From: Peter Eisentraut <peter_e@gmx.net>
Date: Thu, 22 Oct 2015 17:59:58 +0000 (-0400)
Subject: doc: Add advice on updating checkpoint_segments to max_wal_size
X-Git-Tag: REL9_6_BETA1~1171
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=8f2977b3ec2fbb98ee36045d4e2be81ca4c293e0;p=thirdparty%2Fpostgresql.git

doc: Add advice on updating checkpoint_segments to max_wal_size

with suggestion from Michael Paquier
---

diff --git a/doc/src/sgml/release-9.5.sgml b/doc/src/sgml/release-9.5.sgml
index d5b68e73ef5..92443e43c19 100644
--- a/doc/src/sgml/release-9.5.sgml
+++ b/doc/src/sgml/release-9.5.sgml
@@ -152,6 +152,22 @@
      </para>
     </listitem>
 
+    <listitem>
+     <para>
+      The configuration parameter <varname>checkpoint_segments</varname> has
+      been removed.  Its place is taken by the new
+      setting <xref linkend="guc-max-wal-size">.  If you had previously
+      tuned <varname>checkpoint_segments</varname>, the following formula will
+      give you an approximately equivalent setting:
+<programlisting>
+max_wal_size = (3 * checkpoint_segments) * 16MB
+</programlisting>
+      Note that the default setting for <varname>max_wal_size</varname> is
+      much higher than the default <varname>checkpoint_segments</varname> used
+      to be, so setting this might no longer be necessary.
+     </para>
+    </listitem>
+
     <listitem>
 <!--
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