AZ400-Q: deploy an application with a database change
A release adds a non-null database column required by the new application version. The team needs low downtime and a credible rollback path. Which approach is safest?
- A) Deploy the application first and let it fail until the column exists.
- B) Make a destructive schema change and assume the application rollback will restore data.
- C) Use a backward-compatible, ordered migration and application rollout; verify health before finalizing any irreversible schema step. ✓
- D) Run all database changes manually in production after the app deploys.
Answer: C. Database and application deployment must be designed together. Expand/contract-style compatibility and explicit ordering reduce downtime and preserve rollback options.
Why not the others: Application-first and manual changes are unreliable. Destructive changes can make an application rollback impossible.
Related
deployment-automation · rollback-strategy · release-strategy