Robert Haas <robertmhaas@gmail.com> writes:
> What we need is a system where base types are represented
> by an OID, but derived types (list and functional types) are built up
> using type constructors that take other types as arguments.
This is SQL, not Haskell. What you suggest seems about two orders of
magnitude more complex than real-world applications could justify.
(so where is pl/haskell, anyway?)
regards, tom lane