Re: pg_upgrade: optimize replication slot caught-up check

On Wed, Jan 28, 2026 at 10:06 PM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
>
> On Wed, Jan 28, 2026 at 2:06 AM Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> wrote:
> >
> > I missed fixing one place. Attached the new version.
> >
>
> One question/comment on following change:
> + bool use_fast_caught_up_check;
> +
> + logical_slot_infos_query = get_old_cluster_logical_slot_infos_query(cluster,
> + &use_fast_caught_up_check);
> +
> upgrade_task_add_step(task,
> logical_slot_infos_query,
> process_old_cluster_logical_slot_infos,
> true, NULL);
> +
> + /*
> + * Check whether slots have consumed all WAL records efficiently by
> + * using another query, if not during a live_check.
> + */
> + if (use_fast_caught_up_check && !user_opts.live_check)
> + {
>
> Won't this lead to two steps to set caught_up for slots in PG19 and
> following versions? If so, is it possible to use just one step even
> for PG19 and following versions?

Yes, it seems like a good simplification. I've updated the patch accordingly.

Regards,

--
Masahiko Sawada
Amazon Web Services: https://aws.amazon.com