It's considerably more expensive to ship a query over the wire, compile it, execute it, then marshal the results to ship back over the wire to an application that then needs to unmarshal those results than it is to open a local file and suck some bytes into memory. Perhaps, though, that performance difference isn't significant in your application.

A perfectly reasonable approach it to consider the likely upper bound on traffic that your site will need to support, then do the simplest thing that will satisfy that performance requirement. If executing a query (or several queries) per page view works for you, go for it.