System Design Article

Data Warehousing, Data Lakes & OLAP vs OLTP

Difficulty: Hard

OLTP databases are built for fast single-row reads and writes; analytical queries against them choke. This lesson covers why analytics needs its own storage stack: column-oriented warehouses, lake formats, and lakehouse engines that scan billions of rows in seconds. You'll learn the OLTP versus OLAP trade-off, dimensional modeling (star schema), ETL versus ELT, change data capture, and how a modern data platform separates compute from storage so you can query petabytes for the cost of a coffee.