{
  "context": "Tests whether the response correctly identifies the read-then-write race condition and provides a valid database-level fix.",
  "type": "weighted_checklist",
  "checklist": [
    {
      "name": "Identifies read-then-write as the problem",
      "description": "Explains that separate SELECT then UPDATE creates a race window where concurrent requests read the same value before either writes",
      "max_score": 15
    },
    {
      "name": "Recommends atomic UPDATE RETURNING",
      "description": "Suggests using UPDATE ... SET counter = counter + 1 RETURNING counter (or equivalent atomic single-statement approach)",
      "max_score": 15
    },
    {
      "name": "Mentions alternative: transactions with row locking",
      "description": "Mentions SELECT FOR UPDATE or serializable isolation as an alternative approach",
      "max_score": 10
    },
    {
      "name": "No incorrect information",
      "description": "Response does not contain factually wrong statements about PostgreSQL concurrency, transactions, or locking",
      "max_score": 12
    }
  ]
}