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 <sect1 id="release-8-0-26">
  <title>Release 8.0.26</title>

  <note>
  <title>Release Date</title>
  <simpara>2010-10-04</simpara>
  </note>

  <para>
   This release contains a variety of fixes from 8.0.25.
   For information about new features in the 8.0 major release, see
   <xref linkend="release-8-0">.
  </para>

  <para>
   This is expected to be the last <productname>PostgreSQL</> release
   in the 8.0.X series.  Users are encouraged to update to a newer
   release branch soon.
  </para>

  <sect2>
   <title>Migration to Version 8.0.26</title>

   <para>
    A dump/restore is not required for those running 8.0.X.
    However, if you are upgrading from a version earlier than 8.0.22,
    see <xref linkend="release-8-0-22">.
   </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</> 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()</> 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>
      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>
      Defend against functions returning setof record where not all the
      returned rows are actually of the same rowtype (Tom Lane)
     </para>
    </listitem>

    <listitem>
     <para>
      Take care to fsync the contents of lockfiles (both
      <filename>postmaster.pid</> 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>
      Fix <varname>log_line_prefix</>'s <literal>%i</> 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</> when archiving is enabled (Jeff Davis)
     </para>
    </listitem>

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

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

    <listitem>
     <para>
      Improve <filename>contrib/dblink</>'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</> (Itagaki Takahiro)
     </para>
    </listitem>

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

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-0-25">
  <title>Release 8.0.25</title>

  <note>
  <title>Release Date</title>
  <simpara>2010-05-17</simpara>
  </note>

  <para>
   This release contains a variety of fixes from 8.0.24.
   For information about new features in the 8.0 major release, see
   <xref linkend="release-8-0">.
  </para>

  <para>
   The <productname>PostgreSQL</> community will stop releasing updates
   for the 8.0.X release series in July 2010.
   Users are encouraged to update to a newer release branch soon.
  </para>

  <sect2>
   <title>Migration to Version 8.0.25</title>

   <para>
    A dump/restore is not required for those running 8.0.X.
    However, if you are upgrading from a version earlier than 8.0.22,
    see <xref linkend="release-8-0-22">.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

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

     <para>
      Recent developments have convinced us that <filename>Safe.pm</> is too
      insecure to rely on for making <literal>plperl</> trustable.  This
      change removes use of <filename>Safe.pm</> 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</> pragma in a natural way in
      <literal>plperl</>, and that Perl's <literal>$a</> and <literal>$b</>
      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</> (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</> 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</> Tcl
      interpreter unless we are really going to execute a <literal>pltclu</>
      function.  (CVE-2010-1170)
     </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</> for himself, or <literal>ALTER DATABASE ... RESET ALL</> 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</> 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</> 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>
      Update pl/perl's <filename>ppport.h</> 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</> when expanding
      a variable that refers to itself (Tom)
     </para>
    </listitem>

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

    <listitem>
     <para>
      Make server startup deal properly with the case that
      <function>shmget()</> returns <literal>EINVAL</> 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>
      Update time zone data files to <application>tzdata</> release 2010j
      for DST law changes in Argentina, Australian Antarctic, Bangladesh,
      Mexico, Morocco, Pakistan, Palestine, Russia, Syria, Tunisia;
      also historical corrections for Taiwan.
     </para>
    </listitem>

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-0-24">
  <title>Release 8.0.24</title>

  <note>
  <title>Release Date</title>
  <simpara>2010-03-15</simpara>
  </note>

  <para>
   This release contains a variety of fixes from 8.0.23.
   For information about new features in the 8.0 major release, see
   <xref linkend="release-8-0">.
  </para>

  <para>
   The <productname>PostgreSQL</> community will stop releasing updates
   for the 8.0.X release series in July 2010.
   Users are encouraged to update to a newer release branch soon.
  </para>

  <sect2>
   <title>Migration to Version 8.0.24</title>

   <para>
    A dump/restore is not required for those running 8.0.X.
    However, if you are upgrading from a version earlier than 8.0.22,
    see <xref linkend="release-8-0-22">.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

    <listitem>
     <para>
      Add new configuration parameter <varname>ssl_renegotiation_limit</> 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 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>
      Make <function>substring()</> for <type>bit</> types treat any negative
      length as meaning <quote>all the rest of the string</> (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 the <literal>STOP WAL LOCATION</> 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>
      When reading <filename>pg_hba.conf</> and related files, do not treat
      <literal>@something</> as a file inclusion request if the <literal>@</>
      appears inside quote marks; also, never treat <literal>@</> by itself
      as a file inclusion request (Tom)
     </para>

     <para>
      This prevents erratic behavior if a role or database name starts with
      <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"</> 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</> and related files
      (Tom)
     </para>
    </listitem>

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

    <listitem>
     <para>
      Add <literal>volatile</> 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</> command misbehaves if using Tcl 8.5 or later.
     </para>
    </listitem>

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

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

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

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-0-23">
  <title>Release 8.0.23</title>

  <note>
  <title>Release Date</title>
  <simpara>2009-12-14</simpara>
  </note>

  <para>
   This release contains a variety of fixes from 8.0.22.
   For information about new features in the 8.0 major release, see
   <xref linkend="release-8-0">.
  </para>

  <sect2>
   <title>Migration to Version 8.0.23</title>

   <para>
    A dump/restore is not required for those running 8.0.X.
    However, if you are upgrading from a version earlier than 8.0.22,
    see <xref linkend="release-8-0-22">.
   </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>
      Prevent signals from interrupting <literal>VACUUM</> at unsafe times
      (Alvaro)
     </para>

     <para>
      This fix prevents a PANIC if a <literal>VACUUM FULL</> is canceled
      after it's already committed its tuple movements, as well as transient
      errors if a plain <literal>VACUUM</> 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>cidr</> comparisons (Chris
      Mikkelson)
     </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 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</> 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>
      Fix rare crash in exception processing in PL/Python (Peter)
     </para>
    </listitem>

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

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

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

    <listitem>
     <para>
      Update time zone data files to <application>tzdata</> 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-8-0-22">
  <title>Release 8.0.22</title>

  <note>
  <title>Release Date</title>
  <simpara>2009-09-09</simpara>
  </note>

  <para>
   This release contains a variety of fixes from 8.0.21.
   For information about new features in the 8.0 major release, see
   <xref linkend="release-8-0">.
  </para>

  <sect2>
   <title>Migration to Version 8.0.22</title>

   <para>
    A dump/restore is not required for those running 8.0.X.
    However, if you have any hash indexes on <type>interval</> columns,
    you must <command>REINDEX</> them after updating to 8.0.22.
    Also, if you are upgrading from a version earlier than 8.0.6,
    see <xref linkend="release-8-0-6">.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

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

     <para>
      This covers a case that was missed in the previous patch that
      disallowed <command>SET ROLE</> and <command>SET SESSION
      AUTHORIZATION</> inside security-definer functions.
      (See CVE-2007-6600)
     </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 hash calculation for data type <type>interval</> (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</> them
      after updating.
     </para>
    </listitem>

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

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

    <listitem>
     <para>
      Fix overflow for <literal>INTERVAL '<replaceable>x</> ms'</literal>
      when <replaceable>x</> 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</> data type to work in locales where currency
      amounts have no fractional digits, e.g. Japan (Itagaki Takahiro)
     </para>
    </listitem>

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

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

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

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

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

    <listitem>
     <para>
      Improve robustness of <application>libpq</>'s code to recover
      from errors during <command>COPY FROM STDIN</> (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</> 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-8-0-21">
  <title>Release 8.0.21</title>

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

  <para>
   This release contains a variety of fixes from 8.0.20.
   For information about new features in the 8.0 major release, see
   <xref linkend="release-8-0">.
  </para>

  <sect2>
   <title>Migration to Version 8.0.21</title>

   <para>
    A dump/restore is not required for those running 8.0.X.
    However, if you are upgrading from a version earlier than 8.0.6,
    see <xref linkend="release-8-0-6">.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

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

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

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

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

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

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

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-0-20">
  <title>Release 8.0.20</title>

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

  <para>
   This release contains a variety of fixes from 8.0.19.
   For information about new features in the 8.0 major release, see
   <xref linkend="release-8-0">.
  </para>

  <sect2>
   <title>Migration to Version 8.0.20</title>

   <para>
    A dump/restore is not required for those running 8.0.X.
    However, if you are upgrading from a version earlier than 8.0.6,
    see <xref linkend="release-8-0-6">.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

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

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

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

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

    <listitem>
     <para>
      Fix uninitialized variables in <filename>contrib/tsearch2</>'s
      <function>get_covers()</> function (Teodor)
     </para>
    </listitem>

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

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

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-0-19">
  <title>Release 8.0.19</title>

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

  <para>
   This release contains a variety of fixes from 8.0.18.
   For information about new features in the 8.0 major release, see
   <xref linkend="release-8-0">.
  </para>

  <sect2>
   <title>Migration to Version 8.0.19</title>

   <para>
    A dump/restore is not required for those running 8.0.X.
    However, if you are upgrading from a version earlier than 8.0.6,
    see <xref linkend="release-8-0-6">.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

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

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

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

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

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

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

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

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

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

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

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

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-0-18">
  <title>Release 8.0.18</title>

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

  <para>
   This release contains a variety of fixes from 8.0.17.
   For information about new features in the 8.0 major release, see
   <xref linkend="release-8-0">.
  </para>

  <sect2>
   <title>Migration to Version 8.0.18</title>

   <para>
    A dump/restore is not required for those running 8.0.X.
    However, if you are upgrading from a version earlier than 8.0.6,
    see <xref linkend="release-8-0-6">.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

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

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

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

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

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

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

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

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

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

    <listitem>
     <para>
      Fix PL/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>
      Fix PL/Python to work with Python 2.5
     </para>

     <para>
      This is a back-port of fixes made during the 8.2 development cycle.
     </para>
    </listitem>

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

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

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

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-0-17">
  <title>Release 8.0.17</title>

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

  <para>
   This release contains one serious bug fix over 8.0.16.
   For information about new features in the 8.0 major release, see
   <xref linkend="release-8-0">.
  </para>

  <sect2>
   <title>Migration to Version 8.0.17</title>

   <para>
    A dump/restore is not required for those running 8.0.X.
    However, if you are upgrading from a version earlier than 8.0.6,
    see <xref linkend="release-8-0-6">.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

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

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

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-0-16">
  <title>Release 8.0.16</title>

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

  <para>
   This release contains a variety of fixes from 8.0.15.
   For information about new features in the 8.0 major release, see
   <xref linkend="release-8-0">.
  </para>

  <sect2>
   <title>Migration to Version 8.0.16</title>

   <para>
    A dump/restore is not required for those running 8.0.X.
    However, if you are upgrading from a version earlier than 8.0.6,
    see <xref linkend="release-8-0-6">.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-0-15">
  <title>Release 8.0.15</title>

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

  <para>
   This release contains a variety of fixes from 8.0.14,
   including fixes for significant security issues.
   For information about new features in the 8.0 major release, see
   <xref linkend="release-8-0">.
  </para>

  <para>
   This is the last 8.0.X release for which the <productname>PostgreSQL</>
   community will produce binary packages for <productname>Windows</>.
   Windows users are encouraged to move to 8.2.X or later,
   since there are Windows-specific fixes in 8.2.X that
   are impractical to back-port.  8.0.X will continue to
   be supported on other platforms.
  </para>

  <sect2>
   <title>Migration to Version 8.0.15</title>

   <para>
    A dump/restore is not required for those running 8.0.X.  However,
    if you are upgrading from a version earlier than 8.0.6,
    see <xref linkend="release-8-0-6">.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

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

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

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

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

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

     <para>
      The fix that appeared for this in 8.0.14 was incomplete, as it plugged
      the hole for only some <filename>dblink</> functions.  (CVE-2007-6601,
      CVE-2007-3278)
     </para>
    </listitem>

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-0-14">
  <title>Release 8.0.14</title>

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

  <para>
   This release contains a variety of fixes from 8.0.13.
   For information about new features in the 8.0 major release, see
   <xref linkend="release-8-0">.
  </para>

  <sect2>
   <title>Migration to Version 8.0.14</title>

   <para>
    A dump/restore is not required for those running 8.0.X.  However,
    if you are upgrading from a version earlier than 8.0.6,
    see <xref linkend="release-8-0-6">.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

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

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

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

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

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

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

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

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

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

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

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

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-0-13">
  <title>Release 8.0.13</title>

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

  <para>
   This release contains a variety of fixes from 8.0.12,
   including a security fix.
   For information about new features in the 8.0 major release, see
   <xref linkend="release-8-0">.
  </para>

  <sect2>
   <title>Migration to Version 8.0.13</title>

   <para>
    A dump/restore is not required for those running 8.0.X.  However,
    if you are upgrading from a version earlier than 8.0.6,
    see <xref linkend="release-8-0-6">.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

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

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

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

    <listitem>
    <para>
     Fix PANIC during enlargement of a hash index (bug introduced in 8.0.10)
     (Tom)
    </para>
    </listitem>

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

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-0-12">
  <title>Release 8.0.12</title>

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

  <para>
   This release contains one fix from 8.0.11.
   For information about new features in the 8.0 major release, see
   <xref linkend="release-8-0">.
  </para>

  <sect2>
   <title>Migration to Version 8.0.12</title>

   <para>
    A dump/restore is not required for those running 8.0.X.  However,
    if you are upgrading from a version earlier than 8.0.6,
    see <xref linkend="release-8-0-6">.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

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

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-0-11">
  <title>Release 8.0.11</title>

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

  <para>
   This release contains a variety of fixes from 8.0.10, including
   a security fix.
   For information about new features in the 8.0 major release, see
   <xref linkend="release-8-0">.
  </para>

  <sect2>
   <title>Migration to Version 8.0.11</title>

   <para>
    A dump/restore is not required for those running 8.0.X.  However,
    if you are upgrading from a version earlier than 8.0.6,
    see <xref linkend="release-8-0-6">.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

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

    <listitem>
    <para>
     Fix rare bug wherein btree index page splits could fail
     due to choosing an infeasible split point (Heikki Linnakangas)
    </para>
    </listitem>

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

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

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-0-10">
  <title>Release 8.0.10</title>

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

  <para>
   This release contains a variety of fixes from 8.0.9.
   For information about new features in the 8.0 major release, see
   <xref linkend="release-8-0">.
  </para>

  <sect2>
   <title>Migration to Version 8.0.10</title>

   <para>
    A dump/restore is not required for those running 8.0.X.  However,
    if you are upgrading from a version earlier than 8.0.6,
    see <xref linkend="release-8-0-6">.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

   <itemizedlist>

    <listitem>
     <para>
      Improve handling of <function>getaddrinfo()</> on AIX (Tom)
     </para>

     <para>
      This fixes a problem with starting the statistics collector,
      among other things.
     </para>
    </listitem>

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

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

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

    <listitem>
     <para>
      Fix possible deadlock in Windows signal handling (Teodor)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix error when constructing an <literal>ARRAY[]</> made up of multiple
      empty elements (Tom)
     </para>
    </listitem>

    <listitem>
     <para>
      Fix ecpg memory leak during connection (Michael)
     </para>
    </listitem>

    <listitem>
     <para>
      <function>to_number()</> and <function>to_char(numeric)</>
      are now <literal>STABLE</>, not <literal>IMMUTABLE</>, for
      new <application>initdb</> installs (Tom)
     </para>

     <para>
      This is because <varname>lc_numeric</> can potentially
      change the output of these functions.
     </para>
    </listitem>

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

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

    <listitem>
     <para>
      Update timezone database
     </para>

     <para>
      This affects Australian and Canadian daylight-savings rules in
      particular.
     </para>
    </listitem>

   </itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-0-9">
  <title>Release 8.0.9</title>

  <note>
  <title>Release Date</title>
  <simpara>2006-10-16</simpara>
  </note>

  <para>
   This release contains a variety of fixes from 8.0.8.
   For information about new features in the 8.0 major release, see
   <xref linkend="release-8-0">.
  </para>

  <sect2>
   <title>Migration to Version 8.0.9</title>

   <para>
    A dump/restore is not required for those running 8.0.X.  However,
    if you are upgrading from a version earlier than 8.0.6,
    see <xref linkend="release-8-0-6">.
   </para>

  </sect2>

  <sect2>
   <title>Changes</title>

<itemizedlist>
<listitem><para>Fix crash when referencing <literal>NEW</> row
values in rule WHERE expressions (Tom)</para></listitem>
<listitem><para>Fix core dump when an untyped literal is taken as
ANYARRAY</para></listitem>
<listitem><para>Fix mishandling of AFTER triggers when query contains a SQL
function returning multiple rows (Tom)</para></listitem>
<listitem><para>Fix <command>ALTER TABLE ... TYPE</> to recheck
<literal>NOT NULL</> for <literal>USING</> clause (Tom)</para></listitem>
<listitem><para>Fix <function>string_to_array()</> to handle overlapping
 matches for the separator string</para>
<para>For example, <literal>string_to_array('123xx456xxx789', 'xx')</>.
</para></listitem>
<listitem><para>Fix corner cases in pattern matching for
 <application>psql</>'s <literal>\d</> commands</para></listitem>
<listitem><para>Fix index-corrupting bugs in /contrib/ltree
 (Teodor)</para></listitem>
<listitem><para>Numerous robustness fixes in <application>ecpg</> (Joachim
Wieland)</para></listitem>
<listitem><para>Fix backslash escaping in /contrib/dbmirror</para></listitem>
<listitem><para>Fix instability of statistics collection on Win32 (Tom, Andrew)</para></listitem>
<listitem><para>Fixes for <systemitem class="osname">AIX</> and
<productname>Intel</> compilers (Tom)</para></listitem>
</itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-0-8">
  <title>Release 8.0.8</title>

  <note>
  <title>Release Date</title>
  <simpara>2006-05-23</simpara>
  </note>

  <para>
   This release contains a variety of fixes from 8.0.7,
   including patches for extremely serious security issues.
   For information about new features in the 8.0 major release, see
   <xref linkend="release-8-0">.
  </para>

  <sect2>
   <title>Migration to Version 8.0.8</title>

   <para>
    A dump/restore is not required for those running 8.0.X.  However,
    if you are upgrading from a version earlier than 8.0.6,
    see <xref linkend="release-8-0-6">.
   </para>

   <para>
    Full security against the SQL-injection attacks described in
    CVE-2006-2313 and CVE-2006-2314 might require changes in application
    code.  If you have applications that embed untrustworthy strings
    into SQL commands, you should examine them as soon as possible to
    ensure that they are using recommended escaping techniques.  In
    most cases, applications should be using subroutines provided by
    libraries or drivers (such as <application>libpq</>'s
    <function>PQescapeStringConn()</>) to perform string escaping,
    rather than relying on <foreignphrase>ad hoc</> code to do it.
   </para>
  </sect2>

  <sect2>
   <title>Changes</title>

<itemizedlist>
<listitem><para>Change the server to reject invalidly-encoded multibyte
characters in all cases (Tatsuo, Tom)</para>
<para>While <productname>PostgreSQL</> has been moving in this direction for
some time, the checks are now applied uniformly to all encodings and all
textual input, and are now always errors not merely warnings.  This change
defends against SQL-injection attacks of the type described in CVE-2006-2313.
</para></listitem>

<listitem><para>Reject unsafe uses of <literal>\'</> in string literals</para>
<para>As a server-side defense against SQL-injection attacks of the type
described in CVE-2006-2314, the server now only accepts <literal>''</> and not
<literal>\'</> as a representation of ASCII single quote in SQL string
literals.  By default, <literal>\'</> is rejected only when
<varname>client_encoding</> is set to a client-only encoding (SJIS, BIG5, GBK,
GB18030, or UHC), which is the scenario in which SQL injection is possible.
A new configuration parameter <varname>backslash_quote</> is available to
adjust this behavior when needed.  Note that full security against
CVE-2006-2314 might require client-side changes; the purpose of
<varname>backslash_quote</> is in part to make it obvious that insecure
clients are insecure.
</para></listitem>

<listitem><para>Modify <application>libpq</>'s string-escaping routines to be
aware of encoding considerations and
<varname>standard_conforming_strings</></para>
<para>This fixes <application>libpq</>-using applications for the security
issues described in CVE-2006-2313 and CVE-2006-2314, and also future-proofs
them against the planned changeover to SQL-standard string literal syntax.
Applications that use multiple <productname>PostgreSQL</> connections
concurrently should migrate to <function>PQescapeStringConn()</> and
<function>PQescapeByteaConn()</> to ensure that escaping is done correctly
for the settings in use in each database connection.  Applications that
do string escaping <quote>by hand</> should be modified to rely on library
routines instead.
</para></listitem>

<listitem><para>Fix some incorrect encoding conversion functions</para>
<para><function>win1251_to_iso</>, <function>alt_to_iso</>,
<function>euc_tw_to_big5</>, <function>euc_tw_to_mic</>,
<function>mic_to_euc_tw</> were all broken to varying
extents.
</para></listitem>

<listitem><para>Clean up stray remaining uses of <literal>\'</> in strings
(Bruce, Jan)</para></listitem>

<listitem><para>Fix bug that sometimes caused OR'd index scans to
miss rows they should have returned</para></listitem>

<listitem><para>Fix WAL replay for case where a btree index has been
truncated</para></listitem>

<listitem><para>Fix <literal>SIMILAR TO</> for patterns involving
<literal>|</> (Tom)</para></listitem>

<listitem><para>Fix <command>SELECT INTO</> and <command>CREATE TABLE AS</> to
create tables in the default tablespace, not the base directory (Kris
Jurka)</para></listitem>

<listitem><para>Fix server to use custom DH SSL parameters correctly (Michael
Fuhr)</para></listitem>

<listitem><para>Fix for Bonjour on Intel Macs (Ashley Clark)</para></listitem>

<listitem><para>Fix various minor memory leaks</para></listitem>

<listitem><para>Fix problem with password prompting on some Win32 systems
(Robert Kinberg)</para></listitem>
</itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-0-7">
  <title>Release 8.0.7</title>

  <note>
  <title>Release Date</title>
  <simpara>2006-02-14</simpara>
  </note>

  <para>
   This release contains a variety of fixes from 8.0.6.
   For information about new features in the 8.0 major release, see
   <xref linkend="release-8-0">.
  </para>

  <sect2>
   <title>Migration to Version 8.0.7</title>

   <para>
    A dump/restore is not required for those running 8.0.X.  However,
    if you are upgrading from a version earlier than 8.0.6,
    see <xref linkend="release-8-0-6">.
   </para>
  </sect2>

  <sect2>
   <title>Changes</title>

<itemizedlist>

<listitem><para>Fix potential crash in <command>SET
SESSION AUTHORIZATION</> (CVE-2006-0553)</para>
<para>An unprivileged user could crash the server process, resulting in
momentary denial of service to other users, if the server has been compiled
with Asserts enabled (which is not the default).
Thanks to Akio Ishida for reporting this problem.
</para></listitem>

<listitem><para>Fix bug with row visibility logic in self-inserted
rows (Tom)</para>
<para>Under rare circumstances a row inserted by the current command
could be seen as already valid, when it should not be.  Repairs bug
created in 8.0.4, 7.4.9, and 7.3.11 releases.
</para></listitem>

<listitem><para>Fix race condition that could lead to <quote>file already
exists</> errors during pg_clog and pg_subtrans file creation
(Tom)</para></listitem>

<listitem><para>Fix cases that could lead to crashes if a cache-invalidation
message arrives at just the wrong time (Tom)</para></listitem>

<listitem><para>Properly check <literal>DOMAIN</> constraints for
<literal>UNKNOWN</> parameters in prepared statements
(Neil)</para></listitem>

<listitem><para>Ensure <command>ALTER COLUMN TYPE</> will process
<literal>FOREIGN KEY</>, <literal>UNIQUE</>, and <literal>PRIMARY KEY</>
constraints in the proper order (Nakano Yoshihisa)</para></listitem>

<listitem><para>Fixes to allow restoring dumps that have cross-schema
references to custom operators or operator classes (Tom)</para></listitem>

<listitem><para>Allow <application>pg_restore</> to continue properly after a
<command>COPY</> failure; formerly it tried to treat the remaining
<command>COPY</> data as SQL commands (Stephen Frost)</para></listitem>

<listitem><para>Fix <application>pg_ctl</> <literal>unregister</> crash
when the  data directory is not specified (Magnus)</para></listitem>

<listitem><para>Fix <application>ecpg</> crash on AMD64 and PPC
(Neil)</para></listitem>

<listitem><para>Recover properly if error occurs during argument passing
in <application>PL/python</> (Neil)</para></listitem>

<listitem><para>Fix <application>PL/perl</>'s handling of locales on
Win32 to match the backend (Andrew)</para></listitem>

<listitem><para>Fix crash when <literal>log_min_messages</> is set to
<literal>DEBUG3</> or above in <filename>postgresql.conf</> on Win32
(Bruce)</para></listitem>

<listitem><para>Fix <application>pgxs</> <literal>-L</> library path
specification for Win32, Cygwin, macOS, AIX (Bruce)</para></listitem>

<listitem><para>Check that SID is enabled while checking for Win32 admin
privileges (Magnus)</para></listitem>

<listitem><para>Properly reject out-of-range date inputs (Kris
Jurka)</para></listitem>

<listitem><para>Portability fix for testing presence of <function>finite</>
and <function>isinf</> during configure (Tom)</para></listitem>

</itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-0-6">
  <title>Release 8.0.6</title>

  <note>
  <title>Release Date</title>
  <simpara>2006-01-09</simpara>
  </note>

  <para>
   This release contains a variety of fixes from 8.0.5.
   For information about new features in the 8.0 major release, see
   <xref linkend="release-8-0">.
  </para>

  <sect2>
   <title>Migration to Version 8.0.6</title>

   <para>
    A dump/restore is not required for those running 8.0.X.  However,
    if you are upgrading from a version earlier than 8.0.3,
    see <xref linkend="release-8-0-3">.
    Also, you might need to <command>REINDEX</> indexes on textual
    columns after updating, if you are affected by the locale or
    <application>plperl</> issues described below.
   </para>
  </sect2>

  <sect2>
   <title>Changes</title>

<itemizedlist>

<listitem><para>Fix Windows code so that postmaster will continue rather
than exit if there is no more room in ShmemBackendArray (Magnus)</para>
<para>The previous behavior could lead to a denial-of-service situation if too
many connection requests arrive close together.  This applies
<emphasis>only</> to the Windows port.</para></listitem>

<listitem><para>Fix bug introduced in 8.0 that could allow ReadBuffer
to return an already-used page as new, potentially causing loss of
recently-committed data (Tom)</para></listitem>

<listitem><para>Fix for protocol-level Describe messages issued
outside a transaction or in a failed transaction (Tom)</para></listitem>

<listitem><para>Fix character string comparison for locales that consider
different character combinations as equal, such as Hungarian (Tom)</para>
<para>This might require <command>REINDEX</> to fix existing indexes on
textual columns.</para></listitem>

<listitem><para>Set locale environment variables during postmaster startup
to ensure that <application>plperl</> won't change the locale later</para>
<para>This fixes a problem that occurred if the <application>postmaster</> was
started with environment variables specifying a different locale than what
<application>initdb</> had been told.  Under these conditions, any use of
<application>plperl</> was likely to lead to corrupt indexes.  You might need
<command>REINDEX</> to fix existing indexes on
textual columns if this has happened to you.</para></listitem>

<listitem><para>Allow more flexible relocation of installation
directories (Tom)</para>
<para>Previous releases supported relocation only if all installation
directory paths were the same except for the last component.</para></listitem>

<listitem><para>Fix longstanding bug in strpos() and regular expression
handling in certain rarely used Asian multi-byte character sets (Tatsuo)
</para></listitem>

<listitem><para>Various fixes for functions returning <literal>RECORD</>s
(Tom) </para></listitem>

<listitem><para>Fix bug in <filename>/contrib/pgcrypto</> gen_salt,
which caused it not to use all available salt space for MD5 and
XDES algorithms (Marko Kreen, Solar Designer)</para>
<para>Salts for Blowfish and standard DES are unaffected.</para></listitem>

<listitem><para>Fix <filename>/contrib/dblink</> to throw an error,
rather than crashing, when the number of columns specified is different from
what's actually returned by the query (Joe)</para></listitem>

</itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-0-5">
  <title>Release 8.0.5</title>

  <note>
  <title>Release Date</title>
  <simpara>2005-12-12</simpara>
  </note>

  <para>
   This release contains a variety of fixes from 8.0.4.
   For information about new features in the 8.0 major release, see
   <xref linkend="release-8-0">.
  </para>

  <sect2>
   <title>Migration to Version 8.0.5</title>

   <para>
    A dump/restore is not required for those running 8.0.X.  However,
    if you are upgrading from a version earlier than 8.0.3,
    see <xref linkend="release-8-0-3">.
   </para>
  </sect2>

  <sect2>
   <title>Changes</title>

<itemizedlist>

<listitem><para>Fix race condition in transaction log management</para>
<para>There was a narrow window in which an I/O operation could be initiated
for the wrong page, leading to an Assert failure or data
corruption.</para>
</listitem>

<listitem><para>Fix bgwriter problems after recovering from errors
(Tom)</para>
<para>
The background writer was found to leak buffer pins after write errors.
While not fatal in itself, this might lead to mysterious blockages of
later VACUUM commands.
</para>
</listitem>

<listitem><para>Prevent failure if client sends Bind protocol message
when current transaction is already aborted</para></listitem>

<listitem><para><filename>/contrib/ltree</> fixes (Teodor)</para></listitem>

<listitem><para>AIX and HPUX compile fixes (Tom)</para></listitem>

<listitem><para>Retry file reads and writes after Windows
NO_SYSTEM_RESOURCES error (Qingqing Zhou)</para></listitem>

<listitem><para>Fix intermittent failure when <varname>log_line_prefix</>
includes <literal>%i</></para></listitem>

<listitem><para>Fix <application>psql</> performance issue with long scripts
on Windows (Merlin Moncure)</para></listitem>

<listitem><para>Fix missing updates of <filename>pg_group</> flat
file</para></listitem>

<listitem><para>Fix longstanding planning error for outer joins</para>
<para>This bug sometimes caused a bogus error <quote>RIGHT JOIN is
only supported with merge-joinable join conditions</>.</para></listitem>

<listitem><para>Postpone timezone initialization until after
<filename>postmaster.pid</> is created</para>
<para>This avoids confusing startup scripts that expect the pid file to appear
quickly.</para></listitem>

<listitem><para>Prevent core dump in <application>pg_autovacuum</> when a
table has been dropped</para></listitem>

<listitem><para>Fix problems with whole-row references (<literal>foo.*</>)
to subquery results</para></listitem>
</itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-0-4">
  <title>Release 8.0.4</title>

  <note>
  <title>Release Date</title>
  <simpara>2005-10-04</simpara>
  </note>

  <para>
   This release contains a variety of fixes from 8.0.3.
   For information about new features in the 8.0 major release, see
   <xref linkend="release-8-0">.
  </para>

  <sect2>
   <title>Migration to Version 8.0.4</title>

   <para>
    A dump/restore is not required for those running 8.0.X.  However,
    if you are upgrading from a version earlier than 8.0.3,
    see <xref linkend="release-8-0-3">.
   </para>
  </sect2>

  <sect2>
   <title>Changes</title>

<itemizedlist>
<listitem><para>Fix error that allowed <command>VACUUM</> to remove
<literal>ctid</> chains too soon, and add more checking in code that follows
<literal>ctid</> links</para>
<para>This fixes a long-standing problem that could cause crashes in very rare
circumstances.</para></listitem>
<listitem><para>Fix <type>CHAR()</> to properly pad spaces to the specified
length when using a multiple-byte character set (Yoshiyuki Asaba)</para>
<para>In prior releases, the padding of <type>CHAR()</> was incorrect
because it only padded to the specified number of bytes without
considering how many characters were stored.</para></listitem>
<listitem><para>Force a checkpoint before committing <command>CREATE
DATABASE</></para>
<para>This should fix recent reports of <quote>index is not a btree</>
failures when a crash occurs shortly after <command>CREATE
DATABASE</>.</para></listitem>
<listitem><para>Fix the sense of the test for read-only transaction
in <command>COPY</></para>
<para>The code formerly prohibited <command>COPY TO</>, where it should
prohibit <command>COPY FROM</>.
</para></listitem>
<listitem><para>Handle consecutive embedded newlines in <command>COPY</>
CSV-mode input</para></listitem>
<listitem><para>Fix <function>date_trunc(week)</> for dates near year
end</para></listitem>
<listitem><para>Fix planning problem with outer-join ON clauses that reference
only the inner-side relation</para></listitem>
<listitem><para>Further fixes for <literal>x FULL JOIN y ON true</> corner
cases</para></listitem>
<listitem><para>Fix overenthusiastic optimization of <literal>x IN (SELECT
DISTINCT ...)</> and related cases</para></listitem>
<listitem><para>Fix mis-planning of queries with small <literal>LIMIT</>
values due to poorly thought out <quote>fuzzy</> cost
comparison</para></listitem>
<listitem><para>Make <function>array_in</> and <function>array_recv</> more
paranoid about validating their OID parameter</para></listitem>
<listitem><para>Fix missing rows in queries like <literal>UPDATE a=... WHERE
a...</> with GiST index on column <literal>a</></para></listitem>
<listitem><para>Improve robustness of datetime parsing</para></listitem>
<listitem><para>Improve checking for partially-written WAL
pages</para></listitem>
<listitem><para>Improve robustness of signal handling when SSL is
enabled</para></listitem>
<listitem><para>Improve MIPS and M68K spinlock code</para></listitem>
<listitem><para>Don't try to open more than <literal>max_files_per_process</>
files during postmaster startup</para></listitem>
<listitem><para>Various memory leakage fixes</para></listitem>
<listitem><para>Various portability improvements</para></listitem>
<listitem><para>Update timezone data files</para></listitem>
<listitem><para>Improve handling of DLL load failures on Windows</para></listitem>
<listitem><para>Improve random-number generation on Windows</para></listitem>
<listitem><para>Make <literal>psql -f filename</> return a nonzero exit code
when opening the file fails</para></listitem>
<listitem><para>Change <application>pg_dump</> to handle inherited check
constraints more reliably</para></listitem>
<listitem><para>Fix password prompting in <application>pg_restore</> on
Windows</para></listitem>
<listitem><para>Fix PL/pgSQL to handle <literal>var := var</> correctly when
the variable is of pass-by-reference type</para></listitem>
<listitem><para>Fix PL/Perl <literal>%_SHARED</> so it's actually
shared</para></listitem>
<listitem><para>Fix <filename>contrib/pg_autovacuum</> to allow sleep
intervals over 2000 sec</para></listitem>
<listitem><para>Update <filename>contrib/tsearch2</> to use current Snowball
code</para></listitem>
</itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-0-3">
  <title>Release 8.0.3</title>

  <note>
  <title>Release Date</title>
  <simpara>2005-05-09</simpara>
  </note>

  <para>
   This release contains a variety of fixes from 8.0.2, including several
   security-related issues.
   For information about new features in the 8.0 major release, see
   <xref linkend="release-8-0">.
  </para>

  <sect2>
   <title>Migration to Version 8.0.3</title>

   <para>
    A dump/restore is not required for those running 8.0.X.  However,
    it is one possible way of handling two significant security problems
    that have been found in the initial contents of 8.0.X system
    catalogs.  A dump/initdb/reload sequence using 8.0.3's initdb will
    automatically correct these problems.
   </para>

   <para>
    The larger security problem is that the built-in character set encoding
    conversion functions can be invoked from SQL commands by unprivileged
    users, but the functions were not designed for such use and are not
    secure against malicious choices of arguments.  The fix involves changing
    the declared parameter list of these functions so that they can no longer
    be invoked from SQL commands.  (This does not affect their normal use
    by the encoding conversion machinery.)
   </para>

   <para>
    The lesser problem is that the <filename>contrib/tsearch2</> module
    creates several functions that are improperly declared to return
    <type>internal</> when they do not accept <type>internal</> arguments.
    This breaks type safety for all functions using <type>internal</>
    arguments.
   </para>

   <para>
    It is strongly recommended that all installations repair these errors,
    either by initdb or by following the manual repair procedure given
    below.  The errors at least allow unprivileged database users to crash
    their server process, and might allow unprivileged users to gain the
    privileges of a database superuser.
   </para>

   <para>
    If you wish not to do an initdb, perform the same manual repair
    procedures shown in the <link linkend="release-7-4-8">7.4.8 release
    notes</link>.
   </para>
  </sect2>

  <sect2>
   <title>Changes</title>

<itemizedlist>
<listitem><para>Change encoding function signature to prevent
misuse</para></listitem>
<listitem><para>Change <filename>contrib/tsearch2</> to avoid unsafe use of
<type>INTERNAL</> function results</para></listitem>
<listitem><para>Guard against incorrect second parameter to
<function>record_out</></para></listitem>
<listitem><para>Repair ancient race condition that allowed a transaction to be
seen as committed for some purposes (eg SELECT FOR UPDATE) slightly sooner
than for other purposes</para>
<para>This is an extremely serious bug since it could lead to apparent
data inconsistencies being briefly visible to applications.</para></listitem>
<listitem><para>Repair race condition between relation extension and
VACUUM</para>
<para>This could theoretically have caused loss of a page's worth of
freshly-inserted data, although the scenario seems of very low probability.
There are no known cases of it having caused more than an Assert failure.
</para></listitem>
<listitem><para>Fix comparisons of <type>TIME WITH TIME ZONE</> values</para>
<para>
The comparison code was wrong in the case where the
<literal>--enable-integer-datetimes</> configuration switch had been used.
NOTE: if you have an index on a <type>TIME WITH TIME ZONE</> column,
it will need to be <command>REINDEX</>ed after installing this update, because
the fix corrects the sort order of column values.
</para></listitem>
<listitem><para>Fix <function>EXTRACT(EPOCH)</> for
<type>TIME WITH TIME ZONE</> values</para></listitem>
<listitem><para>Fix mis-display of negative fractional seconds in
<type>INTERVAL</> values</para>
<para>
This error only occurred when the
<literal>--enable-integer-datetimes</> configuration switch had been used.
</para></listitem>
<listitem><para>Fix pg_dump to dump trigger names containing <literal>%</>
correctly (Neil)</para></listitem>
<listitem><para>Still more 64-bit fixes for
<filename>contrib/intagg</></para></listitem>
<listitem><para>Prevent incorrect optimization of functions returning
<type>RECORD</></para></listitem>
<listitem><para>Prevent crash on <literal>COALESCE(NULL,NULL)</></para></listitem>
<listitem><para>Fix Borland makefile for libpq</para></listitem>
<listitem><para>Fix <filename>contrib/btree_gist</> for <type>timetz</> type
(Teodor)</para></listitem>
<listitem><para>Make <command>pg_ctl</> check the PID found in
<filename>postmaster.pid</> to see if it is still a live
process</para></listitem>
<listitem><para>Fix <command>pg_dump</>/<command>pg_restore</> problems caused
by addition of dump timestamps</para></listitem>
<listitem><para>Fix interaction between materializing holdable cursors and
firing deferred triggers during transaction commit</para></listitem>
<listitem><para>Fix memory leak in SQL functions returning pass-by-reference
data types</para></listitem>
</itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-0-2">
  <title>Release 8.0.2</title>

  <note>
  <title>Release Date</title>
  <simpara>2005-04-07</simpara>
  </note>

  <para>
   This release contains a variety of fixes from 8.0.1.
   For information about new features in the 8.0 major release, see
   <xref linkend="release-8-0">.
  </para>

  <sect2>
   <title>Migration to Version 8.0.2</title>

   <para>
    A dump/restore is not required for those running 8.0.*.
    This release updates the major version number of the
    <productname>PostgreSQL</productname> libraries, so it might be
    necessary to re-link some user applications if they cannot
    find the properly-numbered shared library.
   </para>
  </sect2>

  <sect2>
   <title>Changes</title>

<itemizedlist>
<listitem><para>Increment the major version number of all interface
libraries (Bruce)</para>
<para>
This should have been done in 8.0.0.  It is required so 7.4.X versions
of PostgreSQL client applications, like <application>psql</>,
can be used on the same machine as 8.0.X applications.  This might require
re-linking user applications that use these libraries.
</para></listitem>
<listitem><para>Add Windows-only <varname>wal_sync_method</> setting of
<option>fsync_writethrough</> (Magnus, Bruce)</para>
<para>
This setting causes <productname>PostgreSQL</productname> to write through
any disk-drive write cache when writing to WAL.
This behavior was formerly called <option>fsync</>, but was
renamed because it acts quite differently from <option>fsync</> on other
platforms.
</para>
</listitem>
<listitem><para>Enable the <varname>wal_sync_method</> setting of
<option>open_datasync</> on Windows, and make it the default for that
 platform (Magnus, Bruce)</para>
<para>
Because the default is no longer <option>fsync_writethrough</>,
data loss is possible during a power failure if the disk drive has
write caching enabled. To turn off the write cache on Windows,
from the <application>Device Manager</>, choose the drive properties,
then <literal>Policies</>.
</para>
</listitem>
<listitem><para>New cache management algorithm <acronym>2Q</> replaces
<acronym>ARC</> (Tom)</para>
<para>
This was done to avoid a pending US patent on <acronym>ARC</>.  The
<acronym>2Q</> code might be a few percentage points slower than
<acronym>ARC</> for some work loads.  A better cache management algorithm
will appear in 8.1.
</para></listitem>
<listitem><para>Planner adjustments to improve behavior on freshly-created
tables (Tom)</para></listitem>
<listitem><para>Allow plpgsql to assign to an element of an array that is
initially <literal>NULL</> (Tom)</para>
<para>
Formerly the array would remain <literal>NULL</>, but now it becomes a
single-element array.  The main SQL engine was changed to handle
<command>UPDATE</> of a null array value this way in 8.0, but the similar
case in plpgsql was overlooked.
</para>
</listitem>
<listitem><para>Convert <literal>\r\n</> and <literal>\r</> to <literal>\n</>
in plpython function bodies (Michael Fuhr)</para>
<para>
 This prevents syntax errors when plpython code is written on a Windows or
 Mac client.
</para>
</listitem>
<listitem><para>Allow SPI cursors to handle utility commands that return rows,
such as <command>EXPLAIN</> (Tom)</para></listitem>
<listitem><para>Fix <command>CLUSTER</> failure after <command>ALTER TABLE
SET WITHOUT OIDS</> (Tom)</para></listitem>
<listitem><para>Reduce memory usage of <command>ALTER TABLE ADD COLUMN</>
(Neil)</para></listitem>
<listitem><para>Fix <command>ALTER LANGUAGE RENAME</> (Tom)</para></listitem>
<listitem><para>Document the Windows-only <literal>register</> and
<literal>unregister</> options of <application>pg_ctl</> (Magnus)</para></listitem>
<listitem><para>Ensure operations done during backend shutdown are counted by
statistics collector</para>
<para>
This is expected to resolve reports of <application>pg_autovacuum</>
not vacuuming the system catalogs often enough &mdash; it was not being
told about catalog deletions caused by temporary table removal during
backend exit.
</para></listitem>
<listitem><para>Change the Windows default for configuration parameter
<varname>log_destination</> to <option>eventlog</> (Magnus)</para>
<para>
By default, a server running on Windows will now send log output to the
Windows event logger rather than standard error.
</para></listitem>
<listitem><para>Make Kerberos authentication work on Windows (Magnus)</para></listitem>
<listitem><para>Allow <command>ALTER DATABASE RENAME</> by superusers
who aren't flagged as having CREATEDB privilege (Tom)</para></listitem>
<listitem><para>Modify WAL log entries for <command>CREATE</> and
<command>DROP DATABASE</> to not specify absolute paths (Tom)</para>
<para>This allows point-in-time recovery on a different machine with possibly
different database location.  Note that <command>CREATE TABLESPACE</> still
poses a hazard in such situations.
</para></listitem>
<listitem><para>Fix crash from a backend exiting with an open transaction
that created a table and opened a cursor on it (Tom)</para></listitem>
<listitem><para>Fix <function>array_map()</> so it can call PL functions
(Tom)</para></listitem>
<listitem><para>Several <filename>contrib/tsearch2</> and
<filename>contrib/btree_gist</> fixes (Teodor)
</para></listitem>
<listitem><para>Fix crash of some <filename>contrib/pgcrypto</>
functions on some platforms (Marko Kreen)</para></listitem>
<listitem><para>Fix <filename>contrib/intagg</> for 64-bit platforms
(Tom)</para></listitem>
<listitem><para>Fix ecpg bugs in parsing of <command>CREATE</> statement
(Michael)</para></listitem>
<listitem><para>Work around gcc bug on powerpc and amd64 causing problems in
ecpg (Christof Petig)</para></listitem>
<listitem><para>Do not use locale-aware versions of <function>upper()</>,
<function>lower()</>, and <function>initcap()</> when the locale is
<literal>C</> (Bruce)</para>
<para>
 This allows these functions to work on platforms that generate errors
 for non-7-bit data when the locale is <literal>C</>.
</para></listitem>
<listitem><para>Fix <function>quote_ident()</> to quote names that match keywords (Tom)</para></listitem>
<listitem><para>Fix <function>to_date()</> to behave reasonably when
<literal>CC</> and <literal>YY</> fields are both used (Karel)</para></listitem>
<listitem><para>Prevent <function>to_char(interval)</> from failing
when given a zero-month interval (Tom)</para></listitem>
<listitem><para>Fix wrong week returned by <function>date_trunc('week')</>
(Bruce)</para>
<para>
<function>date_trunc('week')</>
returned the wrong year for the first few days of January in some years.
</para></listitem>
<listitem><para>Use the correct default mask length for class <literal>D</>
addresses in <type>INET</> data types (Tom)</para></listitem>
</itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-0-1">
  <title>Release 8.0.1</title>

  <note>
  <title>Release Date</title>
  <simpara>2005-01-31</simpara>
  </note>

  <para>
   This release contains a variety of fixes from 8.0.0, including several
   security-related issues.
   For information about new features in the 8.0 major release, see
   <xref linkend="release-8-0">.
  </para>

  <sect2>
   <title>Migration to Version 8.0.1</title>

   <para>
    A dump/restore is not required for those running 8.0.0.
   </para>
  </sect2>

  <sect2>
   <title>Changes</title>

<itemizedlist>
<listitem><para>Disallow <command>LOAD</> to non-superusers</para>
<para>
On platforms that will automatically execute initialization functions of a
shared library (this includes at least Windows and ELF-based Unixen),
<command>LOAD</> can be used to make the server execute arbitrary code.
Thanks to NGS Software for reporting this.</para></listitem>
<listitem><para>Check that creator of an aggregate function has the right to
execute the specified transition functions</para>
<para>
This oversight made it possible to bypass denial of EXECUTE
permission on a function.</para></listitem>
<listitem><para>Fix security and 64-bit issues in
contrib/intagg</para></listitem>
<listitem><para>Add needed STRICT marking to some contrib functions (Kris
Jurka)</para></listitem>
<listitem><para>Avoid buffer overrun when plpgsql cursor declaration has too
many parameters (Neil)</para></listitem>
<listitem><para>Make <command>ALTER TABLE ADD COLUMN</> enforce domain
constraints in all cases</para></listitem>
<listitem><para>Fix planning error for FULL and RIGHT outer joins</para>
<para>
The result of the join was mistakenly supposed to be sorted the same as the
left input.  This could not only deliver mis-sorted output to the user, but
in case of nested merge joins could give outright wrong answers.
</para></listitem>
<listitem><para>Improve planning of grouped aggregate queries</para></listitem>
<listitem><para><command>ROLLBACK TO <replaceable>savepoint</></command>
closes cursors created since the savepoint</para></listitem>
<listitem><para>Fix inadequate backend stack size on Windows</para></listitem>
<listitem><para>Avoid SHGetSpecialFolderPath() on Windows
(Magnus)</para></listitem>
<listitem><para>Fix some problems in running pg_autovacuum as a Windows
service (Dave Page)</para></listitem>
<listitem><para>Multiple minor bug fixes in
pg_dump/pg_restore</para></listitem>
<listitem><para>Fix ecpg segfault with named structs used in
typedefs (Michael)</para></listitem>
</itemizedlist>

  </sect2>
 </sect1>

 <sect1 id="release-8-0">
  <title>Release 8.0</title>

  <note>
   <title>Release Date</title>
   <simpara>2005-01-19</simpara>
  </note>

  <sect2>
   <title>Overview</title>

   <para>
    Major changes in this release:
   </para>

   <variablelist>
    <varlistentry>
     <term>
      Microsoft Windows Native Server
     </term>

     <listitem>
      <para>
       This is the first <productname>PostgreSQL</productname> release
       to run natively on <trademark class="registered">Microsoft Windows</> as
       a server. It can run as a <productname>Windows</> service. This
       release supports NT-based Windows releases like
       <productname>Windows 2000 SP4</>, <productname>Windows XP</>, and
       <productname>Windows 2003</>. Older releases like
       <productname>Windows 95</>, <productname>Windows 98</>, and
       <productname>Windows ME</> are not supported because these operating
       systems do not have the infrastructure to support
       <productname>PostgreSQL</productname>. A separate installer
       project has been created to ease installation on
       <productname>Windows</> &mdash; see <ulink
       url="http://www.postgresql.org/ftp/win32/"></ulink>.
      </para>

      <para>
       Although tested throughout our release cycle, the Windows port
       does not have the benefit of years of use in production
       environments that <productname>PostgreSQL</productname> has on
       Unix platforms.  Therefore it should be treated with the same
       level of caution as you would a new product.
      </para>

      <para>
       Previous releases required the Unix emulation toolkit
       <productname>Cygwin</> in order to run the server on Windows
       operating systems.  <productname>PostgreSQL</productname> has
       supported native clients on Windows for many years.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry>
     <term>
      Savepoints
     </term>

     <listitem>
      <para>
       Savepoints allow specific parts of a transaction to be aborted
       without affecting the remainder of the transaction. Prior
       releases had no such capability; there was no way to recover
       from a statement failure within a transaction except by
       aborting the whole transaction. This feature is valuable for
       application writers who require error recovery within a
       complex transaction.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry>
     <term>
      Point-In-Time Recovery
     </term>

     <listitem>
      <para>
       In previous releases there was no way to recover from disk
       drive failure except to restore from a previous backup or use
       a standby replication server.  Point-in-time recovery allows
       continuous backup of the server.  You can recover either to
       the point of failure or to some transaction in the past.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry>
     <term>
      Tablespaces
     </term>

     <listitem>
      <para>
       Tablespaces allow administrators to select different file systems
       for storage of individual tables, indexes, and databases.
       This improves performance and control over disk space
       usage. Prior releases used <application>initlocation</> and
       manual symlink management for such tasks.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry>
     <term>
      Improved Buffer Management, <command>CHECKPOINT</command>,
      <command>VACUUM</command>
     </term>

     <listitem>
      <para>
       This release has a more intelligent buffer replacement strategy,
       which will make better use of available shared buffers and
       improve performance. The performance impact of vacuum and
       checkpoints is also lessened.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry>
     <term>
      Change Column Types
     </term>

     <listitem>
      <para>
       A column's data type can now be changed with <command>ALTER
       TABLE</command>.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry>
     <term>
      New Perl Server-Side Language
     </term>

     <listitem>
      <para>
       A new version of the <application>plperl</> server-side language now
       supports a persistent shared storage area, triggers, returning records
       and arrays of records, and SPI calls to access the database.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry>
     <term>
       Comma-separated-value (CSV) support in <command>COPY</command>
     </term>

     <listitem>
      <para>
       <command>COPY</command> can now read and write
       comma-separated-value files. It has the flexibility to
       interpret nonstandard quoting and separation characters too.
      </para>
     </listitem>
    </varlistentry>

   </variablelist>
  </sect2>

  <sect2>
   <title>Migration to Version 8.0</title>

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

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

   <itemizedlist>

    <listitem>
     <para>
      In <option>READ COMMITTED</> serialization mode, volatile functions
      now see the results of concurrent transactions committed up to the
      beginning of each statement within the function, rather than up to the
      beginning of the interactive command that called the function.
     </para>
    </listitem>

    <listitem>
     <para>
      Functions declared <option>STABLE</> or <option>IMMUTABLE</> always
      use the snapshot of the calling query, and therefore do not see the
      effects of actions taken after the calling query starts, whether in
      their own transaction or other transactions.  Such a function must be
      read-only, too, meaning that it cannot use any SQL commands other than
      <command>SELECT</>.
     </para>
    </listitem>

    <listitem>
     <para>
      Nondeferred <option>AFTER</> triggers are now fired immediately
      after completion of the triggering query, rather than upon
      finishing the current interactive command. This makes a
      difference when the triggering query occurred within a function:
      the trigger is invoked before the function proceeds to its next
      operation.
     </para>
    </listitem>

    <listitem>
     <para>
      Server configuration parameters <varname>virtual_host</> and
      <varname>tcpip_socket</> have been replaced with a more general
      parameter <varname>listen_addresses</>. Also, the server now listens on
      <literal>localhost</> by default, which eliminates the need for the
      <literal>-i</> postmaster switch in many scenarios.
     </para>
    </listitem>

    <listitem>
     <para>
      Server configuration parameters <varname>SortMem</> and
      <varname>VacuumMem</> have been renamed to <varname>work_mem</>
      and <varname>maintenance_work_mem</> to better reflect their
      use. The original names are still supported in
      <command>SET</command> and <command>SHOW</command>.
     </para>
    </listitem>

    <listitem>
     <para>
      Server configuration parameters <varname>log_pid</>,
      <varname>log_timestamp</>, and <varname>log_source_port</> have been
      replaced with a more general parameter <varname>log_line_prefix</>.
     </para>
    </listitem>

    <listitem>
     <para>
      Server configuration parameter <varname>syslog</> has been
      replaced with a more logical <varname>log_destination</> variable to
      control the log output destination.
     </para>
    </listitem>

    <listitem>
     <para>
      Server configuration parameter <varname>log_statement</> has been
      changed so it can selectively log just database modification or
      data definition statements.  Server configuration parameter
      <varname>log_duration</> now prints only when <varname>log_statement</>
      prints the query.
     </para>
    </listitem>

    <listitem>
     <para>
      Server configuration parameter <varname>max_expr_depth</> parameter has
      been replaced with <varname>max_stack_depth</> which measures the
      physical stack size rather than the expression nesting depth. This
      helps prevent session termination due to stack overflow caused by
      recursive functions.
     </para>
    </listitem>

    <listitem>
     <para>
      The <function>length()</> function no longer counts trailing spaces in
      <type>CHAR(n)</> values.
     </para>
    </listitem>

   <listitem>
    <para>
     Casting an integer to <type>BIT(N)</> selects the rightmost N bits of the
     integer, not the leftmost N bits as before.
    </para>
   </listitem>

   <listitem>
    <para>
     Updating an element or slice of a NULL array value now produces
     a nonnull array result, namely an array containing
     just the assigned-to positions.
    </para>
   </listitem>

    <listitem>
     <para>
      Syntax checking of array input values has been tightened up
      considerably. Junk that was previously allowed in odd places with
      odd results now causes an error. Empty-string element values
      must now be written as <literal>""</>, rather than writing nothing.
      Also changed behavior with respect to whitespace surrounding
      array elements: trailing whitespace is now ignored, for symmetry
      with leading whitespace (which has always been ignored).
     </para>
    </listitem>

    <listitem>
     <para>
      Overflow in integer arithmetic operations is now detected and
      reported as an error.
     </para>
    </listitem>

    <listitem>
     <para>
      The arithmetic operators associated with the single-byte
      <type>"char"</> data type have been removed.
     </para>
    </listitem>

    <listitem>
     <para>
      The <function>extract()</> function (also called
      <function>date_part</>) now returns the proper year for BC dates.
      It previously returned one less than the correct year. The
      function now also returns the proper values for millennium and
      century.
     </para>
    </listitem>

   <listitem>
    <para>
     <type>CIDR</> values now must have their nonmasked bits be zero.
     For example, we no longer allow
     <literal>204.248.199.1/31</literal> as a <type>CIDR</> value. Such
     values should never have been accepted by
     <productname>PostgreSQL</productname> and will now be rejected.
    </para>
   </listitem>

    <listitem>
     <para>
      <command>EXECUTE</command> now returns a completion tag that
      matches the executed statement.
     </para>
    </listitem>

    <listitem>
     <para>
      <application>psql</>'s <command>\copy</> command now reads or
      writes to the query's <literal>stdin/stdout</>, rather than
      <application>psql</>'s <literal>stdin/stdout</>. The previous
      behavior can be accessed via new
      <option>pstdin</>/<option>pstdout</> parameters.
     </para>
    </listitem>

    <listitem>
     <para>
     The JDBC client interface has been removed from the core
     distribution, and is now hosted at <ulink url=
     "http://jdbc.postgresql.org"></ulink>.
     </para>
    </listitem>

    <listitem>
     <para>
     The Tcl client interface has also been removed. There are several
     Tcl interfaces now hosted at <ulink url=
     "http://gborg.postgresql.org"></ulink>.
     </para>
    </listitem>

    <listitem>
     <para>
      The server now uses its own time zone database, rather than the
      one supplied by the operating system. This will provide consistent
      behavior across all platforms.  In most cases, there should be
      little noticeable difference in time zone behavior, except that
      the time zone names used by <command>SET</>/<command>SHOW</>
      <varname>TimeZone</> might be different from what your platform provides.
     </para>
    </listitem>

    <listitem>
     <para>
      <application>Configure</>'s threading option no longer requires
      users to run tests or edit configuration files; threading options
      are now detected automatically.
     </para>
    </listitem>

    <listitem>
     <para>
      Now that tablespaces have been implemented,
      <application>initlocation</> has been removed.
     </para>
    </listitem>

    <listitem>
     <para>
      The API for user-defined GiST indexes has been changed. The
      Union and PickSplit methods are now passed a pointer to a
      special <structname>GistEntryVector</structname> structure,
      rather than a <type>bytea</type>.
     </para>
    </listitem>

   </itemizedlist>
  </sect2>

 <sect2>
  <title>Deprecated Features</title>

  <para>
    Some aspects of <productname>PostgreSQL</productname>'s behavior
    have been determined to be suboptimal. For the sake of backward
    compatibility these have not been removed in 8.0, but they are
    considered deprecated and will be removed in the next major
    release.
    </para>

   <itemizedlist>
    <listitem>
     <para>
      The 8.1 release will remove the <function>to_char()</> function
      for intervals.
     </para>
    </listitem>

     <listitem>
      <para>
       The server now warns of empty strings passed to
       <type>oid</type>/<type>float4</type>/<type>float8</type> data
       types, but continues to interpret them as zeroes as before.
       In the next major release, empty strings will be considered
       invalid input for these data types.
      </para>
     </listitem>

    <listitem>
     <para>
      By default, tables in <productname>PostgreSQL</productname> 8.0
      and earlier are created with <type>OID</>s. In the next release,
      this will <emphasis>not</emphasis> be the case: to create a table
      that contains <type>OID</>s, the <option>WITH OIDS</> clause must
      be specified or the <varname>default_with_oids</varname>
      configuration parameter must be set. Users are encouraged to
      explicitly specify <option>WITH OIDS</> if their tables
      require OIDs for compatibility with future releases of
      <productname>PostgreSQL</productname>.
     </para>
    </listitem>

   </itemizedlist>
  </sect2>

  <sect2>
   <title>Changes</title>

   <para>
    Below you will find a detailed account of the changes between
    release 8.0 and the previous major release.
   </para>

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

     <listitem>
      <para>
       Support cross-data-type index usage (Tom)
      </para>
      <para>
       Before this change, many queries would not use an index if the data
       types did not match exactly. This improvement makes index usage more
       intuitive and consistent.
      </para>
     </listitem>

     <listitem>
      <para>
       New buffer replacement strategy that improves caching (Jan)
      </para>
      <para>
       Prior releases used a least-recently-used (LRU) cache to keep
       recently referenced pages in memory. The LRU algorithm
       did not consider the number of times a specific cache entry was
       accessed, so large table scans could force out useful cache pages.
       The new cache algorithm uses four separate lists to track most
       recently used and most frequently used cache pages and dynamically
       optimize their replacement based on the work load. This should
       lead to much more efficient use of the shared buffer cache.
       Administrators who have tested shared buffer sizes in the past
       should retest with this new cache replacement policy.
      </para>
     </listitem>

     <listitem>
      <para>
       Add subprocess to write dirty buffers periodically to reduce
       checkpoint writes (Jan)
      </para>
      <para>
       In previous releases, the checkpoint process, which runs every few
       minutes, would write all dirty buffers to the operating system's
       buffer cache then flush all dirty operating system buffers to
       disk. This resulted in a periodic spike in disk usage that often
       hurt performance. The new code uses a background writer to trickle
       disk writes at a steady pace so checkpoints have far fewer dirty
       pages to write to disk. Also, the new code does not issue a global
       <function>sync()</> call, but instead <function>fsync()</>s just
       the files written since the last checkpoint. This should improve
       performance and minimize degradation during checkpoints.
      </para>
     </listitem>

     <listitem>
      <para>
       Add ability to prolong vacuum to reduce performance impact (Jan)
      </para>
      <para>
       On busy systems, <command>VACUUM</command> performs many I/O
       requests which can hurt performance for other users. This
       release allows you to slow down <command>VACUUM</command> to
       reduce its impact on other users, though this increases the
       total duration of <command>VACUUM</command>.
      </para>
     </listitem>

     <listitem>
      <para>
       Improve B-tree index performance for duplicate keys (Dmitry Tkach, Tom)
      </para>
      <para>
       This improves the way indexes are scanned when many duplicate
       values exist in the index.
      </para>
     </listitem>

     <listitem>
      <para>
       Use dynamically-generated table size estimates while planning (Tom)
      </para>
      <para>
       Formerly the planner estimated table sizes using the values seen
       by the last <command>VACUUM</command> or <command>ANALYZE</command>,
       both as to physical table size (number of pages) and number of rows.
       Now, the current physical table size is obtained from the kernel,
       and the number of rows is estimated by multiplying the table size
       by the row density (rows per page) seen by the last
       <command>VACUUM</command> or <command>ANALYZE</command>.  This should
       produce more reliable estimates in cases where the table size has
       changed significantly since the last housekeeping command.
      </para>
     </listitem>

     <listitem>
      <para>
       Improved index usage with <literal>OR</> clauses (Tom)
      </para>
      <para>
       This allows the optimizer to use indexes in statements with many OR
       clauses that would not have been indexed in the past.  It can also use
       multi-column indexes where the first column is specified and the second
       column is part of an <literal>OR</> clause.
      </para>
     </listitem>

     <listitem>
      <para>
       Improve matching of partial index clauses (Tom)
      </para>
      <para>
       The server is now smarter about using partial indexes in queries
       involving complex <option>WHERE</> clauses.
      </para>
     </listitem>

     <listitem>
      <para>
       Improve performance of the GEQO optimizer (Tom)
      </para>
      <para>
       The GEQO optimizer is used to plan queries involving many tables (by
       default, twelve or more). This release speeds up the way queries are
       analyzed to decrease time spent in optimization.
      </para>
     </listitem>

     <listitem>
      <para>
       Miscellaneous optimizer improvements
      </para>
      <para>
       There is not room here to list all the minor improvements made, but
       numerous special cases work better than in prior releases.
      </para>
     </listitem>

     <listitem>
      <para>
       Improve lookup speed for C functions (Tom)
      </para>
      <para>
       This release uses a hash table to lookup information for dynamically
       loaded C functions. This improves their speed so they perform nearly as
       quickly as functions that are built into the server executable.
      </para>
     </listitem>

     <listitem>
      <para>
       Add type-specific <command>ANALYZE</command> statistics
       capability (Mark Cave-Ayland)
      </para>
      <para>
       This feature allows more flexibility in generating statistics
       for nonstandard data types.
      </para>
     </listitem>

     <listitem>
      <para>
       <command>ANALYZE</command> now collects statistics for
       expression indexes (Tom)
      </para>
      <para>
       Expression indexes (also called functional indexes) allow users to
       index not just columns but the results of expressions and function
       calls. With this release, the optimizer can gather and use statistics
       about the contents of expression indexes.  This will greatly improve
       the quality of planning for queries in which an expression index is
       relevant.
      </para>
     </listitem>

     <listitem>
      <para>
       New two-stage sampling method for <command>ANALYZE</command>
       (Manfred Koizar)
      </para>
      <para>
       This gives better statistics when the density of valid rows is very
       different in different regions of a table.
      </para>
     </listitem>

     <listitem>
      <para>
       Speed up <command>TRUNCATE</command> (Tom)
      </para>
      <para>
       This buys back some of the performance loss observed in 7.4, while still
       keeping <command>TRUNCATE</command> transaction-safe.
      </para>
     </listitem>

    </itemizedlist>
   </sect3>


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

     <listitem>
      <para>
       Add WAL file archiving and point-in-time recovery (Simon Riggs)
      </para>
     </listitem>

     <listitem>
      <para>
       Add tablespaces so admins can control disk layout (Gavin)
      </para>
     </listitem>

     <listitem>
      <para>
       Add a built-in log rotation program (Andreas Pflug)
      </para>
      <para>
       It is now possible to log server messages conveniently without
       relying on either <application>syslog</> or an external log
       rotation program.
      </para>
     </listitem>

     <listitem>
      <para>
       Add new read-only server configuration parameters to show server
       compile-time settings: <varname>block_size</>,
       <varname>integer_datetimes</>, <varname>max_function_args</>,
       <varname>max_identifier_length</>, <varname>max_index_keys</>  (Joe)
      </para>
     </listitem>

     <listitem>
      <para>
       Make quoting of <literal>sameuser</>, <literal>samegroup</>, and
       <literal>all</> remove special meaning of these terms in
       <filename>pg_hba.conf</> (Andrew)
      </para>
     </listitem>

     <listitem>
      <para>
       Use clearer IPv6 name <literal>::1/128</> for
       <literal>localhost</> in default <filename>pg_hba.conf</> (Andrew)
      </para>
     </listitem>

     <listitem>
      <para>
       Use CIDR format in <filename>pg_hba.conf</> examples (Andrew)
      </para>
     </listitem>

     <listitem>
      <para>
       Rename server configuration parameters <varname>SortMem</> and
       <varname>VacuumMem</> to <varname>work_mem</> and
       <varname>maintenance_work_mem</> (Old names still supported) (Tom)
      </para>
      <para>
       This change was made to clarify that bulk operations such as index and
       foreign key creation use <varname>maintenance_work_mem</>, while
       <varname>work_mem</> is for workspaces used during query execution.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow logging of session disconnections using server configuration
       <varname>log_disconnections</> (Andrew)
      </para>
     </listitem>

     <listitem>
      <para>
       Add new server configuration parameter <varname>log_line_prefix</> to
       allow control of information emitted in each log line (Andrew)
      </para>
      <para>
       Available information includes user name, database name, remote IP
       address, and session start time.
      </para>
     </listitem>

     <listitem>
      <para>
       Remove server configuration parameters <varname>log_pid</>,
       <varname>log_timestamp</>, <varname>log_source_port</>; functionality
       superseded by <varname>log_line_prefix</> (Andrew)
      </para>
     </listitem>

     <listitem>
      <para>
       Replace the <varname>virtual_host</> and <varname>tcpip_socket</>
       parameters with a unified <varname>listen_addresses</> parameter
       (Andrew, Tom)
      </para>
      <para>
       <varname>virtual_host</> could only specify a single IP address to
       listen on.  <varname>listen_addresses</> allows multiple addresses
       to be specified.
      </para>
     </listitem>

     <listitem>
      <para>
       Listen on localhost by default, which eliminates the need for the
       <option>-i</> postmaster switch in many scenarios (Andrew)
      </para>
      <para>
       Listening on localhost (<literal>127.0.0.1</>) opens no new
       security holes but allows configurations like Windows and JDBC,
       which do not support local sockets, to work without special
       adjustments.
      </para>
     </listitem>

     <listitem>
      <para>
       Remove <varname>syslog</> server configuration parameter, and add more
       logical <varname>log_destination</> variable to control log output
       location (Magnus)
      </para>
     </listitem>

     <listitem>
      <para>
       Change server configuration parameter <varname>log_statement</> to take
       values <varname>all</>, <varname>mod</>, <varname>ddl</>, or
       <varname>none</> to select which queries are logged (Bruce)
      </para>
      <para>
       This allows administrators to log only data definition changes or
       only data modification statements.
      </para>
     </listitem>

     <listitem>
      <para>
       Some logging-related configuration parameters could formerly be adjusted
       by ordinary users, but only in the <quote>more verbose</> direction.
       They are now treated more strictly: only superusers can set them.
       However, a superuser can use <command>ALTER USER</> to provide per-user
       settings of these values for non-superusers.  Also, it is now possible
       for superusers to set values of superuser-only configuration parameters
       via <literal>PGOPTIONS</>.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow configuration files to be placed outside the data directory (mlw)
      </para>
      <para>
       By default, configuration files are kept in the cluster's top directory.
       With this addition, configuration files can be placed outside the
       data directory, easing administration.
      </para>
     </listitem>

     <listitem>
      <para>
       Plan prepared queries only when first executed so constants can be
       used for statistics (Oliver Jowett)
      </para>
      <para>
       Prepared statements plan queries once and execute them many
       times. While prepared queries avoid the overhead of re-planning
       on each use, the quality of the plan suffers from not knowing the exact
       parameters to be used in the query.  In this release, planning of
       unnamed prepared statements is delayed until the first execution,
       and the actual parameter values of that execution are used as
       optimization hints.  This allows use of out-of-line parameter passing
       without incurring a performance penalty.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <command>DECLARE CURSOR</command> to take parameters
       (Oliver Jowett)
      </para>
      <para>
       It is now useful to issue <command>DECLARE CURSOR</command> in a
       <function>Parse</> message with parameters. The parameter values
       sent at <function>Bind</> time will be substituted into the
       execution of the cursor's query.
      </para>
     </listitem>

     <listitem>
      <para>
       Fix hash joins and aggregates of <type>inet</type> and
       <type>cidr</type> data types (Tom)
      </para>
      <para>
       Release 7.4 handled hashing of mixed <type>inet</type> and
       <type>cidr</type> values incorrectly.  (This bug did not exist
       in prior releases because they wouldn't try to hash either
       data type.)
      </para>
     </listitem>

     <listitem>
      <para>
       Make <varname>log_duration</> print only when <varname>log_statement</>
       prints the query (Ed L.)
      </para>
     </listitem>

    </itemizedlist>
   </sect3>


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

     <listitem>
      <para>
       Add savepoints (nested transactions) (Alvaro)
      </para>
     </listitem>

     <listitem>
      <para>
       Unsupported isolation levels are now accepted and promoted to the
       nearest supported level (Peter)
      </para>
      <para>
       The SQL specification states that if a database doesn't support a
       specific isolation level, it should use the next more restrictive level.
       This change complies with that recommendation.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <command>BEGIN WORK</command> to specify transaction
       isolation levels like <command>START TRANSACTION</command> does
       (Bruce)
      </para>
     </listitem>

     <listitem>
      <para>
       Fix table permission checking for cases in which rules generate
       a query type different from the originally submitted query (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Implement dollar quoting to simplify single-quote usage (Andrew, Tom,
       David Fetter)
      </para>
      <para>
       In previous releases, because single quotes had to be used to
       quote a function's body, the use of single quotes inside the
       function text required use of two single quotes or other error-prone
       notations. With this release we add the ability to use "dollar
       quoting" to quote a block of text.  The ability to use different
       quoting delimiters at different nesting levels greatly simplifies
       the task of quoting correctly, especially in complex functions.
       Dollar quoting can be used anywhere quoted text is needed.
      </para>
     </listitem>

     <listitem>
      <para>
       Make <literal>CASE val WHEN compval1 THEN ...</> evaluate <literal>val</> only once (Tom)
      </para>
      <para>
       <option>CASE</> no longer evaluates the tested expression multiple
       times. This has benefits when the expression is complex or is
       volatile.
      </para>
     </listitem>

     <listitem>
      <para>
       Test <option>HAVING</> before computing target list of an
       aggregate query (Tom)
      </para>
      <para>
       Fixes improper failure of cases such as <literal>SELECT SUM(win)/SUM(lose)
       ... GROUP BY ... HAVING SUM(lose) &gt; 0</>.  This should work but formerly
       could fail with divide-by-zero.
      </para>
     </listitem>

     <listitem>
      <para>
       Replace <varname>max_expr_depth</> parameter with
       <varname>max_stack_depth</> parameter, measured in kilobytes of stack
       size (Tom)
      </para>
      <para>
      This gives us a fairly bulletproof defense against crashing due to
      runaway recursive functions. Instead of measuring the depth of expression
      nesting, we now directly measure the size of the execution stack.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow arbitrary row expressions (Tom)
      </para>
      <para>
       This release allows SQL expressions to contain arbitrary composite
       types, that is, row values. It also allows functions to more easily
       take rows as arguments and return row values.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <option>LIKE</>/<option>ILIKE</> to be used as the operator
       in row and subselect comparisons (Fabien Coelho)
      </para>
     </listitem>

     <listitem>
      <para>
       Avoid locale-specific case conversion of basic ASCII letters in
       identifiers and keywords (Tom)
      </para>
      <para>
       This solves the <quote>Turkish problem</> with mangling of words
       containing <literal>I</> and  <literal>i</>.  Folding of characters
       outside the 7-bit-ASCII set is still locale-aware.
      </para>
     </listitem>

     <listitem>
      <para>
       Improve syntax error reporting (Fabien, Tom)
      </para>
      <para>
       Syntax error reports are more useful than before.
      </para>
     </listitem>

     <listitem>
      <para>
       Change <command>EXECUTE</command> to return a completion tag
       matching the executed statement (Kris Jurka)
      </para>
      <para>
       Previous releases return an <command>EXECUTE</command> tag for
       any <command>EXECUTE</command> call. In this release, the tag
       returned will reflect the command executed.
      </para>
     </listitem>

     <listitem>
      <para>
       Avoid emitting <option>NATURAL CROSS JOIN</> in rule listings (Tom)
      </para>
      <para>
       Such a clause makes no logical sense, but in some cases the rule
       decompiler formerly produced this syntax.
      </para>
     </listitem>

    </itemizedlist>
   </sect3>


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

     <listitem>
      <para>
       Add <command>COMMENT ON</> for casts, conversions, languages,
       operator classes, and large objects (Christopher)
      </para>
     </listitem>

     <listitem>
      <para>
       Add new server configuration parameter <varname>default_with_oids</> to
       control whether tables are created with <type>OID</>s by default (Neil)
      </para>
      <para>
       This allows administrators to control whether <command>CREATE
       TABLE</command> commands create tables with or without <type>OID</>
       columns by default.  (Note: the current factory default setting for
       <varname>default_with_oids</> is <literal>TRUE</>, but the default
       will become <literal>FALSE</> in future releases.)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <option>WITH</> / <option>WITHOUT OIDS</> clause to
       <command>CREATE TABLE AS</command> (Neil)
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <command>ALTER TABLE DROP COLUMN</> to drop an <type>OID</>
       column (<command>ALTER TABLE SET WITHOUT OIDS</> still works)
       (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Allow composite types as table columns (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <command>ALTER ... ADD COLUMN</> with defaults and
       <option>NOT NULL</> constraints; works per SQL spec (Rod)
      </para>
      <para>
       It is now possible for <option>ADD COLUMN</> to create a column
       that is not initially filled with NULLs, but with a specified
       default value.
      </para>
     </listitem>

     <listitem>
      <para>
       Add <command>ALTER COLUMN TYPE</> to change column's type (Rod)
      </para>
      <para>
       It is now possible to alter a column's data type without dropping
       and re-adding the column.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow multiple <command>ALTER</> actions in a single <command>ALTER
       TABLE</command> command (Rod)
      </para>
      <para>
       This is particularly useful for <command>ALTER</> commands that
       rewrite the table (which include <option>ALTER COLUMN TYPE</> and
       <option>ADD COLUMN</> with a default). By grouping
       <command>ALTER</> commands together, the table need be rewritten
       only once.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <command>ALTER TABLE</command> to add <type>SERIAL</type>
       columns (Tom)
      </para>
      <para>
       This falls out from the new capability of specifying defaults for new
       columns.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow changing the owners of aggregates, conversions, databases,
       functions, operators, operator classes, schemas, types, and tablespaces
       (Christopher, Euler Taveira de Oliveira)
      </para>
      <para>
       Previously this required modifying the system tables directly.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow temporary object creation to be limited to <option>SECURITY
       DEFINER</> functions (Sean Chittenden)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <option>ALTER TABLE ... SET WITHOUT CLUSTER</> (Christopher)
      </para>
      <para>
       Prior to this release, there was no way to clear an auto-cluster
       specification except to modify the system tables.
      </para>
     </listitem>

     <listitem>
      <para>
       Constraint/Index/<type>SERIAL</> names are now
       <replaceable>table_column_type</>
       with numbers appended to guarantee uniqueness within the schema
       (Tom)
      </para>
      <para>
       The SQL specification states that such names should be unique
       within a schema.
      </para>
     </listitem>

     <listitem>
      <para>
       Add <function>pg_get_serial_sequence()</> to return a
       <type>SERIAL</> column's sequence name (Christopher)
      </para>
      <para>
       This allows automated scripts to reliably find the <type>SERIAL</>
       sequence name.
      </para>
     </listitem>

     <listitem>
      <para>
       Warn when primary/foreign key data type mismatch requires costly lookup
      </para>
     </listitem>

     <listitem>
      <para>
       New <command>ALTER INDEX</> command to allow moving of indexes
       between tablespaces (Gavin)
      </para>
     </listitem>

     <listitem>
      <para>
       Make <command>ALTER TABLE OWNER</> change dependent sequence
       ownership too (Alvaro)
      </para>
     </listitem>


    </itemizedlist>
   </sect3>


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

     <listitem>
      <para>
       Allow <command>CREATE SCHEMA</command> to create triggers,
       indexes, and sequences (Neil)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <option>ALSO</> keyword to <command>CREATE RULE</command> (Fabien
       Coelho)
      </para>
      <para>
       This allows <option>ALSO</> to be added to rule creation to contrast it with
       <option>INSTEAD</> rules.
      </para>
     </listitem>

     <listitem>
      <para>
       Add <option>NOWAIT</> option to <command>LOCK</command> (Tatsuo)
      </para>
      <para>
       This allows the <command>LOCK</command> command to fail if it
       would have to wait for the requested lock.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <command>COPY</command> to read and write
       comma-separated-value (CSV) files (Andrew, Bruce)
      </para>
     </listitem>

     <listitem>
      <para>
       Generate error if the <command>COPY</command> delimiter and NULL
       string conflict (Bruce)
      </para>
     </listitem>

     <listitem>
      <para>
       <command>GRANT</command>/<command>REVOKE</command> behavior
       follows the SQL spec more closely
      </para>
     </listitem>

     <listitem>
      <para>
       Avoid locking conflict between <command>CREATE INDEX</command>
       and <command>CHECKPOINT</command> (Tom)
      </para>
      <para>
       In 7.3 and 7.4, a long-running B-tree index build could block concurrent
       <command>CHECKPOINT</>s from completing, thereby causing WAL bloat because the
       WAL log could not be recycled.
      </para>
     </listitem>

     <listitem>
      <para>
       Database-wide <command>ANALYZE</command> does not hold locks
       across tables (Tom)
      </para>
      <para>
       This reduces the potential for deadlocks against other backends
       that want exclusive locks on tables.  To get the benefit of this
       change, do not execute database-wide <command>ANALYZE</command>
       inside a transaction block (<command>BEGIN</command> block); it
       must be able to commit and start a new transaction for each
       table.
      </para>
     </listitem>

     <listitem>
      <para>
       <command>REINDEX</command> does not exclusively lock the index's
       parent table anymore
      </para>
      <para>
       The index itself is still exclusively locked, but readers of the
       table can continue if they are not using the particular index
       being rebuilt.
      </para>
     </listitem>

     <listitem>
      <para>
       Erase MD5 user passwords when a user is renamed (Bruce)
      </para>
      <para>
       <productname>PostgreSQL</productname> uses the user name as salt
       when encrypting passwords via MD5. When a user's name is changed,
       the salt will no longer match the stored MD5 password, so the
       stored password becomes useless.  In this release a notice is
       generated and the password is cleared.  A new password must then
       be assigned if the user is to be able to log in with a password.
      </para>
     </listitem>

     <listitem>
      <para>
       New <application>pg_ctl</> <option>kill</> option for Windows (Andrew)
      </para>
      <para>
       Windows does not have a <literal>kill</> command to send signals to
       backends so this capability was added to <application>pg_ctl</>.
      </para>
     </listitem>

     <listitem>
      <para>
       Information schema improvements
      </para>
     </listitem>

     <listitem>
      <para>
       Add <option>--pwfile</> option to
       <application>initdb</application> so the initial password can be
       set by GUI tools (Magnus)
      </para>
     </listitem>

     <listitem>
      <para>
       Detect locale/encoding mismatch in
       <application>initdb</application> (Peter)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <option>register</> command to <application>pg_ctl</> to
       register Windows operating system service (Dave Page)
      </para>
     </listitem>

    </itemizedlist>
   </sect3>


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

     <listitem>
      <para>
       More complete support for composite types (row types)  (Tom)
      </para>
      <para>
       Composite values can be used in many places where only scalar values
       worked before.
      </para>
     </listitem>

     <listitem>
      <para>
       Reject nonrectangular array values as erroneous (Joe)
      </para>
      <para>
       Formerly, <function>array_in</> would silently build a
       surprising result.
      </para>
     </listitem>

      <listitem>
       <para>
        Overflow in integer arithmetic operations is now detected (Tom)
       </para>
      </listitem>

      <listitem>
       <para>
        The arithmetic operators associated with the single-byte
        <type>"char"</> data type have been removed.
       </para>
       <para>
        Formerly, the parser would select these operators in many situations
        where an <quote>unable to select an operator</> error would be more
        appropriate, such as <literal>null * null</>.  If you actually want
        to do arithmetic on a <type>"char"</> column, you can cast it to
        integer explicitly.
       </para>
      </listitem>

     <listitem>
       <para>
        Syntax checking of array input values considerably tightened up (Joe)
       </para>
      <para>
        Junk that was previously allowed in odd places with odd results
        now causes an <literal>ERROR</>, for example, non-whitespace
        after the closing right brace.
       </para>
     </listitem>

     <listitem>
       <para>
        Empty-string array element values must now be written as
        <literal>""</>, rather than writing nothing (Joe)
       </para>
      <para>
        Formerly, both ways of writing an empty-string element value were
        allowed, but now a quoted empty string is required.  The case where
        nothing at all appears will probably be considered to be a NULL
        element value in some future release.
       </para>
     </listitem>

     <listitem>
       <para>
        Array element trailing whitespace is now ignored (Joe)
       </para>
      <para>
        Formerly leading whitespace was ignored, but trailing whitespace
        between an element value and the delimiter or right brace was
        significant.  Now trailing whitespace is also ignored.
       </para>
     </listitem>

     <listitem>
      <para>
       Emit array values with explicit array bounds when lower bound is not one
       (Joe)
      </para>
     </listitem>

     <listitem>
      <para>
       Accept <literal>YYYY-monthname-DD</> as a date string (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Make <function>netmask</> and <function>hostmask</> functions
       return maximum-length mask length (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Change factorial function to return <type>numeric</type> (Gavin)
      </para>
      <para>
       Returning <type>numeric</type> allows the factorial function to
       work for a wider range of input values.
      </para>
     </listitem>

     <listitem>
      <para>
       <function>to_char</>/<function>to_date()</> date conversion
       improvements (Kurt Roeckx, Fabien Coelho)
      </para>
     </listitem>

     <listitem>
      <para>
       Make <function>length()</> disregard trailing spaces in
       <type>CHAR(n)</> (Gavin)
      </para>
      <para>
       This change was made to improve consistency: trailing spaces are
       semantically insignificant in <type>CHAR(n)</> data, so they
       should not be counted by <function>length()</>.
      </para>
     </listitem>

     <listitem>
      <para>
       Warn about empty string being passed to
       <type>OID</>/<type>float4</>/<type>float8</> data types (Neil)
      </para>
      <para>
       8.1 will throw an error instead.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow leading or trailing whitespace in
       <type>int2</>/<type>int4</>/<type>int8</>/<type>float4</>/<type>float8</>
       input routines
       (Neil)
      </para>
     </listitem>

     <listitem>
      <para>
       Better support for IEEE <literal>Infinity</> and <literal>NaN</>
       values in <type>float4</type>/<type>float8</type> (Neil)
      </para>
      <para>
       These should now work on all platforms that support IEEE-compliant
       floating point arithmetic.
      </para>
     </listitem>

     <listitem>
      <para>
       Add <option>week</> option to <function>date_trunc()</> (Robert Creager)
      </para>
     </listitem>

     <listitem>
      <para>
       Fix <function>to_char</function> for <literal>1 BC</>
       (previously it returned <literal>1 AD</>) (Bruce)
      </para>
     </listitem>

     <listitem>
      <para>
       Fix <function>date_part(year)</> for BC dates (previously it
       returned one less than the correct year) (Bruce)
      </para>
     </listitem>

     <listitem>
      <para>
       Fix <function>date_part()</> to return the proper millennium and
       century (Fabien Coelho)
      </para>
      <para>
       In previous versions, the century and millennium results had a wrong
       number and started in the wrong year, as compared to standard
       reckoning of such things.
      </para>
     </listitem>

     <listitem>
      <para>
       Add <function>ceiling()</> as an alias for <function>ceil()</>,
       and <function>power()</> as an alias for <function>pow()</> for
       standards compliance (Neil)
      </para>
     </listitem>

     <listitem>
      <para>
       Change <function>ln()</>, <function>log()</>,
       <function>power()</>, and <function>sqrt()</> to emit the correct
       <literal>SQLSTATE</> error codes for certain error conditions, as
       specified by SQL:2003 (Neil)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <function>width_bucket()</> function as defined by SQL:2003 (Neil)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <function>generate_series()</> functions to simplify working
       with numeric sets (Joe)
      </para>
     </listitem>

     <listitem>
      <para>
       Fix <function>upper/lower/initcap()</> functions to work with
       multibyte encodings (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Add boolean and bitwise integer <option>AND</>/<option>OR</>
       aggregates (Fabien Coelho)
      </para>
     </listitem>

     <listitem>
      <para>
       New session information functions to return network addresses for client
       and server (Sean Chittenden)
      </para>
     </listitem>

     <listitem>
      <para>
       Add function to determine the area of a closed path (Sean Chittenden)
      </para>
     </listitem>

     <listitem>
      <para>
       Add function to send cancel request to other backends (Magnus)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <type>interval</> plus <type>datetime</> operators (Tom)
      </para>
      <para>
       The reverse ordering, <type>datetime</> plus <type>interval</>,
       was already supported, but both are required by the SQL standard.
      </para>
     </listitem>

     <listitem>
      <para>
       Casting an integer to <type>BIT(N)</> selects the rightmost N bits
       of the integer
       (Tom)
      </para>
      <para>
       In prior releases, the leftmost N bits were selected, but this was
       deemed unhelpful, not to mention inconsistent with casting from bit
       to int.
      </para>
     </listitem>

     <listitem>
      <para>
       Require <type>CIDR</> values to have all nonmasked bits be zero
       (Kevin Brintnall)
      </para>
     </listitem>

    </itemizedlist>
   </sect3>


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

     <listitem>
      <para>
       In <literal>READ COMMITTED</> serialization mode, volatile functions
       now see the results of concurrent transactions committed up to the
       beginning of each statement within the function, rather than up to the
       beginning of the interactive command that called the function.
      </para>
     </listitem>

     <listitem>
      <para>
       Functions declared <literal>STABLE</> or <literal>IMMUTABLE</> always
       use the snapshot of the calling query, and therefore do not see the
       effects of actions taken after the calling query starts, whether in
       their own transaction or other transactions.  Such a function must be
       read-only, too, meaning that it cannot use any SQL commands other than
       <command>SELECT</>.  There is a considerable performance gain from
       declaring a function <literal>STABLE</> or <literal>IMMUTABLE</>
       rather than <literal>VOLATILE</>.
      </para>
     </listitem>

     <listitem>
      <para>
       Nondeferred <option>AFTER</> triggers are now fired immediately
       after completion of the triggering query, rather than upon
       finishing the current interactive command. This makes a difference
       when the triggering query occurred within a function: the trigger
       is invoked before the function proceeds to its next operation. For
       example, if a function inserts a new row into a table, any
       nondeferred foreign key checks occur before proceeding with the
       function.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow function parameters to be declared with names (Dennis Bj&ouml;rklund)
      </para>
      <para>
       This allows better documentation of functions.  Whether the names
       actually do anything depends on the specific function language
       being used.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow PL/pgSQL parameter names to be referenced in the function (Dennis Bj&ouml;rklund)
      </para>
      <para>
       This basically creates an automatic alias for each named parameter.
      </para>
     </listitem>

     <listitem>
      <para>
       Do minimal syntax checking of PL/pgSQL functions at creation time (Tom)
      </para>
      <para>
       This allows us to catch simple syntax errors sooner.
      </para>
     </listitem>

     <listitem>
      <para>
       More support for composite types (row and record variables) in PL/pgSQL
      </para>
      <para>
       For example, it now works to pass a rowtype variable to another function
       as a single variable.
      </para>
     </listitem>

     <listitem>
      <para>
       Default values for PL/pgSQL variables can now reference previously
       declared variables
      </para>
     </listitem>

     <listitem>
      <para>
       Improve parsing of PL/pgSQL FOR loops (Tom)
      </para>
      <para>
       Parsing is now driven by presence of <literal>".."</> rather than
       data type of <option>FOR</> variable. This makes no difference for
       correct functions, but should result in more understandable error
       messages when a mistake is made.
      </para>
     </listitem>

     <listitem>
      <para>
       Major overhaul of PL/Perl server-side language (Command Prompt, Andrew Dunstan)
      </para>
     </listitem>

     <listitem>
      <para>
       In PL/Tcl, SPI commands are now run in subtransactions.  If an error
       occurs, the subtransaction is cleaned up and the error is reported
       as an ordinary Tcl error, which can be trapped with <literal>catch</>.
       Formerly, it was not possible to catch such errors.
      </para>
     </listitem>

     <listitem>
      <para>
       Accept <command>ELSEIF</> in PL/pgSQL (Neil)
      </para>
      <para>
       Previously PL/pgSQL only allowed <command>ELSIF</>, but many people
       are accustomed to spelling this keyword <command>ELSEIF</>.
      </para>
     </listitem>

    </itemizedlist>
   </sect3>


   <sect3>
    <title><application>psql</> Changes</title>
    <itemizedlist>

     <listitem>
      <para>
       Improve <application>psql</> information display about database
       objects (Christopher)
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <application>psql</> to display group membership in
       <command>\du</> and <command>\dg</> (Markus Bertheau)
      </para>
     </listitem>

     <listitem>
      <para>
       Prevent <application>psql</> <command>\dn</command> from showing
       temporary schemas (Bruce)
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <application>psql</> to handle tilde user expansion for file
       names (Zach Irmen)
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <application>psql</> to display fancy prompts, including
       color, via <application>readline</> (Reece Hart, Chet Ramey)
      </para>
     </listitem>

     <listitem>
      <para>
       Make <application>psql</> <command>\copy</> match <command>COPY</command> command syntax
       fully (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Show the location of syntax errors (Fabien Coelho, Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <command>CLUSTER</command> information to <application>psql</>
       <command>\d</> display
       (Bruce)
      </para>
     </listitem>

     <listitem>
      <para>
       Change <application>psql</> <command>\copy stdin/stdout</> to read
       from command input/output (Bruce)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <option>pstdin</>/<option>pstdout</> to read from
       <application>psql</>'s <literal>stdin</>/<literal>stdout</> (Mark
       Feit)
      </para>
     </listitem>

     <listitem>
      <para>
       Add global <application>psql</> configuration file, <filename>psqlrc.sample</filename>
       (Bruce)
      </para>
      <para>
       This allows a central file where global <application>psql</> startup commands can
       be stored.
      </para>
     </listitem>

     <listitem>
      <para>
       Have <application>psql</> <command>\d+</> indicate if the table
       has an <type>OID</> column (Neil)
      </para>
     </listitem>

     <listitem>
      <para>
       On Windows, use binary mode in <application>psql</> when reading files so control-Z
       is not seen as end-of-file
      </para>
     </listitem>

     <listitem>
      <para>
       Have <command>\dn+</> show permissions and description for schemas (Dennis
       Bj&ouml;rklund)
      </para>
     </listitem>

     <listitem>
      <para>
       Improve tab completion support (Stefan Kaltenbrunn, Greg Sabino Mullane)
      </para>
     </listitem>

     <listitem>
      <para>
       Allow boolean settings to be set using upper or lower case (Michael Paesold)
      </para>
     </listitem>

    </itemizedlist>
   </sect3>


   <sect3>
    <title><application>pg_dump</> Changes</title>
    <itemizedlist>

     <listitem>
      <para>
       Use dependency information to improve the reliability of
       <application>pg_dump</> (Tom)
      </para>
      <para>
       This should solve the longstanding problems with related objects
       sometimes being dumped in the wrong order.
      </para>
     </listitem>

     <listitem>
      <para>
       Have <application>pg_dump</> output objects in alphabetical order if possible (Tom)
      </para>
      <para>
       This should make it easier to identify changes between
       dump files.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <application>pg_restore</> to ignore some SQL errors (Fabien Coelho)
      </para>
      <para>
       This makes <application>pg_restore</>'s behavior similar to the
       results of feeding a <application>pg_dump</> output script to
       <application>psql</>. In most cases, ignoring errors and plowing
       ahead is the most useful thing to do. Also added was a pg_restore
       option to give the old behavior of exiting on an error.
      </para>
     </listitem>

     <listitem>
      <para>
       <application>pg_restore</> <option>-l</> display now includes
       objects' schema names
      </para>
     </listitem>

     <listitem>
      <para>
       New begin/end markers in <application>pg_dump</> text output (Bruce)
      </para>
     </listitem>

     <listitem>
      <para>
       Add start/stop times for
       <application>pg_dump</>/<application>pg_dumpall</> in verbose mode
       (Bruce)
      </para>
     </listitem>

     <listitem>
      <para>
       Allow most <application>pg_dump</> options in
       <application>pg_dumpall</> (Christopher)
      </para>
     </listitem>

     <listitem>
      <para>
       Have <application>pg_dump</> use <command>ALTER OWNER</> rather
       than <command>SET SESSION AUTHORIZATION</> by default
       (Christopher)
      </para>
     </listitem>

    </itemizedlist>
   </sect3>


   <sect3>
    <title>libpq Changes</title>
    <itemizedlist>

     <listitem>
      <para>
       Make libpq's <option>SIGPIPE</> handling thread-safe (Bruce)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <function>PQmbdsplen()</> which returns the display length
       of a character (Tatsuo)
      </para>
     </listitem>

     <listitem>
      <para>
       Add thread locking to <application>SSL</> and
       <application>Kerberos</> connections (Manfred Spraul)
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <function>PQoidValue()</>, <function>PQcmdTuples()</>, and
       <function>PQoidStatus()</> to work on <command>EXECUTE</command>
       commands (Neil)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <function>PQserverVersion()</> to provide more convenient
       access to the server version number (Greg Sabino Mullane)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <function>PQprepare/PQsendPrepared()</> functions to support
       preparing statements without necessarily specifying the data types
       of their parameters (Abhijit Menon-Sen)
      </para>
     </listitem>

     <listitem>
      <para>
       Many ECPG improvements, including <command>SET DESCRIPTOR</> (Michael)
      </para>
     </listitem>

    </itemizedlist>
   </sect3>


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

     <listitem>
      <para>
       Allow the database server to run natively on Windows (Claudio, Magnus, Andrew)
      </para>
     </listitem>

     <listitem>
      <para>
       Shell script commands converted to C versions for Windows support (Andrew)
      </para>
     </listitem>

     <listitem>
      <para>
       Create an extension makefile framework (Fabien Coelho, Peter)
      </para>
      <para>
       This simplifies the task of building extensions outside the original
       source tree.
      </para>
     </listitem>

     <listitem>
      <para>
       Support relocatable installations (Bruce)
      </para>
      <para>
       Directory paths for installed files (such as the
       <filename>/share</> directory) are now computed relative to the
       actual location of the executables, so that an installation tree
       can be moved to another place without reconfiguring and
       rebuilding.
      </para>
     </listitem>

     <listitem>
      <para>
       Use <option>--with-docdir</> to choose installation location of documentation; also
       allow <option>--infodir</> (Peter)
      </para>
     </listitem>

     <listitem>
      <para>
       Add <option>--without-docdir</> to prevent installation of documentation (Peter)
      </para>
     </listitem>

     <listitem>
      <para>
       Upgrade to <application>DocBook</> V4.2 SGML (Peter)
      </para>
     </listitem>

     <listitem>
      <para>
       New <literal>PostgreSQL</> <application>CVS</> tag (Marc)
      </para>
      <para>
       This was done to make it easier for organizations to manage their
       own copies of the <productname>PostgreSQL</productname>
       <application>CVS</> repository. File version stamps from the master
       repository will not get munged by checking into or out of a copied
       repository.
      </para>
     </listitem>

     <listitem>
      <para>
       Clarify locking code (Manfred Koizar)
      </para>
     </listitem>

     <listitem>
      <para>
       Buffer manager cleanup (Neil)
      </para>
     </listitem>

     <listitem>
      <para>
       Decouple platform tests from CPU spinlock code (Bruce, Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Add inlined test-and-set code on PA-RISC for <application>gcc</>
       (ViSolve, Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Improve i386 spinlock code (Manfred Spraul)
      </para>
     </listitem>

     <listitem>
      <para>
       Clean up spinlock assembly code to avoid warnings from newer
       <application>gcc</> releases (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Remove JDBC from source tree; now a separate project
      </para>
     </listitem>

     <listitem>
      <para>
       Remove the libpgtcl client interface; now a separate project
      </para>
     </listitem>

     <listitem>
      <para>
       More accurately estimate memory and file descriptor usage (Tom)
      </para>
     </listitem>

     <listitem>
      <para>
       Improvements to the macOS startup scripts (Ray A.)
      </para>
     </listitem>

     <listitem>
      <para>
       New <function>fsync()</> test program (Bruce)
      </para>
     </listitem>

     <listitem>
      <para>
       Major documentation improvements (Neil, Peter)
      </para>
     </listitem>

     <listitem>
      <para>
       Remove <application>pg_encoding</application>; not needed
       anymore
      </para>
     </listitem>

     <listitem>
      <para>
       Remove <application>pg_id</application>; not needed anymore
      </para>
     </listitem>

     <listitem>
      <para>
       Remove <application>initlocation</application>; not needed
       anymore
      </para>
     </listitem>

     <listitem>
      <para>
       Auto-detect thread flags (no more manual testing) (Bruce)
      </para>
     </listitem>

     <listitem>
      <para>
       Use Olson's public domain <application>timezone</> library (Magnus)
      </para>
     </listitem>

     <listitem>
      <para>
       With threading enabled, use thread flags on Unixware for
       backend executables too (Bruce)
      </para>
      <para>
       Unixware cannot mix threaded and nonthreaded object files in the
       same executable, so everything must be compiled as threaded.
      </para>
     </listitem>

     <listitem>
      <para>
       <application>psql</> now uses a <application>flex</>-generated
       lexical analyzer to process command strings
      </para>
     </listitem>

     <listitem>
      <para>
       Reimplement the linked list data structure used throughout the
       backend (Neil)
      </para>
      <para>
       This improves performance by allowing list append and length
       operations to be more efficient.
      </para>
     </listitem>

     <listitem>
      <para>
       Allow dynamically loaded modules to create their own server configuration
       parameters (Thomas Hallgren)
      </para>
     </listitem>

     <listitem>
      <para>
       New Brazilian version of FAQ (Euler Taveira de Oliveira)
      </para>
     </listitem>

     <listitem>
      <para>
       Add French FAQ (Guillaume Lelarge)
      </para>
     </listitem>

     <listitem>
      <para>
       New <application>pgevent</> for Windows logging
      </para>
     </listitem>

     <listitem>
      <para>
       Make libpq and ECPG build as proper shared libraries on macOS (Tom)
      </para>
     </listitem>

    </itemizedlist>
   </sect3>


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

     <listitem>
      <para>
       Overhaul of <filename>contrib/dblink</> (Joe)
      </para>
     </listitem>

     <listitem>
      <para>
       <filename>contrib/dbmirror</> improvements (Steven Singer)
      </para>
     </listitem>

     <listitem>
      <para>
       New <filename>contrib/xml2</> (John Gray, Torchbox)
      </para>
     </listitem>

     <listitem>
      <para>
       Updated <filename>contrib/mysql</filename>
      </para>
     </listitem>

     <listitem>
      <para>
       New version of <filename>contrib/btree_gist</> (Teodor)
      </para>
     </listitem>

     <listitem>
      <para>
       New <filename>contrib/trgm</>, trigram matching for
       <productname>PostgreSQL</productname> (Teodor)
      </para>
     </listitem>

     <listitem>
      <para>
       Many <filename>contrib/tsearch2</> improvements (Teodor)
      </para>
     </listitem>

     <listitem>
      <para>
       Add double metaphone to <filename>contrib/fuzzystrmatch</> (Andrew)
      </para>
     </listitem>

     <listitem>
      <para>
       Allow <filename>contrib/pg_autovacuum</> to run as a Windows service (Dave Page)
      </para>
     </listitem>

     <listitem>
      <para>
       Add functions to <filename>contrib/dbsize</> (Andreas Pflug)
      </para>
     </listitem>

     <listitem>
      <para>
       Removed <filename>contrib/pg_logger</>: obsoleted by integrated logging
       subprocess
      </para>
     </listitem>

     <listitem>
      <para>
       Removed <filename>contrib/rserv</>: obsoleted by various separate projects
      </para>
     </listitem>

    </itemizedlist>
   </sect3>

  </sect2>
 </sect1>
