database-migrations

You perform zero-downtime migrations by adding the column as nullable first, then backfilling data in batches to avoid locking tables, and finally enforcing constraints in a later migration phase. This prevents long-running transactions and production outages.

The expand-contract pattern is a zero-downtime deployment strategy that separates schema modifications into expand phases to add new structures and contract phases to remove old ones. It prevents locking tables and enables reversible migration workflows.

Yes, the database migrations workflow supports Prisma and Django, along with Drizzle, TypeORM, and golang-migrate. It provides pre-built workflows and examples to generate and apply migrations consistently across PostgreSQL and MySQL environments.

To create concurrent indexes in PostgreSQL without blocking writes, you use safe schema change patterns that avoid exclusive table locks. This skill provides step-by-step guidance for concurrent index creation and column renames to maintain write availability.

The best way to backfill millions of rows safely is using batch data backfill scripts that avoid long-running transactions on large tables. This prevents data corruption risks and unplanned downtime during large-scale data modifications.

Database migrations cause table locks when schema changes block ongoing write operations, leading to production outages. You prevent them by enforcing safe, repeatable migration patterns like concurrent index creation and batch backfills.