The Data Pump Import utility is started using the impdp command. The characteristics of the import operation are determined by the import parameters you specify. These parameters can be specified either on the command line or in a parameter file.
Do not start Import as SYSDBA, except at the request of Oracle technical support. SYSDBA is used internally and has specialized functions; its behavior is not the same as for general users.
Be aware that if you are performing a Data Pump Import into a table or tablespace created with the NOLOGGING clause enabled, then a redo log file may still be generated. The redo that is generated in such a case is generally for maintenance of the master table or related to underlying recursive space transactions, data dictionary changes, and index maintenance for indices on the table that require logging.
The following sections contain more information about invoking Import: