Is it possible to downgrade oracle 18.104.22.168.0 to 10.2.0.4.0? The Compatible parameter need to be changed to "10.2.0"? Today I have Compatible set to 10.2.0.4.0.
It's not clear on support.oracle if I need to change or not. This document http://www.oracle.com/technetwork/database/upgrade/upgrade11gr2-downgrade-methods-179029.pdf
The major restriction on the downgrade script is that it cannot be run if the COMPATIBLE parameter has been raised as part of, or after, the upgrade. This is because raising the COMPATIBLE parameter will allow on-disk changes that cannot be understood by the earlier version of Oracle Database. For this reason, downgrades from Oracle Database 11g Release 2 to Oracle Database 9i are not supported. Downgrades from Oracle Database 11g Release 2 to the following versions are supported: 10.1.0.5 10.2.0.2, 10.2.0.3, 10.2.0.4, 10.2.0.5 22.214.171.124, 126.96.36.199
If you are downgrading to Oracle Database 10g Release 2 (10.2), then the COMPATIBLE initialization parameter must be set to 10.2.0 or lower.