Script to find Total wait time by resource types in Oracle

column average_wait format 9999990.00

select
  substr(e.event, 1, 40)  event,
  e.time_waited,
  e.time_waited / (
    e.total_waits - decode(e.event, 'latch free', 0, e.total_timeouts)
  )  average_wait
from
  sys.v_$system_event  e,
  sys.v_$instance  i
where
  e.event = 'buffer busy waits' or
  e.event = 'enqueue' or
  e.event = 'free buffer waits' or
  e.event = 'global cache freelist wait' or
  e.event = 'latch free' or
  e.event = 'log buffer space' or
  e.event = 'parallel query qref latch' or
  e.event = 'pipe put' or
  e.event = 'write complete waits' or
  e.event like 'library cache%' or
  e.event like 'log file switch%' or
  ( e.event = 'row cache lock' and
    i.parallel = 'NO'
  )
union all
select
  'non-routine log file syncs',
  round(e.average_wait * greatest(e.total_waits - s.value, 0)),
  e.average_wait
from
  sys.v_$system_event e,
  sys.v_$sysstat s
where
  e.event = 'log file sync' and
  s.name = 'user commits'
order by
  2 desc
/