Before downgrading the Oracle Database 12c database back to the previous version, ensure that no Singular Value Decomposition models or Expectation Maximization models are present. These algorithms are only available in Oracle Database 12c. Use the DBMS_DATA_MINING.DROP_MODEL
routine to drop these models before downgrading. If you do not do this, the database downgrade process will be aborted.
Issue the following SQL statement in SYS
to verify the downgrade:
SQL>SELECT o.name FROM sys.model$ m, sys.obj$ o WHERE m.obj#=o.obj# AND m.version=2;