The transformation list argument to CREATE_MODEL interacts with the PREP_AUTO setting, which controls Automatic Data Preparation (ADP):
When ADP is on and you specify a transformation list, your transformations are applied with the automatic transformations and embedded in the model. The transformations that you specify are executed before the automatic transformations.
When ADP is off and you specify a transformation list, your transformations are applied and embedded in the model, but no system-generated transformations are performed.
When ADP is on and you do not specify a transformation list, the system-generated transformations are applied and embedded in the model.
When ADP is off and you do not specify a transformation list, no transformations are embedded in the model; you must separately prepare the data sets you use for building, testing, and scoring the model.
See Also:
"Operational Notes" for DBMS_DATA_MINING_TRANSFORM in Oracle Database PL/SQL Packages and Types Reference