pass by reference

In a recent discussion about the MS terra server it was mentioned this could not be done with PHP because the terraserver " has special front-end code that allows images to be passed by reference, so the image data goes directly from the database access back end to the client browser, without having to be copied to and from an intermediate middleware layer." The implication is that the 'middle layer' (PHP) would slow things down to an unusable state. so, when I extract an image from the database and echo it to a webpage, is there any copying done? or is it a direct stream to the webpage? Kind regards Kevin -- ______ (_____ \ _____) ) ____ ____ ____ ____ | ____/ / _ ) / _ | / ___) / _ ) | | ( (/ / ( ( | |( (___ ( (/ / |_| \____) \_||_| \____) \____) Kevin Waterson Port Macquarie, Australia