Re: Logical Replication of sequences

On Mon, Oct 6, 2025 at 4:33 PM vignesh C <vignesh21@gmail.com> wrote:
>
> On Mon, 6 Oct 2025 at 12:07, vignesh C <vignesh21@gmail.com> wrote:
> >
> > On Sat, 4 Oct 2025 at 21:24, Amit Kapila <amit.kapila16@gmail.com> wrote:
> > >
> > > On Tue, Sep 30, 2025 at 9:55 PM vignesh C <vignesh21@gmail.com> wrote:
> > > >
> > >
> > > In the 0001 patch, pg_get_sequence_data() exposes two new fields
> > > log_cnt and page_lsn. I see that the later subscriber-side patch uses
> > > both, the first one in SetSequence(). It is not clear from the
> > > comments or the commit message of 0001 why it is necessary to use
> > > log_cnt when setting the sequence. Can you explain what the problem
> > > will be if we don't use log_cnt during sequence sync?
> >
> > I thought to keep the log_cnt value the same value as the publisher.
> > I have verified from the upgrade that we don't retain the log_cnt
> > value after upgrade, even if we copy log_cnt, the value will not be
> > retained. The attached
> > v20251006-0001-Enhance-pg_get_sequence_data-function.patch has the
> > changes to remove log_cnt.
>
> Here is the rebased remaining patches.

While testing the patches with different combinations to make
publications, I do not understand why we don't support ALL SEQUENCE
with some table option, or is it future pending work.

postgres[1390699]=# CREATE PUBLICATION pub FOR ALL SEQUENCES, table test;
ERROR:  42601: syntax error at or near "table"
LINE 1: CREATE PUBLICATION pub FOR ALL SEQUENCES, table test;
LOCATION:  scanner_yyerror, scan.l:1236


postgres[1390699]=# CREATE PUBLICATION pub FOR table test, ALL SEQUENCES;
ERROR:  42601: syntax error at or near "all"
LINE 1: CREATE PUBLICATION pub FOR table test, all sequences;

I am doing more review/test from a usability perspective, but thought
of asking this, while I am reviewing further.

--
Regards,
Dilip Kumar
Google