Twenty Thousand Leagues Under ActiveRecord
by Pat Shaughnessy
We all know ActiveRecord allows you to perform complex SQL queries using simple, elegant Ruby code. It’s like magic, a useful magic we all use everyday in our Rails apps. But how does it actually work? We’ll find out by first exploring the shallow waters just under ActiveRecord: What is relational algebra? How does the Arel gem generate SQL strings from Ruby objects? Later, we’ll dive into much deeper waters - all the way inside the PostgreSQL database! We’ll discover what does Postgres does with our SQL strings, where our data is actually located, and how Postgres finds what we want. Join me and learn exactly how your Rails app gets the data it needs. Like the strange places and creatures Jules Verne described in his underwater adventure, we’ll discover fascinating data structures and computer science algorithms you never knew you were using.