Choose two.
Which two are true about monitoring waits for sessions and services?
A.V$SERVICE_EVENT displays wait counts for every wait event for each service even including counts of zero for waits that never occurred. B.V$SESSION_WAIT and V$SESSION both contain details of the event on which a non-waiting session last waited. C.V$SESSION_WAIT and V$SESSION both contain details of the event on which a waiting session is currently waiting. D.V$SESSION_EVENT displays all waits events for those events that have occurred at least once for sessions that have now terminated. E.V$SESSION_WAIT_CLASS displays waits broken down by wait class only for terminated sessions.正确答案AC
