Re: Determining which index to create

On Wed, Nov 21, 2001 at 12:53:09PM +0100, Eric Cholet wrote:
> I should have mentionned I tried that, but it isn't being used:
>
> => \d dico_frs_motid_date
>      Index "dico_frs_motid_date"
>  Attribute |           Type
> -----------+--------------------------
>  motid     | integer
>  date      | timestamp with time zone
> btree
>
> => explain select * from dico_frs where motid=4742 order by date desc limit
> 10;
> NOTICE:  QUERY PLAN:
>
> Limit  (cost=0.00..17591.91 rows=10 width=16)
>   ->  Index Scan Backward using dico_frs_date on dico_frs
> (cost=0.00..20023641.63 rows=11382 width=16)

Well, it is doing the scan backwards, which is good. But it's not using the
index. If you drop dico_frs_date index, does it do it then?

Oh, and what version of postgres was this again?
--
Martijn van Oosterhout <kleptog@svana.org>
http://svana.org/kleptog/
> Magnetism, electricity and motion are like a three-for-two special offer:
> if you have two of them, the third one comes free.