Given below is a list of scenarios：
1） A user terminates his session abnormally.
2） The connection between the server and the client application terminates because of a network failure.
3） A schema is accidentally dropped.
4） The tablespace is accidentally dropped from the database.
5） The hard disk gets corrupted and the data files in the disk are lost.
6） The database instance abnormally shuts down because of power failure. 
Which scenarios require DBAintervention to perform recovery（）

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