Thread: pgsql: Don't allow LIMIT/OFFSET clause within sub-selects to bepushed
Don't allow LIMIT/OFFSET clause within sub-selects to be pushed to workers. Allowing sub-select containing LIMIT/OFFSET in workers can lead to inconsistent results at the top-level as there is no guarantee that the row order will be fully deterministic. The fix is to prohibit pushing LIMIT/OFFSET within sub-selects to workers. Reported-by: Andrew Fletcher Bug: 15324 Author: Amit Kapila Reviewed-by: Dilip Kumar Backpatch-through: 9.6 Discussion: https://postgr.es/m/153417684333.10284.11356259990921828616@wrigleys.postgresql.org Branch ------ REL9_6_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/568b4e1fdeb37361b1f5c5b1e1d5a1b998f7a9e9 Modified Files -------------- src/backend/optimizer/path/allpaths.c | 13 +++++++++++++ src/backend/optimizer/plan/planner.c | 3 +-- src/include/optimizer/planner.h | 2 ++ src/test/regress/expected/select_parallel.out | 19 +++++++++++++++++++ src/test/regress/sql/select_parallel.sql | 5 +++++ 5 files changed, 40 insertions(+), 2 deletions(-)