Prem,
check out these great from Franck Pachot:
https://blog.dbi-services.com/oracle-sql-profiles-check-what-they-do-before-accepting-them-blindly/
https://blog.dbi-services.com/oracle-sql-profile-why-multiple-optestimate/
Very nice explanation on the subject.
Regards,
Marko
On Thu, Feb 16, 2017 at 5:44 PM, Chris Taylor <
christopherdtaylor1994@xxxxxxxxx> wrote:
Personally, I *love* SQL Profiles - because plan stability is a DBAs best
friend.
The other thing you can do without a SQL profile is take the hint text and
add it directly to the SQL instead but that makes for some long SQL text
and isn't exactly "pretty" but works just as well.
Chris
On Thu, Feb 16, 2017 at 10:28 AM, Prem Khanna J <jprem@xxxxxxxxxxx> wrote:
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
