What’s the difference between OLTP and OLAP?

• OLTP, online transaction processing, is a ton of small reads and writes happening one row at a time, like updating this user’s cart or inserting an order [1].

on the other hand,

• OLAP, online analytical processing [2], is the opposite shape. A few heavy queries scan a ton of rows but only touch a handful of columns, like averaging field tilt by team across a whole tournament [3].

My South Korea World Cup Analytics Warehouse project is OLAP end to end, over 234K match events sitting in local DuckDB (and now AWS Athena over S3 Parquet), and every query sweeps the whole table, averaging field tilt per team across the tournament, never fetching one event to update it.

Also, the Postgres schema I’m building for my team’s ETL pipeline is the OLTP side, the app reads and writes individual product records, one at a time, under multi-tenant constraints, while SKUs’ rows get enriched and rescored. They are very different.

References

[1] Amazon Web Services, “OLTP vs. OLAP: Difference between data processing systems,” AWS Cloud Comparisons. [Online]. Available: https://aws.amazon.com/compare/the-difference-between-olap-and-oltp/. [Accessed: Jun. 28, 2026].

[2] Amazon Web Services, “What is OLAP?” AWS. [Online]. Available: https://aws.amazon.com/what-is/olap/. [Accessed: Jun. 28, 2026].

[3] ClickHouse, “OLTP vs. OLAP,” ClickHouse Resource Hub, May 27, 2026. [Online]. Available: https://clickhouse.com/resources/engineering/oltp-vs-olap.