1
GATE CSE 2024 Set 1
MCQ (More than One Correct Answer)
+2
-0.66

The symbol → indicates functional dependency in the context of a relational database. Which of the following options is/are TRUE?

A

(X, Y) → (Z, W) implies X → (Z, W)

B

(X, Y) → (Z, W) implies (X, Y) → Z

C

((X, Y) → Z and W → Y) implies (X, W) → Z

D

(X → Y and Y → Z) implies X → Z

2
GATE CSE 2021 Set 2
MCQ (More than One Correct Answer)
+2
-0

Suppose the following functional dependencies hold on a relation U with attributes P, Q, R, S, and T :

P → QR

RS → T

Which of the following functional dependencies can be inferred from the above functional dependencies?  

A
P → R
B
PS → T
C
R → T
D
PS → Q
3
GATE CSE 2021 Set 1
MCQ (Single Correct Answer)
+2
-0.67

Consider the relation R(P, Q, S, T, X, Y, Z, W) with the following functional dependencies.

PQ → X; P → YX; Q → Y; Y → ZW

Consider the decomposition of the relation R into the constituent relations according to the following two decomposition schemes.

D1 : R = [(P, Q, S, T); (P, T, X); (Q, Y); (Y, Z, W)]

D2 : R = [(P, Q, S); (T, X); (Q, Y); (Y, Z, W)]

Which one of the following options is correct?

A

D1 is a lossy decomposition, but D2 is a lossless decomposition.

B
Both D1 and D2 are lossless decompositions.
C
Both D1 and D2 are lossy decompositions.
D
D1 is a lossless decomposition, but D2 is a lossy decomposition.
4
GATE CSE 2020
MCQ (Single Correct Answer)
+2
-0.67
Consider a relational table R that is in 3NF, but not in BCNF. Which one of the following statements is TRUE?
A
A cell in R holds a set instead of an atomic value.
B
R has a nontrivial functional dependency X $$ \to $$ A, where X is not a superkey and A is a non-prime attribute and X is not a proper subset of any key
C
R has a nontrivial functional dependency X $$ \to $$ A, where X is not a superkey and A is a non-prime attribute and X is a proper subset of some key.
D
R has a nontrivial functional dependency X $$ \to $$ A, where X is not a superkey and A is a prime attribute.
GATE CSE Subjects
Software Engineering
Web Technologies
EXAM MAP
Medical
NEETAIIMS
Graduate Aptitude Test in Engineering
GATE CSEGATE ECEGATE EEGATE MEGATE CEGATE PIGATE IN
Civil Services
UPSC Civil Service
Defence
NDA
Staff Selection Commission
SSC CGL Tier I
CBSE
Class 12