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| author | Simon Riggs <simon@2ndQuadrant.com> | 2017-04-05 18:22:32 -0400 |
|---|---|---|
| committer | Simon Riggs <simon@2ndQuadrant.com> | 2017-04-05 18:22:32 -0400 |
| commit | 68ea2b7f9b52d35b5fcd9c8d44d88de5a64be3ba (patch) | |
| tree | ef650aa6a264e2131f56971399b1a04dd8f588c8 /src | |
| parent | 2686ee1b7ccfb9214064d4d2a98ea77382880306 (diff) | |
| download | postgresql-68ea2b7f9b52d35b5fcd9c8d44d88de5a64be3ba.tar.gz postgresql-68ea2b7f9b52d35b5fcd9c8d44d88de5a64be3ba.zip | |
Reduce lock level for CREATE STATISTICS
In line with other lock reductions related to planning.
Simon Riggs
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/commands/statscmds.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/src/backend/commands/statscmds.c b/src/backend/commands/statscmds.c index 8d483dbb3a7..46abadcc811 100644 --- a/src/backend/commands/statscmds.c +++ b/src/backend/commands/statscmds.c @@ -96,7 +96,13 @@ CreateStatistics(CreateStatsStmt *stmt) errmsg("statistics \"%s\" already exist", namestr))); } - rel = heap_openrv(stmt->relation, AccessExclusiveLock); + /* + * CREATE STATISTICS will influence future execution plans but does + * not interfere with currently executing plans so it is safe to + * take only ShareUpdateExclusiveLock on relation, conflicting with + * ANALYZE and other DDL that sets statistical information. + */ + rel = heap_openrv(stmt->relation, ShareUpdateExclusiveLock); relid = RelationGetRelid(rel); if (rel->rd_rel->relkind != RELKIND_RELATION && |