It doesn't have much to do with free vs. non-free. Just because
MySQL is free doesn't mean it's a great product. I do agree
with MS, MySQL isn't. It just lacks too much from what you
should expect from a relational database. While I don't touch
MS products with a 10 foot pole, I wouldn't trust any valuable
data to MySQL either. See also http://openacs.org/philosophy/why-not-mysql.html.
:-) Of course, the first thing on it in big bold letters says
NOTE: This Document was written in May 2000. Thus, it is outdated and does not represent the latest data concerning MySQL. I will attempt to find time to rewrite this with more current information soon (August 10th, 2001)
Nevertheless, I do agree that mySQL is a toy database, even though it has learned a couple of tricks in the meantime. It isn't necessarily a bad choice - many people need little more than a .dbm can offer, and mySQL is a nice lean option. It seems to mainly run web-based messageboards these days anyway, and that it's okay for.