Agent skill · affaan-m
database-migrations
Safe, reversible database migration patterns: forward-only production changes, expand-contract zero-downtime renames, concurrent indexes, batched backfills, and per-tool workflows for PostgreSQL, Prisma, Drizzle, Kysely, Django, and golang-migrate. Use when writing a schema or data migration, adding a column or index to a large table, planning a rollback, or preparing a zero-downtime deploy.
What it needs
About 6k tokens when loaded.
What this skill does
Database Migration Patterns Safe, reversible database schema changes for production systems. When to Activate Creating or altering database tables Adding/removing columns or indexes Running data migrations (backfill, transform) Planning zero-downtime schema changes Setting up migration tooling for a new project Core Principles 1. Every change is a migration — never alter production databases manually 2. Migrations are forward-only in production — rollbacks use new forward migrations 3. Schema and data migrations are separate — never mix DDL and DML in one migration 4. Test migrations against production-sized data — a migration that works on 100 rows may lock on 10M 5. Migrations are immutable once deployed — never edit a migration that has run in production Migration Safety Checklist Before applying any migration: [ ] Migration has both UP and DOWN (or is explicitly marked irreversible) [ ] No full table locks on large tables (use concurrent operations) [ ] New columns have defaults or are nullable (never add NOT NULL without default) [ ] Indexes created concurrently (not inline with CREATE TABLE for existing tables) [ ] Data backfill is a separate migration from schema change [ ] Tested against a copy of production data [ ] Rollback plan documented PostgreSQL Patterns Adding a Column Safely Adding an Index Without Downtime Renaming a Column (Zero-Downtime) Never rename directly in production. …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills affaan-m/database-migrations--a2229c