When to Use the DSTATS Utility

You can execute RUNSTATS following the reorganization of any fragmented table spaces and indexes. For more information on this topic, see About Reorganizing Table Spaces, Partitions, and Indexes.

If you are experiencing slow queries, however, run the DSTATS utility. Slow queries can result when the optimizer chooses an inefficient access path as a result of data skew on nonleading indexed columns or nonindexed columns. In such cases, IBM recommends running the DSTATS utility to collect column distribution statistics on these columns; this can lead to significant improvements in the query time.