Re: understanding OPT_ESTIMATE and SCALE_ROWS !!

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_at_gmail.com> 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_at_outlook.com> 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
>>
>>
>

--
http://www.freelists.org/webpage/oracle-l