Introduction to DBMS (Database Management System)

Importance of DBMS

• Essential for GATE, UGC NET, and other competitive exams
• Crucial for B.Tech and BCA students
• Increasingly important for job interviews, especially in top MNCs like Facebook, Google, Amazon

Database System Overview

Components of a Database System

• Database: Collection of related data
• DBMS (Database Management System): System to manage databases

Examples

• Indian Railways (IRCTC): Has its own database system
• Facebook: Own database system
• Flipkart: Own database system

Database

• Simple definition: Collection of related data
• Example: IRCTC database stores train information, passenger information
• Related data: Data that is contextually relevant and connected
• Cannot mix unrelated data (e.g., Indian Railways data with Passport data)

Types of Data

• Structured Data: Stored in a particular shape or structure (e.g., Indian Railways data, university data)
  • Managed by RDBMS (Relational Database Management System)
• Unstructured Data: No predefined format (e.g., photos, videos, web pages)
  • Majority of the data (90%) is unstructured
  • Technologies like Big Data, Hadoop are used for unstructured data

Structured Data

• Stored in a defined format such as tables (relations)
• Example: University records, train data from IRCTC
• Tables: Consist of columns and rows (similar to Excel files)
• Most commonly used method for storing structured data is in relational form

DBMS Operations

Common Operations

• Insertion: Adding new data
• Deletion: Removing existing data
• Updation: Modifying existing data

Purpose of DBMS

• Provides a system for users to easily perform CRUD (Create, Read, Update, Delete) operations
• User-friendly interface for accessing and manipulating data
• Data location is abstracted from the user (e.g., data stored in different geographical locations)

Examples of DBMS

• Microsoft SQL Server: Developed by Microsoft
• Oracle SQL Server: Various versions (2005, 2008, 2016, etc.)
• MySQL: Developed by Oracle
• IBM DB2: Developed by IBM

Relational DBMS (RDBMS)

Key Terms

• Relation: Table format for storing structured data
• RDBMS: System supporting relational data storage and operations
  • Focus on structured data
  • Common in academic syllabi (B.Tech, GATE, UGC NET)

Importance of RDBMS

• All operations (insert, delete, update) performed on relations
• Key to understanding database management in structured environments