# 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 1 Explanation:
 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 2 Explanation:

 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 3 Explanation:
 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 4 Explanation:
 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
Question 5 Explanation:

There are 5 questions to complete.

### 9 thoughts on “Normal Form”

1. Sir, Please check question number 24. Half question is something else, and half is something else.

• Thank You Ashutosh,
We have updated the question.

2. Ques 2’s answer should be option c. kindly check and confirm.
https://www.geeksforgeeks.org/isro-isro-cs-2020-question-65/

• Answer is (B) only. You can check the details solution.

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

• Thank You Rashmi,
We have updated the option. It is question no 28.

4. Question 45.
3rd option is:-

5. 6. 