DB2 for IBM i Performance

The purpose of this master's thesis is to help programmers working with DB2 for IBM i make up-to-date design decisions. Much has changed in the industry in the past 20 years, and sources of informaton on both the Internet and internal company policies are outdated and misleading. Underlying concepts of IBM i and DB2 that affect performance are explained. A framework for benchmarking database programs on IBM i has been created, using RPG as the programming language and the built-in DB2 database. Its design is presented, and parameters relatng to the performance of both RPG and SQL are explored, to establish how accurate benchmarking tests can be set up. Benchmarks were created for a few practcal scenarios and the results are analyzed, and compared to existng literature, when available. The recommendaton of IBM on index column ordering was shown to be suboptmal when dealing with very large amounts of data. The performance of batch updates can be improved by creatng a temporary table in order to avoid changing the same data that the selecton criteria is based o