ACID vs BASE

🔹 ACID (Mostly for SQL databases)

• Guarantees reliability and integrity of transactions.
• Properties :
  • 1. Atomicity -> All or nothing.
    • A transaction is either fully completed or fully rolled back.
    • Example: Transferring money -> debit + credit must both succeed.
  • 2. Consistency -> Database move from one valid state to another.
    • Ensures rules, contraints, and relationships are always maintained.
  • 3. Isolation -> Transactions run as if they are the only one.
    • Prevents conflicts when multiple users act at the same time.
  • 4. Durability -> Once a transaction is committed, it stays- even if the system crashes.
• 👉 Use Case: Banking, e-commerce payments, healthcare (where correctness is critical).

🔹 BASE (Mostly for NoSQL databases)

• Focus on availability and scalability over strict consistency.
• Principles:
  • 1. Basically Available -> System guarantees availability even if one nodes fail.
  • 2. Soft State -> Data may be in temporary state, not immediately consistent.
  • 3. Eventually Consistent -> Data will become consistent across all nodes eventually.
• 👉 Use Case: Social media feeds, real-time analytics, distributed systems (where speed & availability matter more than strict accuracy).

🔹 Quick Comparison

Feature	ACID (SQL)	BASE (NoSQL)
Data integrity	Very strong ✅	Relaxed ❌
Consistency	Immediate ✅	Eventual ❌
Scalability	Vertical ⬆️	Horizontal ➡️
Performance	Slower (safety first)	Faster (availability first)
Best for	Banking, finance, healthcare	Social media, IoT, e-commerce scale

🔹 Analogy

• ACID: Like a bank transaction — either the full transfer happens or nothing happens. Safety > speed.
• BASE: Like a WhatsApp message delivery — it may first show one tick (sent), then two ticks (delivered), and later double blue (read). Availability & speed > immediate accuracy.