sekab/migrations/SKILL.md· 626 b
---
| name: | "migrations" |
| description: | "Run zero-downtime Postgres migrations. Backfills before constraints, lock-free default adds." |
| agents: | ["claude", "cursor", "mcp"] |
| version: | "2.0.1" |
| tags: | ["postgres", "ops", "migrations"] |
---
Zero-downtime migrations
The runbook for Postgres schema changes that don't block writers.
Rules
- Additive first. New columns go in without
NOT NULL— backfill then constrain. - Double-write during renames. Write to both old and new columns until reads are migrated.
- Index
CONCURRENTLY. Never block writes. - Drop columns last. And only after a full deploy cycle.