Re: Question about explain of index scan

On Fri, Sep 02, 2005 at 11:03:24AM -0400, Tom Lane wrote:
> Alvaro Herrera <alvherre@alvh.no-ip.org> writes:
> > I wonder why we don't support more operators on Xid, so these things are
> > avoided?  Right now we only have =, AFAIR.
> 
> I once started to make a btree opclass for XID, and stopped when it
> occurred to me that XID comparison doesn't obey the transitive law.
> btree won't like that...

Not having it does affect the planner somehow, right?

Maybe we could have the opclass but somehow dictate that making indexes
with it is verboten.

-- 
Alvaro Herrera -- Valdivia, Chile         Architect, www.EnterpriseDB.com
"Right now the sectors on the hard disk run clockwise, but I heard a rumor that
you can squeeze 0.2% more throughput by running them counterclockwise.
It's worth the effort. Recommended."  (Gerry Pourwelle)