From 4b52c3d6dd142264ba29ac592a881232492d6d89 Mon Sep 17 00:00:00 2001
From: "Imseih (AWS)" <simseih@88665a22795f.ant.amazon.com>
Date: Tue, 28 Feb 2023 16:39:40 -0600
Subject: [PATCH 1/1] doc update regarding pg_stat_statements normalization.

It is quite possible that a query text willl not normalize
(replace constants with $1, $2..) when there is a high rate
pgss_hash deallocation. This commit calls this out in docs.
---
 doc/src/sgml/pgstatstatements.sgml | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/doc/src/sgml/pgstatstatements.sgml b/doc/src/sgml/pgstatstatements.sgml
index efc36da602..39e2f8eaec 100644
--- a/doc/src/sgml/pgstatstatements.sgml
+++ b/doc/src/sgml/pgstatstatements.sgml
@@ -516,6 +516,16 @@
    <structname>pg_stat_statements</structname> entry.
   </para>
 
+  <para>
+   Text for a plannable query may be observed with constants in
+   <structname>pg_stat_statements</structname>, especially when there is a high
+   rate of entry deallocations. To reduce the likelihood of this happening, consider
+   increasing <varname>pg_stat_statements.max</varname>.
+   The <structname>pg_stat_statements_info</structname> view, discussed below
+   in <xref linkend="pgstatstatements-pg-stat-statements-info"/>,
+   provides entry deallocation statistics.
+  </para>
+
   <para>
    In some cases, queries with visibly different texts might get merged into a
    single <structname>pg_stat_statements</structname> entry.  Normally this will happen
-- 
2.37.1 (Apple Git-137.1)