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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.128. Release 9.1.6</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-9-1-7.html" title="E.127. Release 9.1.7" /><link rel="next" href="release-9-1-5.html" title="E.129. Release 9.1.5" /></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.128. Release 9.1.6</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="release-9-1-7.html" title="E.127. Release 9.1.7">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-9-1-5.html" title="E.129. Release 9.1.5">Next</a></td></tr></table><hr></hr></div><div class="sect1" id="RELEASE-9-1-6"><div class="titlepage"><div><div><h2 class="title" style="clear: both">E.128. Release 9.1.6</h2></div></div></div><div class="toc"><dl class="toc"><dt><span class="sect2"><a href="release-9-1-6.html#id-1.11.6.132.4">E.128.1. Migration to Version 9.1.6</a></span></dt><dt><span class="sect2"><a href="release-9-1-6.html#id-1.11.6.132.5">E.128.2. Changes</a></span></dt></dl></div><p><strong>Release date: </strong>2012-09-24</p><p>
   This release contains a variety of fixes from 9.1.5.
   For information about new features in the 9.1 major release, see
   <a class="xref" href="release-9-1.html" title="E.134. Release 9.1">Section E.134</a>.
  </p><div class="sect2" id="id-1.11.6.132.4"><div class="titlepage"><div><div><h3 class="title">E.128.1. Migration to Version 9.1.6</h3></div></div></div><p>
    A dump/restore is not required for those running 9.1.X.
   </p><p>
    However, you may need to perform <code class="command">REINDEX</code> operations to
    recover from the effects of the data corruption bug described in the
    first changelog item below.
   </p><p>
    Also, if you are upgrading from a version earlier than 9.1.4,
    see <a class="xref" href="release-9-1-4.html" title="E.130. Release 9.1.4">Section E.130</a>.
   </p></div><div class="sect2" id="id-1.11.6.132.5"><div class="titlepage"><div><div><h3 class="title">E.128.2. 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>.  Fortunately, visibility maps are
      non-critical data in 9.1, so the worst consequence of such corruption
      in 9.1 installations is transient inefficiency of vacuuming.  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 9.1.6.
     </p><p>
      Also, if you intend to do an in-place upgrade to 9.2.X, before doing
      so 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 ensure that any lingering wrong data in the
      visibility maps is corrected before 9.2.X can depend on it.  <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 planner's assignment of executor parameters, and fix executor's
      rescan logic for CTE plan nodes (Tom Lane)
     </p><p>
      These errors 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>
      Fix misbehavior when <a class="link" href="runtime-config-client.html#GUC-DEFAULT-TRANSACTION-ISOLATION"><code class="varname">default_transaction_isolation</code></a>
      is set to <code class="literal">serializable</code> (Kevin Grittner, Tom Lane, Heikki
      Linnakangas)
     </p><p>
      Symptoms include crashes at process start on Windows, and crashes in
      hot standby operation.
     </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>
      Improve page-splitting decisions in GiST indexes (Alexander Korotkov,
      Robert Haas, Tom Lane)
     </p><p>
      Multi-column GiST indexes might suffer unexpected bloat due to this
      error.
     </p></li><li class="listitem"><p>
      Fix cascading privilege revoke to stop if privileges are still held
      (Tom Lane)
     </p><p>
      If we revoke a grant option from some role <em class="replaceable"><code>X</code></em>, but
      <em class="replaceable"><code>X</code></em> still holds that option via a grant from someone
      else, we should not recursively revoke the corresponding privilege
      from role(s) <em class="replaceable"><code>Y</code></em> that <em class="replaceable"><code>X</code></em> had granted it
      to.
     </p></li><li class="listitem"><p>
      Disallow extensions from containing the schema they are assigned to
      (Thom Brown)
     </p><p>
      This situation creates circular dependencies that confuse
      <span class="application">pg_dump</span> and probably other things.  It's confusing
      for humans too, so disallow it.
     </p></li><li class="listitem"><p>
      Improve error messages for Hot Standby misconfiguration errors
      (Gurjeet Singh)
     </p></li><li class="listitem"><p>
      Make <span class="application">configure</span> probe for <code class="function">mbstowcs_l</code> (Tom
      Lane)
     </p><p>
      This fixes build failures on some versions of AIX.
     </p></li><li class="listitem"><p>
      Fix handling of <code class="literal">SIGFPE</code> when PL/Perl is in use (Andres Freund)
     </p><p>
      Perl resets the process's <code class="literal">SIGFPE</code> handler to
      <code class="literal">SIG_IGN</code>, which could result in crashes later on.  Restore
      the normal Postgres signal handler after initializing PL/Perl.
     </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>
      Fix bugs in <code class="filename">contrib/pg_trgm</code>'s <code class="literal">LIKE</code> pattern
      analysis code (Fujii Masao)
     </p><p>
      <code class="literal">LIKE</code> queries using a trigram index could produce wrong
      results if the pattern contained <code class="literal">LIKE</code> escape characters.
     </p></li><li class="listitem"><p>
      Fix <span class="application">pg_upgrade</span>'s handling of line endings on Windows
      (Andrew Dunstan)
     </p><p>
      Previously, <span class="application">pg_upgrade</span> might add or remove carriage
      returns in places such as function bodies.
     </p></li><li class="listitem"><p>
      On Windows, make <span class="application">pg_upgrade</span> use backslash path
      separators in the scripts it emits (Andrew Dunstan)
     </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-9-1-7.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-9-1-5.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">E.127. Release 9.1.7 </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> E.129. Release 9.1.5</td></tr></table></div></body></html>