Introduction (Migrations)

Changing data schema

Takeaways

• Migrations deal with how we manage modifications to our data schema, over time.
• Mistakes to our database schema are very expensive to make. The entire app can go down, so we want to
  • quickly roll back changes, and
  • test changes before we make them
• A migration is a file that keep track of changes to our database schema (structure of our database).
  • Offers version control on our schema.

Upgrades and rollbacks

• Migrations stack together in order to form the latest version of our database schema
• We can upgrade our database schema by applying migrations
• We can roll back our database schema to a former version by reverting migrations that we applied