From 0872ccbfd8c988d69c79a93dd85f0e10f2ee6349 Mon Sep 17 00:00:00 2001 From: Michael Paquier Date: Sat, 25 Sep 2021 15:12:04 +0900 Subject: [PATCH] doc: Improve description of index vacuuming with GUCs Index vacuums may happen multiple times depending on the number of dead tuples stored, as of maintenance_work_mem for a manual VACUUM. For autovacuum, this is controlled by autovacuum_work_mem instead, if set. The documentation mentioned the former, but not the latter in the context of autovacuum. Reported-by: Nikolai Berkoff Author: Laurenz Albe, Euler Taveira Discussion: https://postgr.es/m/161545365522.10134.12195402324485546870@wrigleys.postgresql.org Backpatch-through: 9.6 --- doc/src/sgml/monitoring.sgml | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index c95bbb9e5a..af3e9a7165 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -3909,8 +3909,9 @@ SELECT pg_stat_get_backend_pid(s.backendid) AS pid, VACUUM is currently vacuuming the indexes. If a table has any indexes, this will happen at least once per vacuum, after the heap has been completely scanned. It may happen multiple times per vacuum - if is insufficient to - store the number of dead tuples found. + if (or, in the case of autovacuum, + if set) is insufficient to store + the number of dead tuples found.