Show 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

/