What is the difference between OLTP and OLAP?

Question

Accepted Answer

**OLTP** — Online Transaction Processing (operations). **OLAP** — Online Analytical Processing (analytics).

**OLTP:**
- Day-to-day operations.
- Many short transactions.
- Normalized schema.
- Real-time data.
- Row-oriented storage.

```
OLTP: INSERT order, UPDATE inventory, SELECT user
Schema: 3NF, many tables, foreign keys
```

**OLAP:**
- Analytical queries.
- Few complex queries.
- Denormalized schema (star/snowflake).
- Historical data.
- Column-oriented storage.

```
OLAP: SELECT category, SUM(sales) GROUP BY category
Schema: Star schema (fact + dimensions)
```

**Key differences:**
- **OLTP** — operations.
- **OLAP** — analysis.
- **OLTP** — current data.
- **OLAP** — historical data.

Systems Analyst: What is the difference between OLTP and OLAP?