From 2be0fe94bf20e9125a47aa216ee9b07d96ff0fae Mon Sep 17 00:00:00 2001 From: David Rowley Date: Wed, 2 Apr 2025 14:04:31 +1300 Subject: [PATCH] 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 Discussion: https://postgr.es/m/CAApHDvp738G75HfkKcfXaf3a8s%3D6mmtOLh46tMD0D2hAo1UCzA%40mail.gmail.com Backpatch-through: 13 --- doc/src/sgml/ddl.sgml | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml index 7f3d7e2c3e8..dd00bbdaa79 100644 --- a/doc/src/sgml/ddl.sgml +++ b/doc/src/sgml/ddl.sgml @@ -4812,7 +4812,9 @@ EXPLAIN SELECT count(*) FROM measurement WHERE logdate >= DATE '2008-01-01'; It is possible to determine the number of partitions which were removed during this phase by observing the Subplans Removed property in the - EXPLAIN output. + EXPLAIN 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.