To many developers the database is a black box. You expect to be able to put data into your database, have it to stay there, and get it out when you query it... hopefully in a performant manner. When its not performant enough the two options are usually add some indexes or throw some hardware at it. We'll walk through a bit of a clearer guide of how you can understand how database is doing from a 30,000 foot perspective as well as analyze specific problematic queries and how to tune them. In particular we'll cover: * Postgres Caching * Postgres Indexing * Explain Plans * Extensions * Locking * More