A、You must use Oracle predefined names to identify raw partitions that will hold OMF structures. 

B、You must define directories for two online redo log groups and three copies of the control file. 

C、If your CREATE DATABASE command fails, any OMF database files that have already been created will be dropped automatically. 

D、You must use only OMF data files when adding new tablespaces or data files to your database in the future.