On Tue, 13 Sept 2022 at 12:40, Pantelis Theodosiou <yperc...@gmail.com> wrote: > > Forgive me if this is not related but if there is a savepoint between > the insertion and deletion, wouldn't it be possible for the > transaction to recover the deleted tuples?
Savepoints result in changed TransactionIds (well, subtransactions with their own ids), so if a tuple was created before a savepoint and deleted after, the values in xmin and xmax would be different, as you can see in the following: matthias=> CREATE TABLE tst(i int); matthias=> BEGIN; INSERT INTO tst VALUES (1); SAVEPOINT s1; DELETE FROM tst; ROLLBACK TO SAVEPOINT s1; CREATE TABLE BEGIN INSERT 0 1 SAVEPOINT DELETE 1 ROLLBACK matthias=*> SELECT xmin, xmax FROM tst; xmin | xmax -------+------- 62468 | 62469 (1 row) Note that this row has different xmin/xmax from being created and deleted in different subtransactions. This means that this needs no specific handling in the HTSVH code that Laurenz asked about. Kind regards, Matthias van de Meent
