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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>E.108. Release 9.2.1</title><link rel="stylesheet" type="text/css" href="stylesheet.css" /><link rev="made" href="pgsql-docs@postgresql.org" /><meta name="generator" content="DocBook XSL Stylesheets V1.79.1" /><link rel="prev" href="release-9-2-2.html" title="E.107. Release 9.2.2" /><link rel="next" href="release-9-2.html" title="E.109. Release 9.2" /></head><body><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">E.108. Release 9.2.1</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="release-9-2-2.html" title="E.107. Release 9.2.2">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="release.html" title="Appendix E. Release Notes">Up</a></td><th width="60%" align="center">Appendix E. Release Notes</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 11.1 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="release-9-2.html" title="E.109. Release 9.2">Next</a></td></tr></table><hr></hr></div><div class="sect1" id="RELEASE-9-2-1"><div class="titlepage"><div><div><h2 class="title" style="clear: both">E.108. Release 9.2.1</h2></div></div></div><div class="toc"><dl class="toc"><dt><span class="sect2"><a href="release-9-2-1.html#id-1.11.6.112.4">E.108.1. Migration to Version 9.2.1</a></span></dt><dt><span class="sect2"><a href="release-9-2-1.html#id-1.11.6.112.5">E.108.2. Changes</a></span></dt></dl></div><p><strong>Release date: </strong>2012-09-24</p><p>
   This release contains a variety of fixes from 9.2.0.
   For information about new features in the 9.2 major release, see
   <a class="xref" href="release-9-2.html" title="E.109. Release 9.2">Section E.109</a>.
  </p><div class="sect2" id="id-1.11.6.112.4"><div class="titlepage"><div><div><h3 class="title">E.108.1. Migration to Version 9.2.1</h3></div></div></div><p>
    A dump/restore is not required for those running 9.2.X.
   </p><p>
    However, you may need to perform <code class="command">REINDEX</code> and/or
    <code class="command">VACUUM</code> operations to recover from the effects of the data
    corruption bug described in the first changelog item below.
   </p></div><div class="sect2" id="id-1.11.6.112.5"><div class="titlepage"><div><div><h3 class="title">E.108.2. Changes</h3></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>
      Fix persistence marking of shared buffers during WAL replay
      (Jeff Davis)
     </p><p>
      This mistake can result in buffers not being written out during
      checkpoints, resulting in data corruption if the server later crashes
      without ever having written those buffers.  Corruption can occur on
      any server following crash recovery, but it is significantly more
      likely to occur on standby slave servers since those perform much
      more WAL replay.  There is a low probability of corruption of btree
      and GIN indexes.  There is a much higher probability of corruption
      of table <span class="quote">“<span class="quote">visibility maps</span>”</span>, which might lead to wrong answers
      from index-only scans.  Table data proper cannot be corrupted by this
      bug.
     </p><p>
      While no index corruption due to this bug is known to have occurred
      in the field, as a precautionary measure it is recommended that
      production installations <code class="command">REINDEX</code> all btree and GIN
      indexes at a convenient time after upgrading to 9.2.1.
     </p><p>
      Also, it is recommended to perform a <code class="command">VACUUM</code> of all tables
      while having <a class="link" href="runtime-config-client.html#GUC-VACUUM-FREEZE-TABLE-AGE"><code class="varname">vacuum_freeze_table_age</code></a>
      set to zero.  This will fix any incorrect visibility map data.  <a class="link" href="runtime-config-resource.html#GUC-VACUUM-COST-DELAY"><code class="varname">vacuum_cost_delay</code></a>
      can be adjusted to reduce the performance impact of vacuuming, while
      causing it to take longer to finish.
     </p></li><li class="listitem"><p>
      Fix possible incorrect sorting of output from queries involving
      <code class="literal">WHERE <em class="replaceable"><code>indexed_column</code></em> IN
      (<em class="replaceable"><code>list_of_values</code></em>)</code> (Tom Lane)
     </p></li><li class="listitem"><p>
      Fix planner failure for queries involving <code class="literal">GROUP BY</code>
      expressions along with window functions and aggregates (Tom Lane)
     </p></li><li class="listitem"><p>
      Fix planner's assignment of executor parameters (Tom Lane)
     </p><p>
      This error could result in wrong answers from queries that scan the
      same <code class="literal">WITH</code> subquery multiple times.
     </p></li><li class="listitem"><p>
      Improve planner's handling of join conditions in index scans (Tom Lane)
     </p></li><li class="listitem"><p>
      Improve selectivity estimation for text search queries involving
      prefixes, i.e. <em class="replaceable"><code>word</code></em><code class="literal">:*</code> patterns  (Tom Lane)
     </p></li><li class="listitem"><p>
      Fix delayed recognition of permissions changes (Tom Lane)
     </p><p>
      A command that needed no locks other than ones its transaction already
      had might fail to notice a concurrent <code class="command">GRANT</code> or
      <code class="command">REVOKE</code> that committed since the start of its transaction.
     </p></li><li class="listitem"><p>
      Fix <code class="command">ANALYZE</code> to not fail when a column is a domain over an
      array type (Tom Lane)
     </p></li><li class="listitem"><p>
      Prevent PL/Perl from crashing if a recursive PL/Perl function is
      redefined while being executed (Tom Lane)
     </p></li><li class="listitem"><p>
      Work around possible misoptimization in PL/Perl (Tom Lane)
     </p><p>
      Some Linux distributions contain an incorrect version of
      <code class="filename">pthread.h</code> that results in incorrect compiled code in
      PL/Perl, leading to crashes if a PL/Perl function calls another one
      that throws an error.
     </p></li><li class="listitem"><p>
      Remove unnecessary dependency on <span class="application">pg_config</span> from
      <span class="application">pg_upgrade</span> (Peter Eisentraut)
     </p></li><li class="listitem"><p>
      Update time zone data files to <span class="application">tzdata</span> release 2012f
      for DST law changes in Fiji
     </p></li></ul></div></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="release-9-2-2.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="release.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="release-9-2.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">E.107. Release 9.2.2 </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> E.109. Release 9.2</td></tr></table></div></body></html>