Additionally, the indexed expression must be on the left.

LNAME + FNAME = "Smith" will be optimized but "Smith" = LNAME + FNAME will not be optimized.

>In order to get rushmore optimisation, the index must match exactly the expression in the where clause. In your case, and in general, I suggest having separate index tags instead or in addition to the two field index.
>
>And by the way, Set enginebehavior has nothing to do with rushmore. ALWAYS use Set enginebehavior 90 in production, other values must ONLY be used as "band aid" until you have fixed your select statements.