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| author | Robert Haas <rhaas@postgresql.org> | 2016-06-09 12:40:23 -0400 |
|---|---|---|
| committer | Robert Haas <rhaas@postgresql.org> | 2016-06-09 12:43:36 -0400 |
| commit | b12fd41c695b43c76b0a9a4d19ba43b05536440c (patch) | |
| tree | 966a7ca8b9c268b70f38257a56aeccaa25fd82b2 /src/backend/optimizer/util/placeholder.c | |
| parent | e7bcd983f56136a9580076b60d5c19eb2fd83301 (diff) | |
| download | postgresql-b12fd41c695b43c76b0a9a4d19ba43b05536440c.tar.gz postgresql-b12fd41c695b43c76b0a9a4d19ba43b05536440c.zip | |
Don't generate parallel paths for rels with parallel-restricted outputs.
Such paths are unsafe. To make it cheaper to detect when this case
applies, track whether a relation's default PathTarget contains any
non-Vars. In most cases, the answer will be no, which enables us to
determine cheaply that the target list for a proposed path is
parallel-safe. However, subquery pull-up can create cases that
require us to inspect the target list more carefully.
Amit Kapila, reviewed by me.
Diffstat (limited to 'src/backend/optimizer/util/placeholder.c')
| -rw-r--r-- | src/backend/optimizer/util/placeholder.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/src/backend/optimizer/util/placeholder.c b/src/backend/optimizer/util/placeholder.c index b210914b853..5b85a4ddadc 100644 --- a/src/backend/optimizer/util/placeholder.c +++ b/src/backend/optimizer/util/placeholder.c @@ -393,6 +393,7 @@ add_placeholders_to_base_rels(PlannerInfo *root) rel->reltarget->exprs = lappend(rel->reltarget->exprs, copyObject(phinfo->ph_var)); + rel->reltarget_has_non_vars = true; /* reltarget's cost and width fields will be updated later */ } } @@ -427,6 +428,7 @@ add_placeholders_to_joinrel(PlannerInfo *root, RelOptInfo *joinrel, /* Yup, add it to the output */ joinrel->reltarget->exprs = lappend(joinrel->reltarget->exprs, phinfo->ph_var); + joinrel->reltarget_has_non_vars = true; joinrel->reltarget->width += phinfo->ph_width; /* |