1/2 Hey , we’ve observed on 13.3 snapshot recovery conflict on standby despite hot_standby_feedback = on. That’s on "Btree/REUSE_PAGE” where the btpo xact is soo old leading to the diff in TransactionIdFollows() being >= 2^31 +1 so “wrongly” returning false.
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2/2 It looks like e5d8a999030418a1b9e53d5f15ccaca7ed674877 is fixing this as using ResolveRecoveryConflictWithSnapshotFullXid() in btree_xlog_reuse_page(). Do you agree?
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Wish it could have been backported... but that's a really big non-trivial diff and likely an uncommon problem, I can see why it could be pg14 only
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right! Did not look at the details yet but i'm wondering if the whole patch needs to be back-ported to fix this particular issue (means if the PG 14 patch fixes multiples issues and only a "subset" could be back-ported for this particular issue).
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Is the concern just that the page cannot be reused indefinitely? Or something else as well?
The concern is that there is « false » snapshot recovery conflict if the diff between the backend xid on the standby and the btpo xact is > 2^31 + 1 . This is due to the (int32) casting in TransactionIdFollows().
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Yes - IIUC sounds like it breaks some queries on hot standby