Jeff Davis <pgsql@j-davis.com> writes: > On Sat, 2023-03-04 at 18:04 -0500, Dave Cramer wrote: >> Most of the clients know how to decode the builtin types. I'm not >> sure there is a use case for binary encode types that the clients >> don't have a priori knowledge of.
> The client could, in theory, have a priori knowledge of a non-builtin > type.
I don't see what's "in theory" about that. There seems plenty of use for binary I/O of, say, PostGIS types. Even for built-in types, do we really want to encourage people to hard-wire their OIDs into applications?
How does a client read these? I'm pretty narrowly focussed. The JDBC API doesn't really have a way to read a non built-in type. There is a facility to read a UDT, but the user would have to provide that transcoder. I guess I'm curious how other clients read binary UDT's ?
I don't see a big problem with driving this off a GUC, but I think it should be a list of type names not OIDs. We already have plenty of precedent for dealing with that sort of thing; see search_path for the canonical example. IIRC, there's similar caching logic for temp_tablespaces.
I have no issue with allowing names, OID's were compact, but we could easily support both
