I was going to say, if you really need to do stats on resultsets of that magnitude you'd have to consider one of the specialist big-iron stats packages rather than trying to roll your own.

There's another perspective - many line of business applications have a need for the occasional "walk on the analytic wild-side"....another example, just because 1 chart in an application needs to calculate slope, doesn't mean shelling out major bucks for a stats package. It makes more sense to invest a few more hours (or a day or two) of development instead of product purchase overkill. :)