Just a quick note here (I'm in the middle of programming, don't want to get too distracted!) about a new practice I'm trying out: the design of data models using XSL to output SQL customized for different database engines.
So far I've only been working with MySQL and SQLite, but I believe it could work for many more engines. If you think this is an interesting idea, please comment on this post, thanks!
As a specific reference to what I'm describing, see the data model for Private Wiki.