You make the change in multiple phases. 1. Add the new table. 2. Update code to write/read from both the new and old data sources (e.g., read from the new tabl

You make the change in multiple phases. 1. Add the new table. 2. Update code to write/read from both the new and old data sources (e.g., read from the new table first before falling back to the old column). 3. Copy data from the column to the new table. 4. Update code to stop using the old column. 5. Remove the old column from the database. I wrote a blog post about this: https://medium.com/edx-engineering/django-migration-donts-f4588fd11b64 https://medium.com/edx-engineering/django-migration-donts-f4....