Collecting history statistics

You can save statistics history information in catalog history tables.

Procedure

To save history statistics in the catalog:

  1. Specify the HISTORY option when you run the RUNSTATS utility or collect inline statistics with another utility.
    When you specify the HISTORY option, the utility stores the statistics that were updated in the catalog tables in history records in the corresponding catalog history tables.
  2. Remove old statistics from the catalog history tables by taking one of the following actions:
    • Run the MODIFY STATISTICS utility.
    • Issue a DELETE statement.
    Deleting outdated information from the catalog history tables can help improve the performance of processes that access the data in these tables.