Re: [PATCH] Preserve replication origin OIDs in pg_upgrade

On Thu, Apr 30, 2026 at 7:37 PM shveta malik <shveta(dot)malik(at)gmail(dot)com> wrote:
>
>
> I’m not sure how preserving the subscription OID would ensure that the
> origin ID is also preserved for sub-associated origins. Could you
> please elaborate?
>
> As I understand it, roident values are assigned independently during
> origin creation. Even if subscription OIDs are preserved, the origin
> IDs could still be reassigned differently on the new cluster. For
> example, suppose we have two subscriptions, sub1 and sub2, with
> roident values 2 and 3, assuming 1 was previously used and dropped.
> After upgrade, origin creation may start allocating from 1 again,
> resulting in roident values 1 and 2 instead. Since pg_commit_ts stores
> the numeric roident, not the origin name, this mismatch could still
> lead to incorrect conflict detection. Wouldn’t that result in the same
> wrong conflict detection issue we are trying to avoid?
> Please let me know if my understanding is wrong.

In the first patch, the replication origins were duplicated from the
old cluster to the new with matching roidents and ronames. This
couldn't be done for subscription replication origins as subscriptions
weren't preserving OIDs on the new cluster and therefore the
corresponding roname which is derived from the subscription OIDs also
differed. Now with matching roname and roident, all the replication
origins from the old cluster can be copied over to the new cluster in
one shot.

regards,
Ajin Cherian
Fujitsu Australia