UNIT 1
Introduction to Databases 

1.1 Introduction

• A Database Management System (DBMS) is an organized collection of interrelated data and a set of programs to manage, store, and access that data efficiently.

• The DBMS serves as an intermediary between users and the database, ensuring that data is stored, retrieved, and manipulated securely and effectively.

• It allows users to interact with the database without having to worry about the underlying technical details of data storage

To understand a DBMS, we should look at its two main parts: Database and Management System.

Database:

A database is basically an organized collection of data. The data in a database is typically

organized in rows and columns, where:

• Rows are called Tuples or Records.

• Columns are called Attributes or Fields.

 A database is a collection of related tables (relations).

 Data : Data refers to raw facts or figures that don't have meaning on their own, such

 as numbers or text like "1", "ABC", or "19".

 Record: A record is a collection of related data items that together form meaningful information.

 For example, a collection of student data such as Roll number, Name, and Age can form a record.

Management System:

• The Management System is the set of software tools and programs that facilitate the creation, manipulation, and maintenance of a database.

• A DBMS is software that helps store, organize, and retrieve data efficiently. It manages:

o Large amounts of data

o Multiple users accessing data simultaneously

o Data security, integrity, and backup

1.2 Database-System Applications:

There are many applications of DBMS (Database Management System). A DBMS is required wherever data is needed to be stored and managed efficiently. Databases play a critical role in various sectors. Some of the major areas where DBMS are applied include:

• Railway and Airline Reservation System:

The database keeps a record of ticket booking, arrival time, departure time, delays, and even seat numbers of airplanes or trains.

• Banking:

Managing customer accounts, transactions, loans, and banking services.

• Credit card transactions:

For purchases on credit cards and generation of monthly statements.

• Universities:

Storing student records, course registrations, grades, and faculty information.

Manufacturing and Selling

Managing production processes, inventory, supply chain, and sales data.

• Human Resources

Storing employee information, payroll, salaries, benefits, and tax data.

• Health Information Systems

Storing patient records, treatment histories, and appointment scheduling.

• Social Media Platforms

Managing user profiles, posts, and interactions.

• E-commerce Websites

Storing product catalogues, customer orders, and payment details.

• Telecommunication

To track call records, generate monthly invoices, manage prepaid calling card balances, and store details about communication networks.

• Document databases

 For maintaining collections of new articles, patents, published research papers, etc.

• Navigation Systems

For maintaining the locations of varies places of interest along with the exact routes of roads, train systems, buses, etc.