We all love Rails, and lots of us love ActiveRecord. It's intuitive and easy to use in small apps that don't have lots of models. You can select, join, and where your way into a great, working app in no time. Then your app starts to grow, you add more models, and you need to start building more and more complex queries. This talk describes how to harness the awesomeness of aRel, ActiveRecord's powerful relational algebra system, to perform arbitrarily complex queries using nothing but pure Ruby.
Cameron Dutro works on Twitter's International Engineering team, primarily on the Twitter Translation Center, a large Rails application. He's been building stuff in Ruby for the past three years, including the TwitterCLDR internationalization library, and loving every minute of it.