private boolean hasUnsupportedVectorizedParquetDataType(
        Class<? extends InputFormat> inputFileFormatClass, List<TypeInfo> allTypeInfoList) {
      if (!inputFileFormatClass.equals(org.apache.hadoop.hive.ql.io.parquet.MapredParquetInputFormat.class)) {
        return false;
      }

      /*
       * Currently, VectorizedParquetRecordReader cannot handle nested complex types.
       */
      for (TypeInfo typeInfo : allTypeInfoList) {
        if (!(typeInfo instanceof PrimitiveTypeInfo)) {
          switch (typeInfo.getCategory()) {
          case LIST:
            if (!(((ListTypeInfo) typeInfo).getListElementTypeInfo() instanceof PrimitiveTypeInfo)) {
              return true;
            }
            break;
          case MAP:
            {
              MapTypeInfo mapTypeInfo = (MapTypeInfo) typeInfo;
              if (!(mapTypeInfo.getMapKeyTypeInfo() instanceof PrimitiveTypeInfo)) {
                return true;
              }
              if (!(mapTypeInfo.getMapValueTypeInfo() instanceof PrimitiveTypeInfo)) {
                return true;
              }
            }
            break;
          case STRUCT:
            {
              StructTypeInfo structTypeInfo = (StructTypeInfo) typeInfo;
              List<TypeInfo> fieldTypeInfos = structTypeInfo.getAllStructFieldTypeInfos();
              for (TypeInfo fieldTypeInfo : fieldTypeInfos) {
                if (!(fieldTypeInfo instanceof PrimitiveTypeInfo)) {
                  return true;
                }
              }
            }
            break;
          case UNION:
            // Not supported at all.
            return false;
          default:
            throw new RuntimeException(
                "Unsupported complex type category " + typeInfo.getCategory());
          }
        }
      }
      return false;
    }
Decimal types can be specified with different precision and scales e.g. decimal(10,5),
as opposed to other data types which can be represented by constant strings.
The regex matches only the {@link serdeConstants#DECIMAL_TYPE_NAME} prefix of the type.
ql/src/java/org/apache/hadoop/hive/ql/optimizer/physical/Vectorizer.java