You wanna learn PostgreSQL, and you wanna use a sample database with big real-world data, the same kinds of issues that pop up with real-life data distribution skew, and fun query challenges.
StackOverflow.com provides a free data dump in XML format with their data as of 2024-04. The data is licensed under cc-by-sa 4.0, which means whenever you use it for public demos, you’ll need to link back to their original data source there, just as I did.
Some quick facts about the data:
You’ll need Postgres 18 or higher, and about 250GB of free space users table: 22.5M