Garfield Lewis <garfield.le...@lzlabs.com> writes:
> I think you are right in the case of INPUT/RECEIVE, however we should be able
> to get that info during OUTPUT/SEND (I think) since it is fixed at that
> point. At the time I return the information to the user I could augment the
> output to add that information to the output. However, I still don't know if
> it is even possible to get that information in those functions. Is that at
> all possible?
No, it's the same problem in reverse: the output function cannot
know where the value came from. There is no hard and fast
reason that it must have come out of a table, either. Consider
something as simple as
SELECT 'blah blah'::yourtype;
This'll invoke the type's input function to parse the literal string,
and later it'll invoke the output function to reconstruct a string
to send to the client, and there's no table involved.
regards, tom lane
