From: David Rowley <drowley@postgresql.org>
Date: Wed, 2 Apr 2025 01:03:48 +0000 (+1300)
Subject: Doc: add information about partition locking
X-Git-Tag: REL_17_5~54
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=e962d6d12b7e8185775da26ef0f77a3ac63d18a0;p=thirdparty%2Fpostgresql.git

Doc: add information about partition locking

The documentation around locking of partitions for the executor startup
phase of run-time partition pruning wasn't clear about which partitions
were being locked.  Fix that.

Reviewed-by: Tender Wang <tndrwang@gmail.com>
Discussion: https://postgr.es/m/CAApHDvp738G75HfkKcfXaf3a8s%3D6mmtOLh46tMD0D2hAo1UCzA%40mail.gmail.com
Backpatch-through: 13
---

diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index c150dd217f9..bef12758711 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -4986,7 +4986,9 @@ EXPLAIN SELECT count(*) FROM measurement WHERE logdate &gt;= DATE '2008-01-01';
        It is possible to determine the number of partitions which were
        removed during this phase by observing the
        <quote>Subplans Removed</quote> property in the
-       <command>EXPLAIN</command> output.
+       <command>EXPLAIN</command> output.  It's important to note that any
+       partitions removed by the partition pruning done at this stage are
+       still locked at the beginning of execution.
       </para>
      </listitem>