Re-allow planner to use Merge Append to efficiently implement UNION.
This reverts commit 7204f35919b7e021e8d1bc9f2d76fd6bfcdd2070,
thus restoring 66c0185a3 (Allow planner to use Merge Append to
efficiently implement UNION) as well as the follow-on commits
d5d2205c8, 3b1a7eb28, 7487044d6.
Per further discussion on pgsql-release, we wish to ship beta1 with
this feature, and patch the bug that was found just before wrap,
rather than shipping beta1 with the feature reverted.
Branch
------
master
Details
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https://git.postgresql.org/pg/commitdiff/12933dc6048902ba891f9572cab96981f50ef669
Modified Files
--------------
contrib/postgres_fdw/expected/postgres_fdw.out | 7 +
contrib/postgres_fdw/sql/postgres_fdw.sql | 9 +
src/backend/optimizer/path/allpaths.c | 5 +-
src/backend/optimizer/path/equivclass.c | 61 +++
src/backend/optimizer/path/pathkeys.c | 19 +
src/backend/optimizer/plan/planner.c | 116 +++-
src/backend/optimizer/plan/subselect.c | 15 +-
src/backend/optimizer/prep/prepunion.c | 720 +++++++++++++++++--------
src/backend/parser/analyze.c | 3 +-
src/include/nodes/pathnodes.h | 2 +
src/include/optimizer/paths.h | 4 +
src/include/optimizer/planner.h | 3 +-
src/include/optimizer/prep.h | 2 +-
src/test/regress/expected/collate.icu.utf8.out | 2 +
src/test/regress/expected/incremental_sort.out | 13 +-
src/test/regress/expected/union.out | 46 +-
src/test/regress/sql/collate.icu.utf8.sql | 2 +
src/test/regress/sql/union.sql | 19 +-
18 files changed, 761 insertions(+), 287 deletions(-)