Oracle Performance Tuning Script - Top Recent Wait Events

col EVENT format a60 select * from ( select active_session_history.event, sum(active_session_history.wait_time + active_session_history.time_waited) ttl_wait_time from v$active_session_history active_session_history where active_session_history.event is not null group by active_session_history.event order by 2 desc) where rownum < 6 /