From: dblock <dblockdotorg@...>
Date: 2011-01-20T10:55:31+09:00
Subject: Re: Improving performance of hash math

In case someone reads this for the purpose of the algorithms, and not
that it influences benchmarks, but the last two have bugs: the second
sum needs to do ! lhs.has_key? k. You want to do (right[i] - left[i])
** 2 for the left hash (items in the left hash only and in both the
left and the right hash), then add right[i] for all items that are in
the right hash only.

Back to the original question: anyone thinks we can do this for
millions of items?