| From: | Thomas Munro <tmunro(at)postgresql(dot)org> |
|---|---|
| To: | pgsql-committers(at)lists(dot)postgresql(dot)org |
| Subject: | pgsql: Prevent Parallel Hash Join for JOIN_UNIQUE_INNER. |
| Date: | 2019-06-18 14:20:44 |
| Message-ID: | E1hdEya-0008P7-Bg@gemulon.postgresql.org |
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| Lists: | pgsql-committers |
Prevent Parallel Hash Join for JOIN_UNIQUE_INNER.
WHERE EXISTS (...) queries cannot be executed by Parallel Hash Join
with jointype JOIN_UNIQUE_INNER, because there is no way to make a
partial plan totally unique. The consequence of allowing such plans
was duplicate results from some EXISTS queries.
Back-patch to 11. Bug #15857.
Author: Thomas Munro
Reviewed-by: Tom Lane
Reported-by: Vladimir Kriukov
Discussion: https://postgr.es/m/15857-d1ba2a64bce0795e%40postgresql.org
Branch
------
REL_11_STABLE
Details
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https://git.postgresql.org/pg/commitdiff/14d8b539d3bd4cf9faf65ca86a733bada202107f
Modified Files
--------------
src/backend/optimizer/path/joinpath.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
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