{
  "context": "This criteria evaluates how well the engineer uses ConnectorX's multiple output format support to load database query results into different dataframe formats (pandas, arrow, polars, arrow_stream) with format-specific features like index columns and batch processing.",
  "type": "weighted_checklist",
  "checklist": [
    {
      "name": "Uses read_sql function",
      "description": "Implementation uses connectorx.read_sql() as the primary method to load data from the database rather than implementing custom database connection logic.",
      "max_score": 15
    },
    {
      "name": "Pandas format support",
      "description": "Correctly uses return_type='pandas' (or default behavior) to export query results as a pandas DataFrame.",
      "max_score": 15
    },
    {
      "name": "Arrow format support",
      "description": "Correctly uses return_type='arrow' to export query results as a pyarrow Table.",
      "max_score": 15
    },
    {
      "name": "Polars format support",
      "description": "Correctly uses return_type='polars' to export query results as a polars DataFrame.",
      "max_score": 15
    },
    {
      "name": "Arrow stream support",
      "description": "Correctly uses return_type='arrow2' (or 'arrow_stream') with the partition_on parameter or similar approach to enable streaming batch processing, returning a RecordBatchReader.",
      "max_score": 15
    },
    {
      "name": "Index column feature",
      "description": "Correctly uses the index_col parameter in read_sql() to set a specified column as the DataFrame index when output_format='pandas'.",
      "max_score": 10
    },
    {
      "name": "Batch size configuration",
      "description": "Correctly passes the batch_size parameter to read_sql() when return_type='arrow_stream' to control the size of batches in the RecordBatchReader.",
      "max_score": 10
    },
    {
      "name": "Format validation",
      "description": "Validates that the output_format parameter contains a supported value and raises appropriate errors for unsupported formats.",
      "max_score": 5
    }
  ]
}