Ninja's_RGR'us (10/3/2007)
One general hint for the clustered index is when you need to a range scan (Select all data between those 2 dates). One other great candidate is when you need to return the data into a particular order. Select all order items from this order ordered by itemid (item Order).
As I understand the "Advanced scanning" topic in BOL, the order in which rows may be returned cannot be guaranteed without an ORDER BY clause. In single user testing it will always be so, but in a multi-user environment it may not be so