THE GOAL | Part B | Chapter 8 Notes

📖 CHAPTER 8 • SOURCE-BASED EXAM NOTES

Introduction to Database Management System

Complete exam-oriented revision notes for CBSE Class 10 Information Technology (402), prepared by matching the uploaded NCERT Domestic Data Entry Operator — Class X (2023–24) textbook.

✍️ Read • Revise • Recall

Source check: Chapter 8 is part of Unit 3 — Database Management System using LibreOffice Base. The chapter introduces databases, DBMS, data models, relational database terminology and RDBMS objects.

01. Data and Information

What is Data?

Data refers to raw facts. These facts may be related to a person, place, activity or thing.

Data can be stored in different forms such as text, graphics, audio and video.

Examples of Data

Marks scored by students
Weight of a person
Price of a product
Number of items sold
Name of an employee
Name of a product
Address
Tax code

What is Information?

Information is the processed or organised form of data.

📌 Example

Marks obtained by students and their roll numbers are data. When these values are organised into a report card or sheet, they become information.

✏️ EXAM POINT

Data → Raw facts
Information → Processed / organised data

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02. Database

Definition of Database

A database is a collection of logically related data items stored in an organised manner.

Examples of Databases

Railway ticket booking system
Library records
Salary details
ATM transaction records

A database can contain different types of data such as text, images, audio and video.

🧠 Remember

Database = Collection of logically related data items stored in an organised manner.

03. Database Management System

What is DBMS?

DBMS stands for Database Management System.

A DBMS is software used to create, update and retrieve data from a database.

Examples of DBMS

MS Access
OpenOffice Base
LibreOffice Base
Oracle
Ingres
MySQL

🎯 Full Form — Must Remember

DBMS = Database Management System

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04. Data Model

Definition

A Data Model is the structure of a database. It describes the manner in which data will be stored and retrieved.

Types of Data Models

Hierarchical Data Model
Network Data Model
Relational Data Model

Data Model	Main Feature
Hierarchical	Data is organised in a tree-like structure.
Network	Multiple records are linked to the same master file.
Relational	Relationships are established between two or more tables.

05. Hierarchical Data Model

In the Hierarchical Data Model, data is organised into a tree-like structure.

The data is stored in the form of linked records.

✏️ EXAM POINT

Hierarchical Data Model → Tree-like structure
Data → Linked records

06. Network Data Model

In the Network Data Model, multiple records are linked to the same master file.

🧠 Easy Recall

Network → Multiple records → Same master file

07. Relational Data Model

The Relational Data Model is based on the principle of setting relationships between two or more tables of the same database.

Data in a relational database is organised into tables containing rows and columns.

📌 Exam Definition

Relational Data Model is based on setting relationships between two or more tables of the same database.

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08. Relational Database Terminology

The relational database model uses several important terms which are very important for examination.

Entity

→

Attribute

→

Table

→

Field

→

Record

Other important terms include:

Data Value
Primary Key
Foreign Key
Candidate Key
Alternate Key

09. Entity

Definition

An Entity is a real-world object about which information is to be stored in a database.

Examples

Student
Employee
Customer
Product
Book

✏️ EXAM POINT

Entity → Real-world object about which information is stored.

10. Attribute

The details associated with an entity are called attributes.

Example

For a Student entity, possible attributes may include:

Name
Roll Number
Class
Address

🧠 Remember

Entity = Object
Attribute = Details of the object

11. Table

A table is a collection of logically related records .

A table is organised as a set of columns and can contain rows.

Roll No.	Name	Class
101	Rahul	X
102	Priya	X

In the above example, the complete table contains logically related student records.

12. Field

A field is the smallest entity in the database .

Fields represent individual record characteristics and are presented as columns within a table.

✏️ EXAM POINT

Field → Column of a table
Field → Smallest entity in the database

13. Data Value

Data values are the raw data represented in numeric, character or alphanumeric form.

🧠 Data Value Forms

Numeric • Character • Alphanumeric

14. Record

The data values for all the fields related to a person or object are called a record.

A record is presented as a row within a table.

Roll No.	Name	Class
101	Rahul	X

The complete row containing Roll No., Name and Class represents one record.

🔥 Field vs Record

Field	Record
Presented as a column	Presented as a row
Smallest entity in database	Collection of data values for all fields

— ✦ — ✦ — ✦ —

15. Primary Key

A Primary Key is a field that uniquely identifies a row in a table.

Example

If every student has a unique Roll Number, then Roll Number can be used as the Primary Key.

⭐ Must Remember

Primary Key → Uniquely identifies a row.

16. Foreign Key

A Foreign Key helps to build a relation between two or more tables in a database.

✏️ EXAM POINT

Foreign Key → Helps establish relation between tables.

17. Candidate Key

All the field values that are eligible to be the Primary Key are called Candidate Keys.

🧠 Easy Recall

Candidate Key = Eligible to become Primary Key

18. Alternate Key

Out of the candidate keys, one or more are selected as the Primary Key.

The remaining candidate keys are called Alternate Keys.

🎯 Key Concept

Candidate Keys → Keys eligible to become Primary Key.

Selected Candidate Key → Primary Key.

Remaining Candidate Keys → Alternate Keys.

— ✦ — ✦ — ✦ —

19. Important Keys — Quick Comparison

Key	Meaning
Primary Key	Uniquely identifies a row in a table.
Foreign Key	Helps build a relation between two or more tables.
Candidate Key	Field values eligible to become Primary Key.
Alternate Key	Candidate Key not selected as Primary Key.

20. Objects of RDBMS

An object in a database is a structure or feature used to store, represent or retrieve data .

Important RDBMS Objects

Tables
Forms
Reports
Queries

Object	Main Purpose
Table	Stores logically related records.
Form	Provides easy and user-friendly data entry.
Query	Retrieves desired information from the database.
Report	Presents retrieved/query output in a formal layout.

21. Forms

A Form is a database feature used to enter data into a table in an easy and user-friendly manner.

The data entered through forms is stored in tables.

✏️ EXAM POINT

Form → Easy and user-friendly data entry.

22. Queries

A Query is used to retrieve the desired information from the database.

Easy Definition

A query can be understood as a question asked from a database .

Example

Suppose a student database contains marks of students. A query can be used to retrieve the names of students who scored more than 50 marks.

🧠 Remember

Query → Retrieves desired information.

23. Reports

The output of a query may be displayed in the form of Reports.

Reports present retrieved data in a more formal and properly formatted layout .

✏️ EXAM POINT

Query → Retrieves information
Report → Presents retrieved information formally

— ✦ — ✦ — ✦ —

24. Chapter 8 — Complete Concept Flow

Data

→

Database

→

DBMS

→

Tables

→

Queries

→

Reports

🧠 Relational Database Recall

Entity → Attributes → Table → Fields + Records → Keys → Forms / Queries / Reports

25. Check Your Progress — Exam Focus

📌 IMPORTANT QUESTIONS

Very Short Answer / MCQ Concepts

What is a database?
What is DBMS?
What is a Data Model?
Which data model uses a tree-like structure?
Which data model establishes relationships between tables?
What is an Entity?
What is an Attribute?
What is a Field?
What is a Record?
What is a Primary Key?
What is a Foreign Key?
What is a Candidate Key?
What is an Alternate Key?
What is a Form?
What is a Query?
What is a Report?

26. Most Important Differences

Data vs Information

Data	Information
Raw facts.	Processed or organised form of data.
Example: Marks and roll numbers.	Example: Report card.

Field vs Record

Field	Record
Presented as a column.	Presented as a row.
Smallest entity in database.	Data values for all fields related to a person/object.

Primary Key vs Foreign Key

Primary Key	Foreign Key
Uniquely identifies a row.	Helps establish relation between tables.

27. Last-Minute Revision

⚡ CHAPTER 8 — RAPID REVISION

Data: Raw facts.
Information: Processed or organised data.
Database: Collection of logically related data items stored in an organised manner.
DBMS: Database Management System.
DBMS Function: Create, update and retrieve data.
Data Model: Structure of a database describing how data is stored and retrieved.
Hierarchical Model: Tree-like structure.
Network Model: Multiple records linked to the same master file.
Relational Model: Relationships between two or more tables.
Entity: Real-world object.
Attribute: Details associated with an entity.
Table: Collection of logically related records.
Field: Column / smallest entity in the database.
Record: Row containing data values for all fields.
Primary Key: Uniquely identifies a row.
Foreign Key: Helps build relation between tables.
Candidate Key: Eligible to become Primary Key.
Alternate Key: Candidate Key not selected as Primary Key.
Form: Easy and user-friendly data entry.
Query: Retrieves desired information.
Report: Presents retrieved information in a formal layout.

28. One-Minute Exam Memory

🔥 If You Remember Only This...

Data = Raw facts

Information = Processed data

DBMS = Creates, updates and retrieves data

Hierarchical = Tree

Network = Master file connection

Relational = Tables + Relationships

Field = Column

Record = Row

Primary Key = Unique identification

Foreign Key = Relationship between tables

Candidate Key = Eligible Primary Key

Alternate Key = Candidate Key not selected

Form = Data Entry

Query = Information Retrieval

Report = Formal Output