To develop Codebelay, I set up SQL tables using normalization. The database I selected was MySQL.
Hivelogic has an excellent tutorial called Building Ruby, Rails, LightTPD, and MySQL on Tiger.
I built my ruby on rails set up the hivelogic way, and have been quite happy with how fast LightTPD and fastCGI serve out database dependent web pages.
The only thing I would change is adding a root account to my MacMini and using su to compiling and install files.
Typing sudo tar zxvf some_package.tar.gz ; sudo ./configure ; sudo make ; sudo make test ; sudo make install — and then having to type in a password all on top of it turned out to be really tedious.