-- Attached file included as plaintext by Ecartis -- We tried both queries with and without statistics. Same results. Are you sure about OPIMIZER_MODE=RULE invoking the CBO if there are statistics. The Reference manual says otherwise (not that it's never been wrong). ----- Original Message ----- From: Goulet, Dick To: Multiple recipients of list ORACLE-L Sent: Friday, January 30, 2004 11:39 AM Subject: RE: Changes to RULE based optimizer between Oracle8 and 9i Logic says one thing, experience says another. Question one, are the tables analyzed? If so, since RBO is deprecated in 9i even setting OPTIMIZER_MODE=RULE will invoke the CBO. Dick Goulet Senior Oracle DBA Oracle Certified 8i DBA -----Original Message----- From: Keith Moore [mailto:kmoore7@xxxxxxxxxxxx] Sent: Friday, January 30, 2004 11:54 AM To: Multiple recipients of list ORACLE-L Subject: Changes to RULE based optimizer between Oracle8 and 9i We move an application that uses OPTIMIZER_MODE=RULE from Oracle8 to 9i. Most of it is fine, but there are two queries that have a very different execution plan. In one case, the execution time increases from less than a minute to more than an hour. Neither query uses any of the new Oracle 9i features. My understanding is that the Rule optimizer code has not changed, except to account for new features like IOT's. Has anyone else seen this type of behavior? Keith Moore Oracle Certified Professional 972-431-5126 kmoore7@xxxxxxxxxxxx -- Attached file included as plaintext by Ecartis -- -- Desc: Signature The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. If the reader of this message is not the intended recipient, you are hereby notified that your access is unauthorized, and any review, dissemination, distribution or copying of this message including any attachments is strictly prohibited. If you are not the intended recipient, please contact the sender and delete the material from any computer. ---------------------------------------------------------------- Please see the official ORACLE-L FAQ: http://www.orafaq.com ---------------------------------------------------------------- To unsubscribe send email to: oracle-l-request@xxxxxxxxxxxxx put 'unsubscribe' in the subject line. -- Archives are at //www.freelists.org/archives/oracle-l/ FAQ is at //www.freelists.org/help/fom-serve/cache/1.html -----------------------------------------------------------------