Re: ToDo: add documentation for operator IS OF

"Pavel Stehule" <pavel(dot)stehule(at)hotmail(dot)com> writes:
> Nobody worked on this subject a lot of years. Who need it, knows about it
> and use it. I am for this topic is documented and in doc is note about
> difference from standard and about some incompletness of this operator.

Once we document it there's going to be a backward-compatibility issue
for any proposals to fix it. And I do think it is broken in a number
of ways:
http://archives.postgresql.org/pgsql-patches/2003-08/msg00060.php

Per the link Joe cited, I'm not real thrilled with the spec's special
treatment of NULL, but I'd like to see us fix IS OF so that it can be
a substitute for testing tableoid to see which child table a tuple
came from. And we definitely need to consider the domain issue.

regards, tom lane