Re: review: More frame options in window functions

Dimitri Fontaine <dfontaine@hi-media.com>

From: Dimitri Fontaine <dfontaine@hi-media.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Robert Haas <robertmhaas@gmail.com>, Martijn van Oosterhout <kleptog@svana.org>, Hitoshi Harada <umi.tanuki@gmail.com>, Erik Rijkers <er@xs4all.nl>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2010-02-11T21:33:34Z
Lists: pgsql-hackers
Tom Lane <tgl@sss.pgh.pa.us> writes:
> However, what it *is* associated with is a sort ordering, and the notion
> that btree opclasses are what define orderings is sufficiently deeply
> wired into the system that undoing it would be a huge PITA.  So unless
> we can see a pretty clear future need for more information in this
> category, I'm not really inclined to invent some new structure
> altogether.  I'm just wondering if anyone does see that...

I think there's the associativity property of operators that we might
want to have someday, in order for the planner to know some more about
joins on A = B then on B = C, or replace with < if you will.

Regards,
-- 
dim