Re: DBWR pegged out
Date: Tue, 8 Mar 2011 08:10:21 -0800 (PST)
Can you offer us a little more information? Is this for one type of process? If it is from one type of process, have you traced it to see what is it truly waiting on? Are the waits due to the dbwr or is it simply i/o waits on your tempfiles?
I think we need more information on the actual waits to determine that you are looking at dbwr, as I'm not seeing that here...
From: Doug Gernaat <dag_at_its.msstate.edu> To: oracle-l_at_freelists.org
Sent: Tue, March 8, 2011 8:55:04 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
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, TEMPdatafile: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 18.104.22.168 on solaris sparc 64.
http://www.freelists.org/webpage/oracle-l Received on Tue Mar 08 2011 - 10:10:21 CST