πŸ”— Counting unique items in sliding window using Redis and HyperLogLog algorithm /via @artur_ejsmont

This article starts from giving intuitions behind LogLog algorithm, then shows how to change it to support "sliding window" queries, then how to do that for HyperLogLog algorithm, and finally presents a working implementation using Redis.

🌎 http://qbolec-memdump.blogspot.fr/2014/01/counting-unique-items-in-sliding-window.html