Django Migrations: A Retrospective

A talk I gave at DjangoCon AU 2014.

Transcript

1. Andrew Godwin @andrewgodwin migrations: a retrospective
2. Andrew Godwin Author of South migrations library Hi, I'm Author of 1.7 Django migrations I like my tea iced, and my schemas explicit
3. Django/Python backend I work for Discovery? Mobile? Storage? UI? On-site? ...auditing? We have it all. We're hiring!
4. Migrations They're pretty good.
5. South ...it was good for its time
6. The Initial Plan Django Schema backend ORM Hooks South 2 Migration handling User interface
7. The Revised Plan Django Schema backend ORM Hooks South 2 Migration handling User interface Backport for 1.4 - 1.6
8. The Revised Revised Plan Django Schema backend ORM Hooks Migration handling User interface
9. Logically Separate SchemaEditor Schema Migrations field.deconstruct() ModelOptions.apps Operations Loader / Graph Executor Autodetector Optimiser State
10. makemigrations field.deconstruct() Loader / Graph Autodetector Optimiser State Writer 1 2 State 3 5 4
11. migrate SchemaEditor ModelOptions.apps Operations Loader / Graph Executor State 1 2 Recorder 3
12. Moving South into Django instead, "Adding migrations to Django"
13. A New Format More concise Declarative Introspectable
14. Migration actions Frozen ORM
16. In-memory running Creates models from migration sets Autodetector diffs created from on-disk Used to feed SchemaEditor / ORM
17. But what went wrong?
18. Swappable Models
19. Your migration dependencies myapp/0001 myapp/0002 otherapp/0001 auth/0001 contenttypes/0001
20. myapp/0001 myapp/0002 otherapp/0001 auth/0001 contenttypes/0001 thirdapp/0001 Your migration dependencies on swappable models
21. what? Your migration dependencies on swappable models myapp/0001 myapp/0002 otherapp/0001 auth/0001 contenttypes/0001 thirdapp/0001 ???
22. what? Your migration dependencies on swappable models myapp/0001 myapp/0002 otherapp/0001 auth/0001 contenttypes/0001 thirdapp/0001 ???
23. Unmigrated Apps
24. Test persistence
25. Test persistence on MySQL
26. Random Meta options order_with_respect_to? Really?
27. Proxy Models
28. But we're close! Django 1.7, coming to a server near you soon.
29. Thanks! Andrew Godwin andrewgodwin@eventbrite.com