[hywel]

It doesn't actually use bitfields, it describes an alternative to them that was a better choice in this specific instance.

Huffman would have been much slower to access, which would have been unacceptable for the use case (iterating 100 million data points multiple times a second).

[uxcn]

I'm not familiar with the dataset you were working with, but I would be willing to bet certain values occur a lot more frequently than others. In which case, you could work with the compressed values, and only uncompress them for the results.