ClickHouse Data Cookbook: Visitor Segmentation with Theta Sketches

ClickHouse has a lot of built-in functionality that is just there for analysts and data engineers to discover. Today, I am once more going to revisit one of my old Druid blogs . It’s about the difficulty of counting unique things, which is particularly relevant for any kind of clickstream or media analytics, where you want to count unique visitors over arbitrary segments of content, time,…