On Sat, Sep 13, 2025 at 3:12 PM, Sophie Alpert <[email protected]> wrote: > And indeed, like I mentioned in my previous message, my isolation test > `permutation tid1 tidsucceed2 c1 c2 read` from eval-plan-qual.spec in > my patch will fail if Recheck were to return false in this case. Though > somewhat contrived, you can imagine this happening with multiple > sessions driven by the same application:
Another case where returning FALSE does not give the correct behavior is when two relations are involved, only one of which is modified: S1: BEGIN; S2: BEGIN; S1: UPDATE accounts SET balance = balance + 100 WHERE ctid = '(0,1)' RETURNING accountid, balance; S2: SELECT * FROM accounts JOIN accounts_ext USING (accountid) WHERE accounts_ext.ctid = '(0,1)' FOR UPDATE OF accounts; S1: COMMIT; S2: COMMIT; In my patch the S2 query correctly returns one row, whereas with your proposed change it incorrectly returns none. accountid|balance|balance2|balance|other|newcol|newcol2 ---------+-------+--------+-------+-----+------+------- checking | 700| 1400| 600|other| 42| Sophie
