Re: Logical Replication of sequences - Mailing list pgsql-hackers

From vignesh C
Subject Re: Logical Replication of sequences
Date
Msg-id CALDaNm358_xkcedVhey0EQ5je0=1pFvHvUQB6nQV=sEFtFzydw@mail.gmail.com
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In response to Re: Logical Replication of sequences  (Amit Kapila <amit.kapila16@gmail.com>)
Responses Re: Logical Replication of sequences
List pgsql-hackers
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.

Regards,
Vignesh

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