alt Hacker NewsThey mentioned that they use 125 MiB/s SSD. However, one can notice that the column seems to contain only about 47500 unique values. Probably there are many reviews with zero or one votes. This column is probably stored compressed so it can be loaded much faster.
That’s true. With such a small data domain, there would be a lot repeated numbers in the 160M values, leading to highly compressible data.