Database Systems Learning Quizzes: Test Your Knowledge

Question 1

Which data model employs a tree-like structure to represent data, with each record having a single parent and multiple children?

Accepted Answer

Hierarchical model

Answer

Network model

Answer

Relational model

Answer

Document-oriented model

Question 2

Which characteristic is NOT associated with a database management system (DBMS)?

Accepted Answer

Limited data manipulation capabilities

Answer

Data independence

Answer

Concurrency control

Answer

Centralized data storage

Question 3

Which database design principle focuses on eliminating data redundancy and maintaining data consistency?

Accepted Answer

Normalization

Answer

Denormalization

Answer

Data modeling

Answer

Query optimization

Question 4

When designing a database, which data type is most appropriate for storing dates and times?

Accepted Answer

TIMESTAMP

Answer

INTEGER

Answer

VARCHAR

Answer

CHAR

Question 5

What is the primary purpose of a foreign key constraint in a database?

Accepted Answer

To establish relationships between tables and enforce referential integrity

Answer

To ensure that all data in a table is unique

Answer

To identify the primary key of a table

Answer

To restrict access to specific rows in a table

Question 6

Which advantage is associated with utilizing a database programming language?

Accepted Answer

Enhanced performance and flexibility

Answer

Increased data security

Answer

Simplified database maintenance

Answer

Reduced storage requirements

Question 7

Which SQL command is commonly used to retrieve data from a database?

Accepted Answer

SELECT

Answer

UPDATE

Answer

DELETE

Answer

CREATE TABLE

Question 8

What is the primary function of a database schema?

Accepted Answer

To define the structure, organization, and constraints of a database

Answer

To store the actual data within the database

Answer

To control user access and permissions

Answer

To optimize database performance

Question 9

Which of the following is the defining characteristic of a primary key?

Accepted Answer

It uniquely identifies each row in a table.

Answer

It stores the most important data in a table.

Answer

It is used to sort the data in a table.

Answer

It is used to filter the data in a table.

Question 10

Which data model represents data as a collection of objects with properties and relationships?

Accepted Answer

Object-oriented model

Answer

Relational model

Answer

Hierarchical model

Answer

Network model

Question 11

Which SQL command is used to create a new table?

Accepted Answer

CREATE TABLE

Answer

SELECT

Answer

INSERT

Answer

UPDATE

Question 12

What is the key difference between a join and a subquery?

Accepted Answer

A join combines rows from multiple tables, while a subquery returns a set of rows that can be used in a query.

Answer

A subquery can be used to filter data, while a join can be used to combine data.

Answer

Joins are more efficient than subqueries.

Answer

Subqueries are more secure than joins.

Question 13

What is the primary objective of database normalization?

Accepted Answer

To reduce data redundancy and improve data consistency

Answer

To increase database performance

Answer

To make the database more secure

Answer

To make the database easier to use

Question 14

Explain the ACID properties that ensure the reliability and consistency of transactions in database systems.

Accepted Answer

Atomicity, Consistency, Isolation, Durability

Answer

Availability, Consistency, Integrity, Durability

Answer

Atomicity, Completeness, Isolation, Durability

Answer

Atomicity, Consistency, Independence, Durability

Question 15

What is the primary goal of normalisation in database design?

Accepted Answer

To reduce data redundancy and improve data integrity

Answer

To increase data storage efficiency

Answer

To simplify data retrieval and manipulation

Answer

To enhance database security

Question 16

Which SQL statement is used to select data from a database table?

Accepted Answer

SELECT

Answer

INSERT

Answer

UPDATE

Answer

DELETE

Question 17

What is the difference between a primary key and a foreign key?

Accepted Answer

A primary key uniquely identifies a row in a table, while a foreign key references a primary key in another table.

Answer

A foreign key uniquely identifies a row in a table, while a primary key references a foreign key in another table.

Answer

A primary key and a foreign key are the same thing.

Answer

There is no difference between a primary key and a foreign key.

Question 18

What is the main purpose of a transaction in a database system?

Accepted Answer

To ensure the atomicity, consistency, isolation, and durability of data

Answer

To improve the database's performance

Answer

To provide a way to roll back changes to the database

Answer

To protect the database from unauthorised access

Question 19

Which of the following data models represents relationships between entities using tables?

Accepted Answer

Relational model

Answer

Hierarchica model

Answer

Network model

Question 20

What is the purpose of a primary key in a database table?

Accepted Answer

To uniquely identify each row in the table

Answer

To enforce data validation rules

Answer

To store the most important data in the table

Answer

To create relationships between tables

Question 21

What is the purpose of the SELECT statement in SQL?

Accepted Answer

To retrieve data from a database

Answer

To create a new database

Answer

To update data in a database

Answer

To delete data from a database

Question 22

What is the purpose of a data dictionary in a database system?

Accepted Answer

To store information about the structure and relationships of the data in the database

Answer

To store the actual data in the database

Answer

To manage user access and permissions