Chapter 8. Performance Tuning

Performance is one of the most important keys in any type of database system. This chapter focuses on a number of performance tuning tips with DB2 Universal Database (UDB). Although some tuning tips are the same regardless of the database workload, there are differences between OLTP and DSS type workloads, and these differences will be noted where applicable.

An OLTP workload typically consists of many applications concurrently running short transactions that include not only selects but also inserts, updates, and deletes. In contrast, DSS workloads are generally read-only transactions, but the transactions are much more complex and normally read much more data.

Performance of a database and the applications that access it are influenced by many factors. This chapter first discusses some fundamentals of performance tuning as it relates to DB2. It then concentrates on how to configure DB2 for optimal performance, using database and database manager configuration parameters, as well as DB2 registry variables. In the database configuration parameter monitoring and tuning section, this chapter will present a list of database manager and database configuration parameters in their order of importance and make recommendations for setting and monitoring these parameters.