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| author | Robert Haas <rhaas@postgresql.org> | 2016-04-20 17:48:55 -0400 |
|---|---|---|
| committer | Robert Haas <rhaas@postgresql.org> | 2016-04-20 17:48:55 -0400 |
| commit | 9c75e1a36b6b2f3ad9f76ae661f42586c92c6f7c (patch) | |
| tree | b0e710aea7791c8d17a4a0d154e9fd8faf70c214 | |
| parent | cfb863f20a2a005ac89f393265d4c37ad9baab41 (diff) | |
| download | postgresql-9c75e1a36b6b2f3ad9f76ae661f42586c92c6f7c.tar.gz postgresql-9c75e1a36b6b2f3ad9f76ae661f42586c92c6f7c.zip | |
Forbid parallel Hash Right Join or Hash Full Join.
That won't work. You'll get bogus null-extended rows.
Mithun Cy
| -rw-r--r-- | src/backend/optimizer/path/joinpath.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/src/backend/optimizer/path/joinpath.c b/src/backend/optimizer/path/joinpath.c index 41b60d01d37..f8e02b9c45d 100644 --- a/src/backend/optimizer/path/joinpath.c +++ b/src/backend/optimizer/path/joinpath.c @@ -1450,10 +1450,14 @@ hash_inner_and_outer(PlannerInfo *root, * If the joinrel is parallel-safe, we may be able to consider a * partial hash join. However, we can't handle JOIN_UNIQUE_OUTER, * because the outer path will be partial, and therefore we won't be - * able to properly guarantee uniqueness. Also, the resulting path - * must not be parameterized. + * able to properly guarantee uniqueness. Similarly, we can't handle + * JOIN_FULL and JOIN_RIGHT, because they can produce false null + * extended rows. Also, the resulting path must not be parameterized. */ - if (joinrel->consider_parallel && jointype != JOIN_UNIQUE_OUTER && + if (joinrel->consider_parallel && + jointype != JOIN_UNIQUE_OUTER && + jointype != JOIN_FULL && + jointype != JOIN_RIGHT && outerrel->partial_pathlist != NIL && bms_is_empty(joinrel->lateral_relids)) { |