Stack Overflow, the place where most of your production code comes from, shares a version of their data in XML format from time to time, and then I import it into SQL Server format.
Stack Overflow’s database makes for great blog post examples because it’s real-world data: real data distributions, lots of different data types, easy to understand tables, simple joins. Some of the tables include:
Comments: 85M rows, 16GB data PostHistory: 150M rows, 250GB (most of which is text, though) Posts: 56M rows; 150GB Users: 18M rows, 2GB Votes: 230M rows; 4.5GB, making for fun calculations and grouping demos