Question

Question 1 2 Marks Briefly explain the referential integrity rule. Provide a suitable situation when the referential integrity constraint is violated.

Question 2 2 Marks This question refers to the Part table as used in this unit lecture slides about the customers to order homeware parts. Using SQL DCL command to write a statement to permit a user with the log in ID of JOHNSON to access the Part table and update its UnitPrice value.

Question 3 2 Marks Consider a relation named STUDENT_ ACCOMMODATION (StudentID, Buidling, AccommodationFee) as shown in the figure below. Explain why this relation is in 2NF but not in 3NF.

StudentID	Building	AccommadtionFee
101	Alpha	$320
102	Betta	$250
103	Alpha	$320
104	Betta	$250
105	Gemma	$400

Question 4 2 Marks Explain the purpose of transaction logs and checkpoints. Question 5 2 Marks Compare and contrast Data Warehousing against Database

Answer 1

Question 1:

A referential integrity rule is defined as that a key (a column or groups of columns can be a private key or foreign key) in one table that ensures guarantees that the values in that key match the values in a key in a related table (the referenced value can be primary key or foreign key).

Situation where referential integrity ruler will be violated where the referenced value does not exist or we can say that a child cannot exist without a parent and situation where we have created a reference value and delete the data from one table than the referential integrity ruler will need violated as the second table does not have the parent to it or reference value.