Only make buffer strategy for vacuum when it's likely needed

david-rowley · david-rowley · commit 32fbe0239b03 · 2023-04-03T19:19:45.000+12:00
VACUUM FULL and VACUUM ONLY_DATABASE_STATS will not use the vacuum strategy ring created in vacuum(), so don't waste effort making it in those cases. There are other conceivable cases where the buffer strategy also won't be used, but those are probably less common and not worth troubling over too much. For example VACUUM (PROCESS_MAIN false, PROCESS_TOAST false). There are other cases too, but many of these are only discovered once inside vacuum_rel(). Author: Melanie Plageman Reviewed-by: David Rowley Discussion: https://postgr.es/m/CAAKRu_ZLRuzkM3zKogiZAz2hUony37yLY4aaLb8fPf8fgqs5Og@mail.gmail.com
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
@@ -393,7 +393,9 @@ vacuum(List *relations, VacuumParams *params,
 	 * If caller didn't give us a buffer strategy object, make one in the
 	 * cross-transaction memory context.
 	 */
-	if (bstrategy == NULL)
+	if (bstrategy == NULL &&
+		!(params->options & VACOPT_ONLY_DATABASE_STATS ||
+		  params->options & VACOPT_FULL))
 	{
 		MemoryContext old_context = MemoryContextSwitchTo(vac_context);
 
