Do you have another, smaller table with one record for each store? If
so, you could try:

select st.store_no
from store_table st
where exists(select * from big_table bt
where bt.store_no = st.store_no)

Such a query could benefit from the index on big_table and should be
reasonably fast.

HTH,
Set

--- In firebird-support@yahoogroups.com, "buppcpp" wrote:
> It has nothing to do with normalization, store_no is part of a 2
> field primary key.
>
> But instead of wondering why another database can handle these types
> of queries so fast and Firebird can't, and what we can do to
> possible make Firebird run better in these situations, you want to
> try to belittle the person that is looking for answers.
>
> I'm trying to become a potentially large customer of IBPhoenix and
> the only way that can happen is if Firebird can at "least" do what
> my current database can do.