Solaris 9, veritas 3.5, hitachi san. Mount points look like: /u01 on /dev/vx/dsk/rootdg/u01 read/write/setuid/delaylog/largefiles/qio/ioerror=mwdisable/dev=3d40005 on Thu Mar 18 23:25:59 2010 /u02 on /dev/vx/dsk/rootdg/u02 read/write/setuid/delaylog/largefiles/qio/ioerror=mwdisable/dev=3d40006 on Thu Mar 18 23:26:04 2010 /u03 on /dev/vx/dsk/rootdg/u03 read/write/setuid/delaylog/largefiles/qio/ioerror=mwdisable/dev=3d40007 on Thu Mar 18 23:26:09 2010 filesystemio_options = asynch For what its worth, 32gb server, 12gb sga, 7gb pga aggregate target, we're always maxed out on RAM and swap, and our iowait, during business hours, hovers around 25-30%. On Tue, May 4, 2010 at 2:46 PM, Harel Safra <harel.safra@xxxxxxxxx> wrote: > Even if you're using direct io it still could be caching at the storage > level. > What is your disk/lun configuration? > > Harel Safra > > > On 04/05/2010 16:11, Stephens, Chris wrote: > > Since blocks from the heaviest hit tablespace are more likely to be in > the os-cache, that would account for Oracle thinking blocks read from that > tablespace are faster. I guess that assumes you aren’t using direct-io. > > > > Chris > > > > *From:* oracle-l-bounce@xxxxxxxxxxxxx [ > mailto:oracle-l-bounce@xxxxxxxxxxxxx <oracle-l-bounce@xxxxxxxxxxxxx>] *On > Behalf Of *Neil Kodner > *Sent:* Tuesday, May 04, 2010 7:35 AM > *To:* oracle-l-freelists; Neil Kodner > *Subject:* Inconsistent file IO times on AWR report > > > > I'm trying to get to the bottom of some performance issues and one of the > things that stumps me is that my AWR reports show wildly inconsistent read > times for my tablespaces. The heaviest-hit tablespace consistently shows an > average read time of .59ms. The others range from 13 to 25ms in avg read > time. I dont find anything obvious when comparing matviews_index and > matviews_data to the rest of the tablespaces when looking in > dba_tablespaces. > > > > Given that all of the tablespaces are on the same hardware device and mount > points, I would expect the average read times to be somewhat similar across > the board. Is this an invalid assumption? > > > > The tablespace and file details from awr can be found at > http://goo.gl/CTaO > > > > I'll update the document with additional information as requested. > > > > Thanks, > > > > Neil > > CONFIDENTIALITY NOTICE: > This message is intended for the use of the individual or entity to which > it is addressed and may contain information that is privileged, confidential > and exempt from disclosure under applicable law. If the reader of this > message is not the intended recipient or the employee or agent responsible > for delivering this message to the intended recipient, you are hereby > notified that any dissemination, distribution or copying of this > communication is strictly prohibited. If you have received this > communication in error, please notify us immediately by email reply. > > >