Introduction

Storing Data: How to Read This Module

The last module was about the arrows. This one is about the heaviest box on the diagram: the database.

Here's why it deserves its own module. Almost everything else in your system is replaceable at a moment's notice: API servers hold no data, so you can add ten more or lose three and nobody notices. The database is different. It holds the facts: who paid, who owns what, what happened. You can't just "add another one," because now there are two sets of facts, and they will disagree