{
  "pack": "edtech-practice-evalpack",
  "misata_version": "0.8.7.1",
  "seed": 42,
  "spec_sha256": "442a7dd34251d5d05e7e8face9ae50add7034f11507daf5706a823fb0c6bb55f",
  "generated_at": "2026-07-16T15:06:04.534636+00:00",
  "verifier": {
    "engine": "duckdb",
    "version": "1.4.2"
  },
  "sql_dialect": "duckdb",
  "answer_comparison": "numeric at round_decimals (never string equality); strings compared exactly",
  "fk_integrity": [
    {
      "relationship": "practice_attempts.student_id -> students.student_id",
      "orphans": 0,
      "verified": true
    }
  ],
  "conformance_warnings": [],
  "questions": [
    {
      "id": "q001",
      "gold_sql": "SELECT ROUND(SUM(\"duration_seconds\"), 2) FROM \"practice_attempts\" WHERE \"attempted_at\" >= TIMESTAMP '2025-01-01 00:00:00' AND \"attempted_at\" < TIMESTAMP '2025-02-01 00:00:00'",
      "expected": 500000.0,
      "observed": 500000,
      "match": true
    },
    {
      "id": "q002",
      "gold_sql": "SELECT ROUND(SUM(\"duration_seconds\"), 2) FROM \"practice_attempts\" WHERE \"attempted_at\" >= TIMESTAMP '2025-02-01 00:00:00' AND \"attempted_at\" < TIMESTAMP '2025-03-01 00:00:00'",
      "expected": 520000.0,
      "observed": 520000,
      "match": true
    },
    {
      "id": "q003",
      "gold_sql": "SELECT ROUND(SUM(\"duration_seconds\"), 2) FROM \"practice_attempts\" WHERE \"attempted_at\" >= TIMESTAMP '2025-03-01 00:00:00' AND \"attempted_at\" < TIMESTAMP '2025-04-01 00:00:00'",
      "expected": 540000.0,
      "observed": 540000,
      "match": true
    },
    {
      "id": "q004",
      "gold_sql": "SELECT ROUND(SUM(\"duration_seconds\"), 2) FROM \"practice_attempts\" WHERE \"attempted_at\" >= TIMESTAMP '2025-04-01 00:00:00' AND \"attempted_at\" < TIMESTAMP '2025-05-01 00:00:00'",
      "expected": 560000.0,
      "observed": 560000,
      "match": true
    },
    {
      "id": "q005",
      "gold_sql": "SELECT ROUND(SUM(\"duration_seconds\"), 2) FROM \"practice_attempts\" WHERE \"attempted_at\" >= TIMESTAMP '2025-05-01 00:00:00' AND \"attempted_at\" < TIMESTAMP '2025-06-01 00:00:00'",
      "expected": 580000.0,
      "observed": 580000,
      "match": true
    },
    {
      "id": "q006",
      "gold_sql": "SELECT ROUND(SUM(\"duration_seconds\"), 2) FROM \"practice_attempts\" WHERE \"attempted_at\" >= TIMESTAMP '2025-06-01 00:00:00' AND \"attempted_at\" < TIMESTAMP '2025-07-01 00:00:00'",
      "expected": 600000.0,
      "observed": 600000,
      "match": true
    },
    {
      "id": "q007",
      "gold_sql": "SELECT ROUND(SUM(\"duration_seconds\"), 2) FROM \"practice_attempts\" WHERE \"attempted_at\" >= TIMESTAMP '2025-01-01 00:00:00' AND \"attempted_at\" < TIMESTAMP '2025-07-01 00:00:00'",
      "expected": 3300000.0,
      "observed": 3300000,
      "match": true
    },
    {
      "id": "q008",
      "gold_sql": "SELECT COUNT(*) FROM \"practice_attempts\" WHERE \"attempted_at\" >= TIMESTAMP '2025-01-01 00:00:00' AND \"attempted_at\" < TIMESTAMP '2025-02-01 00:00:00'",
      "expected": 2273,
      "observed": 2273,
      "match": true
    },
    {
      "id": "q009",
      "gold_sql": "SELECT COUNT(*) FROM \"practice_attempts\" WHERE \"attempted_at\" >= TIMESTAMP '2025-02-01 00:00:00' AND \"attempted_at\" < TIMESTAMP '2025-03-01 00:00:00'",
      "expected": 2364,
      "observed": 2364,
      "match": true
    },
    {
      "id": "q010",
      "gold_sql": "SELECT COUNT(*) FROM \"practice_attempts\" WHERE \"attempted_at\" >= TIMESTAMP '2025-03-01 00:00:00' AND \"attempted_at\" < TIMESTAMP '2025-04-01 00:00:00'",
      "expected": 2455,
      "observed": 2455,
      "match": true
    },
    {
      "id": "q011",
      "gold_sql": "SELECT COUNT(*) FROM \"practice_attempts\" WHERE \"attempted_at\" >= TIMESTAMP '2025-04-01 00:00:00' AND \"attempted_at\" < TIMESTAMP '2025-05-01 00:00:00'",
      "expected": 2545,
      "observed": 2545,
      "match": true
    },
    {
      "id": "q012",
      "gold_sql": "SELECT COUNT(*) FROM \"practice_attempts\" WHERE \"attempted_at\" >= TIMESTAMP '2025-05-01 00:00:00' AND \"attempted_at\" < TIMESTAMP '2025-06-01 00:00:00'",
      "expected": 2636,
      "observed": 2636,
      "match": true
    },
    {
      "id": "q013",
      "gold_sql": "SELECT COUNT(*) FROM \"practice_attempts\" WHERE \"attempted_at\" >= TIMESTAMP '2025-06-01 00:00:00' AND \"attempted_at\" < TIMESTAMP '2025-07-01 00:00:00'",
      "expected": 2727,
      "observed": 2727,
      "match": true
    },
    {
      "id": "q014",
      "gold_sql": "SELECT strftime(date_trunc('month', \"attempted_at\"), '%Y-%m') AS period FROM \"practice_attempts\" GROUP BY 1 ORDER BY SUM(\"duration_seconds\") DESC, 1 ASC LIMIT 1",
      "expected": "2025-06",
      "observed": "2025-06",
      "match": true
    },
    {
      "id": "q017",
      "gold_sql": "SELECT ROUND(AVG(CASE WHEN \"correct\" = TRUE THEN 1.0 ELSE 0.0 END), 4) FROM \"practice_attempts\" WHERE \"attempted_at\" >= TIMESTAMP '2025-03-01 00:00:00' AND \"attempted_at\" < TIMESTAMP '2025-04-01 00:00:00'",
      "expected": 0.602,
      "observed": 0.602,
      "match": true
    },
    {
      "id": "q019",
      "gold_sql": "SELECT ROUND(AVG(CASE WHEN \"correct\" = TRUE THEN 1.0 ELSE 0.0 END), 4) FROM \"practice_attempts\" WHERE \"attempted_at\" >= TIMESTAMP '2025-05-01 00:00:00' AND \"attempted_at\" < TIMESTAMP '2025-06-01 00:00:00'",
      "expected": 0.654,
      "observed": 0.654,
      "match": true
    },
    {
      "id": "q021",
      "gold_sql": "SELECT COUNT(*) FROM \"practice_attempts\" c LEFT JOIN \"students\" p ON c.\"student_id\" = p.\"student_id\" WHERE p.\"student_id\" IS NULL AND c.\"student_id\" IS NOT NULL",
      "expected": 0,
      "observed": 0,
      "match": true
    }
  ],
  "all_match": true
}