Hi, i have about 400,000 records on my table Cliente and about
400,000 on
Cliente_Mailing and when i run this query:

Select Cliente.Nome
From Cliente,Cliente_Mailing Where
(Cliente_Mailing.id_mailing=9 or Cliente_Mailing.id_mailing=8)
and Cliente.id_cliente=Cliente_Mailing.id_cliente
Order by nome

It Takes about 24 minutes

But if i test only Cliente_Mailing.id_mailing=9 like this:
Select Cliente.Nome
From Cliente,Cliente_Mailing Where
(Cliente_Mailing.id_mailing=9)
and Cliente.id_cliente=Cliente_Mailing.id_cliente
Order by nome

it takes 1 second

Why and how to speed the top query
Thanks