Robert Haas <robertmhaas@gmail.com> writes:
> If your point here is that you don't want to spend time hacking on
> this because it's a fairly marginal feature and therefore not terribly
> high on your priority list, I can understand that. But if you're
> actually defending the current implementation, I'm going to have to
> respectfully disagree. It's broken, and it sucks, and this is not the
> first complaint we've had about it.
The spec's definition of USING is broken and sucky, and we're
implementing it as best we can. I don't feel a need to invent
strange nonstandard behavior to work around the fact that USING
is fragile *by definition*. Complain to the standards committee
about that.
(Question: would you also have us try to work around the fact that
USING stops working if you rename one of the join columns?)
regards, tom lane