TL;DR: ActiveRecord in Rails 3.0.2 is faster than 2.3.x for some queries because ARel was rewritten. HEY INTERNET, HOW ARE YOU DOING? I’m doing GREAT, thanks for asking! Recently, I released a new version of ARel. What is ARel, you may ask? Well, some people would tell you that ARel is a “relational algebra library”. I like calling ARel a “relation algebra library” because that is a rather vague d