Database / DuckDB Interview questions
What is the difference between OLAP and OLTP, and where does DuckDB fit?
OLTP (Online Transaction Processing) systems are optimized for many small, concurrent read/write operations, typically touching a few rows at a time, like processing individual orders in an e-commerce system. OLAP (Online Analytical Processing) systems are optimized for the opposite pattern: complex queries that scan, aggregate, and join large volumes of data, often touching millions of rows, to answer analytical questions.
| OLTP | OLAP |
| Many small, concurrent transactions. | Fewer, larger analytical queries. |
| Row-oriented storage typically favored. | Columnar storage typically favored. |
| Optimized for point lookups and small writes. | Optimized for scans, aggregations, and joins over large data volumes. |
DuckDB is explicitly designed and optimized for the OLAP side of this divide; its columnar, vectorized engine is built for exactly the scan-heavy, aggregation-heavy query patterns analytical work involves, not for the high-concurrency, small-transaction workload a production OLTP application (like a payments system's core database) typically needs, which is a system like PostgreSQL or MySQL is generally the better fit for that instead.
More Related questions...
