Sometimes a PHP script needs to load a lot of data from a db and do some processing on it before use by the main chunk of the script, and that same script is used to process the submission of a form created by the first invocation of the script. I can see two ways of making that processed data generated during the first invocation available to the second. The normal way is simply to re-do the db lookups and the processing each time the script is invoked. The second way is to save the data in _SESSION so that later invocations just *have* the data pulled in by the system. (If the user has cookies disabled it has to revert to the re-lookup of course). I have used both methods but I'm wondering if anyone has ever done any real server load testing to compare the two methods. The second method is subjectively as fast, but I'm not able to compare the two. Thanks, David .