Re: DBWR pegged out

From: Kevin Closson <ora_kclosson_at_yahoo.com>
Date: Tue, 8 Mar 2011 09:59:13 -0800 (PST)
Message-ID: <859633.64375.qm_at_web161709.mail.bf1.yahoo.com>

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?

kevinclosson.wordpress.com

---

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-

--

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

--

http://www.freelists.org/webpage/oracle-l Received on Tue Mar 08 2011 - 11:59:13 CST