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@xxxxxxxxx
Sent from my iPhone
On Jan 11, 2021, at 6:18 AM, Shane Borden <sborden76@xxxxxxxxx> 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@xxxxxxxxx
Sent from my iPhone
On Jan 11, 2021, at 4:57 AM, Pap <oracle.developer35@xxxxxxxxx> 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
