May 26, 2009 10:37 PM|Nai-Dong Jin - MSFT|LINK
From your description, it seems that you want to active the database lookup logic only when you are requesting for a virtual url, right?
I'm not sure what your httpModule looks like, generally, you can add your custom logic to identity if the current request is virtual or physical according to your rules. For samples:
void context_BeginRequest(object sender,