Steroids for the Optimizer – An Introduction to (Advanced) Statistics

Db2 uses a cost-based query optimizer that is vitally dependent on appropriate statistics to generate efficient execution plans. However, it is often not obvious when to use which of the many options for the RUNSTATS command to collect the "right" kind of statistics. This session presents a set of practical examples to explain how different types of statistics affect query optimization. We also discuss RUNSTATS measurements to illustrate the overhead of collecting more advanced statistics. As a result you will be able to determine when it is worthwhile to use more advanced concepts such as distribution statistics, column group statistics, or statistical views. Provide the right steroids to the optimizer to boost performance!