What problem does it solve? Changing persistent data structures without a deliberate design step leads to broken invariants, unsafe migrations, and tenant isolation gaps. This Skill provides a structured design gate for proposing or reviewing relational database schemas before any services, routes, or migrations are implemented. ## Core Features & Use Cases - Schema Design and Review: Defines entities, ownership, cardinality, keys, nullability, constraints, and indexes derived from concrete query patterns rather than habit. - Concurrency and Tenant Safety Checks: Identifies race conditions requiring constraints or locking, and verifies tenant isolation and authorization-relevant ownership boundaries. - Migration Impact Analysis: Assesses forward-only migration, backfill, rollback, and compatibility implications for existing rows, readers, and writers. - Use Case: Before building a new feature that adds tables, run this Skill against the approved feature SPEC to produce a reviewed schema proposal with a ready-for-planning verdict, then hand off to implementation planning. ## Quick Start Ask the assistant to review the proposed schema for the new feature against its approved SPEC and report constraints, indexes, and migration implications before any implementation.
