Ask Slashdot: Which OSS Database Project To Help?

DoofusOfDeath writes "I've done a good bit of SQL development / tuning in the past. After being away from the database world for a while to finish grad school, I'm about ready to get back in the game. I want to start contributing to some OSS database project, both for fun and perhaps to help my employment prospects in western Europe. My problem is choosing which OSS DB to help with. MySQL is the most popular, so getting involved with it would be most helpful to my employment prospects. But its list of fundamental design flaws (video) seems so severe that I can't respect it as a database. I'm attracted to the robust correctness requirements of PostgreSQL, but there don't seem to be many prospective employers using it. So while I'd enjoy working on it, I don't think it would be very helpful to my employment prospects. Any suggestions?"