> In the newly-released data, each "negotiated rate" (or simply "price") is associated with a lot of metadata, but it boils down to: who's paying, who's getting paid, what they're getting paid for, plus some extra fluff to keep track of versioning. The hundreds of billions of prices in the dataset (probably over a trillion) result from all the possible combinations of these things.
They basically denormalized all the dimensions.
Imagine you have a function which takes 5 arguments and returns one value. You could give me the source code and let me run this function. Or you could give me a mapping of every possible combination of the 5 inputs to the returned value. The former could be quite small, but the latter would be a massive number of rows.