top 5 database objects in use, along with the event associated with that database object, over the past 15 minutes

SELECT * FROM
(
SELECT o.object_name, o.object_type, s.event,
SUM(s.wait_time + s.time_waited) total_waited
FROM v$active_session_history s, dba_objects o
WHERE s.sample_time between sysdate - 1/24/4 and sysdate
AND s.current_obj# = o.object_id
GROUP BY o.object_name, o.object_type, s.event
ORDER BY 4 desc
) 

WHERE rownum <= 5;