9 The TimesTen Query Optimizer

The TimesTen query optimizer is a cost-based optimizer that determines the most efficient way to run a given query by considering possible query plans. The query optimizer uses information about an application's tables and their available indexes to choose a fast path to the data.

Application developers can examine the plan chosen by the optimizer to check that indexes are used appropriately. If necessary, application developers can provide hints to influence the optimizer's behavior so that it considers a different plan.

This chapter includes the following topics:

• Using the Query Optimizer to Choose Optimal Plan

• Viewing SQL Statements Stored in the SQL Command Cache

• Viewing SQL Query Plans

• Modifying a SQL Query Execution Plan