DjangoCon US 2023

Django migrations are a great tool for keeping track of changes you made to your models over time.
After years of changes in a project they can become very numerous and you may notice that it takes a long time to create the test database.

squashmigrations can help you reduce an existing set of many migrations down to one (or sometimes a few), which still represent the same changes.
However it has some limitations, and it could work in a way you don't need.

Let's inspect this command and the alternative of creating migrations "from scratch" in an existing project for improving your tests speed.

• inspecting django migration commands
  • makemigrations
  • migrate
  • showmigrations
  • sqlmigrate
• creating a sample project with multiple migrations
• analyzing test performances
• inspecting the squashmigrations command
• squashing migrations in the sample project and comparing performances
• not enough? Let's try an "exotic/drastic" way to squash our migrations
• comparing performances of the "exotic/drastic" solution

The key point of this talk is to speed up django testing in projects with many migrations