Good test database on Windows to play around with data retrieval operations in SQL?

Question

I need a test database to practice joins and other kinds of data retrieval operations in SQL.

What's a good free test database and RDBMS system to use on Windows?

Answer 1

Every major RDBMS provider has some free edition. Those are full versions limited by database size and maximum memory usage.

Top players:

• Sql Server Express
• Oracle Express
• IBM DB2 Express-C

Then, there is number of open source products:

• PostgreSQL
• Firebird
• MySQL
• SQLite (not really a RDBMS, but understands SQL and it can be used for your purposes. Also, very small and compact)

If this is not enough, check this Wikipedia article: Comparison of relational database management systems.
There's more than 50 RDBMS's listed and you'll probably find something that suits your needs.