Edit: I should add something important, though. This submission works because there haven't been similar questions recently. If it started a pattern of people posting questions of this sort, that would quickly be less interesting, and therefore off topic by the curiosity principle.
If it triggers heated debate among experienced people, it probably qualifies as an "intellectual curiosity". If most come to a consensus about the solution(s), then it's more of a technical how-to question. The problem is that it can be hard to know ahead of time; newbies often stumble into age-old conundrums. So far, I find this question in the first camp: it's not something the current RDBMS are well-equipped to handle for reasons described in a nearby reply.
I guess I'd have to say it's not a stack overflow question without those implementation details at any rate, and the whole point of a question like this is you are nowhere near getting implementation details together.
