RE: Oracle's use of Indexes

Craig

   I'm sorry, you said they were on the same instance, I just didn't read carefully enough.

   I believe that all the statistics that CBO uses to make a decision are in USER_TABLES and USER_INDEXES. You might compare the values for both tables to see if there is a difference that might cause the CBO to make a different decision. Are you using different usernames? Any chance one session is doing an ALTER SESSION?

Dennis Williams
DBA, 80%OCP, 100% DBA
Lifetouch, Inc.
dwilliams_at_lifetouch.com

-----Original Message-----
Sent: Monday, June 02, 2003 10:30 AM
To: Multiple recipients of list ORACLE-L

> -----Original Message-----
> From: Stephane Faroult [mailto:sfaroult_at_oriolecorp.com]
>
> Does 'etc' include doing something to tables as well? I
> would, from your posting, being tempted to say 'no'. Could it
> have anything to do with histograms ? The only thing I can
> currently think of is differences in the way statistics were gathered.

No, I didn't do anything to the tables. I did drop and recreate the index that was being used, to no effect. I use analyze from within TOAD, and tried estimating and computing statistics, and calculated statistics on the index when I recreated it. I haven't tried deleting statistics. Never used histograms before.

Dennis - Same instance, we're using separate schemas for test and production.

Craig Healey

This email and any files transmitted with it are confidential and intended solely
for the use of the individual or entity to whom they are addressed and may contain
confidential and/or privileged material. Any review, retransmission, dissemination
or other use of, or taking of any action in reliance upon, this information by
persons or entities other than the intended recipient is prohibited. Statements
and opinions expressed in this e-mail may not represent those of the company.   

If you have received this email in error please notify system.administrator_at_hhsuk.com  

This footnote also confirms that this email message has been swept by MIMEsweeper
for the presence of computer viruses (www.mimesweeper.com)

-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.net
-- 
Author: Craig Healey
  INET: c.healey_at_hhsuk.com

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: ListGuru_at_fatcity.com (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: DWILLIAMS_at_LIFETOUCH.COM

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: ListGuru_at_fatcity.com (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).