SQL command :
SQL> COLUMN EVENT FORMAT a30;
SQL> SELECT
2 event,
total_waits,
3 4 time_waited,
5 avg_ms,
6 round(RATIO_TO_REPORT(TIME_WAITED)OVER()*100)PERCENT
7 from
8 (SELECT
9 SUBSTR(EVENT,1,30) EVENT,
10 TOTAL_WAITS,
11 TIME_WAITED,
12 ROUND(TIME_WAITED_MICRO/TOTAL_WAITS/1000,2) AVG_MS
13 FROM V$SYSTEM_EVENT
14 WHERE
15 WAIT_CLASS != ‘idle’ AND
16 EVENT NOT IN
17 (‘db file parallel write’,'log file parallel write’,
18 ‘log file sequential read’,'control file parallel write’,
‘control file sequential read’,'Log archive I/O’)
19 20 UNION
21 SELECT ‘CPU’ EVENT,NULL,VALUE,NULL
22 FROM V$SYSSTAT
23 WHERE STATISTIC# = 12
24 ORDER BY 3 DESC)
25 WHERE ROWNUM <=10;

EVENT TOTAL_WAITS TIME_WAITED AVG_MS PERCENT
—————————— ———– ———– ———- ———-
SQL*Net message from client 3909276122 1.6511E+10 42.24 81
db file sequential read 3611229673 1289634393 3.57 6
rdbms ipc message 13365176 974207627 728.91 5
CPU 767306206 4
log file sync 26707350 297795901 111.5 1
read by other session 797062395 233188784 2.93 1
enq: TX – row lock contention 45655383 170080074 37.25 1
RMAN backup & recovery I/O 76442209 85095872 11.13 0
Streams AQ: qmn coordinator id 55336 74544752 13471.29 0
Streams AQ: qmn slave idle wai 27279 74544046 27326.53 0

10 rows selected.