How to downgrade oracle 12.1.0.2 to 11.2.0.4

Hi Everyone,

I have a requirement to downgrade the Oracle version from 12.1.0.2 to 11.2.0.4. I cannot perform DB restore, I need to retain the data that is currently being used in 12.1.0.2. We are using a single DB instance database.

I searched the Oracle documentation and found that "You cannot downgrade a database once you have set the compatible initialization parameter to 12.1.0.2.".

Is there a way to perform the downgrade? Please route me to some documentation as well.

Regards,

Somesh