diff options
| author | Tom Lane <tgl@sss.pgh.pa.us> | 2016-08-19 14:03:07 -0400 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2016-08-19 14:03:13 -0400 |
| commit | da1c91631e3577ea5818f855ebb5bd206d559006 (patch) | |
| tree | 90bdd7e1f5929851e2cb948cd08db891c0a24479 /src/backend/optimizer/util/pathnode.c | |
| parent | 6f79ae7fe549bed8bbd1f54ddd9b98f8f9a315f5 (diff) | |
| download | postgresql-da1c91631e3577ea5818f855ebb5bd206d559006.tar.gz postgresql-da1c91631e3577ea5818f855ebb5bd206d559006.zip | |
Speed up planner's scanning for parallel-query hazards.
We need to scan the whole parse tree for parallel-unsafe functions.
If there are none, we'll later need to determine whether particular
subtrees contain any parallel-restricted functions. The previous coding
retained no knowledge from the first scan, even though this is very
wasteful in the common case where the query contains only parallel-safe
functions. We can bypass all of the later scans by remembering that fact.
This provides a small but measurable speed improvement when the case
applies, and shouldn't cost anything when it doesn't.
Patch by me, reviewed by Robert Haas
Discussion: <3740.1471538387@sss.pgh.pa.us>
Diffstat (limited to 'src/backend/optimizer/util/pathnode.c')
| -rw-r--r-- | src/backend/optimizer/util/pathnode.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/src/backend/optimizer/util/pathnode.c b/src/backend/optimizer/util/pathnode.c index ce7ad545a95..abb7507d8e4 100644 --- a/src/backend/optimizer/util/pathnode.c +++ b/src/backend/optimizer/util/pathnode.c @@ -2178,7 +2178,7 @@ create_projection_path(PlannerInfo *root, pathnode->path.parallel_aware = false; pathnode->path.parallel_safe = rel->consider_parallel && subpath->parallel_safe && - !has_parallel_hazard((Node *) target->exprs, false); + is_parallel_safe(root, (Node *) target->exprs); pathnode->path.parallel_workers = subpath->parallel_workers; /* Projection does not change the sort order */ pathnode->path.pathkeys = subpath->pathkeys; @@ -2285,7 +2285,7 @@ apply_projection_to_path(PlannerInfo *root, * target expressions, then we can't. */ if (IsA(path, GatherPath) && - !has_parallel_hazard((Node *) target->exprs, false)) + is_parallel_safe(root, (Node *) target->exprs)) { GatherPath *gpath = (GatherPath *) path; @@ -2306,7 +2306,7 @@ apply_projection_to_path(PlannerInfo *root, target); } else if (path->parallel_safe && - has_parallel_hazard((Node *) target->exprs, false)) + !is_parallel_safe(root, (Node *) target->exprs)) { /* * We're inserting a parallel-restricted target list into a path |