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

On Mon, Jul 21, 2025 at 8:49 PM Amit Kapila <amit.kapila16@gmail.com> wrote:
>
> 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?

Oh I misread it. Sorry for the noise.

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

I've reviewed the 0001 patch and it looks good to me. The patch still
has XXX comments at several places. Do we want to keep all of them as
they are (i.e., as something like TODO or FIXME)?

Regards,

--
Masahiko Sawada
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