Re: Skipping logical replication transactions on subscriber side

On Mon, Jul 12, 2021 at 11:13 AM Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> wrote:
>
> On Mon, Jul 12, 2021 at 1:15 PM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
> >
> > On Mon, Jul 12, 2021 at 9:37 AM Alexey Lesovsky <lesovsky(at)gmail(dot)com> wrote:
> > >
> > > On Mon, Jul 12, 2021 at 8:36 AM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
> > >>
> > >> >
> > >> > Ok, looks nice. But I am curious how this will work in the case when there are two (or more) errors in the same subscription, but different relations?
> > >> >
> > >>
> > >> We can't proceed unless the first error is resolved, so there
> > >> shouldn't be multiple unresolved errors.
> > >
> > >
> > > Ok. I thought multiple errors are possible when many tables are initialized using parallel workers (with max_sync_workers_per_subscription > 1).
> > >
> >
> > Yeah, that is possible but that covers under the second condition
> > mentioned by me and in such cases I think we should have separate rows
> > for each tablesync. Is that right, Sawada-san or do you have something
> > else in mind?
>
> Yeah, I agree to have separate rows for each table sync. The table
> should not be processed by both the table sync worker and the apply
> worker at a time so the pair of subscription OID and relation OID will
> be unique. I think that we have a boolean column in the view,
> indicating whether the error entry is reported by the table sync
> worker or the apply worker, or maybe we also can have the action
> column show "TABLE SYNC" if the error is reported by the table sync
> worker.
>

Or similar to backend_type (text) in pg_stat_activity, we can have
something like error_source (text) which will display apply worker or
tablesync worker? I think if we have this column then even if there is
a chance that both apply and sync worker operates on the same
relation, we can identify it via this column.

--
With Regards,
Amit Kapila.