We have tools for Django that show what queries are executed and the time it takes. But what next? What is going on there? Is it good that it’s doing that? Is the query supposed to take this much time? Will some indexes help? In this talk, I will help you decipher database query plans and give some rules of thumb to understand if the database is doing the best it can. We will also use query plans to find the best indexes for queries by observing what the database is looking for. I will also share several anti-patterns I have seen in Django projects and show how to rewrite them in a database-friendly way.