Descubra o waited for latches da sua instancia

col event format a30
select event
, time_waited
, round(time_waited*100/ SUM (time_waited) OVER(),2) wait_pct
from (
 select event
 , time_waited
 from v$system_event
 where event not in (
  'Null event'
  ,'client message'
  ,'rdbms ipc reply'
  ,'smon timer'
  ,'rdbms ipc message'
  ,'PX Idle Wait'
  ,'PL/SQL lock timer'
  ,'file open'
  ,'pmon timer'
  ,'WMON goes to sleep'
  ,'virtual circuit status'
  ,'dispatcher timer'
  ,'SQL*Net message from client'
  ,'parallel query dequeue wait'
  ,'pipe get')
 union
  (
  select name
  ,  value
  from v$sysstat
  where name like 'CPU used when call started'
  )
 )
order by 2 desc
/