Master Database Fundamentals: A Comprehensive Guide for IT Professionals

Question 1

What is the primary purpose of using constraints in a database table?

Accepted Answer

To enforce data integrity and validity

Answer

To improve database performance

Answer

To prevent unauthorized access to data

Answer

To simplify database administration

Question 2

What is the purpose of an index in a database table?

Accepted Answer

To enhance data retrieval speed

Answer

To ensure data correctness

Answer

To prevent data duplication

Answer

To encrypt sensitive data

Question 3

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

Accepted Answer

To guarantee the ACID (atomicity, consistency, isolation, durability) properties of data operations

Answer

To enhance database performance

Answer

To protect data from unauthorized access

Answer

To simplify database administration

Question 4

Which characteristic is NOT a feature of relational databases?

Accepted Answer

Documents

Answer

Tables

Answer

Fields

Question 5

Which SQL statement updates the 'name' field to 'John Smith' for the record with 'customer_id' 10 in the 'customers' table?

Accepted Answer

UPDATE customers SET name = 'John Smith' WHERE customer_id = 10;

Answer

SELECT * FROM customers WHERE name = 'John Smith';

Answer

DELETE FROM customers WHERE customer_id = 10;

Question 6

What is the main purpose of normalizing a database?

Accepted Answer

To improve data accuracy and consistency

Answer

To reduce the number of tables in a database

Answer

To speed up data retrieval queries

Question 7

In a relational database, which element does NOT exist?

Accepted Answer

Objects

Answer

Tables

Answer

Rows

Answer

Columns

Question 8

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

Accepted Answer

To uniquely identify each row in the table

Answer

To store the most essential data in the table

Answer

To establish relationships with other tables

Answer

To maintain data accuracy and consistency

Question 9

Which data model depicts data as a tree-like structure, with each node containing one or more child nodes?

Accepted Answer

Hierarchical

Answer

Relational

Answer

Object-oriented

Answer

Network

Question 10

To create a new database in SQL, which command should be used?

Accepted Answer

CREATE DATABASE

Answer

CREATE TABLE

Answer

INSERT INTO

Answer

SELECT * FROM

Question 11

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

Accepted Answer

A primary key uniquely identifies each row, while a foreign key references another table's primary key

Answer

A foreign key uniquely identifies each row, while a primary key references another table's foreign key

Answer

Both primary and foreign keys uniquely identify each row

Answer

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

Question 12

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

Accepted Answer

To create, manage, and access databases

Answer

To provide a user interface for interacting with data

Answer

To enforce data integrity and security

Answer

To perform complex data analysis

Question 13

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

Accepted Answer

SELECT

Answer

INSERT

Answer

UPDATE

Answer

DELETE

Question 14

What is the primary objective of database tuning?

Accepted Answer

To optimize database performance

Answer

To reduce database size

Answer

To improve data security

Answer

To simplify database maintenance

Question 15

Which of the following is **not** a type of data model?

Accepted Answer

Hypertext Markup Language (HTML)

Answer

Relational model

Answer

Network model

Answer

Hierarchical model

Question 16

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

Accepted Answer

Manage and control access to data

Answer

Design the database schema without external input

Answer

Execute SQL queries without user interaction

Answer

Generate reports without user intervention

Question 17

Which SQL statement is used to create a new table?

Accepted Answer

CREATE TABLE

Answer

INSERT

Answer

SELECT

Question 18

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

Accepted Answer

Uniquely identify each row

Answer

Store the most important data

Answer

Link the table to other tables solely

Answer

Enforce data integrity on its own

Question 19

Which of the following is an advantage of using a relational database model?

Accepted Answer

Data independence

Answer

High performance only

Answer

Simplicity of design only

Answer

Low cost only

Question 20

What is the difference between a JOIN and a UNION operation in SQL?

Accepted Answer

JOIN combines rows from multiple tables, while UNION combines rows from the same table.

Answer

JOIN is used to create new tables, while UNION is used to update existing tables.

Answer

JOIN combines columns from multiple tables, while UNION combines columns from the same table.

Question 21

What is the purpose of an index in a database?

Accepted Answer

Speed up data retrieval

Answer

Enforce data integrity solely

Answer

Compress data to save space only

Answer

Store frequently used data only

Question 22

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

Accepted Answer

Establish relationships between tables

Answer

Store metadata solely

Answer

Enforce data integrity solely

Answer

Identify primary keys solely