包含在类内的方法很慢

I have an include statement that I call dynamically based on method arguments. It takes 2.7 sec. If the same include is above the class there's no delay.

class queryDao 
{
    function queryDao($plugindir,$queryname,$tablename)
    {
        //$time_start = microtime_float();

        include_once $plugindir."/resources/queries/$queryname".".php";

        //$time_end = microtime_float();
        //echo "elapsed seconds1 $time_end  $time_start  : ".($time_end-$time_start). " seconds";

        if($tablename!="")
        {       

        }
        else
        {
          $this->myquery=new $queryname();
        }       
    }
}

Any ideas?