Normal Form


Question 1
In a relational data model, which one of the following statements is TRUE?
A
A relation with only two attributes is always in BCNF.
B
If all attributes of a relation are prime attributes, then the relation is in BCNF.
C
Every relation has at least one non-prime attribute.
D
BCNF decompositions preserve functional dependencies.
GATE CSE 2022   Database Management System
Question 2
Suppose the following functional dependencies hold on a relation U with attributes P, Q, R, S, \text{ and } T:

P \rightarrow QR \\ RS \rightarrow T

Which of the following functional dependencies can be inferred from the above functional dependencies?
[MSQ]
A
PS \rightarrow T
B
R \rightarrow T
C
P \rightarrow R
D
PS \rightarrow Q
GATE CSE 2021 SET-2   Database Management System


Question 3
If every non-key attribute functionally dependent on the primary key, then the relation will be in
A
First normal form
B
Second normal form
C
Third normal form
D
Fourth Normal form
ISRO CSE 2020   Database Management System
Question 4
Consider a relational table R that is in 3NF, but not in BCNF. Which one of the following statements is TRUE?
A
R has a nontrivial functional dependency X\rightarrow A, where X is not a superkey and A is a prime attribute.
B
R has a nontrivial functional dependency X\rightarrow 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\rightarrow A, where X is not a superkey and A is a non-prime attribute and X is a proper subset of some key.
D
A cell in R holds a set instead of an atomic value.
GATE CSE 2020   Database Management System
Question 5
Let the set of functional dependencies F=\{QR\rightarrow S,R\rightarrow P,S\rightarrow Q\} hold on a relation schema X = (PQRS). X is not in BCNF. Suppose X is decomposed into two schemas Y and Z where Y = (PR) and Z = (QRS).
Consider the two statements given below:

I. Both Y and Z are in BCNF
II. Decomposition of X into Y and Z is dependency preserving and lossless.

Which of the above statements is/are correct?
A
Both I and II
B
I only
C
II only
D
Neither I nor II
GATE CSE 2019   Database Management System


There are 5 questions to complete.

9 thoughts on “Normal Form”

  3. In Question Number 34, there is printing mistake in ( A→→BC )
    The correct option is : i) if A→→B and A→→C then A→BC

    Reply

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