On Mon, Aug 15, 2022 at 4:56 PM Melih Mutlu <m.melihmu...@gmail.com> wrote: > > Hi Amit, > > Amit Kapila <amit.kapil...@gmail.com>, 6 Ağu 2022 Cmt, 16:01 tarihinde şunu > yazdı: >> >> I think there is some basic flaw in slot reuse design. Currently, we >> copy the table by starting a repeatable read transaction (BEGIN READ >> ONLY ISOLATION LEVEL REPEATABLE READ) and create a slot that >> establishes a snapshot which is first used for copy and then LSN >> returned by it is used in the catchup phase after the copy is done. >> The patch won't establish such a snapshot before a table copy as it >> won't create a slot each time. If this understanding is correct, I >> think we need to use ExportSnapshot/ImportSnapshot functionality to >> achieve it or do something else to avoid the problem mentioned. > > > I did not really think about the snapshot created by replication slot while > making this change. Thanks for pointing it out. > I've been thinking about how to fix this issue. There are some points I'm > still not sure about. > If the worker will not create a new replication slot, which snapshot should > we actually export and then import? >
Can we (export/import) use the snapshot we used the first time when a slot is created for future transactions that copy other tables? Because if we can do that then I think we can use the same LSN as returned for the slot when it was created for all other table syncs. -- With Regards, Amit Kapila.
