Fix concurrent delete handling in MERGE ... WHEN NOT MATCHED BY SOURCE.
When executing a WHEN NOT MATCHED BY SOURCE action in MERGE, if the
tuple from the target table was concurrently deleted, the retry code
would incorrectly execute a WHEN NOT MATCHED BY TARGET action for the
row instead, giving incorrect results.
Fix in ExecMergeMatched() -- when handling a TM_Deleted failure
status, it should only set *matched to false (telling the caller to
execute any WHEN NOT MATCHED BY TARGET actions) if the failed action
was a WHEN MATCHED action. For a failed WHEN NOT MATCHED BY SOURCE
action, the source tuple did not exist, and the target tuple has just
been deleted, so it should do nothing.
Back-patch to v17, where support for WHEN NOT MATCHED BY SOURCE
actions was introduced.
Reported-by: Jeff Davis <pgsql@j-davis.com>
Author: Tender Wang <tndrwang@gmail.com>
Reviewed-by: Dean Rasheed <dean.a.rasheed@gmail.com>
Discussion: https://postgr.es/m/ccdab5ba02c65af195b5a6d2d744a01d9de47cd3.camel@j-davis.com
Backpatch-through: 17
Branch
------
REL_18_STABLE
Details
-------
https://git.postgresql.org/pg/commitdiff/ce9bd103e0e34b37187edae5e3b0bd90fedf1373
Modified Files
--------------
src/backend/executor/nodeModifyTable.c | 35 ++++--
src/test/isolation/expected/merge-delete.out | 158 +++++++++++++++++++++++++++
src/test/isolation/specs/merge-delete.spec | 37 +++++++
3 files changed, 220 insertions(+), 10 deletions(-)
