Monday, November 9, 2020

Quiz questions in database management systems with answers 17

MCQ on various aspects in DBMS including database introduction, user types, join techniques, normalization, database views, query optimizers and multivalued dependency questions with answers, RDBMS Multiple Choice Questions with Answers

Normalization Process - MCQ Exam Questions 

1. The normalization process in database management system helps us to

a) Eliminate redundant data stored in the database.

b) Convert the data to a canonical form to promote schema integration.

c) Reduce the number of joins required to satisfy a query.

d) Reduce the number of anomalies that can occur during inserts, deletes, and updates.

Answer: (a) and (d)

A normalized database has fewer repeated values – redundancy is replaced with foreign key references to the redundant data.

The primary purpose of normalization process is to eliminate the anomalies that can occur during insert, delete and update operations.


It is the process of organizing (or defining) the structure (the columns / attributes) of a relation (a table) in such a way to avoid data redundancy, and to avoid anomalies caused by operations like insert, delete, and update.


2. Assume that we have a relation R(A, B, C) with tuples (r1, r2, r3), (r4, r2, r3), (r5, r3, r3), and (r5, r3, r4). Which of the following functional dependencies does not hold in R?

a) A B

b) BC A

c) B C

d) B ->-> C

Answer: (b) BC à A

The functional dependency, BC uniquely determines A (BC à A) does not hold in R because a given BC {r2, r2} has two A values {r1} and {r4}. These two tuples violates the uniqueness property.

The other functional dependencies and multi-valued dependency hold in R.


Related posts:

Quiz questions with answers on DBMS introduction concepts

Find the valid functional dependencies for the given data

List down various purposes of normalization process in DBMS

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