Re: [PATCH] Preserve replication origin OIDs in pg_upgrade

On Mon, 18 May 2026 at 16:13, Ajin Cherian <itsajin(at)gmail(dot)com> wrote:
>
> Rebased the patch as it was no longer applying.
>
Hi Ajin,

I have started reviewing the patch. Here is my comment for v6-0002 patch:

Suppose we have a replication setup: publisher -> subscriber
and we are upgrading subscriber to subscriber_new.
And if initially 'subscriber_new' has a replication origin, upgrading
the cluster can error out.

Example:
We set up a logical replication between publisher node and subscriber node.

On subscriber node:
postgres=# SELECT * FROM pg_replication_origin;
roident | roname
---------+----------
1 | pg_16393
(1 row)

And initially subscriber_new has a replication origin:
postgres=# select pg_replication_origin_create('myname');
pg_replication_origin_create
------------------------------
1
(1 row)

postgres=# SELECT * FROM pg_replication_origin;
roident | roname
---------+--------
1 | myname
(1 row)

Now, if we run pg_upgrade to upgrade subscriber node to subscriber_new
node, we get an error:
```
SELECT pg_catalog.binary_upgrade_create_replication_origin('1'::pg_catalog.oid,
'pg_16393'::pg_catalog.name, '0/01743078'::pg_catalog.pg_lsn);
psql:subscriber_new/pg_upgrade_output.d/20260522T140312.807/dump/pg_upgrade_dump_globals.sql:37:
ERROR: replication origin with ID 1 already exists
```

This error occurs in "Performing Upgrade" stage. Should we add a check
in the "Performing Consistency Checks" stage so that we don't need to
re-initdb the new cluster to perform the upgrade?
Maybe we can add a check similar to
check_new_cluster_replication_slots(), where pg_upgrade errors out if
the new cluster already contains replication origins. Thoughts?

Thanks,
Shlok Kyal