database-migrations

Zero-downtime database migrations use the expand-contract pattern to separate schema changes from data backfills. This approach applies concurrent indexes and forward-only migrations to deploy updates safely across PostgreSQL and MySQL without locking tables.

Yes, this database migration guidance supports common ORMs including Prisma, Drizzle, TypeORM, Django, and golang-migrate. It provides tooling recommendations and best practices for safe schema changes and rollback planning across these specific ecosystems.

The expand-contract pattern for schema changes splits migrations into separate expand and contract phases. You first apply forward-only schema additions and backfill data, then safely remove deprecated columns in a later deployment step to ensure continuous availability.

A safe rollback plan for data migrations requires separate UP and DOWN strategies for every schema change. You must document specific rollback procedures and test them against production-scale data before executing any forward-only migrations.

Separating schema changes from data migrations prevents table locking and reduces deployment risk. Applying schema modifications independently from data backfills ensures zero-downtime deployments and allows independent rollback if issues occur.

Forward-only database migrations limit your ability to automatically revert destructive schema changes. Because this approach prioritizes zero-downtime safety, you must manually plan and document separate DOWN strategies and rollback procedures before deployment.