I haven't used a database backend for sessions, so I couldn't honestly say, but I'd certainly try it. Think of the overhead of using a RDBMS, as opposed to a simpler method. I could be wrong, but I think it's at least worth considering. And if you need something accessible by multiple machines, like I mentioned, there's memcached, which is designed for this sort of thing to begin with (and easy to set up, too, based on my brief experimentation with it). On the other hand, if it turns out that I'm wrong or if someone else knows better, feel free to tell me, too.