parquet-hive/parquet-hive-storage-handler/src/main/java/org/apache/hadoop/hive/ql/io/parquet/convert/HiveSchemaConverter.java
private static GroupType convertMapType(final String name, final MapTypeInfo typeInfo) {
    final Type keyType = convertType(ParquetHiveSerDe.MAP_KEY.toString(),
        typeInfo.getMapKeyTypeInfo(), Repetition.REQUIRED);
    final Type valueType = convertType(ParquetHiveSerDe.MAP_VALUE.toString(),
        typeInfo.getMapValueTypeInfo());
    return ConversionPatterns.mapType(Repetition.OPTIONAL, name, keyType, valueType);
  }
private static GroupType convertMapType(final String name, final MapTypeInfo typeInfo) {
    final Type keyType = convertType(ParquetHiveSerDe.MAP_KEY.toString(),
        typeInfo.getMapKeyTypeInfo(), Repetition.REQUIRED);
    final Type valueType = convertType(ParquetHiveSerDe.MAP_VALUE.toString(),
        typeInfo.getMapValueTypeInfo());
    return ConversionPatterns.mapType(Repetition.OPTIONAL, name, keyType, valueType);
  }
private static GroupType convertMapType ( final String name , final MapTypeInfo typeInfo ) { final Type keyType = convertType ( ParquetHiveSerDe . MAP_KEY . toString ( ) , typeInfo . getMapKeyTypeInfo ( ) , Repetition . REQUIRED ) ; final Type valueType = convertType ( ParquetHiveSerDe . MAP_VALUE . toString ( ) , typeInfo . getMapValueTypeInfo ( ) ) ; return ConversionPatterns . mapType ( Repetition . OPTIONAL , name , keyType , valueType ) ; }
2 elements: "key", "value"
2 elements : key value