Database Design: Master the Fundamentals for Data Management

Question 1

What is the first normal form (1NF) condition in database normalization?

Accepted Answer

Every column contains atomic values.

Answer

Every row is uniquely identified.

Answer

There are no repeating groups within rows.

Answer

All columns depend on the primary key.

Question 2

Which of the following data types is most appropriate for storing email addresses in a database?

Accepted Answer

VARCHAR(255)

Answer

CHAR(255)

Answer

TEXT

Answer

INT

Question 3

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

Accepted Answer

To document database structure, metadata, and business rules

Answer

To store actual data in the database

Answer

To enforce data integrity constraints

Answer

To create database backups

Question 4

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

Accepted Answer

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

Answer

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

Answer

Both primary and foreign keys identify rows uniquely.

Answer

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

Question 5

Which of the following SQL statements is used to create a database table?

Accepted Answer

CREATE TABLE

Answer

INSERT INTO

Answer

SELECT FROM

Answer

UPDATE

Question 6

What is the purpose of using a query optimizer in a database system?

Accepted Answer

To improve the performance of database queries by choosing the most efficient execution plan

Answer

To ensure the security of database data

Answer

To manage database backups

Answer

To create database indexes

Question 7

Which primary objective of database normalization is to eliminate data redundancy, ensuring that each piece of data is stored only once?

Accepted Answer

Eliminating data redundancy

Answer

Ensuring data consistency

Answer

Improving database performance

Answer

Facilitating data modification

Question 8

In an entity-relationship diagram (ERD), which symbol represents the relationship between two entities?

Accepted Answer

Diamond

Answer

Square

Answer

Triangle

Answer

Circle

Question 9

Which of the following is NOT a type of data constraint used to enforce data integrity?

Accepted Answer

Suggested

Answer

Primary key

Answer

Foreign key

Answer

Unique

Question 10

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

Accepted Answer

To uniquely identify each row in a table

Answer

To enforce referential integrity

Answer

To ensure data consistency

Answer

To improve database performance

Question 11

Which of the following data types is most appropriate for storing dates and times?

Accepted Answer

Date

Answer

Integer

Answer

String

Answer

Boolean

Question 12

What is the key difference between a view and a materialized view in a database?

Accepted Answer

A materialized view stores data physically, while a view does not.

Answer

A view can be updated, while a materialized view cannot.

Answer

A materialized view is faster to query than a view.

Answer

There is no difference between a view and a materialized view.

Question 13

What is the primary role of an index in a database?

Accepted Answer

To accelerate data retrieval by providing a fast lookup mechanism

Answer

To enforce data integrity by preventing duplicate values

Answer

To improve data storage efficiency by reducing data redundancy

Answer

To facilitate data modification by ensuring data consistency

Question 14

What is the term for the process of converting a logical database design into a physical database implementation?

Accepted Answer

Database mapping

Answer

Database translation

Answer

Database transformation

Answer

Database conversion

Question 15

Which of the following represents the highest level of data normalization?

Accepted Answer

Boyce-Codd Normal Form (BCNF)

Answer

First Normal Form (1NF)

Answer

Second Normal Form (2NF)

Answer

Third Normal Form (3NF)

Question 16

What is the primary purpose of an Entity-Relationship Diagram (ERD)?

Accepted Answer

Depict the relationships between various entities within a database

Answer

Establish the structure of database tables

Answer

Enforce constraints to maintain data integrity

Answer

Generate SQL code for database operations

Question 17

Which of the options below does NOT constitute a data integrity constraint?

Accepted Answer

Stored procedure

Answer

Primary key

Answer

Foreign key

Answer

CHECK constraint

Question 18

Why are composite keys used in database design?

Accepted Answer

To uniquely identify entities when no single attribute is sufficient

Answer

To ensure data integrity by enforcing referential constraints

Answer

To improve query performance by creating additional indexes

Answer

To facilitate data manipulation by simplifying updates and deletions

Question 19

Which of these practices is NOT recommended for optimizing database queries?

Accepted Answer

Employing subqueries instead of joins

Answer

Utilizing indexes to enhance performance

Answer

Avoiding the use of ORDER BY clauses whenever possible

Answer

Limiting the number of columns retrieved

Question 20

What is the preferred method for storing dates in a database?

Accepted Answer

Integers representing days since a fixed date

Answer

Character strings

Answer

Floating-point numbers representing date and time

Answer

A combination of character strings and integers

Question 21

What is the key purpose of an Entity-Relationship Diagram (ERD)?

Accepted Answer

To visually depict the relationships between entities in a database

Answer

To specify the physical structure of a database

Answer

To define the business rules governing a database

Answer

To generate SQL code for database creation

Question 22

Which of the following is not a type of data integrity constraint?

Accepted Answer

Stored procedure

Answer

Primary key

Answer

Foreign key

Answer

Unique constraint

Question 23

What is the primary objective of a referential integrity constraint?

Accepted Answer

To ensure that related data is consistent across tables

Answer

To prevent duplicate data entries

Answer

To enforce business rules

Answer

To optimize database performance

Question 24

Which data type is suitable for storing extensive text content?

Accepted Answer

TEXT

Answer

VARCHAR

Answer

INTEGER

Answer

FLOAT

Question 25

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

Accepted Answer

Accelerates data retrieval by organizing data in a specific order

Answer

Enhances data security by encrypting sensitive information

Answer

Reduces storage space by compressing data

Answer

Simplifies data manipulation by automating certain tasks

Question 26

What is the primary responsibility of a Database Administrator (DBA)?

Accepted Answer

Managing, designing, and maintaining databases

Answer

Writing SQL queries and generating reports

Answer

Providing user support and training

Answer

Enforcing data security and performing backups

Question 27

Which of the following is NOT a security measure primarily intended to prevent unauthorized database access?

Accepted Answer

Regular backups

Answer

Encryption

Answer

Authentication

Answer

Firewalls

Question 28

What are the essential steps in normalizing a database?

Accepted Answer

Identifying dependencies, creating tables, and removing redundancy.

Answer

Creating tables, assigning keys, and defining relationships.

Answer

Converting data into a hierarchical format.

Answer

Implementing triggers and stored procedures.

Question 29

Why is it crucial to follow best practices in database design? Provide specific examples to illustrate your answer.

Accepted Answer

Ensures data integrity and reduces inconsistencies

Accepted Answer

Simplifies database management and updates

Accepted Answer

Optimizes data storage for faster queries

Answer

Protects database security from unauthorized access

Question 30

In an entity-relationship diagram, what shape denotes a relationship between entities?

Accepted Answer

Diamond

Answer

Rectangle

Answer

Oval

Answer

Square

Question 31

Which data constraint prevents a column from accepting null values?

Accepted Answer

NOT NULL

Answer

UNIQUE

Answer

PRIMARY KEY

Answer

FOREIGN KEY

Question 32

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

Accepted Answer

To establish a connection between tables

Answer

To guarantee data accuracy

Answer

To create a unique index

Answer

To store additional information about a row

Question 33

Which normalization form ensures that all attributes in a table are fully dependent on the primary key?

Accepted Answer

Boyce-Codd Normal Form (BCNF)

Answer

First Normal Form (1NF)

Answer

Second Normal Form (2NF)

Answer

Third Normal Form (3NF)

Question 34

What is the main role of a data dictionary in a database system?

Accepted Answer

To store information about the database's structure

Answer

To enforce data integrity rules

Answer

To document the database

Answer

To optimize database performance

Question 35

Which of the following is not a valid data type in SQL?

Accepted Answer

ARRAY

Answer

INTEGER

Answer

VARCHAR

Answer

DATE

Question 36

What is the purpose of a database schema?

Accepted Answer

To outline the structure and organization of a database

Answer

To store the actual data in a database

Answer

To ensure data integrity

Answer

To enhance query performance

Question 37

Which of the following is a primary benefit of database normalization?

Accepted Answer

Enhancing data consistency

Answer

Minimizing storage space

Answer

Heightening data security

Answer

Increasing data redundancy

Question 38

Which of the following is NOT a primary objective of database normalization?

Accepted Answer

Improving query performance

Answer

Eliminating data redundancy

Answer

Enhancing data consistency

Answer

Simplifying database design

Question 39

An entity-relationship diagram (ERD) is a graphical representation of:

Accepted Answer

The relationships between entities in a database.

Answer

The fields in a database table.

Answer

The indexes in a database.

Answer

The tables in a database.

Question 40

What is the primary purpose of normalization in database design?

Accepted Answer

To reduce data redundancy and improve data integrity.

Answer

To make a database easier to design.

Answer

To increase the performance of a database.

Question 41

What is the main 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 primary key is always a number, while a foreign key is always a character string.

Question 42

Which of the following SQL data types is used to store variable-length text data?

Accepted Answer

VARCHAR

Answer

FLOAT

Answer

INT

Answer

DATE

Question 43

What is the purpose of an index in a database?

Accepted Answer

To speed up the retrieval of data.

Answer

To prevent duplicate data from being entered.

Answer

To ensure the integrity of the data.

Answer

To compress the data.

Question 44

What is the primary responsibility of a database management system (DBMS)?

Accepted Answer

To manage and control access to a database.

Answer

To create and modify databases.

Answer

To design and implement database applications.

Answer

To query and retrieve data from a database.

Question 45

Which of these is NOT a fundamental principle of data normalization?

Accepted Answer

Data Redundancy

Answer

Atomicity of Attributes

Answer

Transitive Dependency

Answer

Functional Dependency

Question 46

In an entity-relationship diagram (ERD), which symbol is used to represent a weak entity?

Accepted Answer

Double Rectangle

Answer

Triangle

Answer

Single Rectangle

Answer

Ellipsis

Question 47

Which database constraint is used to ensure that every record in a table has a unique identifier?

Accepted Answer

UNIQUE

Answer

NOT NULL

Answer

FOREIGN KEY

Answer

DEFAULT

Question 48

Up to which normal form does normalization eliminate transitive functional dependencies?

Accepted Answer

3NF (Third Normal Form)

Answer

4NF (Fourth Normal Form)

Answer

1NF (First Normal Form)

Answer

2NF (Second Normal Form)

Question 49

What is the main purpose of a foreign key constraint?

Accepted Answer

To maintain referential integrity between tables.

Answer

To ensure data uniqueness.

Answer

To enforce data types.

Answer

To limit the number of records in a table.

Question 50

Which situation violates Boyce-Codd Normal Form (BCNF)?

Accepted Answer

A non-key attribute depends on a part of a candidate key, not the whole key.

Answer

A non-key attribute depends on the entire primary key.

Question 51

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

Accepted Answer

A primary key is a specific choice of a candidate key, which uniquely identifies a record.

Answer

A primary key is a foreign key, while a candidate key is a primary key.

Question 52

Which tool is primarily used for creating a conceptual database design?

Accepted Answer

Entity-Relationship Diagram (ERD)

Answer

Flowchart

Answer

Use Case Diagram

Question 53

What does cardinality represent in an ERD?

Accepted Answer

The number of instances of one entity that can be related to one instance of another entity.

Answer

The type of relationship between entities.

Answer

The data type of an attribute.

Question 54

What is NOT a benefit of normalizing a database?

Accepted Answer

Increased data redundancy.

Answer

Reduced data anomalies.

Answer

Improved data integrity.