On Tue, Apr 27, 2021 at 11:50 AM Dilip Kumar <dilipbal...@gmail.com> wrote: > > On Tue, Apr 27, 2021 at 11:43 AM Amit Kapila <amit.kapil...@gmail.com> wrote: > > > > On Mon, Apr 26, 2021 at 7:52 PM Dilip Kumar <dilipbal...@gmail.com> wrote: > > > > > > On Mon, Apr 26, 2021 at 6:59 PM Amit Kapila <amit.kapil...@gmail.com> > > > wrote: > > > > > > > > On Mon, Apr 26, 2021 at 5:55 PM Dilip Kumar <dilipbal...@gmail.com> > > > > wrote: > > > > > > > > > > I am able to reproduce this and I think I have done the initial > > > > > investigation. > > > > > > > > > > The cause of the issue is that, this transaction has only one change > > > > > and that change is XLOG_HEAP2_NEW_CID, which is added through > > > > > SnapBuildProcessNewCid. Basically, when we add any changes through > > > > > SnapBuildProcessChange we set the base snapshot but when we add > > > > > SnapBuildProcessNewCid this we don't set the base snapshot, because > > > > > there is nothing to be done for this change. Now, this transaction is > > > > > identified as the biggest transaction with non -partial changes, and > > > > > now in ReorderBufferStreamTXN, it will return immediately because the > > > > > base_snapshot is NULL. > > > > > > > > > > > > > Your analysis sounds correct to me. > > > > > > > > > > Thanks, I have attached a patch to fix this. > > > > > > > Can't we use 'txns_by_base_snapshot_lsn' list for this purpose? It is > > ensured in ReorderBufferSetBaseSnapshot that we always assign > > base_snapshot to a top-level transaction if the current is a known > > subxact. I think that will be true because we always form xid-subxid > > relation before processing each record in > > LogicalDecodingProcessRecord. > > Yeah, we can do that, but here we are only interested in top > transactions and this list will give us sub-transaction as well so we > will have to skip it in the below if condition. >
I am not so sure about this point. I have explained above why I think there won't be any subtransactions in this. Can you please let me know what am I missing if anything? -- With Regards, Amit Kapila.
