database-migrations

Plan reversible database schema and data migrations for PostgreSQL and MySQL.

Updated Feb 5, 2026

Search Tags:#rollback #postgresql #zero-downtime #prisma #database-migrations #data-migration

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npx skills add https://github.com/gugug168/claudecode-tutorial --skill database-migrations-gugug168

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Please help me install this Agent Skill.
Skill: database-migrations
Source: https://github.com/gugug168/claudecode-tutorial/tree/main/everything-claude-code-learning/02-Skills/database-migrations
Command: npx skills add https://github.com/gugug168/claudecode-tutorial --skill database-migrations-gugug168

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Provides clear, production-ready patterns and operational guidance to perform schema and data changes without causing downtime, unexpected locking, or irreversible mistakes in live databases.

Core Features & Use Cases

Production-safe schema changes: guidance for adding/removing columns, indexes, and renames using expand-and-contract patterns.
Data migration best practices: strategies for batching/backfilling large tables, separating DDL and DML, and testing on production-sized datasets.
Tool-specific workflows: actionable workflows for PostgreSQL, MySQL, Prisma, Drizzle, Django, TypeORM, and golang-migrate.
Use Case: Add a nullable avatar_url column to a users table, backfill values in batches, create indexes concurrently, and then safely remove the old column with no downtime.

Quick Start

Use this skill to plan and execute a zero-downtime migration that adds a new nullable column, backfills data in batches, applies concurrent indexes, and then retires the old column.

Frequently Asked Questions about database-migrations

High-intent search queries and answers about installing and using this skill.

FAQPage Schema

What is the best way to perform zero-downtime database migrations in PostgreSQL?▼

Zero-downtime database migrations in PostgreSQL require the expand-and-contract pattern: adding new schema elements, backfilling data in batches, and retiring old structures separately to avoid locks. This approach ensures production safety by separating DDL and DML operations.

How do I backfill large tables during a data migration without causing downtime?▼

Backfilling large tables during data migration requires batching updates into smaller chunks and separating DDL and DML commands. This strategy minimizes table locking and transaction log bloat, allowing production-scale data migrations to execute safely without blocking concurrent application traffic.

Does Prisma support concurrent index creation and expand-and-contract migrations?▼

Prisma supports concurrent index creation and expand-and-contract migrations by providing actionable workflows for schema changes. It enables production-safe migrations by guiding you to add nullable columns, apply concurrent indexes, and batch backfill data before safely removing old database structures.

Can I use Django or TypeORM for reversible schema changes in production?▼

Django and TypeORM both support reversible schema changes in production through tool-specific migration workflows. These ORMs enable forward-rollbacks and safe deployments by applying expand-and-contract patterns and concurrent index creation to ensure database schema changes do not cause unexpected locking.

Why do I need to separate DDL and DML commands during a database migration?▼

Separating DDL and DML commands during a database migration is required to prevent long-running table locks and transactional conflicts. This separation ensures that schema modifications and bulk data updates execute independently, maintaining application availability and ensuring forward-rollback safety.

How do I safely remove an old column with no downtime after a data backfill?▼

To safely remove an old column with no downtime after a data backfill, you apply the contract phase of the expand-and-contract pattern. This involves verifying the new column is fully populated and application traffic has shifted, allowing the old structure to be retired safely.