]> git.ipfire.org Git - thirdparty/postgresql.git/commit
Add missing EPQ recheck for TID Scan
authorDavid Rowley <drowley@postgresql.org>
Tue, 16 Sep 2025 23:50:58 +0000 (11:50 +1200)
committerDavid Rowley <drowley@postgresql.org>
Tue, 16 Sep 2025 23:50:58 +0000 (11:50 +1200)
commit2eb7ea97d8af4f4a8c65ff9f95fcbe4e4ab8e7a8
tree7fb793d0da8656e477025d18529302714540b991
parent85d6ed31fc7cd61fb5717a29044f3b3d5f61222d
Add missing EPQ recheck for TID Scan

The EvalPlanQual recheck for TID Scan wasn't rechecking the TID qual
still passed after following update chains.  This could result in tuples
being updated or deleted by plans using TID Scans where the ctid of the
new (updated) tuple no longer matches the clause of the scan.  This isn't
desired behavior, and isn't consistent with what would happen if the
chosen plan had used an Index or Seq Scan, and that could lead to hard to
predict behavior for scans that contain TID quals and other quals as the
planner has freedom to choose TID or some other scan method for such
queries, and the chosen plan could change at any moment.

Here we fix this by properly implementing the recheck function for TID
Scans.

Backpatch to 13, oldest supported version

Reported-by: Sophie Alpert <pg@sophiebits.com>
Author: Sophie Alpert <pg@sophiebits.com>
Author: David Rowley <dgrowleyml@gmail.com>
Reviewed-by: David Rowley <dgrowleyml@gmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/4a6268ff-3340-453a-9bf5-c98d51a6f729@app.fastmail.com
Backpatch-through: 13
src/backend/executor/nodeTidscan.c
src/test/isolation/expected/eval-plan-qual.out
src/test/isolation/specs/eval-plan-qual.spec