public void updateFunctionClass(UDFInformation udfInformation, UDFClassLoader classLoader)
      throws ClassNotFoundException {
    Class<?> functionClass = Class.forName(udfInformation.getClassName(), true, classLoader);
    if (udfInformation.getUdfType().isTreeModel()) {
      functionToClassMap
          .get(Model.TREE)
          .put(udfInformation.getFunctionName().toUpperCase(), functionClass);
    } else {
      functionToClassMap
          .get(Model.TABLE)
          .put(udfInformation.getFunctionName().toUpperCase(), functionClass);
    }
  }
maintain a map for creating instance, model -> functionName -> class
iotdb-core/node-commons/src/main/java/org/apache/iotdb/commons/udf/UDFTable.java