Re: Skipping logical replication transactions on subscriber side

On Tue, Jan 11, 2022 at 11:22 AM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
>
> On Mon, Jan 10, 2022 at 2:57 PM vignesh C <vignesh21(at)gmail(dot)com> wrote:
> >
> > 2) Can we have an option to specify last_error_xid of
> > pg_stat_subscription_workers. Something like:
> > alter subscription sub1 skip ( XID = 'last_subscription_error');
> >
> > When the user specified last_subscription_error, it should pick
> > last_error_xid from pg_stat_subscription_workers.
> > As this operation is a critical operation, if there is an option which
> > could automatically pick and set from pg_stat_subscription_workers, it
> > would be useful.
> >
>
> I think having some automatic functionality around this would be good
> but I am not so sure about this idea because it is possible that the
> error has not reached the stats collector and the user might be
> referring to server logs to set the skip xid. In such cases, even
> though an error would have occurred but we won't be able to set the
> required xid. Now, one can imagine that if we don't get the required
> value from pg_stat_subscription_workers then we can return an error to
> the user indicating that she can cross-verify the server logs and set
> the appropriate xid value but IMO it could be confusing. I feel even
> if we want some automatic functionality like you are proposing or
> something else, it could be done as a separate patch but let's wait
> and see what Sawada-San or others think about this?

Agreed. The automatically setting XID would be a good idea but we can
do that in a separate patch so we can keep the first patch simple.

Regards,

--
Masahiko Sawada
EDB: https://www.enterprisedb.com/