From 8d33fbacbac93ed70757ea47cd8a4b4fae61528a Mon Sep 17 00:00:00 2001
From: Nathan Bossart
Date: Fri, 11 Jul 2025 11:51:25 -0500
Subject: Add FLUSH_UNLOGGED option to CHECKPOINT command.

This option, which is disabled by default, can be used to request
the checkpoint also flush dirty buffers of unlogged relations.  As
with the MODE option, the server may consolidate the options for
concurrently requested checkpoints.  For example, if one session
uses (FLUSH_UNLOGGED FALSE) and another uses (FLUSH_UNLOGGED TRUE),
the server may perform one checkpoint with FLUSH_UNLOGGED enabled.

Author: Christoph Berg <myon@debian.org>
Reviewed-by: Laurenz Albe <laurenz.albe@cybertec.at>
Reviewed-by: Fujii Masao <masao.fujii@oss.nttdata.com>
Reviewed-by: Dilip Kumar <dilipbalaut@gmail.com>
Discussion: https://postgr.es/m/aDnaKTEf-0dLiEfz%40msg.df7cb.de
---
 doc/src/sgml/ref/checkpoint.sgml | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

(limited to 'doc/src')

diff --git a/doc/src/sgml/ref/checkpoint.sgml b/doc/src/sgml/ref/checkpoint.sgml
index 36a9e323f44..cd981cf2cab 100644
--- a/doc/src/sgml/ref/checkpoint.sgml
+++ b/doc/src/sgml/ref/checkpoint.sgml
@@ -25,6 +25,7 @@ CHECKPOINT [ ( option [, ...] ) ]
 
 <phrase>where <replaceable class="parameter">option</replaceable> can be one of:</phrase>
 
+    FLUSH_UNLOGGED [ <replaceable class="parameter">boolean</replaceable> ]
     MODE { FAST | SPREAD }
 </synopsis>
  </refsynopsisdiv>
@@ -76,6 +77,17 @@ CHECKPOINT [ ( option [, ...] ) ]
   <title>Parameters</title>
 
   <variablelist>
+   <varlistentry>
+    <term><literal>FLUSH_UNLOGGED</literal></term>
+    <listitem>
+     <para>
+      Normally, <command>CHECKPOINT</command> does not flush dirty buffers of
+      unlogged relations.  This option, which is disabled by default, enables
+      flushing unlogged relations to disk.
+     </para>
+    </listitem>
+   </varlistentry>
+
    <varlistentry>
     <term><literal>MODE</literal></term>
     <listitem>
@@ -93,6 +105,20 @@ CHECKPOINT [ ( option [, ...] ) ]
      </para>
     </listitem>
    </varlistentry>
+
+   <varlistentry>
+    <term><replaceable class="parameter">boolean</replaceable></term>
+    <listitem>
+     <para>
+      Specifies whether the selected option should be turned on or off.
+      You can write <literal>TRUE</literal>, <literal>ON</literal>, or
+      <literal>1</literal> to enable the option, and <literal>FALSE</literal>,
+      <literal>OFF</literal>, or <literal>0</literal> to disable it.  The
+      <replaceable class="parameter">boolean</replaceable> value can also
+      be omitted, in which case <literal>TRUE</literal> is assumed.
+     </para>
+    </listitem>
+   </varlistentry>
   </variablelist>
  </refsect1>
 
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