What is the difference between ACID and BASE properties?

Question

Accepted Answer

**ACID** — transaction guarantees. **BASE** — distributed system properties.

**ACID (SQL):**
- **Atomicity** — all or nothing.
- **Consistency** — valid state transitions.
- **Isolation** — concurrent transactions don't interfere.
- **Durability** — committed data persists.

```
ACID Example:
BEGIN TRANSACTION
  UPDATE accounts SET balance = balance - 100
  UPDATE accounts SET balance = balance + 100
COMMIT
(Either both succeed or both fail)
```

**BASE (NoSQL):**
- **Basically Available** — system is available.
- **Soft state** — state may change over time.
- **Eventually consistent** — data will become consistent.

```
BASE Example:
Write to Node A → Replicate to B, C
(Eventually all nodes have same data)
```

**Key differences:**
- **ACID** — strong consistency.
- **BASE** — eventual consistency.
- **ACID** — single node.
- **BASE** — distributed.

Systems Analyst: What is the difference between ACID and BASE properties?