Re: Huge numbers in SYS,AUX_STAT$
Date: Wed, 7 Sep 2011 17:23:42 -0700 (PDT)
On Sep 7, 7:32 pm, Mladen Gogala <gogala.mla..._at_gmail.com> wrote:
> Great note! I wish I saw it earlier, I would have known immediately. It
> does need an update, though. In Oracle11, you should collect stats for
> SYSMAN, not SYSADM.
Thanks for the feedback regarding the article. The slides and slide notes are from a presentation that I gave to Oracle DBAs for a specific ERP package - that ERP package places the ERP data into the SYSADM schema. I should have better clarified that point when I made the blog post.
--- I first noticed the system statistics bug roughly a year ago. I was testing Oracle Database 184.108.40.206 on a crazy expensive laptop with two 256GB SSD drives in RAID 0 - when I gathered the system statistics and saw the roughly 2.5 second single block read time and roughly 9 second multi-block read time, I thought of 3 possible causes: * The laptop is so fast that the numbers wrapped around zero. :-) * The scale of the numbers changed so that the numbers were no longer presented in milliseconds. * There is a potentially ugly bug in 220.127.116.11 (and carried through to 18.104.22.168). I was running tests at the time comparing 10.2.0.x, 11.1.0.x and 11.2.0.x and wanted to make certain that the tests were reasonably equal, so I borrowed the system statistics that were collected by either 10.2.0.4 or 22.214.171.124 and simply forgot about the problem. A couple of months later, I read an article on Christian Antognini's Blog ( http://antognini.ch/2010/11/workload-system-statistics-in-11g/ ) that explained the bug that I simply brushed off. Randolf Geist recently wrote an article that describes another change that he had noticed in 126.96.36.199 that is related to execution plan costing: http://oracle-randolf.blogspot.com/2011/07/cost-is-time-next-generation.html --- I am sorry to hear about the chapter 7 problem. Charles Hooper Co-author of "Expert Oracle Practices: Oracle Database Administration from the Oak Table" http://hoopercharles.wordpress.com/ IT Manager/Oracle DBA K&M Machine-Fabricating, Inc.Received on Wed Sep 07 2011 - 19:23:42 CDT