>But, here is the interesting part. If I add another set of fields after Item.AI, the result is fully optimized:
>
>

>SELECT Member.*,Item.AI,Status.* FROM Member;
> INNER JOIN Status ON Member.NoStatus=Status.Numero;
> INNER JOIN Item ON Member.NoDBUsers=Item.Numero;
> WHERE Item.Numero=3042 AND Member.NoEntity=1 AND;
> (Status.Numero=2 OR Status.Numero=9 OR Status.Numero=3 OR Status.Numero=5 OR Status.Numero=16)
>

>
>So, this shows that there is something buggy in the way the engine works. This could be affected on some data corruption, bad tags or something like that. But, it just doesn't make any sense that I will get an immediate result just because I add Status.* at the end of the field list.

Caching will happen because the second set of joins and the where clause is the same as the first. SQL Server does the same thing via "Simple Parameterization"