Our application supposedly fixed the lob issue with a patch, but the patch blew up on our system so I haven't been able to test it. Once we fix this issue I'll restest it as a baseline. I noticed in their script the offending lob table hasn't changed, so my changes will be on top of their improvements. Unfortunately I'm not sure what improvements they have made as it is in their binaries. Thanks, I'll update the thread once I am able to test my improvements. Ken -----Original Message----- From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Laimutis.Nedzinskas@xxxxxx Sent: Friday, August 27, 2010 12:03 AM To: oracle-l@xxxxxxxxxxxxx Subject: RE: Lob Performance Metalink has some good articles. In my practice I've encountered the following issues: - "hw contention" event which is for example fixed in 10.2.0.4 but the fix is not enabled by default. You have to set an event. Metalink has few articles how to detect if you are suffering and how to fix it. - if lob is "small" (for example, average is 8K ) then enabling LOB caching improves performance. Note, that LOB's are supposed to be LARGE OBJECTS meaning caching is disabled by default else it would blow out the cache. But more often than not LOB size is something just above what ordinary varchar2 column would hold. ---------------------------------------------------------------------------- ----- Please consider the environment before printing this e-mail "Kenneth Naim" <kennethnaim@gmai l.com> To Sent by: "'Leyi Zhang \(Kamus\)'" oracle-l-bounce@f <kamusis@xxxxxxxxx> reelists.org cc <oracle-l@xxxxxxxxxxxxx> Subject 2010.08.23 13:22 RE: Lob Performance Please respond to kennethnaim@gmail .com Yes, I have. I'm looking for something more definitive, less theory and more application. Thanks, Ken From: Leyi Zhang (Kamus) [mailto:kamusis@xxxxxxxxx] Sent: Monday, August 23, 2010 2:34 AM To: kennethnaim@xxxxxxxxx Cc: oracle-l@xxxxxxxxxxxxx Subject: Re: Lob Performance Have you read online doc: OracleR Database SecureFiles and Large Objects Developer's Guide http://download.oracle.com/docs/cd/E11882_01/appdev.112/e10645/adlob_perform ance.htm#i1007089 -- Kamus <kamusis@xxxxxxxxx> Visit my blog for more : http://www.dbform.com. Join ACOUG: http://www.acoug.org. On Mon, Aug 23, 2010 at 6:01 AM, Kenneth Naim <kennethnaim@xxxxxxxxx> wrote: I haven't dealt with lob performance much. Can someone point to a good site or whitepaper how to measure lob size, test and improve (b)lob performance. I'm checking google and mos and haven't found a comprehensive article. Thanks, Ken -- //www.freelists.org/webpage/oracle-l -- //www.freelists.org/webpage/oracle-l -- //www.freelists.org/webpage/oracle-l