Re: Really strange performance issue

From: Chris Taylor <christopherdtaylor1994_at_gmail.com>
Date: Thu, 30 Oct 2014 10:07:12 -0500
Message-ID: <CAP79kiRNS4k4hL66EXryCVp+DSWGR_uPWw5zCQOC79i_6wwOjQ_at_mail.gmail.com>

Wouldn't it be better to attack the problem instead of changing the whole "world" by setting the db parameter?

If it's one SQL statement, I'd use a SQL Profile to guarantee the plan that I want is used before forcing something at the db level.

Chris

On Thu, Oct 30, 2014 at 10:03 AM, Andrew Kerber <andrew.kerber_at_gmail.com> wrote:

> And we have a winner. The actual plan must have changed, even though when
> I just ran the explain command it did not. I turned off
> _optimizer_use_feedback and that fixes it. The question is why?
>
> Sent from my iPad
>
> On Oct 30, 2014, at 9:49 AM, Mauro Pagano <mauro.pagano_at_gmail.com> wrote:
>
> Does the execution plan change between first and second execution?
> If no the ignore the rest of my message but if yes then an educated guess
> (since we have no other info available) would be "cardinality feedback",
> you can test it setting "optimizer_use_feedback" = false
>
> On Thu, Oct 30, 2014 at 10:42 AM, Howard Latham <howard.latham_at_gmail.com>
> wrote:
>
>> Any chance of seeing the Query please?
>> --
>> http://www.freelists.org/webpage/oracle-l
>>
>>
>>
>
>
> --
> http://about.me/mauro.pagano
>
>

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Received on Thu Oct 30 2014 - 16:07:12 CET