Hmm, that's a good idea.

I wonder, actually how do databases work? You can freely modify records (i.e. change their sizes), add new and remove existing ones and it's all done very fast... I'd like to know how to make such a system. Are B+trees the way to go? How to use them? It'd be easy if the records were fixed-size. But they just can't - I cannot limit anyone only to 255 characters long strings...

Or maybe I'm complicating things while the answer is really nearby? What do you think?