Re: Indexes with descending date columns

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)

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Jim C. Nasby, Sr. Engineering Consultant      jnasby@pervasive.com
Pervasive Software      http://pervasive.com    work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf       cell: 512-569-9461