If you change the data item before writing it to the cache structure and at the same time you intend to write the data item to permanent storage, specify CHANGED=NO to mark the data item as unchanged. The technique is typically used in a store-through cache environment when you are writing the changed data item to both the cache structure and to permanent storage. In this case, you must also code CROSSINVAL=YES to invalidate copies of the data item in the local cache buffers of other users and deregister their interest in the data item.

You can optionally specify GETCOLOCK=YES to obtain the cast-out lock for the data item. By holding the cast-out lock, you serialize the update to permanent storage. If another user makes a request to obtain the cast-out lock that you hold, the request fails. You can also use PROCESSID to identify your task or process as the holder of the cast-out lock. After successfully writing the data item to permanent storage, issue a REQUEST=UNLOCK_CASTOUT or REQUEST=UNLOCK_CO&NAME to free the cast-out lock.