I'm running a public web-based forum that is read frequently (about 10,000 hits per day), but gets relatively few postings (in the range of 20 to 60 per day). The board software is Phorum, a nice open-source PHP application. Although the site has other popular pages to offer, Phorum's read.php file is the clear number one in my Apache hit and download volume statistics. Most of these hits are apparently caused by users pressing "reload" to check for updates every now and then.

With the rather small number of new postings, it is obvious that Phorum and its underlying DBMS (in our case, PostgreSQL) have to repeatedly generate lots of identical responses to identical queries. This is a waste of bandwidth and server load and makes browsing the forum appear slower than necessary, particularly for users with slow connections. It also renders the caching efforts of proxy servers virtually useless.