IBM BPM, V8.0.1, All platforms > Tuning > Advanced tuning > Database: DB2 for z/OS specific tuning
Update database statistics
It is important to update the statistics so that DB2 can optimize access to key tables. Statistics are maintained on tables and indexes, and are used by the DB2 query optimizer to determine the access plan for evaluating a query.
Examples of statistics include the number of rows in a table and the number of distinct values in a certain column of a table. Updating statistics allows the DB2 query optimizer to create better-performing access plans for evaluating queries. Updating the statistics is best scheduled to avoid times when the system load is high.