How to Refresh a Cached Excel Services Report

This post doesn't so much describe how to do something as why you shouldn't worry about something you may see. It can be unnerving to make a change in a SharePoint object, then not see the change when you check for it. Here is a case where there is an explanation for that behavior. Here is a case where caching, which helps with rendering speed and performance, may impact how you specify an Excel Services data source. It's not a big inconvenience, but I wanted to point it out nonetheless.