Exercise 4

Determine whether or not the following Σ11 and Σ12 are equivalent. Show and explain your answer

R1= {A, B, C}, Σ11 = {A->B, A->C, C->A} and Σ12 = {A->B, AB->C, A->C, C->A} on R1, respectively.

Exercise 5

Decompose the following into BCNF R = (A, B, C) F = {A → B, B → C}

Exercise 6

George withdraws $100 from his account (T1) while Mary deposits$500 into George’s account (T2) in the following transaction process.

Draw up the steps with equivalent transactions and then explain what the problem is what the process.

T1: SELECT balance FROM Account WHERE name=’George’;

T1: UPDATE Account SET balance=balance-100 WHERE name=’George’;

T2: SELECT balance FROM Account WHERE name=’George’;

T1: ROLLBACK;

T2: UPDATE Account SET balance=balance+500 WHERE name=’George’;

T2: COMMIT;

Exercise 7

TRANSPORTONE is a newly established company on transportation network in Australia.

Consider the relation schema ORDER={Customer, Date, OrderID, Employee, Manager}and the

following set Σ of FDs:

Fd1:{Customer, Date}→{OrderID}

Fd2:{Employee}→{Manager
}

Fd3:{OrderID, Date}→{Customer, Employee}

Fd4:{Date}→{Manager}

1.Normalize into BCNF

2.Normalize into 3NF

3.An order can be identified using the customer who submitted the order and date of submission of the order. Write down the functional dependency.