What is a bloom filter?
A Bloom filter is a space-efficient probabilistic data structure, designed to test whether an element is a member of a set. Because of its probabilistic nature, it can guess if an element is in a set with a certain precision or tell for sure if an element is not in a set. That is an important detail to design around as we’ll see later. If you’re curious about the math involved,
MORE INFO https://ve.godaddy.com/engineering/2018/09/11/redis-ruby-bloom-filter/