If I
If the index is (a,b) then

"select * from foo order by a, b" uses the index in the plan, but what I need is:

"select * from foo order by a desc, b"


How can I create a index to be used in the above sql statement?

--- In firebird-support@yahoogroups.com, "Martijn Tonies" <m.tonies@...> wrote:
>
> > I want to improve the performance of
> >
> > select * from foo order by a asc, b desc
> >
> >
> >
> > If I create 2 indexs, the plan is "natural" and the indexs are not used.
>
>
> Don't depend on indices for sorting, depend on indices for filtering.
>
>
> With regards,
>
> Martijn Tonies
> Upscene Productions
> http://www.upscene.com
>
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