where can i get a large sample database for practising mysql query optimization

Question

Can anyone give a reference to a substantially large sample database which I can import into MySQL to test and learn optimization and benchmarking?
The database should have at least 6-8 tables with lots of foreign keys in between them, i.e a complete database. The MySQL employees database looked promising, but the download page has 3 download links, clicking on any of which opens a page in a browser with a god-awful amount of binary data, dont know what to do with that.

Answer 1

There are a number of ways where you can find the databases for practicing MySQL query optimization. Some of the sources are:

• Government published dataset based on different fields
• Financial Firms 
• Space agencies 

It’s recommended to Download them with Bit torrent.