On Sun, 2021-01-17 at 17:07 -0500, Tom Lane wrote: > Peter Eisentraut <peter.eisentr...@2ndquadrant.com> writes: > > [ v2-0001-Add-primary-keys-and-unique-constraints-to-system.patch ] > > [...] do we really want to prefer > using the OID indexes as the primary keys? In most cases there's some > other index that seems to me to be what a user would think of as the > pkey, for example pg_class_relname_nsp_index for pg_class or > pg_proc_proname_args_nsp_index for pg_proc. Preferring OID where it > exists is a nice simple rule, which has some attractiveness, but the > OID indexes seem to me like a lookup aid rather than the "real" object > identity.
I disagree. The OID is the real, immutable identity of an object. The "relname" of a "pg_class" encatalogtry can change any time. Since there are no foreign keys that reference catalogs, that won't cause problems, but I still think that primary keys should change as little as possible. Yours, Laurenz Albe
