UNIT 3

SYLLABUS

Data Processing: Meaning & Data Storage Hierarchy; File Management System- File Types, Organizations & Utilities; Database Management System- Database Models, Components of DBMS, Creating and using a Database.

Data Processing

Meaning of Data

• Data refers to raw facts and figures.

• Data by itself has no meaning.

• Example: 100, 200, A, B, Jan → these are just data.

Meaning of Information

• Information is processed data that is meaningful and useful for decision-making.

• Example: “Total sales in January = ₹200,000”

Meaning of Data Processing

Data Processing is the process of collecting, organizing, manipulating, and transforming raw data into meaningful information.

📌 Definition:

Data processing is the systematic transformation of raw data into useful information using manual or computerized methods.

Data Processing Cycle

The data processing follows a cycle:

1. Data Collection – Gathering raw data

2. Data Input – Entering data into the system

3. Processing – Calculations, sorting, classifying

4. Output – Producing reports/information

5. Storage – Saving data for future use

6. Feedback – Corrections and improvements

Types of Data Processing

1. Manual Data Processing – Done by humans (registers, files)

2. Mechanical Data Processing – Using calculators, machines

3. Electronic Data Processing (EDP) – Using computers (ERP, Excel, DBMS)

Importance of Data Processing for Managers

• Helps in decision making

• Improves accuracy

• Saves time and cost

• Enables planning, forecasting & control

• Supports MIS and DSS

MIS  (Management Information System) is a system that:

• Collects data from different departments

• Processes this data

• Converts it into useful information

• Provides regular reports to managers

How computers/networks support MIS:

• Store large amounts of organizational data (sales, finance, HR, production)

• Generate reports like:

  • Daily sales reports

  • Monthly profit reports

  • Employee performance reports

• Help managers in planning, organizing, and controlling business activities

Example:

• A company uses computers to generate monthly sales reports for managers.

• Banks use MIS to monitor transactions and customer accounts.

👉 Thus, computers support MIS by providing accurate, timely, and structured information to management.

Supports DSS (Decision Support System)

What is DSS?

DSS is a computer-based system that:

• Helps managers take complex and non-routine decisions

• Uses data, models, and analytical tools

• Supports decision-making, not replaces it

How computers/networks support DSS:

• Analyze large volumes of data

• Perform “what-if” analysis

• Compare multiple alternatives

• Forecast future outcomes

Example:

• A company uses DSS to decide:

  • Whether to launch a new product

  • Which location is best for opening a new branch

• Banks use DSS to assess loan risks.

👉 Thus, computers support DSS by providing analytical tools and decision-making models.

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Data Storage Hierarchy

Data is stored in computers in a hierarchical order based on speed, cost, and capacity.

Meaning of Data Storage Hierarchy

It refers to the arrangement of storage devices from fastest and most expensive to slowest and cheapest.

Levels of Data Storage Hierarchy

Importance of Storage Hierarchy

• Balances performance and cost

• Improves system efficiency

• Enables large data handling

• Supports business continuity

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File Management System (FMS)

Meaning of File

A file is a collection of related data stored under a single name.

📌 Example: Employee file, Customer file

Meaning of File Management System

A File Management System is a system that organizes, stores, retrieves, and manages files on a storage device.

File Types

1. Text Files – .txt, .doc

2. Binary Files – .exe, .bin

3. Master Files – Permanent data (Employee file)

4. Transaction Files – Daily transactions (Sales file)

5. Backup Files – Copy of data

6. Temporary Files – Created during processing

7. Log Files – Record system activities

File Organization Methods

1. Sequential Organization

   • Records stored one after another

   • Example: Payroll system

   • Simple but slow access

2. Direct (Random) Organization

   • Direct access using key

   • Faster retrieval

   • Example: Bank account records

3. Indexed Sequential Organization

   • Combination of sequential + index

   • Fast and flexible

   • Used in large organizations

File Utilities

File utilities are tools used to manage files.

Common File Utilities:

• Copy

• Delete

• Rename

• Backup

• Restore

• Compression

• Disk Cleanup

📌 Examples: Windows Explorer, Disk Defragmenter

Limitations of File Management System

• Data redundancy

• Data inconsistency

• Poor security

• Difficult data sharing

• No centralized control

➡️ These limitations led to the development of DBMS

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Database Management System (DBMS)

Meaning of Database

A database is an organized collection of related data stored in a structured format.

Meaning of DBMS

A Database Management System (DBMS) is software that creates, stores, manages, retrieves, and controls access to databases.

📌 Examples: MySQL, Oracle, SQL Server, MS Access

Objectives of DBMS

• Reduce data redundancy

• Improve data security

• Ensure data integrity

• Enable data sharing

• Support decision making

Database Models

Hierarchical Model

• Data organized in tree structure

• Parent-child relationship

• One-to-many relationship

• Example: Organization structure

Network Model

• Multiple parent-child relationships

• More flexible than hierarchical

• Complex structure

Relational Model (Most Important for Exam)

• Data stored in tables (rows & columns)

• Uses primary key

• Easy to use

• Example: Student table, Employee table

📌 Used in MySQL, Oracle, SQL Server

Object-Oriented Model

• Data stored as objects

• Supports multimedia data

• Used in advanced applications

Components of DBMS

1. Hardware – Computers, storage devices

2. Software – DBMS software

3. Data – Actual stored data

4. Procedures – Rules and instructions

5. Database Administrator (DBA) – Manages DBMS

6. Users – End users, managers, programmers

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7. Creating and Using a Database

 Steps to Create a Database

1. Identify data requirements

2. Design tables

3. Define fields and data types

4. Set primary keys

5. Establish relationships

6. Store data

 Using a Database

• Insert data

• Update data

• Delete data

• Retrieve data using queries

• Generate reports

• Perform analysis

 Example (Managerial Use)

• HR Database → Employee records

• Sales Database → Customer & sales analysis

• Finance Database → Budgeting & forecasting

 Importance of DBMS for Managers

• Quick decision making

• Accurate reports

• Better planning

• Data security

• Integration with ERP & MIS

Data processing transforms raw data into useful information. Data storage hierarchy ensures efficient data access. File Management Systems manage data but have limitations, which are overcome by Database Management Systems. DBMS provides structured, secure, and efficient data handling, making it an essential tool for modern managers in decision-making, planning, and control.