From f58198415cf38d8cf29c9d28e77fb9c251a6e951 Mon Sep 17 00:00:00 2001 From: Rustam Khamidullin Date: Fri, 24 Jul 2026 11:10:18 +0700 Subject: [PATCH] Fix reversed sort order in autovacuum's db_comparator() Commit 3b42bdb4716 inadvertently reversed the sort order of databases in rebuild_database_list(). The original comparator sorted in descending order by adl_score, but the commit replaced the manual comparison with pg_cmp_s32(a, b), which produces ascending order. As a result, the scheduling order of databases for autovacuum was reversed each time the database list was rebuilt. Restore the intended descending order by swapping the arguments to pg_cmp_s32(). Update the surrounding comments to make the expected sort direction explicit. --- src/backend/postmaster/autovacuum.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c index 45abf48768a..e0c2c9b306f 100644 --- a/src/backend/postmaster/autovacuum.c +++ b/src/backend/postmaster/autovacuum.c @@ -1068,7 +1068,10 @@ rebuild_database_list(Oid newdb) while ((db = hash_seq_search(&seq)) != NULL) memcpy(&(dbary[i++]), db, sizeof(avl_dbase)); - /* sort the array */ + /* + * Sort the array in descending order so that the databases with the + * highest score get the least adl_next_worker time. + */ qsort(dbary, nelems, sizeof(avl_dbase), db_comparator); /* @@ -1109,12 +1112,12 @@ rebuild_database_list(Oid newdb) MemoryContextSwitchTo(oldcxt); } -/* qsort comparator for avl_dbase, using adl_score */ +/* qsort comparator for avl_dbase, using adl_score in descending order */ static int db_comparator(const void *a, const void *b) { - return pg_cmp_s32(((const avl_dbase *) a)->adl_score, - ((const avl_dbase *) b)->adl_score); + return pg_cmp_s32(((const avl_dbase *) b)->adl_score, + ((const avl_dbase *) a)->adl_score); } /* -- 2.54.0