Chapter 16. Database Performance Considerations

Performance is probably the most important factor in databases and database applications. If performance was not important, people would simply create applications that store their data in flat files rather than purchase highly optimized relational database management systems.

Tuning a DB2 system to obtain optimal performance can be a lengthy process. Poor performance is usually a result of:

• Suboptimal system (hardware) design

• Suboptimal instance configuration

• Suboptimal database configuration

• Lack of proper maintenance

• Inefficient SQL

While you may not have a lot of control over the server and disks that are used for the database server, especially in a large UNIX shop, the hardware does have a big impact on the overall performance of the database system.

In this chapter you will learn about:

• The Database Manager (i.e., instance-level) Configuration parameters

• Database configuration parameters that have the largest impact on the performance of the system

• DB2 registry variables

• Maintenance operations that you must perform to ensure that the system continues to perform optimally once you have it running