Re: Conflict detection for update_deleted in logical replication - Mailing list pgsql-hackers

On Mon, Jul 21, 2025 at 11:27 PM Masahiko Sawada <sawada.mshk@gmail.com> wrote:
>
> On Sun, Jul 20, 2025 at 9:00 PM Amit Kapila <amit.kapila16@gmail.com> wrote:
> >
>
> > If so, I agree
> > with you, we don't need XIDs of other databases as logical WALSender
> > will anyway won't process transactions in other databases, so we can
> > exclude those. The function GetOldestActiveTransactionId() is called
> > from two places in patch get_candidate_xid() and
> > ProcessStandbyPSRequestMessage(). We don't need to care for XIDs in
> > other databases at both places but care for
> > Commit_Critical_Section_Phase when called from
> > ProcessStandbyPSRequestMessage(). So, we probably need two parameters
> > to distinguish those cases.
>
> Why do we need to include all XIDs even in the cases called from
> ProcessStandbyPSRequestMessage()?
>

No, we don't need all XIDs even in the case of
ProcessStandbyPSRequestMessage(). That is what I wrote: "The function
GetOldestActiveTransactionId() is called from two places in patch
get_candidate_xid() and ProcessStandbyPSRequestMessage(). We don't
need to care for XIDs in other databases at both places ...". Am I
missing something or you misread it?

> I guess that there is no chance that
> the changes happening on other (non-subscribed) databases could
> conflict with something on the subscriber.
>

Right.

--
With Regards,
Amit Kapila.