SQL vs NoSQL: Real-World Differences
- SQL (Relational Databases) → Structured, tabular data with predefined schema (e.g., MySQL, PostgreSQL).
- NoSQL (Non-Relational Databases) → Flexible, schema-less data (e.g., MongoDB, Cassandra).
- A bank stores customer transactions in an SQL database (structured & consistent).
- A social media platform stores user posts in a NoSQL database (dynamic & scalable).
- SQL → Vertically scalable (adding more CPU, RAM).
- NoSQL → Horizontally scalable (adding more servers).
- Amazon DynamoDB (NoSQL) scales globally for real-time shopping data.
- A small business may use MySQL (SQL) for structured order management.
3. Transactions & ACID vs. BASE
- SQL → Follows ACID (Atomicity, Consistency, Isolation, Durability).
- NoSQL → Follows BASE (Basically Available, Soft state, Eventually consistent).
- A banking system (SQL) needs strict ACID compliance for transaction integrity.
- A social media feed (NoSQL) can tolerate eventual consistency for fast updates.
- SQL → Uses SQL (Structured Query Language).
- NoSQL → Uses JSON-like queries, key-value pairs, or graph queries.
- Fetching user data: SQL: SELECT * FROM users WHERE id = 1; NoSQL (MongoDB): { find: "users", filter: { id: 1 } }
- NoSQL (MongoDB): { find: "users", filter: { id: 1 } }
- SQL: Banking, e-commerce order processing, airline reservations.
- NoSQL: Netflix recommendations, IoT data storage, social media analytics.