> -----Original Message-----
> From: pgsql-hackers-owner@hub.org [mailto:pgsql-hackers-owner@hub.org]On
> Behalf Of Zeugswetter Andreas SB
>
> > I still think there must be sorting going on, as the result
> > is returned
> > instantly if you remove the ORDER BY. I don't know - I do think it's
> > much better now.
>
> Are you doing the exact query I wrote for you ?
> That is:
> order by mail_list desc, mail_date desc
>
> explain should tell you if it does a sort. There should not be a
> difference
> with
> or without the order by.
> Hiroshi, I think you implemented the backwards index scan ?
Yes,but I didn't implement backwards index path for cost estimate.
Regards.
Hiroshi Inoue
Inoue@tpf.co.jp
