RE: [PoC] pg_upgrade: allow to upgrade publisher node

Dear Julien,

> Well, even if physical replication slots were eventually preserved during
> pg_upgrade, maybe users would like to only keep one kind of the others so
> having both options could make sense.

You meant to say that we can rename options like "logical-*" and later add a new
option for physical slots if needed, right? PSA the new patch which handled the comment.

> That being said, I have a hard time believing that we could actually preserve
> physical replication slots. I don't think that pg_upgrade final state is fully
> reproducible: not all object oids are preserved, and the various pg_restore
> are run in parallel so you're very likely to end up with small physical
> differences that would be incompatible with physical replication. Even if we
> could make it totally reproducible, it would probably be at the cost of making
> pg_upgrade orders of magnitude slower. And since many people are already
> complaining that it's too slow, that doesn't seem like something we would want.

Your point made sense to me. Thank you for giving your opinion.

Best Regards,
Hayato Kuroda
FUJITSU LIMITED