Re: Add hint for function named "is"

Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> Half a percent for two productions is not bad, but I think the real
> win would be in removing ambiguity from the grammar. We get periodic
> complaints about the fact that things like "SELECT 3 cache" don't work
> because cache is an unreserved keyword, and postfix operators are one
> of the reasons why we can't do better:

Agreed, if postfix operators were the only thing standing between us and
fixing that, it would be a pretty strong argument for removing them.

> I think I experimented with this a while ago and found that even after
> removing postfix operators there was at least one other grammar
> problem that prevented us from accepting ColLabel there. I gave up
> and didn't dig further, but maybe we should.

Yes, it would be good to find that out. I think there's a whole bunch of
intertwined issues there, though; this isn't likely to be an easy change.
The comment at gram.y lines 679ff lists several things that are relevant,
and might or might not be simplifiable without postfix ops.

regards, tom lane