On any platform, good database performance depends on good design. And good design includes a solid understanding of indexes and column statistics: how many to build, their structure and complexity, and their maintenance requirements.
This is especially true for DB2 UDB for iSeries, which provides a robust set of choices for indexing and allows indexes to play a key role in several aspects of query optimization. On the IBM eServer iSeries platform, the use of indexes is a powerful tool, but also requires some knowledge on their application.
This paper starts with basic information about indexes in DB2 UDB for iSeries, the data structures underlying them, and how the server uses them. In the second part of the paper, index strategies are presented. Part three discusses additional indexing considerations related to maintenance, tools, and methods. Parts four and five cover column statistics and statistics collection strategies. And finally, the appendices provide examples and references