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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/include/nodes/relation.h | |
| 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/include/nodes/relation.h')
| -rw-r--r-- | src/include/nodes/relation.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/src/include/nodes/relation.h b/src/include/nodes/relation.h index 88669f38765..b2b204693f7 100644 --- a/src/include/nodes/relation.h +++ b/src/include/nodes/relation.h @@ -490,6 +490,8 @@ typedef struct RelOptInfo /* default result targetlist for Paths scanning this relation */ struct PathTarget *reltarget; /* list of Vars/Exprs, cost, width */ + bool reltarget_has_non_vars; /* true if any expression in + * PathTarget is a non-Var */ /* materialization information */ List *pathlist; /* Path structures */ |