> 1) The old cache entry is overwritten with the new. > 2) The old cache entry is expired, thus forcing a database hit (and > subsequent cache load) on the next request.
3) Cache only stuff which doesn't expire (except on server restarts). We don't cache any mutable data, and there are no sessions. We let the database do the caching. We use Oracle, which has a pretty good cache. We do cache some stuff that doesn't change, e.g. default permissions, and we release weekly, which involves a server restart and a refresh of the cache. If you hit http://www.bivio.com , you'll get a page back in under 300ms. There are probably 10 database queries involved if you are logged in. This page is complex, but far from our most complex. For example, this page http://www.bivio.com/demo_club/accounting/investments sums up all the holdings of a portfolio from the individual transactions (buys, sells, splits, etc.). It also comes back in under 300ms. Sorry if this wasn't the answer you were looking for. :) Rob
