Do both instances have (the same) system stats? What differences do you see in the 10053 trace? ________________________________ From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of rjamya What might cause a query using NL (in 9204) use Hash Outer Join (in 9208) when all optimizer and memory parameter being same. Privileged/Confidential Information may be contained in this message or attachments hereto. Please advise immediately if you or your employer do not consent to Internet email for messages of this kind. Opinions, conclusions and other information in this message that do not relate to the official business of this company shall be understood as neither given nor endorsed by it.