Understanding Data, Information, and Databases: A Complete Guide

What is Data?

Data consists of raw facts and figures that, on their own, do not convey any meaning. It can be numbers, text, images, or symbols collected from various sources.

• Key Characteristics:

  • Raw and unprocessed.
  • Lacks context and meaning.
  • Can be in different forms, such as text, numbers, or media.
• Examples:
  • Student Name: "Alice"
  • Age: 22
  • City: London

What is Information?

Information is the outcome of processing raw data to make it meaningful and useful. When data is structured and analyzed, it provides insights that aid decision-making.

• Key Characteristics:

  • Organized and structured.
  • Helps in decision-making.
  • Provides valuable insights.
• Example:
  • Data: "Alice, 22, London."
  • Information: "Alice, a 22-year-old student, resides in London and is pursuing a degree in Computer Science."

Types of Data Storage

1. Temporary Storage:

• Holds data temporarily while a system is running.
• Information is lost when the system shuts down.
• Example: RAM (Random Access Memory) – used for fast, temporary data processing.

2. Permanent Storage:

• Retains data even after a system is turned off.
• Used for long-term data preservation.
• Examples: Hard drives, databases, cloud storage.

Disadvantages of File

• Data Redundancy:

  • When the same data is stored multiple times in different files is called redundancy.
  • It wastes storage space and increases the possibility of inconsistencies.

• Data Inconsitency:

  • When redundant data is updated in one file but not in others is called inconsistency.
  • It leads to incorrect information.

• Difficulty in Accessing Data:

  • Finding data from multiple files can be challenging and time-consuming.

• Intigrity Problem:

  • Maintaining data integrity (accuracy) is difficult with files.
  • Example:
    • Account balance should not be less than 1000.
    • Customer id must be unique.

• Atomicity problem:

  • Fund transfer must be atomic.
  • For the fund transfer to be atomic both the debit and credit must occur and neither occurs.
  • Files processing system do not ensure atomicity of data.

• Data Indexing:

  • If we want to retrieve data very quickly, databases use indexing mechanism.

• Concurrency:

  • File will not provide concurrent access by multiple users.

Types of Data

Data is categorized into three primary types based on its structure:

• Structured data
• Semi-Structured data
• Unstructured data

Structured Data

• Structured data means organized and formatted data.
• Example:
  • Customer information:
    • Name: John
    • Age: 30
    • Address: 123 Main St
    • Phone: 555-1234

Semi-Structured Data

• Partially organized with some level of formatting.
• Example
  • JSON data

  {
    "name": "John ",
    "age": 30,
    "address": "123 Main St"
  }
  

Unstructured data

• Unorganized data is called unstructured.
• Example;
  • Image
  • Audio
  • Video
  • Etc.

What is a Database Management System (DBMS)?

• A Database Management System (DBMS) is software that enables efficient storage, retrieval, and management of structured data.

• Why Use DBMS Instead of Files?

  • Eliminates data redundancy.
  • Ensures data consistency.
  • Provides faster access to information.

Types of DBMS

• Hierarchical DBMS – Stores data in a tree-like structure.
• Network DBMS – Uses a network-based model.
• Relational DBMS (RDBMS) – Organizes data in tables (e.g., MySQL, PostgreSQL).
• Object-Oriented DBMS – Uses objects to store data (e.g., MongoDB).

What is RDBMS (Relational Database Management System)?

An RDBMS is a type of database system that structures data into tables with rows and columns, allowing relationships between data.

• Key Features:

  • Data is stored in tables.
  • Each row represents a unique record.
  • Uses primary keys to ensure uniqueness.
  • Supports SQL for querying data.
• Example of a Table in RDBMS: