You are using flat files as the data source for one of your data warehousing applications. You plan to move the data from the flat file structures to an Oracle database to optimize the application performance. In your database you have clustered tables. 
While migrating the data， you want to have minimal impact on the database performance and optimize the data load operation. Which method would you use to load data into Oracle database？（）

A.recover using Oracle Flashback Database technology
B.restore the data files from backup and perform a complete recovery
C.restore only the corrupted data file and perform tablespace recovery
D.restore the data files from backup and perform cancel­based recovery
E.restore the entire database from the most recent backup and start the instance and open the database

A.The data files can be recovered till the last committed transaction.
B.The data files can be recovered without shutting down the database.
C.The data file is taken offline automatically; the database remains open.
D.The data files can be recovered to the time of the most recent backup.

A.The database instance aborts.
B.The database operation temporarily halts till the member becomes available.
C.Writing proceeds as normal. LGWR writes to the available members of a group and ignores the unavailable members.
D.The member would be marked as STALE and an error message would be written to the alert log file and LGWR trace file.
E.The status of the group changes to INACTIVE and an error message would be written to the alert log file and LGWR trace file.