database-migrations

The expand-contract pattern enables zero-downtime database migrations by splitting schema changes into multiple deployments: first adding new structures, then migrating data, and finally removing old ones. This minimizes lock time and ensures safe rollbacks.

The expand-contract pattern enables zero-downtime database migrations by splitting schema changes into multiple deployments: first adding new structures, then migrating data, and finally removing old ones. This minimizes lock time and ensures safe rollbacks.

Yes, the database migration guidance provides practical workflows for ORMs including Prisma, Django, Drizzle, and TypeORM. It covers framework-specific patterns for safe UP and DOWN migrations across production and staging environments.

Data backfill during production database migrations requires separating schema changes from data updates using the expand-contract workflow. Batch processing and explicit UP and DOWN migration paths prevent long table locks and service disruption.

A database migration safety checklist should verify explicit UP and DOWN paths, safe default values, non-blocking index creation, and staging test runs. These safeguards minimize deployment risk across PostgreSQL and MySQL environments.

Database migrations cause table locks when schema changes alter existing columns or block concurrent operations. Using non-blocking index creation and the expand-contract pattern avoids long locks during zero-downtime production deployments.