understanding OPT_ESTIMATE and SCALE_ROWS !!
From: Prem Khanna J <jprem_at_outlook.com>
Date: Thu, 16 Feb 2017 16:28:45 +0000
Message-ID: <TY1PR01MB05389231AFC94F79BC81ED25BC5A0_at_TY1PR01MB0538.jpnprd01.prod.outlook.com>
Hi Friends ,
Date: Thu, 16 Feb 2017 16:28:45 +0000
Message-ID: <TY1PR01MB05389231AFC94F79BC81ED25BC5A0_at_TY1PR01MB0538.jpnprd01.prod.outlook.com>
Hi Friends ,
My customer is on oracle R12.1. I am in the mid of tuning a SELECT SQL statement . Used SQL Tuning advisor and it says accepting a profile will result in 90% improvement. Before even I accept the profile, I want to understand what it does and want to do the same - if possible - without profiles .
I am trying to understand the OPT_ESTIMATE part of the advisor (dba_advisor_rationale) . Hard though , as I could not find much about it on internet. Looks like SCALE_ROWS part of it does the magic . Can anyone explain or point me to a doc/URL which helps how to read and understand the OPT_ESTIMATE line .
How can one give optimizer the info' ... which OPT_ESTIMATE can give ? How do you guys approach this .
Thanks and Regards,
Prem
-- http://www.freelists.org/webpage/oracle-lReceived on Thu Feb 16 2017 - 17:28:45 CET