Which three are true about monitoring waits for sessions and services? (Choose three.)
A.V$SESSION_EVENT displays all waits for all past and existing sessions if the wait has occurred at least once for a session. B.V$SERVICE_EVENT displays all waits for all services if the wait has occurred at least once for a service. C.V$SESSION_WAIT _CLASS displays waits broken down by wait class only for waiting sessions. D.V$SESSION_WAIT and V$SESSION both contain details of the event on which a non-waiting正确答案BEF
Session last waited. E.V$SESSION_EVENT displays all waits for all past sessions if the wait has occurred at least once for a session. F.V$SESSION_WAIT and V$SESSION both contain details of the event on which a session is currently waiting.
