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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2016-11-21 13:19:14 -0500 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2016-11-21 13:19:23 -0500 |
| commit | 4324ade9a6880113b08070305482ace2e8a2617c (patch) | |
| tree | cd8ad8bd6fb338c60b2b71b422d759d00a6eeda9 /src | |
| parent | a734fd5d1c309cc553b7c8c79fba96218af090f7 (diff) | |
| download | postgresql-4324ade9a6880113b08070305482ace2e8a2617c.tar.gz postgresql-4324ade9a6880113b08070305482ace2e8a2617c.zip | |
Fix optimization for skipping searches for parallel-query hazards.
Fix thinko in commit da1c91631: even if the original query was free of
parallel hazards, we might introduce such a hazard by adding PARAM_EXEC
Param nodes. Adjust is_parallel_safe() so that it will scan the given
expression whenever any such nodes have been created. Per report from
Andreas Seltenreich.
Discussion: <878tse6yvf.fsf@credativ.de>
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/optimizer/util/clauses.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c index 1688310b805..9598f28bab3 100644 --- a/src/backend/optimizer/util/clauses.c +++ b/src/backend/optimizer/util/clauses.c @@ -1150,8 +1150,14 @@ is_parallel_safe(PlannerInfo *root, Node *node) { max_parallel_hazard_context context; - /* If max_parallel_hazard found nothing unsafe, we don't need to look */ - if (root->glob->maxParallelHazard == PROPARALLEL_SAFE) + /* + * Even if the original querytree contained nothing unsafe, we need to + * search the expression if we have generated any PARAM_EXEC Params while + * planning, because those are parallel-restricted and there might be one + * in this expression. But otherwise we don't need to look. + */ + if (root->glob->maxParallelHazard == PROPARALLEL_SAFE && + root->glob->nParamExec == 0) return true; /* Else use max_parallel_hazard's search logic, but stop on RESTRICTED */ context.max_hazard = PROPARALLEL_SAFE; |