I hear the points about query optimizers that you and the other repliers have made. (And they are valid points, all. I was just misinformed about MySQL.) I was more addressing the points made about database design decisions w/respect to data type choice and their effect on storage requirements and speed. I was wondering, specifically, if it is technically feasible to allow designers to specify 'text' or 'string' at design time, enter in some typical data, and have the engine choose the optimum type subject to its implementation constraints.

That said, it seems like I need to educate myself on the various products, though any prototypes I build will still use MySQL just because of the price point. :o)