Re: DBWR pegged out
Date: Tue, 8 Mar 2011 10:51:41 -0800
Message-ID: <AANLkTinoTs+pgagZcb4Tkbs3QqxNyx+j6fRpef-iCX3H_at_mail.gmail.com>
I'd be asking what "write complete waits" have to due with temp. Looks to me that its something to do with transactions and rollback/undo.
http://download.oracle.com/docs/cd/E11882_01/server.112/e17110/waitevents003.htm#sthref4131
What does the ASH report show?
On Tue, Mar 8, 2011 at 9:59 AM, Kevin Closson <ora_kclosson_at_yahoo.com> wrote:
> I'd be asking myself (and oracle perhaps) two questions: 1) why am I writing
> to TEMP at all and 2) if sessions need to spill to temp on 11.2 why are they
> not doing so in the direct path?
>
> BTW, what class of server is this?
>
> ________________________________
> From: Doug Gernaat <dag_at_its.msstate.edu>
> To: oracle-l_at_freelists.org
> Sent: Tue, March 8, 2011 7:55:04 AM
> Subject: DBWR pegged out
>
> after oracle suggested bumping up db_writer_processes from 2 to 4, at times
> it
> is still getting pegged out. "write complete waits" will become a top time
> event.
> drilling down will show:
>
> SID User Wait state/time Waiting Location
> 23 db_user In waiting (2ms) write complete waits, TEMP
> datafile:604
> 30 db_user In waiting (88ms) write complete waits, TEMP
> datafile:604
> 179 db_user In waiting (101ms) write complete waits, TEMP
> datafile:604
> 189 db_user In waiting (0ms) write complete waits, TEMP
> datafile:604
> 354 db_user In waiting (109ms) write complete waits, TEMP
> datafile:604
> 1532 db_user In waiting (6ms) write complete waits, TEMP
> datafile:604
>
> and diff users will fall in out of these write complete waits. i always see
> TEMP... not any other dfiles.
> also during these times... ora_ckpt will start blocking other sessions. is
> this I/O contention? any suggestions?
>
> dbwr_io_slaves is set to 0.
> this is 11.2.0.2 on solaris sparc 64.
>
> thanks
> -doug-
-- Regards, Greg Rahn http://structureddata.org -- http://www.freelists.org/webpage/oracle-lReceived on Tue Mar 08 2011 - 12:51:41 CST