Re: Indexes with descending date columns

On Thu, 2006-03-23 at 16:16, Alvaro Herrera wrote:
> Theo Kramer wrote:
>
> > All good input - thanks, however, before I start messing with my stuff
> > which I know will be complex - some questions to any of the developers
> > on the list.
> >
> > i Is it feasible to extend index creation to support descending
> > columns? ... this is supported on other commercial and non
> > commercial databases, but I do not know if this is a SQL standard.
>
> This can be done. You need to create an operator class which specifies
> the reverse sort order (i.e. reverse the operators), and then use it in
> the new index.

Hmmm, would that then result in the following syntax being valid?

create index my_idx on my_table (c1, c2 desc, c3, c4 desc) ;

where my_table is defined as

create table my_table (
c1 text,
c2 timestamp,
c3 integer,
c4 integer
);

If so, I would appreciate any pointers on where to start on this -
already fumbling my way through Interfacing Extensions To Indexes in the
manual...

Regards
Theo
--
Regards
Theo