Ludek Finstrle <luf@pzkagis.cz> writes:
> I don't want to reinvent the wheel.
Why do you feel a need to distinguish the domain from its underlying
type on the client side? They're the same as regards representation
and so on.
The reason for the backend change was that client-side drivers (such as
JDBC and ODBC) want to know the underlying datatype so that they know
what representation to use etc. Distinguishing domains made their job
harder not easier.
If you want an add-on datatype that is really different from OID, then
make a real datatype (CREATE TYPE). You can still piggyback on OID as
the representation type --- steal its I/O functions and so on.
regards, tom lane