Re: Logical Replication of sequences

On Fri, Sep 5, 2025 at 2:46 PM vignesh C <vignesh21(at)gmail(dot)com> wrote:
>
> On Fri, 5 Sept 2025 at 04:01, Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> wrote:
> >
> > On Wed, Aug 20, 2025 at 4:57 AM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
> > >
> > > On Mon, Aug 18, 2025 at 3:36 PM vignesh C <vignesh21(at)gmail(dot)com> wrote:
> > > >
> > > > Thanks for the comments, the updated version has the changes for the same.
> > > >
> > >
> > > I wanted to first discuss a few design points. The patch implements
> > > "ALTER SUBSCRIPTION ... REFRESH PUBLICATION SEQUENCES" such that it
> > > copies the existing sequences values and also adds/removes any missing
> > > sequences. For the second part (add/remove sequences), we already have
> > > a separate command "ALTER SUBSCRIPTION ... REFRESH PUBLICATION". So, I
> > > feel the new command should only copy the sequence values, as that
> > > will keep the interface easy to define and understand. Additionally,
> > > it will help to simplify the code in the patch, especially in the
> > > function AlterSubscription_refresh.
> >
> > While I agree that the new command just copies the sequence values,
> > I'm not sure the command should be implemented as an extension of
> > ALTER SUBSCRIPTION ... REFRESH PUBLICATION command. Probably what the
> > new command does is quite different from what REFRESH PUBLICATION
> > command does?
>
> Alternatively, the syntax options could be:
> ALTER SUBSCRIPTION subname RESYNC PUBLICATION SEQUENCES;
> or
> ALTER SUBSCRIPTION subname RESYNC SEQUENCES;
>

The other option on these lines is to use SYNC instead of RESYNC as
for users RESYNC sounds more like redo where something has failed and
we are trying to do it again. Also, this will be used even for the
first time sync of sequences. I prefer the first alternative among
these as having the PUBLICATION keyword suggests that we are syncing
the sequences corresponding to all the publications that are part of
subscription but I am okay with the second too.

--
With Regards,
Amit Kapila.