If you ask a room full of Oracle database administrators, “What is the single biggest part of your job?”, chances are that the almost universal response will be “Configuration and tuning of the database.” Oracle is a very complex and powerful product, and part of its power lies in its ability to get the best possible performance out of each individual database configuration. This chapter presents our approach to the configuration and tuning of an Oracle database and provides guidelines for implementing a high-performance database at your site.

The ongoing, day-to-day responsibility of most Oracle DBAs is to get the best possible performance from the Oracle database. A number of definitions may be offered for “performance,” but we define performance as the objective, measurable amount of time required to perform a typical operation in the database in question. Yes, this is a simplistic definition that ignores other metrics like resource utilization, but let’s face it: the database is expected to be as fast as possible, so this is a reasonable definition for this purpose.

Entire books have been written on the subject of Oracle performance (see the appendix, Resources for the DBA, for some we consider worthy of your attention^[1]), so we cannot hope to address all the intricacies of Oracle performance tuning in a single chapter. Rather, we hope to document a straightforward approach to performance tuning and to provide some practical guidelines that can be applied to a variety of installations.

It is important to realize that every Oracle installation is different in terms of its physical and logical database implementation, the types of transactions processed, and the performance requirements for those transactions. As a result, there cannot be an automatic tuning methodology, although several vendors, including Oracle, have attempted to provide one. Nor can a single set of rules provide a method for maximizing database performance. What can be provided, however, is a methodology that, when properly applied and combined with the knowledge and experience of a working DBA, will result in good performance for any given database.