From 09a72188cd5cdd179dc814c6729f8a3785b23c36 Mon Sep 17 00:00:00 2001 From: Michael Paquier Date: Wed, 16 Nov 2022 10:49:05 +0900 Subject: [PATCH] Avoid some overhead with open and close of catalog indexes This commit improves two code paths to open and close indexes a minimum amount of times when doing a series of catalog updates or inserts. CatalogTupleInsert() is costly when using it for multiple inserts or updates compared to CatalogTupleInsertWithInfo(), as it would need to open and close the indexes of the catalog worked each time an operation is done. This commit updates the following places: - REINDEX CONCURRENTLY when copying statistics from one index relation to the other. Multi-INSERTs are avoided here, as this would begin to show benefits only for indexes with multiple expressions, for example, which may not be the most common pattern. This change is noticeable in profiles with indexes having many expressions, for example, and it would improve any callers of CopyStatistics(). - Update of statistics on ANALYZE, that mixes inserts and updates. In each case, the catalog indexes are opened only if at least one insertion and/or update is required, to minimize the cost of the operation. Like the previous coding, no indexes are opened as long as at least one insert or update of pg_statistic has happened. Author: Ranier Vilela Reviewed-by: Kyotaro Horiguchi, Michael Paquier Discussion: https://postgr.es/m/CAEudQAqh0F9y6Di_Wc8xW4zkWm_5SDd-nRfVsCn=h0Nm1C_mrg@mail.gmail.com --- src/backend/catalog/heap.c | 10 +++++++++- src/backend/commands/analyze.c | 11 +++++++++-- 2 files changed, 18 insertions(+), 3 deletions(-) diff --git a/src/backend/catalog/heap.c b/src/backend/catalog/heap.c index 5b49cc5a09..bdd413f01b 100644 --- a/src/backend/catalog/heap.c +++ b/src/backend/catalog/heap.c @@ -2856,6 +2856,7 @@ CopyStatistics(Oid fromrelid, Oid torelid) SysScanDesc scan; ScanKeyData key[1]; Relation statrel; + CatalogIndexState indstate = NULL; statrel = table_open(StatisticRelationId, RowExclusiveLock); @@ -2878,13 +2879,20 @@ CopyStatistics(Oid fromrelid, Oid torelid) /* update the copy of the tuple and insert it */ statform->starelid = torelid; - CatalogTupleInsert(statrel, tup); + + /* fetch index information when we know we need it */ + if (indstate == NULL) + indstate = CatalogOpenIndexes(statrel); + + CatalogTupleInsertWithInfo(statrel, tup, indstate); heap_freetuple(tup); } systable_endscan(scan); + if (indstate != NULL) + CatalogCloseIndexes(indstate); table_close(statrel, RowExclusiveLock); } diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index ff1354812b..bf0ec8b374 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -1624,6 +1624,7 @@ update_attstats(Oid relid, bool inh, int natts, VacAttrStats **vacattrstats) { Relation sd; int attno; + CatalogIndexState indstate = NULL; if (natts <= 0) return; /* nothing to do */ @@ -1725,6 +1726,10 @@ update_attstats(Oid relid, bool inh, int natts, VacAttrStats **vacattrstats) Int16GetDatum(stats->attr->attnum), BoolGetDatum(inh)); + /* Open index information when we know we need it */ + if (indstate == NULL) + indstate = CatalogOpenIndexes(sd); + if (HeapTupleIsValid(oldtup)) { /* Yes, replace it */ @@ -1734,18 +1739,20 @@ update_attstats(Oid relid, bool inh, int natts, VacAttrStats **vacattrstats) nulls, replaces); ReleaseSysCache(oldtup); - CatalogTupleUpdate(sd, &stup->t_self, stup); + CatalogTupleUpdateWithInfo(sd, &stup->t_self, stup, indstate); } else { /* No, insert new tuple */ stup = heap_form_tuple(RelationGetDescr(sd), values, nulls); - CatalogTupleInsert(sd, stup); + CatalogTupleInsertWithInfo(sd, stup, indstate); } heap_freetuple(stup); } + if (indstate != NULL) + CatalogCloseIndexes(indstate); table_close(sd, RowExclusiveLock); } -- 2.39.5