The database users are connecting to the PROD database from different 
applications， thereby degrading the database performance. The senior database administrator suspects the large number of concurrent connections to be the reason for low performance and asks you to restrict the number concurrent connections per database user to one. 
Which action would you take to achieve this objective？（）

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？（）