Tuning
From dbawiki
Wait-based tuning query
set pages 999
set lines 190
column c1 heading 'Event|Name' format a40
column c2 heading 'Total|Waits' format 999,999,999,999
column c3 heading 'Seconds|Waiting' format 999,999,999,999
column c4 heading 'Total|Timeouts' format 999,999,999,999
column c5 heading 'Average|Wait|(in secs)' format 99,999.999
ttitle 'System-wide Wait Analysis|for current wait events'
select
event c1,
total_waits c2,
time_waited / 100 c3,
total_timeouts c4,
average_wait /100 c5
from
sys.v_$system_event
where
event not in (
'dispatcher timer',
'lock element cleanup',
'Null event',
'parallel query dequeue wait',
'parallel query idle wait - Slaves',
'pipe get',
'PL/SQL lock timer',
'pmon timer',
'rdbms ipc message',
'slave wait',
'smon timer',
'SQL*Net break/reset to client',
'SQL*Net message from client',
'SQL*Net message to client',
'SQL*Net more data to client',
'virtual circuit status',
'WMON goes to sleep'
)
AND
event not like 'DFS%'
and
event not like '%done%'
and
event not like '%Idle%'
AND
event not like 'KXFX%'
order by
c2 desc