Hannu Krosing <hannuk(at)google(dot)com> writes:
> I think we do preserve role oids
Oh ... I'd been looking for mentions of "role" in
pg_upgrade_support.c, but what I should have looked for was
"pg_authid". So yeah, we do preserve role OIDs, and maybe that's
enough to make this workable, at least with source versions that
share the same rules for what goes into pg_largeobject_metadata and
pg_shdepend. It's not something I'd risk back-patching though.
regards, tom lane