On Aug 13, 11:54 am, "fitzjarr..._at_cox.net" <fitzjarr..._at_cox.net>
wrote:
> On Aug 13, 12:10 am, dean <deanbrow..._at_yahoo.com> wrote:
>
>
>
>
>
> > 10g
>
> > select * from V$SYSTEM_WAIT_CLASS order by TIME_WAITED desc;
>
> > WAIT_CLASS_ID WAIT_CLASS# WAIT_CLASS TOTAL_WAITS TIME_WAITED
> > ------------- ----------- -------------- ----------- -----------
> > 2723168908 6 Idle 15742538 990583927
> > 1740759767 8 User I/O 1501104 541245
> > 2000153315 7 Network 35587647 227757
> > 4108307767 9 System I/O 690084 194154
> > 3386400367 5 Commit 70951 23803
> > 3875070507 4 Concurrency 11212 13790
> > 4217450380 1 Application 12112 5730
> > 1893977003 0 Other 7106 5411
> > 3290255840 2 Configuration 171 1979
>
> > This is the first time I have looked at this view, and I'm trying to
> > understand it - does this indicate performance issues with the disk i/
> > o?
>
> > Thanks!
>
> > Dean
>
> Not necessarily; the TIME_WAITED values are in centiseconds (1/100 of
> a second) and are cumulative for all sessions for as long as the
> database is running uninterrupted. The User I/O number you posted
> represents roughly 90 minutes of wait time for ALL sessions since the
> database started. Presuming you have more than one connected session
> and that the database has been up and running for more than two hours
> I'd say no; follow Daniel's advice and file this away for future
> reference. When and if a user (or group of users) decides to complain
> about performance you can resurrect these values and compare them to
> the current numbers (again, presuming you haven't shut down the
> database between now and then) and possibly find the area or areas
> which have changed.
>
> There is no need to create problems where none currently exist.
>
> David Fitzjarrell- Hide quoted text -
>
> - Show quoted text -
Ok thanks to both. There is no problem here on the development server,
I just wanted to familiarize myself. I wasn't sure if this was
indicating we could use a faster set of drives (forgot it was in
centiseconds).
Received on Mon Aug 13 2007 - 11:02:08 CDT
