Northwind database is a popular demo database and originally came from Microsoft Access. It is great for students to practice SQL challenges and it has been ported to many RDBMS, open source or not.
We have ported it to Apache Spark SQL, a convenience for those who have setup Apache Spark, and need a demo database to test.
I have posted a video on youtube and in the video description area, there is a link to the github site where you can clone a repo if interested in. Thank you very much.