On Jul 25, 2:14 am, Lew <l...@lewscanon.nospam> wrote:
>
> How about two indexes, one on each column? Then the indexes will cooperate
> when combined in a WHERE clause.
> <http://www.postgresql.org/docs/8.2/interactive/indexes-bitmap-scans.html>
>
> I don't believe the index makes a semantic difference with regard to ascending
> or descending. An index is used to locate records in the selection phase of a
> query or modification command.
>
> --
> Lew
Ordered indexes (b-tree in this case) are also used to get the needed
record order and it is absolutely not necessary to have a WHARE clause
in your select statement to use them when you are using ORDER BY.
--
Valentine
