Oracle Database 10g SQL (Osborne ORACLE Press Series)

In this chapter, you will

• Be introduced to SQL tuning

• See SQL tuning tips that you can use to shorten the length of time your queries take to execute

• Learn about the Oracle optimizer

• See how to compare the cost of performing queries

• Examine how to pass hints to the optimizer

• Learn about some additional tuning tools

Introducing SQL Tuning

One of the main strengths of SQL is that you don t have to tell the database exactly how to obtain the data requested . You simply issue a query specifying the information you want, and the database software figures out the best way to get it. Sometimes, you can improve the performance of your SQL statements by tuning them. In the following sections, you ll see tuning tips that can make your queries run faster; later, you ll see more advanced tuning techniques.