On Friday, August 9, 2024 7:45 PM Michail Nikolaev <michail.nikol...@gmail.com> wrote: > There are some comments on this patch related to issue [0]. In short: any > DirtySnapshot index scan may fail to find an existing tuple in the case of a > concurrent update. > > - FindConflictTuple may return false negative result in the case of > concurrent update because > ExecCheckIndexConstraints uses SnapshotDirty. > - As a result, CheckAndReportConflict may fail to report the conflict. > - In apply_handle_update_internal we may get an CT_UPDATE_MISSING instead of > CT_UPDATE_DIFFER > - In apply_handle_update_internal we may get an CT_DELETE_MISSING instead of > CT_DELETE_DIFFER > - In apply_handle_tuple_routing we may get an CT_UPDATE_MISSING instead of > CT_UPDATE_DIFFER > > If you're interested, I could create a test to reproduce the issue within the > context of logical replication. Issue [0] itself includes a test case to > replicate the problem. > > It also seems possible that a conflict could be resolved by a concurrent > update > before the call to CheckAndReportConflict, which means there's no guarantee > that the conflict will be reported correctly. Should we be concerned about > this?
Thanks for reporting. I think this is an independent issue which can be discussed separately in the original thread[1], and I have replied to that thread. Best Regards, Hou zj
