v22-0004-Documentation-for-wal_skip_threshold.patch

From f5d58a918925c345f5e3efd75d81564892818312 Mon Sep 17 00:00:00 2001
From: Kyotaro Horiguchi <horiguchi.kyotaro@lab.ntt.co.jp>
Date: Wed, 28 Aug 2019 14:05:30 +0900
Subject: [PATCH v22 4/5] Documentation for wal_skip_threshold

---
 doc/src/sgml/config.sgml | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 886632f..f928c5a 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -1833,6 +1833,32 @@ include_dir 'conf.d'
       </listitem>
      </varlistentry>
 
+     <varlistentry id="guc-wal-skip-min_size" xreflabel="wal_skip_threshold">
+      <term><varname>wal_skip_threshold</varname> (<type>integer</type>)
+      <indexterm>
+       <primary><varname>wal_skip_threshold</varname> configuration parameter</primary>
+      </indexterm>
+      </term>
+      <listitem>
+       <para>
+         When wal_level is minimal and a transaction commits after creating or
+         rewriting a permanent table, materialized view, or index, this
+         setting determines how to persist the new data.  If the data is
+         smaller than this setting, write it to the WAL log; otherwise, use an
+         fsync of the data file.  Depending on the properties of your storage,
+         raising or lowering this value might help if such commits are slowing
+         concurrent transactions.  The default is 64 kilobytes (64kB).
+       </para>
+       <para>
+        When <xref linkend="guc-wal-level"/> is <literal>minimal</literal>,
+        WAL-logging is skipped for tables created in-trasaction.  If a table
+        is smaller than that size at commit, it is WAL-logged instead of
+        issueing <function>fsync</function> on it.
+
+       </para>
+      </listitem>
+     </varlistentry>
+
      </variablelist>
      </sect2>
 
-- 
2.9.2