Purpose of Database

1. Why is a Database Needed?

In modern applications, data plays a crucial role. Storing data in simple files creates many problems. Databases are needed to overcome these limitations.

• To store large volumes of data
• To manage data efficiently
• To allow multiple users to access data
• To maintain accuracy and consistency

2. Main Purposes of a Database

• Centralized data storage
• Easy data retrieval
• Data sharing among users
• Data security and privacy
• Backup and recovery
• Reduction of data redundancy

3. File System vs Database

Databases were introduced to solve the problems of traditional file systems.

Traditional File System          Database System
------------------------         -------------------------
Data redundancy                  Minimal redundancy
Poor data security               High data security
Difficult data access            Easy and fast access
No concurrency control           Supports multi-user access
Manual backup                    Automatic backup & recovery

4. Reduction of Data Redundancy

Data redundancy means duplication of data at multiple locations. A database stores data at a single place and shares it across applications.

Without Database:
Student File → Name, Course
Fees File    → Name, Course

With Database:
STUDENT TABLE
Name | Course | Fees

5. Maintaining Data Consistency

Consistency means that data remains correct and up-to-date across the entire system. When redundancy is reduced, consistency automatically improves.

• Single source of truth
• Automatic update propagation

6. Data Sharing

A database allows multiple users to access the same data simultaneously without conflicts.

User A ─┐
        ├── DATABASE ─── Shared Data
User B ─┘

7. Data Security

Databases provide security mechanisms to protect data from unauthorized access.

• User authentication
• Authorization & access control
• Data encryption

8. Backup and Recovery

Databases support automatic backup and recovery to protect data from system failure, crashes, or power loss.

• Periodic backups
• Crash recovery
• Data restoration

9. Real-Life Uses of Database

• Bank account management
• Online shopping websites
• Student information systems
• Hospital records
• Railway and airline booking

Practice Questions

1. What is the purpose of a database?
2. Why databases are preferred over file systems?
3. Explain data redundancy.
4. How does a database ensure data security?
5. Explain backup and recovery.

Practice Task