Indexes and Performance

Indexes generally improve the performance of queries and DML statements that operate on a single, existing row or a small number of existing rows. However, too many indexes can increase the processing overhead for statements that add, modify, or delete rows.

To determine if you can improve application performance with more indexes, you can run the SQL Access Advisor in Oracle Enterprise Manager Database Control (Database Control). See "Running the SQL Access Advisor".

Before you add additional indexes, examine the performance of your database for queries and DML. You can then compare performance after the new indexes are added.