public static TableFunctionResolver getTableFunctionResolver(String functionName)
      throws SemanticException {
    FunctionInfo tfInfo = getFunctionInfo(functionName);
    if (tfInfo != null && tfInfo.isTableFunction()) {
      return (TableFunctionResolver) ReflectionUtils.newInstance(tfInfo.getFunctionClass(), null);
    }
    return null;
  }
Both UDF and UDAF functions can imply order for analytical functions

@param functionName
         name of function
@return true if a GenericUDF or GenericUDAF exists for this name and implyOrder is true, false
        otherwise.
@throws SemanticException
ql/src/java/org/apache/hadoop/hive/ql/exec/FunctionRegistry.java