4 　
　　
　　Q. 12 : Rollback segment stores
　　
　　1. old values of the data changed by each transaction
　　2. new values of the data changed by each transaction
　　3. both old and new values of the data changed by each transaction
　　4. none
　　
　　1

Q. 1 : When will the rollback information applied in the event of a database crash
　　
　　1. before the crash occurs
　　2. after the recovery is complete
　　3. immediately after re-opening the database before the recovery
　　4. roll back infrmation is never applied if the database crashes
　　
　　2
　　　
　　Q. 2 : The data dictionary tables and views are stored in
　　
　　1. USERS tablespace
　　2. SYSTEM tablespace
　　3. TEMPORARY tablespace
　　4. any of the three
　　
　　3
　　　
　　Q. 3 : Oracle uses the data dictionary tables and views
　　
　　1. to make the database user friendly
　　2. to store user data
　　3. to store application data
　　4. for proper database functioning