Re: 12.1 Optimizer feature stability

Thank you Shane.

Actually team says 12.1 is the buggier one and also all the .1 releases having most of the issues , so trying to play safe by keeping OFE at 11.2. So I wanted to check if it's really true. But i think , as per your point, we should really stick with all defaults for that version, i.e. in our case OFE- 12.1 only.

Thanks and regards
Pap

On Mon, Jan 11, 2021 at 4:59 PM Shane Borden <sborden76_at_yahoo.com> wrote:

> One last thing, it’s not like Oracle really tests this configuration
> either. So if you really need OFE or some else set for a query, do it
> with a profile or hint for that sql not systemwide.
>
> Shane Borden
> sborden76_at_yahoo.com
> Sent from my iPhone
>
> > On Jan 11, 2021, at 6:18 AM, Shane Borden <sborden76_at_yahoo.com> wrote:
> >
> > On an upgrade, I always reset the parameters to all defaults unless you
> know you need to address a specific requirement such as Peoplesoft or EBS.
> >
> > Doing it this way gives you a chance to get back to default
> characteristics and eliminate technical debt that people likely can’t prove
> the need to be there anyway.
> >
> > Also, don’t let the App team dictate how to set it up unless they can
> prove the need. The worst reason ever is “that’s the way it’s always
> been”.
> >
> > Shane Borden
> > sborden76_at_yahoo.com
> > Sent from my iPhone
> >
> >> On Jan 11, 2021, at 4:57 AM, Pap <oracle.developer35_at_gmail.com> wrote:
> >>
> >> 
> >> Hello All, We are moving from version 11.2.0.4 to version12.1.0.2.0 of
> Oracle. We can't go to the latest versions(like 19C/18C) because of certain
> application dependencies which are running on this database. Team is
> suggesting to keep the optimizer_feature_enable as it was for existing
> version i.e. 11.2.0.4, as because there are issues/bugs for version
> 12.1.0.2.0.
> >>
> >> So I wanted to check with experts here , if it's really so and have
> such a bad experience with OFE- 12.1.0.2.0 and we must keep the optimizer
> feature at 11.2.0.4 even if the database version would be 12.1.0.2?
> >>
> >> For information, We do use a lot of Global temporary tables in our
> application code, but then we are thinking these will get the benefit of
> the private session level stats on OFE- 12.1 and it won't happen such if we
> keep the OFE at 11.2. Even if we don't change the code to gather stats on
> the GTT immediately during migration , then that will still keep on using
> dynamic sampling(in absence of session level stats) as it used to happen on
> version 11.2. And gradually we will change our code to gather session level
> stats in application code where estimation is going bad impacting execution
> path.
> >>
> >> Regards
> >> Pap
> >>
>
>

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