.
      </para>
     </listitem>

     <listitem>
      <para>
       Drastically reduce postmaster's memory usage when it has many child
       processes (Magnus)
      </para>
     </listitem>

     <listitem>
      <para>
       Allow regression tests to be started by an administrative
       user (Magnus)
      </para>
     </listitem>

     <listitem>
      <para>
       Add native shared memory implementation (Magnus)
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title>Server Programming Interface (<acronym>SPI</acronym>)</title>
    <itemizedlist>

     <listitem>
      <para>
       Add cursor-related functionality in SPI (Pavel Stehule)
      </para>

      <para>
       Allow access to the cursor-related planning options, and add
       <command>FETCH</command>/<command>MOVE</command> routines.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow execution of cursor commands through
       <function>SPI_execute</function> (Tom)
      </para>

      <para>
       The macro <literal>SPI_ERROR_CURSOR</literal> still exists but will
       never be returned.
      </para>
     </listitem>

     <listitem>
      <para>
       SPI plan pointers are now declared as <literal>SPIPlanPtr</literal> instead of
       <literal>void *</literal> (Tom)
      </para>

      <para>
       This does not break application code, but switching is
       recommended to help catch simple programming mistakes.
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title>Build Options</title>
    <itemizedlist>

     <listitem>
      <para>
       Add <application>configure</application> option <literal>--enable-profiling</literal>
       to enable code profiling (works only with <application>gcc</application>)
       (Korry Douglas and Nikhil Sontakke)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <application>configure</application> option <literal>--with-system-tzdata</literal>
       to use the operating system's time zone database (Peter)
      </para>
     </listitem>

     <listitem>
      <para>
       Fix <acronym>PGXS</acronym> so extensions can be built against PostgreSQL
       installations whose <application>pg_config</application> program does not
       appear first in the <varname>PATH</varname> (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Support <command>gmake draft</command> when building the
       <acronym>SGML</acronym> documentation (Bruce)
      </para>

      <para>
       Unless <literal>draft</literal> is used, the documentation build will
       now be repeated if necessary to ensure the index is up-to-date.
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

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

     <listitem>
      <para>
       Rename macro <literal>DLLIMPORT</literal> to <literal>PGDLLIMPORT</literal> to
       avoid conflicting with third party includes (like Tcl) that
       define <literal>DLLIMPORT</literal> (Magnus)
      </para>
     </listitem>

     <listitem>
      <para>
       Create <quote>operator families</quote> to improve planning of
       queries involving cross-data-type comparisons (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Update GIN <function>extractQuery()</function> API to allow signalling
       that nothing can satisfy the query (Teodor)
      </para>
     </listitem>

     <listitem>
      <para>
       Move <literal>NAMEDATALEN</literal> definition from
       <filename>postgres_ext.h</filename> to <filename>pg_config_manual.h</filename>
       (Peter)
      </para>
     </listitem>

     <listitem>
      <para>
       Provide <function>strlcpy()</function> and
       <function>strlcat()</function> on all platforms, and replace
       error-prone uses of <function>strncpy()</function>,
       <function>strncat()</function>, etc (Peter)
      </para>
     </listitem>

     <listitem>
      <para>
       Create hooks to let an external plugin monitor (or even replace) the
       planner and create plans for hypothetical situations (Gurjeet
       Singh, Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Create a function variable <literal>join_search_hook</literal> to let plugins
       override the join search order portion of the planner (Julius
       Stroffek)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <function>tas()</function> support for Renesas' M32R processor
       (Kazuhiro Inaoka)
      </para>
     </listitem>

     <listitem>
      <para>
       <function>quote_identifier()</function> and
       <application>pg_dump</application> no longer quote keywords that are
       unreserved according to the grammar (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Change the on-disk representation of the <type>NUMERIC</type>
       data type so that the <structfield>sign_dscale</structfield> word comes
       before the weight (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Use <acronym>SYSV</acronym> semaphores rather than POSIX on Darwin
       &gt;= 6.0, i.e., macOS 10.2 and up (Chris Marcellino)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <link linkend="acronyms">acronym</link> and <link
       linkend="creating-cluster-nfs">NFS</link> documentation
       sections (Bruce)
      </para>
     </listitem>

     <listitem>
      <para>
       "Postgres" is now documented as an accepted alias for
       "PostgreSQL" (Peter)
      </para>
     </listitem>

     <listitem>
      <para>
       Add documentation about preventing database server spoofing when
       the server is down (Bruce)
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

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

     <listitem>
      <para>
       Move <filename>contrib</filename> <filename>README</filename> content into the
       main <productname>PostgreSQL</productname> documentation (Albert Cervera i
       Areny)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <filename>contrib/pageinspect</filename> module for low-level
       page inspection (Simon, Heikki)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <filename>contrib/pg_standby</filename> module for controlling
       warm standby operation (Simon)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <filename>contrib/uuid-ossp</filename> module for generating
       <type>UUID</type> values using the OSSP UUID library (Peter)
      </para>

      <para>
       Use <application>configure</application>
       <literal>--with-ossp-uuid</literal> to activate. This takes
       advantage of the new <type>UUID</type> builtin type.
      </para>
     </listitem>

     <listitem>
      <para>
       Add <filename>contrib/dict_int</filename>,
       <filename>contrib/dict_xsyn</filename>, and
       <filename>contrib/test_parser</filename> modules to provide
       sample add-on text search dictionary templates and parsers
       (Sergey Karpov)
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <application>contrib/pgbench</application> to set the fillfactor (Pavan
       Deolasee)
      </para>
     </listitem>

     <listitem>
      <para>
       Add timestamps to <application>contrib/pgbench</application> <literal>-l</literal>
       (Greg Smith)
      </para>
     </listitem>

     <listitem>
      <para>
       Add usage count statistics to
       <filename>contrib/pgbuffercache</filename> (Greg Smith)
      </para>
     </listitem>

     <listitem>
      <para>
       Add GIN support for <filename>contrib/hstore</filename> (Teodor)
      </para>
     </listitem>

     <listitem>
      <para>
       Add GIN support for <filename>contrib/pg_trgm</filename> (Guillaume Smet, Teodor)
      </para>
     </listitem>

     <listitem>
      <para>
       Update OS/X startup scripts in
       <filename>contrib/start-scripts</filename> (Mark Cotner, David
       Fetter)
      </para>
     </listitem>

     <listitem>
      <para>
       Restrict <function>pgrowlocks()</function> and
       <function>dblink_get_pkey()</function> to users who have
       <literal>SELECT</literal> privilege on the target table (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Restrict <filename>contrib/pgstattuple</filename> functions to
       superusers (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       <filename>contrib/xml2</filename> is deprecated and planned for
       removal in 8.4 (Peter)
      </para>

      <para>
       The new XML support in core PostgreSQL supersedes this module.
      </para>
     </listitem>

    </itemizedlist>

   </sect3>
  </sect2>
 </sect1>
