{
  "context": "This evaluation assesses how well the engineer uses ConnectorX's read_sql() function and its features to load data from a PostgreSQL database. The criteria focus on proper usage of the package's query execution capabilities, multiple query handling, and output format specification.",
  "type": "weighted_checklist",
  "checklist": [
    {
      "name": "Uses read_sql function",
      "description": "Uses connectorx.read_sql() as the primary method for loading data from the database. Implementation should import and call this function rather than using alternative database libraries.",
      "max_score": 20
    },
    {
      "name": "Single query execution",
      "description": "Correctly implements load_user_activities() using read_sql() with a single SQL query. The implementation should pass the connection string and query string to read_sql(), constructing appropriate WHERE clauses when user_id is provided.",
      "max_score": 15
    },
    {
      "name": "Aggregation queries",
      "description": "Correctly implements load_daily_summary() using read_sql() with aggregation SQL (GROUP BY, COUNT, SUM). The implementation should construct queries with date range filtering and aggregation functions.",
      "max_score": 15
    },
    {
      "name": "Multiple queries parameter",
      "description": "Correctly implements load_multiple_datasets() using read_sql() with the sql parameter accepting a list of query strings. The implementation should pass the list of queries directly to read_sql() to execute them in parallel.",
      "max_score": 20
    },
    {
      "name": "Output format specification",
      "description": "Correctly implements load_to_arrow() using read_sql() with the return_type='arrow' parameter (or return_type='arrow2' for PyArrow Table). The implementation should specify the output format parameter to get Arrow format instead of the default pandas DataFrame.",
      "max_score": 20
    },
    {
      "name": "Connection string usage",
      "description": "Passes connection strings directly to read_sql() without modification. The implementation should use the provided PostgreSQL connection strings as-is, allowing ConnectorX to handle the database connection.",
      "max_score": 10
    }
  ]
}