Performance considerations

IRRDBU00 processes either a copy of the RACF® database, a backup RACF database, or the active RACF database. You must have UPDATE authority to the database. It is recommended that you run the utility against a recent copy of your RACF database using the NOLOCKINPUT option.

While processing, IRRDBU00 serializes on one profile at a time (this is also the case in IRRUT100 processing). When IRRDBU00 has finished copying a profile, it releases the serialization. Consider this possible impact to performance if you select your active RACF database as input. Running IRRDBU00 against a copy of the database causes the least impact to system performance.

Note: If your system is enabled for sysplex communication RACF serializes database accesses by using global resource serialization instead of hardware RESERVEs when the system is operating in data sharing mode or in read-only mode and unloading an active database.

An installation can choose to unload its database with one utility invocation, or if it has split its database, it can unload individual pieces of its database with separate utility invocations. These utility invocations can execute concurrently.