Re: Functions returning sets

Don Baccus <dhogaza@pacifier.com> writes:
> What's so hard about writing "IN" rather than "=" ???

Even more to the point, if we did adopt such a (crazy IMHO)
interpretation of '=', what makes anyone think that it'd be
any more efficient than IN?

AFAICT, mlw is hoping that redefining '=' would magically avoid the
performance problems with IN, but my bet is it'd be just the same.

What we need to do is teach the system how to handle WHERE ... IN ...
as a form of join.  Changing semantics of operators isn't necessary
nor helpful.
        regards, tom lane