Re: Log file sync waits

From: Andrew Kerber <andrew.kerber_at_gmail.com>
Date: Mon, 15 Jun 2015 20:09:39 -0500
Message-ID: <CAJvnOJYzE9RExVGsuELV7gQQPT-tnheaOCWCGwBpRTG58Cmcvg_at_mail.gmail.com>

While I do intend to review the other suggestions I received, below is what I was really looking for, and I was able to produce it with a little research. Thanks all for your help:

select a.snap_id, b.snap_id, a.total_waits_fg, b.total_waits_fg, a.time_waited_micro_fg, b.time_waited_micro_fg,

  b.total_waits_fg-a.total_waits_fg,
(((b.time_waited_micro_fg-a.time_waited_micro_fg)/1000)/(b.total_waits_fg-a.total_waits_FG)) avg_wait

from dba_hist_system_event a, dba_hist_system_event b where b.snap_id=a.snap_id+1 and (b.total_waits_fg-a.total_waits_fg) !=0 and a.event_name='log file sync'

and a.event_name=b.event_name
order by a.snap_id;

On Fri, Jun 12, 2015 at 4:45 PM, Jeremy Schneider < jeremy.schneider_at_ardentperf.com> wrote:

> andrew - try this, personally i think it beats any other suggestions
> here for log file sync specifically... :)
>
>
> https://github.com/fidelinho/SAP_Note_1438410_V49/blob/master/SystemStatistics_LGWR.txt
>
> report columns:
> - REDO_GB/H
> - WRITES/S
> - KB/WRITE
> - MS/WRT_REQ
> - WRT_MB/S
> - WRT_BUSY_%
> - SYNCS/S
> - MS/SYNC
> - SYNC_SESS
> - COMMITS/S
>
>
> --
> http://about.me/jeremy_schneider
>
>
> On Thu, Jun 11, 2015 at 10:11 AM, Andrew Kerber <andrew.kerber_at_gmail.com>
> wrote:
> > Does anyone have a query that will allow me to track the history of log
> file sync times? We hit a big slow up today and I am trying to track the
> history to see when it started.
> >
> > Sent from my iPhone--
> > http://www.freelists.org/webpage/oracle-l
> >
> >
>

-- 
Andrew W. Kerber

'If at first you dont succeed, dont take up skydiving.'

--
http://www.freelists.org/webpage/oracle-l

Received on Tue Jun 16 2015 - 03:09:39 CEST