Re: small exclusion constraints patch

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Bruce Momjian <bruce@momjian.us>, Jeff Davis <pgsql@j-davis.com>, pgsql-hackers@postgresql.org
Date: 2010-05-29T22:11:57Z
Lists: pgsql-hackers
Robert Haas <robertmhaas@gmail.com> writes:
> The only disadvantage I see of just documenting this is that someone
> might write a user-defined index opclass that works like this, and
> they won't be able to use this until at least 9.1 (or at least, not
> without patching the source).

I don't actually think that anyone's very likely to write a <>-like index
operator.  It's approximately useless to use an index for such a query.

Or, to put it differently: if nobody's done that in the past twenty
years, why is it likely to happen before 9.1?

			regards, tom lane