>Putting timing aside, does this query really give you what you want? To me it looks like Invoice join has no role other than checking if the client has an invoice with that amount (if a particular client has 2 or more matches?). Maybe a query like this would be more appropriate:
>
>

>-- If it is OK that you are not interested 
>-- in records that are modified after you passed them
>set transaction isolation level read uncommitted
>
>SELECT Numero 
>FROM Client
>WHERE 
>  NoEntity=@NoEntity AND 
>  Fic_Date < @Fic_Date AND 
>  Loss_Code=@Loss_Code AND 
>  CType=@CType AND
>  Numero in
>  (SELECT NoClient FROM Invoice WHERE Invoice.Amount=@Amount)
>

Thanks, I tried to create an example as close as the one we have. But, this approach is also something I tried. So, once we test it, I will be able to see if that helps. This is something that never caused a problem in VFP but only in SQL Server.