Re: [HACKERS] Hash Functions

Robert Haas <robertmhaas@gmail.com> writes:
> I think this takes care of adding not only the infrastructure but
> support for all the core data types, but I'm not quite sure how to
> handle upgrading types in contrib.  It looks like citext, hstore, and
> several data types provided by isn have hash opclasses, and I think
> that there's no syntax for adding a support function to an existing
> opclass.  We could add that, but I'm not sure how safe it would be.

ALTER OPERATOR FAMILY ADD FUNCTION ... ?

That would result in the functions being considered "loose" in the
family rather than bound into an operator class.  I think that's
actually the right thing, because they shouldn't be considered
to be required.
        regards, tom lane