[
  {
    "mode": "NULLABLE",
    "name": "bool_col",
    "type": "BOOLEAN"
  },
  {
    "mode": "NULLABLE",
    "name": "bignumeric_col",
    "type": "BIGNUMERIC"
  },
  {
    "mode": "NULLABLE",
    "name": "bytes_col",
    "type": "BYTES"
  },
  {
    "mode": "NULLABLE",
    "name": "date_col",
    "type": "DATE"
  },
  {
    "mode": "NULLABLE",
    "name": "datetime_col",
    "type": "DATETIME"
  },
  {
    "mode": "NULLABLE",
    "name": "float64_col",
    "type": "FLOAT"
  },
  {
    "mode": "NULLABLE",
    "name": "geography_col",
    "type": "GEOGRAPHY"
  },
  {
    "mode": "NULLABLE",
    "name": "int64_col",
    "type": "INTEGER"
  },
  {
    "mode": "NULLABLE",
    "name": "interval_col",
    "type": "INTERVAL"
  },
  {
    "mode": "NULLABLE",
    "name": "numeric_col",
    "type": "NUMERIC"
  },
  {
    "mode": "REQUIRED",
    "name": "rowindex",
    "type": "INTEGER"
  },
  {
    "mode": "NULLABLE",
    "name": "string_col",
    "type": "STRING"
  },
  {
    "mode": "NULLABLE",
    "name": "time_col",
    "type": "TIME"
  },
  {
    "mode": "NULLABLE",
    "name": "timestamp_col",
    "type": "TIMESTAMP"
  }
]