> On Nov 19, 2024, at 10:32 AM, Kris Deugau <kdeugau(at)vianet(dot)ca> wrote:
>
> as otherwise the old PG won't start properly, due to the changes made by pg_upgrade.
Not true, pg_upgrade leaves it in a state where either can be started. By taking the snapshot after, if you roll back to it, you can attempt changes on either the old or new. (Taking care to take additional snapshots as needed, to preserve the ability to roll back to this state.)