Do not use a discrete profile and the STATISTICS option to protect a heavily accessed resource. Doing so increases I/O to the database and decreases system performance, because STATISTICS are kept on all discrete profiles in the same resource class.

If you wish to keep statistics for some data sets, protect those with discrete profiles, and use generic profiles to protect the remainder of your data sets.

There is a relationship between STATISTICS and the POSIT number in the class descriptor table (CDT). Several classes in the CDT might share the same POSIT number because the resource classes have similar processing needs. Because those classes share the same POSIT number, if you activate STATISTICS on the discrete profiles in one class, you simultaneously activate STATISTICS on all discrete profiles in the classes that share the same POSIT number.

We recommend that you not record statistics on your backup database, because your system performance might decrease sharply. However, if it is critical that you record statistics on your backup database, consider enabling RACF® for sysplex communication. This causes RACF to allocate in-storage buffers for the backup database, which should improve the performance of recording the statistics. Also, make sure that your backup database is an exact copy of the primary (made by using IRRUT200), as this further improves the performance of recording the statistics.

See the SETROPTS command in z/OS Security Server RACF Command Language Reference for further information.