Oracle FAQ Your Portal to the Oracle Knowledge Grid
HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US
 

Home -> Community -> Usenet -> c.d.o.server -> Re: lots of waiting on 'db file parallel write'

Re: lots of waiting on 'db file parallel write'

From: peter <p_msantos_at_yahoo.com>
Date: 27 Feb 2006 19:23:01 -0800
Message-ID: <1141096981.613204.7170@j33g2000cwa.googlegroups.com>


When I said that there are lots of waits on 'db file parallel write' I should have said that a few times a day without any sort of consistency I will noticed that 1 or all of my 4 db writers are hanging and waiting on the 'db file parallel write' event to complete...the writers will wait anywhere between 10-140 seconds and then they won't wait anymore on that event for another couple of hours.. It's very intermitent.. but when it happens the db writers might wait for the event 'db file parallel write' for up to 140 seconds.. meaning the v$SESSION_WAIT.seconds_in_wait may show up to 140 seconds of wait time... Again I'm not monitoring this regularly yet, but I'd say that during a business day this will happen 3-5 times...

Equally, the 'free buffer waits' might get lost in the AWR hourly report because this type of problem will only occur every so often..

I would say that because this type of problem is rare, when it happens the waits are extreme (in my opinion anything more than 1-2 seconds is extreme).

I'm planning on setting up a job to run every 5 minutes to get a feel for how often it really happens... But as I mentioned in my response to Joel, the load on our system can change dramatically from 1 minute to the next.

-peter Received on Mon Feb 27 2006 - 21:23:01 CST

Original text of this message

HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US