Database Systems Quizzes for Computer Science Students

Question 1

Which SQL statement is used to create a new table?

Accepted Answer

CREATE TABLE

Answer

INSERT

Answer

SELECT

Answer

UPDATE

Question 2

What is the main purpose of a primary key in a relational database?

Accepted Answer

To uniquely identify each row in a table

Answer

To link tables together

Answer

To enforce data integrity constraints

Answer

To store additional information about the data

Question 3

What is the key difference between a clustered and a non-clustered index in a database?

Accepted Answer

Clustered index physically sorts data based on the index key, while non-clustered index does not

Answer

Non-clustered index physically sorts data based on the index key, while clustered index does not

Answer

Clustered index is faster for range queries, while non-clustered index is faster for equality queries

Answer

There is no difference between clustered and non-clustered indexes

Question 4

What is the primary purpose of a Database Management System (DBMS) in the context of relational databases?

Accepted Answer

To define and manage the organization, storage, retrieval, and modification of data in a database.

Answer

To provide a graphical user interface for creating and editing databases.

Answer

To control user access and security in the database.

Answer

To optimize query performance and minimize resource usage.

Question 5

Which SQL command is used to select and retrieve specific data from a database table?

Accepted Answer

SELECT

Answer

INSERT

Answer

UPDATE

Answer

DELETE

Question 6

What is the primary purpose of a database schema in the context of relational database design?

Accepted Answer

To define the structure and relationships of data stored within a database, including tables, columns, and constraints.

Answer

To provide a visual representation of the database structure, simplifying design and comprehension.

Answer

To store the actual data values within the database.

Answer

To control user access and privileges within the database.

Question 7

Which of the following SQL statements is used for modifying the structure of a table, rather than its data?

Accepted Answer

ALTER TABLE table_name ADD COLUMN new_column_name data_type

Answer

UPDATE table_name SET column_name = new_value

Answer

INSERT INTO table_name (column_list) VALUES (value_list)

Answer

DELETE FROM table_name WHERE condition

Question 8

Which SQL statement is primarily used to retrieve data from a database?

Accepted Answer

SELECT

Answer

INSERT

Answer

UPDATE

Answer

DELETE

Question 9

In the relational data model, which of the following is NOT a characteristic associated with an entity?

Accepted Answer

Can represent a relationship between two or more entities

Answer

Can be assigned a primary key

Answer

Can be linked to other entities through foreign keys

Answer

Composed of attributes that define its properties

Question 10

Which of these accurately defines a primary key?

Accepted Answer

A column that distinctly identifies each record in a table

Answer

A column that holds the same value across all rows in a table

Answer

A column that helps sort rows in a table

Answer

A column that groups rows in a table

Question 11

Which SQL command is used to retrieve data from a table?

Accepted Answer

SELECT

Answer

INSERT

Answer

UPDATE

Answer

DELETE

Question 12

How does a primary key differ from a candidate key?

Accepted Answer

A primary key is always a candidate key, but not vice versa

Answer

A primary key is unique, while a candidate key is not

Answer

A candidate key is unique, while a primary key is not

Answer

There is no difference between a primary key and a candidate key

Question 13

What is the function of a data dictionary?

Accepted Answer

To store information about the structure of a database

Answer

To store the actual data

Answer

To manage user access to the database

Answer

To optimize query performance

Question 14

In MySQL, which syntax correctly creates a database named 'university'?

Accepted Answer

CREATE DATABASE university

Answer

CREATE university

Answer

university = CREATE DATABASE

Answer

CREATE DATABASE FROM university

Question 15

Which data model organizes data in a hierarchical structure?

Accepted Answer

Network model

Answer

Relational model

Answer

Object-oriented model

Answer

Entity-relationship model

Question 16

Which of the following is NOT an advantage of using a database system?

Accepted Answer

Lower data accessibility

Answer

Enhanced data integrity and consistency

Answer

Improved data security

Answer

Reduced data redundancy

Question 17

Which SQL command is used to fetch data from a table?

Accepted Answer

SELECT

Answer

INSERT

Answer

UPDATE

Answer

DELETE

Question 18

How does a primary key differ from a foreign key?

Accepted Answer

A primary key uniquely identifies each record in a table, while a foreign key references a primary key in a different table

Answer

A foreign key uniquely identifies each record in a table, while a primary key references a foreign key in a different table

Answer

There is no distinction between a primary key and a foreign key

Answer

Both primary keys and foreign keys are employed to maintain data integrity

Question 19

Which type of database normalization is represented by 3NF?

Accepted Answer

Third normal form (3NF)

Answer

First normal form (1NF)

Answer

Second normal form (2NF)

Answer

Fourth normal form (4NF)

Question 20

What is the primary purpose of using an index in a database?

Accepted Answer

To optimize data retrieval operations for improved performance

Answer

To ensure data integrity

Answer

To reduce data redundancy

Answer

To enhance data storage efficiency

Question 21

Explain the difference between a clustered index and a non-clustered index.

Accepted Answer

A clustered index physically organizes table data based on the indexed column, unlike a non-clustered index

Answer

A non-clustered index physically organizes table data based on the indexed column, unlike a clustered index

Answer

There is no distinction between a clustered index and a non-clustered index

Answer

A clustered index enhances data retrieval performance, while a non-clustered index optimizes data insertion performance

Question 22

Identify the data model centered around the concept of real-world entities and their interrelationships.

Accepted Answer

Entity-Relationship Model

Answer

Network Model

Answer

Hierarchical Model

Answer

Relational Model

Question 23

Which of the following is not among the primary responsibilities of a Database Management System (DBMS)?

Accepted Answer

Data Entry

Answer

Data Storage and Management

Answer

Data Security and Integrity

Answer

Data Retrieval and Processing

Question 24

In SQL, identify the statement utilized to create a new table.

Accepted Answer

CREATE TABLE

Answer

SELECT

Answer

UPDATE

Answer

INSERT

Question 25

In the context of relational databases, specify the essential qualities of a primary key constraint.

Accepted Answer

Unique and Not Null

Answer

Unique and Nullable

Answer

Non-unique and Non-null

Question 26

Which database schema design technique centers on minimizing data duplication?

Accepted Answer

Normalization

Answer

Object-Oriented Modeling

Answer

Entity-Relationship Modeling

Answer

Denormalization

Question 27

Identify the type of database query designed to retrieve data from multiple tables.

Accepted Answer

Join Query

Answer

Delete Query

Answer

Update Query

Answer

Select Query

Question 28

Which type of database system excels in handling vast amounts of unstructured data?

Accepted Answer

NoSQL Database

Answer

Hierarchical Database

Answer

Relational Database

Answer

Object-Oriented Database