Re: Performance issues with SSD on DELL servers
- From: Timur Akhmadeev <timur.akhmadeev@xxxxxxxxx>
- To: dbaorapps@xxxxxxxxx
- Date: Tue, 30 Aug 2016 13:52:40 +0300
On Mon, Aug 29, 2016 at 8:06 AM, Apps DBA <dbaorapps@xxxxxxxxx> wrote:
Thanks for your response. I dont see any problem in the wait events,
You need to look at the histogram of wait events of a particular type in
AWR report or with a direct query:
col event_name format a30
select
-- instance_number inst_id,
-- event_name,
to_char(begin_interval_time, 'yyyymmdd hh24mi') end_period,
max(decode(wait_time_milli, 1, wait_count)) "1ms",
max(decode(wait_time_milli, 2, wait_count)) "2ms",
max(decode(wait_time_milli, 4, wait_count)) "4ms",
max(decode(wait_time_milli, 8, wait_count)) "8ms",
max(decode(wait_time_milli, 16, wait_count)) "16ms",
max(decode(wait_time_milli, 32, wait_count)) "32ms",
max(decode(wait_time_milli, 64, wait_count)) "64ms",
max(decode(wait_time_milli, 128, wait_count)) "128ms",
max(decode(wait_time_milli, 256, wait_count)) "256ms",
max(decode(wait_time_milli, 512, wait_count)) "512ms",
max(decode(wait_time_milli, 1024, wait_count)) "1024ms",
max(decode(wait_time_milli, 2048, wait_count)) "2048ms"
from
(
select
s.begin_interval_time,
h.event_name,
wait_time_milli,
wait_count - lag(wait_count) over (partition by h.dbid,
h.instance_number, h.event_name, h.wait_time_milli order by
s.begin_interval_time) wait_count
from
dba_hist_event_histogram h,
dba_hist_snapshot s
where
h.dbid = s.dbid and
h.snap_id = s.snap_id and
h.instance_number = s.instance_number and
s.begin_interval_time between sysdate - 14 and sysdate and
h.event_name in ('&event_name')
)
group by event_name, to_char(begin_interval_time, 'yyyymmdd hh24mi')
order by 2
;
And yes, few AWR/ASH/ADDM reports covering good/bad periods is a good
starting point.
--
Regards
Timur Akhmadeev
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