Hi all,
Just noticed the mention of SAPdb and figured I's throw in my 2 cents...
SAPdb is really only an enterprise level software package, the learning curve is extremely high, the documentation is lacking and the community/developer support just isn't there. I had to test and implement SAPdb for a company that I work for and am writing from hands on experience. I would advise using PostgreSQL as an alternative to mySQL if more advanced features are needed.. or you could just wait for mySQL 4+

For a link of my research you can view: http://www.suprtool.com/move/

Thanks for your time,
Aaron Holmes
www.pureguru.com