Check Rushmore topics in help.
You need indexes for Rushmore to do its work.

But you need indexes with high selectivity. If they are not, network performance is not good, because parts of index which are not useful are read over wire.

>I admit my total ignorance :-( but reading this thread i realized that I don't know how to do to make rushmore optimization working !!!
>How come that i always obtain rushmore optimization NONE after running an select statement ? Is there anything to do ? I didn't think Rushmore worked with SQL statemnt.....
>