AI agent skill · by @Archive228

Schema Diff

Compare two schema states and surface the risky changes. Use before applying migrations or after a model change.

Archived 2026-10-23 · Source updated 2026-07-14 · License: MIT. Check the original repository for the latest version.

SKILL.md instructions

# Schema Diff
Diff old vs new schema. Flag by risk:
- **Destructive** (high): dropped column/table, narrowed type, new NOT NULL on existing rows, dropped index a query relies on.
- **Locking** (high at scale): index without CONCURRENTLY, type change that rewrites the table.
- **Safe**: new nullable column, new table, new index CONCURRENTLY.
For each destructive change: is data lost? is it reversible? is there a backfill? Output a risk-ranked list and a go/no-go with the safe rollout order.