The optimizer of IBM® DB2® for Linux®, UNIX®, and Windows® relies on a cost-based design. Using an SQL statement input by a user or application, the optimizer selects an execution plan with the lowest cost to achieve the best performance. If the performance still doesn't meet requirements after you have used all the best practices for tuning the SQL statement, you can use an optimization profile to guide DB2 to create the execution plan that the user expects. This article explains how to use optimization profiles within DB2 stored procedures.