Everything You Wanted To Know About Caching

It's still a nice resource, but it's been posted many times before.

http://news.ycombinator.com/item?id=3598773

Great primer on web caching.

in the scripts section he says "Generate Content-Length response headers. It’s easy to do, and it will allow the response of your script to be used in a persistent connection. This allows clients to request multiple representations on one TCP/IP connection, instead of setting up a connection for every request. It makes your site seem much faster."

does he mean, for example, when serving up a dynamic php page, where the content might change for each request, you should still generate a content-length header before outputing the content?