Em 15/7/2010 08:12, Andreas Rulle escreveu:

> Hello,
> This query (extremely simplified) uses no Index:
>
> select t1.s1 from t1 left join t2 on t1.s1=t2.s1
>
> PLAN JOIN (T1 NATURAL,T2 NATURAL)
>
>

It's strange, it should use the index.

> Question: What can be done to optimize the statement on Firebird 2.1.3?
>
>

I don't know what you did to upgrade from 1.X to 2.X

Could you please show us the ODS version ?

Did you refresh the indices statistics ?

I think this is the first thing you should try.

> Greetings
>
> Andreas
>
>

see you !