Jeff Davis <pgsql@j-davis.com> writes:
> btree_gist is essentially required for exclusion constraints to be
> useful in a practical way.
> In fact, can you submit it for the next commitfest to be included in
> core? That would allow range types and exclusion constraints to be used
> out-of-the-box in 9.2.
> Only if you think it's reasonable to put it in core, of course. If
> extensions are easy enough to install, maybe that's not really
> necessary.
btree_gist is entirely unready to be included in core.
http://archives.postgresql.org/pgsql-bugs/2010-10/msg00104.php
regards, tom lane