From: David Rowley <drowley@postgresql.org>
To: pgsql-committers@lists.postgresql.org
Subject: pgsql: Add missing EPQ recheck for TID Range Scan
Date: Wed, 17 Sep 2025 00:20:09 +0000
Message-ID: <E1uyfu5-00156f-06@gemulon.postgresql.org> (raw)
Add missing EPQ recheck for TID Range Scan
The EvalPlanQual recheck for TID Range 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 Range 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 Range or some other non-TID 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
Range Scans.
Backpatch to 14, where TID Range Scans were added
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: 14
Branch
------
REL_18_STABLE
Details
-------
https://git.postgresql.org/pg/commitdiff/78e6047dcea588ec127f6a71c7cebd5c0f41d795
Modified Files
--------------
src/backend/executor/nodeTidrangescan.c | 10 ++++++++++
src/test/isolation/expected/eval-plan-qual.out | 23 +++++++++++++++++++++++
src/test/isolation/specs/eval-plan-qual.spec | 5 ++++-
3 files changed, 37 insertions(+), 1 deletion(-)
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To: pgsql-committers@postgresql.org
Cc: drowley@postgresql.org, pgsql-committers@lists.postgresql.org
Subject: Re: pgsql: Add missing EPQ recheck for TID Range Scan
In-Reply-To: <E1uyfu5-00156f-06@gemulon.postgresql.org>
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