Re: User defined I/O conversion casts

(Resurrecting an old thread.)

Tom Lane wrote:
> Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com> writes:
>> Patch attached. I'm using a magic OID "1" in pg_cast.castfunc field to
>> mark these extra I/O conversion casts.
>
> Ugh. That's really unacceptable (doesn't it make the oidjoins
> regression test fail?),

Yeah, a magical OID clearly has some issues. A new field in pg_cast is
the obvious alternative. How about adding a "castmethod" char field,
with values:
b = binary-compatible cast (CREATE CAST ... WITHOUT FUNCTION)
i = I/O coercion cast (the new beast, CREATE CAST ... WITH INOUT)
f = use cast function specified in castfunc field.

castfunc is 0 for methods b and i.

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com