Introduction to Databases

What is a Database?

A database is an organized collection of data that can be easily accessed, managed, and updated. It is used to store information in a structured way so that users and programs can retrieve and manipulate it efficiently.

Key Points

• Data Storage: Stores information like names, numbers, dates, etc.
• Organization: Data is usually organized in tables (like spreadsheets), with rows, and columns.
• Access: You can use queries (e.g., SQL) to search for, insert, update, or delete data.
• Management Systems: Databases are managed by software called Database Management Systems (DBMS), It is a software that interacts with users, applications, and the database itself to manage the data. It provides tools for:
  • Inserting, querying, updating, and deleting data
  • Enforcing security and data integrity
  • Managing transactions and performance
  • Popular DBMS Tools:
    • MySQL: Open-source and widely used
    • PostgreSQL: Feature-rich and ideal for complex queries
    • MongoDB (for NoSQL databases): Leading document-based NoSQL database
    • SQLite: Lightweight and embedded, perfect for mobile apps

Types of Databases

1. Relational Database (RDBMS): Data is stored in tables with relationships. Uses SQL.
   1. Example: MySQL, PostgreSQL
2. NoSQL Database: Stores data in formats like key-value pairs, documents, or graphs.
   1. Example: MongoDB, Redis
3. In-Memory Database: Stores data in RAM for fast access.
   1. Example: Redis
4. Cloud Database: Hosted on cloud platforms like AWS, Azure, Google Cloud.

Database vs Spreadsheet

You might wonder: Why not just use Excel or Google Sheets or any other similar software?

While spreadsheets are great for small datasets and simple calculations, databases shine when:

• Data is large and complex
• Multiple users access data simultaneously
• You need to maintain integrity, security, and scalability

Comparison Table: