RE: Statistics problem

From: DENNIS WILLIAMS <DWILLIAMS_at_LIFETOUCH.COM>
Date: Wed, 25 Jun 2003 09:50:48 -0700
Message-ID: <F001.005B957B.20030625084450@fatcity.com>

Dennis

   Couple of ideas:

1. Use your test system to run various analyzes and then run the queries in question.
2. Note the values in USER_TABLES, etc., then issue an analyze command that analyzes more rows. When it completes, examine the new values and see if there is a difference.
3. Is is possible that you have skewed data in some columns, and you should be considering histograms?

Dennis Williams
DBA, 80%OCP, 100% DBA
Lifetouch, Inc.
[EMAIL PROTECTED] -----Original Message-----
Sent: Wednesday, June 25, 2003 10:15 AM
To: Multiple recipients of list ORACLE-L

Hi All,
I have a very large database that is experiencing performance problems due to bad query plans. While I suspect the cause is bad statistics ( insufficient number of rows being analyzed ), I don't want to change our analyze scripts without seeing some proof. Is there anyway I can query against the database to show that the statistics are indeed bad?

TIA Dennis

Fat City Network Services    -- 858-538-5051 http://www.fatcity.com
San Diego, California        -- Mailing list and web hosting services
---------------------------------------------------------------------

To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
--

Please see the official ORACLE-L FAQ: http://www.orafaq.net
--

Author: Meng, Dennis
  INET: [EMAIL PROTECTED]

Fat City Network Services    -- 858-538-5051 http://www.fatcity.com
San Diego, California        -- Mailing list and web hosting services
---------------------------------------------------------------------

To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
--

Please see the official ORACLE-L FAQ: http://www.orafaq.net
--

Author: DENNIS WILLIAMS
  INET: [EMAIL PROTECTED]

Fat City Network Services    -- 858-538-5051 http://www.fatcity.com
San Diego, California        -- Mailing list and web hosting services
---------------------------------------------------------------------

To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). Received on Wed Jun 25 2003 - 11:50:48 CDT