Monday, 18 January 2021

Functional Dependencies MCQ

 

Functional Dependencies


1. We can use the following three rules to find logically implied functional dependencies. This collection of rules is called

a) Axioms

b) Armstrong’s axioms

c) Armstrong

d) Closure


2. Which of the following is not Armstrong’s Axiom?

a) Reflexivity rule

b) Transitivity rule

c) Pseudotransitivity rule

d) Augmentation rule


3.  There are two functional dependencies with the same set of attributes on the left side of the arrow:

A->BC

A->B

This can be combined as

a) A->BC

b) A->B

c) B->C

d) None of the mentioned


4. Consider a relation R(A,B,C,D,E) with the following functional dependencies:

ABC -> DE and

D -> AB

The number of superkeys of R is:

a) 2

b) 7

c) 10

d) 12


5. Suppose relation R(A,B,C,D,E) has the following functional dependencies:

A -> B

B -> C

BC -> A

A -> D

E -> A

D -> E

Which of the following is not a key?

a) A

b) E

c) B, C

d) D


Let R= (A, B, C, D, E, F) be a relation scheme with the following  dependencies: C->F, E->A, EC->D, A->B.  Which of the following is a key for R?

A.) CD

B.) EC

C.) AE

D.) AC



Consider a relation scheme R = (A, B, C, D, E, H) on which the following functional dependencies hold: {A–>B, BC–>D, E–>C, D–>A}. What are the candidate keys of R?

A). AE, BE

B). AE, BE, DE

C). AEH, BEH, BCH

D). AEH, BEH, DEH



Relation R has eight attributes ABCDEFGH. Fields of R contain only atomic values.

F={CH->G, A->BC, B->CFH, E->A, F- >EG} is a set of functional dependencies (FDs) so that F + is exactly the set of FDs that hold for R. How many candidate keys does the relation R have?


A.) 3

B.) 4

C.) 5

D.) 6



Consider the relation scheme R=(E,F,G,H,I,J,K,L,M,N) and the set of functional dependencies 

{{E,F}→{G},{F}→{I,J},{E,H}→{K,L},{K}→ {M},{L}→{N}} on R. What is the key for R?

A.) {E,F}

B.) {E,F,H}

C.) {E,F,H,K,L}

D.) {E}



If a functional dependency set F is {A→B, BC→E, ED→A, EF→G, E→F}, find the closure of attribute set (AC)

A.) {A,B,C,E,F,G}

B.) {A,B,C,D,E,F,G}

C.) {A,B,C,D,E,F}

D.) {A,B,C,D,E,G}



A relation R(ABC) is having the following 4 tuples: (1,2,3), (4,2,3), (5,3,3) and (2,4,4). Which of the following dependency can you infer doesn't hold over relation R?

A.) A→B

B.) AB→C

C.) B→C

D.) C→B

Sunday, 17 January 2021

17 Jan 2021 Test Result

 17 Jan 2021 Test Result


S. No.

Name

Marks

1

Shubham Bhardwaj

35

2

Salvi Vatsa

33

3

Chirag Kashyap

30

4

Rohit Kumar

29

5

Priyanka Yadav

28

6

Priyanka Arora

28

7

Manish Kumar Garg

28

8

Vipin Kumar

28

9

Shehbaz

28

10

Vibhakar

27

11

Sanjay

27

12

Gopal Sharma

27

13

Akshay Sharma

27

14

Md Tehran

26

15

Ranjeet Yadav

26

16

Annu

25

17

Mukesh Roy

25

18

Lovely

24

19

Rajesh Kumar

24

20

Satyam

24

21

Piyush Kumar

23

22

Jitender

22

23

Poonam Yadav

21

24

Ankit Pandey

21

25

Sandeep Kumar

20

26

Anuj Kashyap

20

27

Pritam Kumari

19

28

Priya Chaurasia

19

29

Sanjeev

19

30

Himanshu

19

31

Sonika Beniwal

18

32

Raj

18

33

Richa Dubey

18

34

Rakesh

18

35

Hitesh Kumar

18

36

Nisha

18

37

Gaurav Gahlot

17

38

Lalit Gupta

17

39

Sunaina Bizenia

16

40

Chandan

16

41

Shahib

16

42

Dilip Gupta

16

43

Ajay Gupta

16

44

Ajay Kumar

16

45

Pragati

15

46

Akanksha Sharma

14

47

Janisar Akhter

14

48

Anil Yadav

14

49

Priyanka Soni

13

50

Meerayadav

13

51

Shailja

13

52

Suhail Malik

13

53

Hemant Kumar Singh

12

54

Sonika

9