Re: [PATCH] Preserve replication origin OIDs in pg_upgrade

On Wed, Jul 8, 2026 at 11:51 AM Hayato Kuroda (Fujitsu)
<kuroda(dot)hayato(at)fujitsu(dot)com> wrote:
>
> > For this reason, my inclination is to revert to the previous
> > implementation, where we compare old_cluster.nsubs with
> > max_active_replication_origins. But I'd like to hear what others think
> > before we make this change.
>
> But if origin created by users (or any extensions) have already been tracking the
> Remote_lsn, they should be taken into account. If there are three enabled
> subscriptions, two active user-created origins but the max_active_origin is set
> to three on the new node, the upgrading should fail.
>

Fair point but isn't it sufficient to check the tracked_origins rather
than all origins? In docs of max_active_replication_origins, we say:
"Setting it to a lower value than the current number of tracked
replication origins (reflected in pg_replication_origin_status) will
prevent the server from starting." which suggests here we should have
a tight check of tracked_origins against
max_active_replication_origins.

> I prefer to preserve the current behavior of the patch, which compares
> max_active_origin and total number of origins. It might cause the false-positive,
> but even now it can happen. E.g., if there was a subscription which has never
> been enabled.
>

I think it is possible that non-tracked origins (e.g for subscriptions
that get enabled only after upgrade) could lead to ERROR after upgrade
and starting the server but users can always increase
max_active_replication_origins to accommodate that which she anyway
needs to do even before upgrade.

--
With Regards,
Amit Kapila.