CS3402 Tutorial 3:
1. Suppose each of the following Update operations is applied directly to the database below. Discuss all integrity constraints violated by each operation, if any, and the different ways of enforcing these constraints:
(a) Insert < 'ProductA', 4, 'Bellaire', 2 > into PROJECT.
(b) Insert < 'Production', 4, '943775543', '01-OCT-88' > into DEPARTMENT.
(c) Insert < '677678989', null, '40.0' > into WORKS_ON.
(d) Delete the EMPLOYEE tuple with SSN= ‘987654321’.
(e) Delete the PROJECT tuple with PNAME= ‘ProductX’.
(f) Modify the SUPERSSN attribute of the EMPLOYEE tuple with SSN= ‘999887777’ to ‘943775543’.
2 Consider the relation REFRIG(MODEL#, YEAR, PRICE, MANUF_PLANT, COLOR), which is abbreviated as REFRIG(M, Y, P, U, C), and the following set of F of functional dependencies: F={M -> U, {M,Y} -> P, U -> C}. Evaluate each of the following as a candidate key for REFRIG, giving reasons why it can or cannot be a key: {M}, {M,Y}, {M,C}