{
  "skill_name": "db-schema-design",
  "evals": [
    {
      "id": 1,
      "prompt": "Design the schema for an order-history feature. Queries: fetch one order by id, list a customer's orders newest-first, and report daily totals by region.",
      "assertions": [
        "Access patterns are listed before the schema, with frequency and selectivity",
        "The paradigm choice is justified against those access patterns — relational-by-default needs no defence, every move past it does",
        "Keys and partitioning are justified by the actual queries; a random UUIDv4 clustered primary key is not used without a stated reason",
        "Every index maps to a real predicate from the listed queries rather than being speculative",
        "Denormalization, where proposed, names the read it serves and the write cost it adds"
      ]
    }
  ]
}