public static RelDataType convert(StructTypeInfo structType, RelDataTypeFactory dtFactory) {
    List<RelDataType> fTypes = new ArrayList<RelDataType>(structType.getAllStructFieldTypeInfos().size());
    for (TypeInfo ti : structType.getAllStructFieldTypeInfos()) {
      fTypes.add(convert(ti,dtFactory));
    }
    return dtFactory.createStructType(fTypes, structType.getAllStructFieldNames());
  }
******************** Convert Hive Types To Calcite Types **********************
ql/src/java/org/apache/hadoop/hive/ql/optimizer/calcite/translator/TypeConverter.java