>
>You might also consider moving your loc.state='OR' up into the JOIN.
>
>In SQL server you should avoid SELECT * in a query when none of the fields are actually used or you don't need all of them, you force a read of the data page even if can determine the result only from reading index pages. I/O is slow. Use SELECT 'X' instead.

It doesn't apply to EXISTS subqueries because SQL Server doesn't retrieve any data for them.