On 10/17/15 10:25 AM, Michael Paquier wrote:
> I think that we should just suggest a reverse formula of the maximum
> soft limit of checkpoint_segments for max_wal_size in the release notes
> of 9.5, basically:
> (3 * your_old_checkpoint_segments + 1) * 16MB = max_wal_size
How about this patch?
(Actually, I'd remove the + 1 to make the numbers come out rounder.)
From ca0ed24ac6a770d637740142a1aed3d76a70a3b3 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter_e@gmx.net>
Date: Tue, 20 Oct 2015 14:09:03 -0400
Subject: [PATCH] doc: Add advice on updating checkpoint_segments to
max_wal_size
---
doc/src/sgml/release-9.5.sgml | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/doc/src/sgml/release-9.5.sgml b/doc/src/sgml/release-9.5.sgml
index d5b68e7..37de29d 100644
--- a/doc/src/sgml/release-9.5.sgml
+++ b/doc/src/sgml/release-9.5.sgml
@@ -153,6 +153,22 @@ <title>Migration to Version 9.5</title>
</listitem>
<listitem>
+ <para>
+ The configuration parameter <varname>checkpoint_segments</varname> has
+ been removed. Its place it 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 + 1) * 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>
<!--
2015-07-28 [6087d95] Andres..: Remove ssl renegotiation support.
-->
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