Bruce Momjian <pgman@candle.pha.pa.us> writes:
> Yes, good point about pg_shadow. They don't have databases. How do we
> get multiple pg_class tables in the same directory? Is the
> pg_class.relversion file a number like 1,2,3,4, or does it come out of
> some global counter like oid. If so, we could put them in the same
> directory.
I think we could get away with insisting that each database store its
pg_class and friends in a separate tablespace (physically distinct
directory) from any other database. That gets around the OID conflict.
It's still an open question whether OID+version is better than
unique-ID for naming files that belong to different versions of the
same relation. I can see arguments on both sides.
regards, tom lane