On Tue, Jul 20, 2021 at 9:54 AM Amit Kapila <amit.kapila16@gmail.com> wrote:
>
> On Mon, Jul 19, 2021 at 4:31 PM Dilip Kumar <dilipbalaut@gmail.com> wrote:
> >
> > On Mon, Jul 19, 2021 at 3:12 PM Amit Kapila <amit.kapila16@gmail.com> wrote:
> >
> > > > Maybe a second option is to have replication change any UPDATE into
> > > > either an INSERT or a DELETE, if the old or the new row do not pass the
> > > > filter, respectively. That way, the databases would remain consistent.
> >
> > Yeah, I think this is the best way to keep the data consistent.
> >
>
> Today, while studying the behavior of this particular operation in
> other databases, I found that IBM's InfoSphere Data Replication does
> exactly this. See [1]. I think there is a merit if want to follow this
> idea.
>
As per my initial analysis, there shouldn't be much difficulty in
implementing this behavior. We need to change the filter API
(pgoutput_row_filter) such that it tells us whether the filter is
satisfied by the old row, new row or both and then the caller should
be able to make a decision based on that. I think that should be
sufficient to turn update to insert/delete when required. I might be
missing something here but this doesn't appear to require any drastic
changes in the patch.
--
With Regards,
Amit Kapila.
