Re: OO database?

After a long battle with technology, db@traceroute.dk (Socketd), an earthling, wrote:
> Hi all
>
> I can see Postgresql calls itself a "object-relational database
> management system", but what's the object part of it?
>
> I have found inheritance, but are there more OO features in postgresql?

It offers "method dispatch" where the system can invoke different
methods dependent on the types of values passed into a function.
--
select 'cbbrowne' || '@' || 'acm.org';
http://www3.sympatico.ca/cbbrowne/sgml.html
Q: What does the function NULL do?
A: The function NULL tests whether or not its argument is NIL or not.  If
   its argument is NIL the value of NULL is NIL.
-- Ken Tracton, Programmer's Guide to Lisp, page 73.