You are reviewing the design of a student dimension table in an existing data warehouse hosted on SQL
Azure.
The current dimension design does not allow the retention of historical changes to student attributes
such as ParentOccupation.
You need to redesign the dimension to enable the full historical reporting of changes to multiple student
attributes including ParentOccupation.
What should you do?

A.
Add CurrentValue and PreviousValue columns to the student dimension.

B.
Enable Snapshot Isolation on the data warehouse.

C.
Add an IsCurrent column to the student dimension.

D.
Add StartDate and EndDate columns to the student dimension.

Explanation:
Adding a start and end date will give you this ability as when a record is inserted and given a start and
end date, you’ll have the ability to determine when they were active therefore giving you a retention of
historical changes