public function rollBack()
 {
     $start = millitime();
     $ret = parent::rollBack();
     function_log('PDO->rollBack()', millitime() - $start);
     return $ret;
 }
 public function execute(array $input_parameters = null)
 {
     $start = millitime();
     $ret = parent::execute($input_parameters);
     function_log('PDOStatement->execute()', millitime() - $start);
     return $ret;
 }