Rolling back migrations in Supabase - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ service_behavior

intermediate

What happens when you run a rollback migration in Supabase?

In Supabase, you apply migrations to update your database schema. What is the result of running a rollback migration?

A The migration is applied again, adding new tables and columns.

B The database schema deletes all tables and data permanently.

C The database schema reverts to the previous state before the last migration was applied.

D The database connection is reset but schema remains unchanged.

💡 Hint

Think about what rollback means in the context of database changes.

Rolling back a migration means undoing the last change to the database schema, restoring it to the previous state.

❓ Configuration

intermediate

Which command correctly rolls back the last migration in Supabase CLI?

You want to undo the last migration applied to your Supabase database using the CLI. Which command should you use?

A supabase db revert

B supabase db rollback

C supabase db migrate undo

D supabase migration down

💡 Hint

Check the official Supabase CLI commands for migration rollback.

The correct command to rollback the last migration is supabase db rollback. Other commands are invalid or do not exist.

❓ Architecture

advanced

What is the best practice to ensure safe rollback of migrations in a production Supabase database?

When managing migrations in production, what practice helps ensure that rolling back a migration does not cause data loss or downtime?

A Avoid using migrations and manually change the schema in production.

B Delete the production database and restore from backup after rollback.

C Apply rollbacks directly in production without testing to save time.

D Always write reversible migrations with explicit down scripts and test them in staging before production.

💡 Hint

Think about how to avoid surprises when undoing database changes.

Writing reversible migrations with down scripts and testing them in staging ensures rollbacks are safe and predictable in production.

❓ security

advanced

Which security risk is most relevant when rolling back migrations in Supabase?

Rolling back migrations can affect database security. What is a key security risk to consider?

A Rollback might remove security policies or roles, exposing data unintentionally.

B Rollback encrypts all data, making it inaccessible.

C Rollback disables all user authentication temporarily.

D Rollback automatically grants admin rights to all users.

💡 Hint

Consider what schema elements control access and how rollback affects them.

Rolling back migrations can remove or alter security policies or roles, potentially exposing data if not handled carefully.

🧠 Conceptual

expert

After rolling back a migration that dropped a column, what happens to the data in that column in Supabase?

You rolled back a migration that previously dropped a column from a table. What is the state of the data that was in that column?

A The column is restored but all previous data in it is lost permanently.

B The column and all its data are fully restored as before the drop.

C The column remains dropped and data is unrecoverable.

D The column is restored with data encrypted and inaccessible.

💡 Hint

Think about how databases handle dropped columns and data storage.

Dropping a column deletes its data permanently. Rolling back the migration restores the column structure but not the lost data.