Best Database For Rails?

I have done some exploratory work with DB2, more out of stubbornness
than anything else. There are some minor issues, such as a config
modification, but for me the biggest problem was the 8-character table
naming restriction. If you can live with that, DB2 is certainly
scalable, and the Community version is free. See for
details. In my limited experience, using DB2 means you have to jump
through hoops, using MySQL everything just falls into place.