Shared RACF database

The change count in the inventory control block (ICB), corresponding to the block type (profile or index), is updated whenever a block is updated.
In data sharing mode, RACF® uses MVS™ XES services to communicate the changes needed to blocks in the local buffers. This method provides a more granular scheme for invalidating buffers.
If RACF is not running in data sharing mode, index block buffers are marked as out-of-date if the change count in the ICB for that level differs from the change count in the in-storage buffer.
If RACF is not running in data sharing mode, profile buffers are marked as out-of-date if the change count in the ICB for profile blocks differs from the change count in the in-storage buffer.
If you are sharing a database and using in-storage data blocks, statistical information in RACF profiles might not be accurate.

Note: If the RACF database is shared, you do not need to specify the same number of resident data blocks for all systems that share the RACF database. However, if you are using sysplex data sharing, you must define coupling facility structure definitions large enough for the largest specification made for that database by any of the sharing systems. See Defining RACF structures for the coupling facility for information on coupling facility structure definitions.