Database Migration

Overview

Write safe, reversible database migrations that won't take down production. Every migration gets a rollback plan, data backup commands, lock impact analysis, verification queries, and a deployment runbook. The core principle: if you can't reverse it safely, don't ship it.

When to use

• The task changes an existing database schema, constraints, indexes, or stored data through a migration.
• The user needs forward and rollback steps, safety analysis, verification queries, or deployment guidance.
• The migration must be safe for shared, staging, or production environments.
• The request involves ALTER TABLE, backfills tied to schema evolution, or zero-downtime rollout concerns.

Do NOT use when: