St-Cyr,
I work with databases quite a bit even though I'm not an actual DBA. (I use Access and mySQL). I don't see any really _useful_ way in which an RDB could be used by players or modders, though... which I think is why you don't see many people talking about them here.
What sort of things would you be talking about doing with SE4 and an RDB?
(Within the game, of course, I can see a lot of call for all sorts of relations, but that's somethign else
LL/Eric Snyder II