I have an asp.net project, and I load a base aspx page to display to the user. Then I ajax in the results of an ascx component and inject it via innerHTML in javascript.
I have noticed that the ascx component loads slowly on the first page load, but instantly thereafter. This is really cool, but I do not understand how this can be cached, as the contents are generated by making several db calls.
Does the server send some kind of hash to compare the contents to, to see if it changed on the server or not? Is this a browser thing or an asp.net thing?
What you are experiencing is most likely just in time compiling and has very little to do with the user control itself.
Watch the performance monitor counters for .net. This will tell you a lot about what’s going on.