Mark Kirkwood <markir@paradise.net.nz> writes:
> An obvious deduction is that the TPCH dataset is much more amenable to
> run compression than my synthetic Zipfian data was. The interesting
> question is how well "real" datasets are run compressable,
Yeah --- the back-of-the-envelope calculations I was making presupposed
uniform random distribution, and we know that's often not realistic for
real datasets. A nonuniform distribution would probably mean that some
of the bitmaps compress better-than-expected and others worse. I have
no idea how to model that and guess what the overall result is ...
regards, tom lane
