During shutdown immediate or normal, the shutdown process must wait for all the dispatchers to shutdown. As each dispatcher is signaled, the session that causes the shutdown is waits on this event until the requested dispatcher is no longer alive.
Wait Time: 1 second
Indicates the cumulative wait time. After 5 minutes, the session writes to the alert and trace files to indicate that there might be a problem.
Oracle Database SQL Language Reference for information about shutting down a dispatcher using
SHUTDOWN clause of the SQL
ALTER SYSTEM statement