On Fri, 2006-03-24 at 12:21, Jim C. Nasby wrote:
> On Thu, Mar 23, 2006 at 01:09:49PM +0200, Theo Kramer wrote:
> > ii If no to i, is it feasible to extend PostgreSQL to allow traversing
> > an index in column descending and column ascending order - assuming
> > an order by on more than one column with column order not
> > in the same direction and indexes existing? ... if that makes sense.
>
> Yes.
>
> stats=# explain select * from email_contrib order by project_id desc, id desc, date desc limit 10;
> QUERY PLAN
>
------------------------------------------------------------------------------------------------------------------------
> Limit (cost=0.00..31.76 rows=10 width=24)
> -> Index Scan Backward using email_contrib_pkey on email_contrib (cost=0.00..427716532.18 rows=134656656
width=24)
> (2 rows)
Not quite what I mean - redo the above as follows and then see what
explain returns
explain select * from email_contrib order by project_id, id, date desc
limit 10;
--
Regards
Theo
