No, this kind of statement will not use an index at all, at least not in
Firebird 1.0. In fact, I often add OR to my statements to prevent Firebird
from using indexes.

Set

At 09:03 15.07.2003 +0000, you wrote:

>Thanks Markus.
>
>Does anyone know whats the performance of this kind of sql?
>
> select *
> from customer
> where (type = :paramtype) or (Cast('*' as VarChar(3)) = :paramtype)
>
>Does it uses the indexes properly? how about on large table?