RE: stats document links.
Date: Wed, 23 Mar 2011 13:04:03 -0400
Someone also sent Relation between Table Monitoring and STATISTICS_LEVEL parameter in 10g [ID 252597.1] which I pulled enough out of to satisfy.
The other links and suggestions are also appreciated.
From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of David Mann Sent: Wednesday, March 23, 2011 11:50 AM To: oracle-l_at_freelists.org
Subject: Re: stats document links.
> From: <Joel.Patterson_at_crowley.com>
> Date: Tue, 22 Mar 2011 13:18:23 -0400
> Subject: stats document links.
> I use default stats collection method on 10.2.0.4 database. I get questioned (via email) about someones attention being drawn to the fact that many tables have not had stats collected in months, and some have had them recently.
> Does anyone off hand have some nice links I an send these people, I believe this last on is a project manager type.
I get this too... Usually consultants brought into check app performance and looking for a finger to point. Managers are CCed, momentum builds for blaming the DBAs. Good times.
After educating them a little on the how/when/why of stats I usually show consultants and customers what is going on with key tables via the [DBA_|ALL_|USER_]TAB_MODIFICATIONS view.
Often the case is explaining that activity != modifications and that stats are stale once they don't properly describe the data they are supposed to represent, not when they are are generated X days ago.
If they are convinced statistics are the issue then there are ways to dig deeper and see if inaccurate statistics are causing an issue with executing the query, 10053 trace, and running the query with GATHER_PLAN_STATISTICS hint are good tools.
-- Dave Mann www.brainio.us www.ba6.us - Database Stuff - http://www.ba6.us/rss.xml -- http://www.freelists.org/webpage/oracle-l -- http://www.freelists.org/webpage/oracle-lReceived on Wed Mar 23 2011 - 12:04:03 CDT