From 5ddfebded41f7754b3c4fc1b576ca33736efcab6 Mon Sep 17 00:00:00 2001 From: Michael Paquier Date: Wed, 5 Jan 2022 10:27:47 +0900 Subject: [PATCH] Reduce relcache access in WAL sender streaming logical changes get_rel_sync_entry(), which is called each time a change needs to be logically replicated, is a rather hot code path in the WAL sender sending logical changes. This code path was doing a relcache access on relkind and relpartition for each logical change, but we only need to know this information when building or re-building the cached information for a relation. Some measurements prove that this is noticeable in perf profiles, particularly when attempting to replicate changes from relations that are not published as these cause less overhead in the WAL sender, delaying further the replication of changes for relations that are published. Issue introduced in 83fd453. Author: Hou Zhijie Reviewed-by: Kyotaro Horiguchi, Euler Taveira Discussion: https://postgr.es/m/OS0PR01MB5716E863AA9E591C1F010F7A947D9@OS0PR01MB5716.jpnprd01.prod.outlook.com Backpatch-through: 13 --- src/backend/replication/pgoutput/pgoutput.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/src/backend/replication/pgoutput/pgoutput.c b/src/backend/replication/pgoutput/pgoutput.c index abd5217ab1b..d29e1c5e9b2 100644 --- a/src/backend/replication/pgoutput/pgoutput.c +++ b/src/backend/replication/pgoutput/pgoutput.c @@ -1008,8 +1008,6 @@ static RelationSyncEntry * get_rel_sync_entry(PGOutputData *data, Oid relid) { RelationSyncEntry *entry; - bool am_partition = get_rel_relispartition(relid); - char relkind = get_rel_relkind(relid); bool found; MemoryContext oldctx; @@ -1041,6 +1039,8 @@ get_rel_sync_entry(PGOutputData *data, Oid relid) List *pubids = GetRelationPublications(relid); ListCell *lc; Oid publish_as_relid = relid; + bool am_partition = get_rel_relispartition(relid); + char relkind = get_rel_relkind(relid); /* Reload publications if needed before use. */ if (!publications_valid)