Re: operator exclusion constraints [was: generalized index constraints]

On Sun, 2009-09-20 at 13:28 -0400, Tom Lane wrote:
> What I'm arguing for is a syntax in which the question doesn't even
> arise, ie, a CONSTRAINT doesn't reference an existing index at all.
> If that's not possible for whatever reason, then I think that
> disallowing multiple references isn't going to buy any simplicity.

I believe that syntax is possible by specifying the index access method,
e.g.:

  CONSTRAINT <name> EXCLUSION (a =, b &&) USING gist;

versus:

  CONSTRAINT <name> EXCLUSION (a =, b &&) INDEX <indexname>;

And the former could build the index implicitly. I haven't written the
code yet, but I don't see any major problems.

So, should I eliminate the latter syntax and only support the former, or
should I support both?

Regards,
	Jeff Davis