Use the performance tuning capabilities that are available with the Oracle database software

Open the Automatic Database Diagnostic Monitor (ADDM) from the Database Control home page or from Advisor Central.

This tool helps you diagnose problems, identify their causes, and make recommendations.

About acting on ADDM recommendations:

Make configuration changes to the database or operating system as necessary.
The SQL Tuning Advisor might recommend rewriting some SQL statements. However, the SQL statements cannot be rewritten.
Add database indexes as needed.
Caution: Take note of all new indexes. Before upgrading, you must drop them to ensure that they do not cause conflicts with new indexes that have been added to the product. After the upgrade is finished, you can add the indexes back.

Note: Contact Oracle Global Support to forward SQL statement recommendations or request index changes in the product.

The most common configuration recommendations from ADDM are:

SGA_TARGET
PGA_AGGREGATE_TARGET
DB_FILE_MULTIBLOCK_READ_COUNT
- Reset to zero instead of using an explicit value.
- Oracle automatically manages this parameter value if it is set to zero.

For more information, see the Oracle database software documentation.