On Wed, Jun 19, 2024 at 09:17:00AM -0400, Robert Haas wrote: > OK, I have a (probably) stupid question. The comment says: > > + * In binary upgrade mode, we can skip this checkpoint because neither of > + * these problems applies: we don't ever replay the WAL generated during > + * pg_upgrade, and we don't concurrently modify template0 (not to mention > + * that trying to take a backup during pg_upgrade is pointless). > > But what happens if the system crashes during pg_upgrade? Does this > patch make things worse than they are today? And should we care?
My understanding is that you basically have to restart the upgrade from scratch if that happens. I suppose there could be a problem if you try to use the half-upgraded cluster after a crash, but I imagine you have a good chance of encountering other problems if you do that, too. So I don't think we care... -- nathan