dear seam,

i just answer to dmitry.

i just want to add that a natural scan is not possible because of the amount of row (8 000 000 and the requierement is to make the system working on more than 80 000 000 row).

we must found a wa out using the index or denormalize the database or something else ?

thanks for all !
stephane

--- In firebird-support@yahoogroups.com, "Leyne, Sean" <Sean@...> wrote:
>
> Dimitry,
>
> > > create a index on (fieldA, fieldB) seam to no help too much (it's
> > speed only the work on FieldA, but not on fieldB)
> >
> > Drop this useless composite index and create two indexes one single
> > fields. i.e. index on fieldA and another index on fieldB.
>
> You don't have enough information to make such a broad statement!
>
> It is possible that indexing either column is the wrong answer, and that a natural table scan would be the faster approach.
>
> But to know the correct answer we need to ask questions, and not jump to conclusions.
>
>
> Sean
>