I'm a bit of an amateur when it comes to web development, but I need to do something a little more sophisticated than usual at work and I'm not sure how best to proceed.The setup is as follows.  I have a web server set up which takes some input from the user, gathers a reasonably large amount of data from various web APIs, does some processing, and sends some processed data back to the user.  In particular, the server is stateless.What I want to do next is allow the user to inspect the output and dynamically request additional information about the unprocessed data.  I can think of two potentially sensible ways to do this:Give the user all of the data and let him or her sort it out.Store the unprocessed data in a database and retrieve it when asked.I can rule out option 1 because some of the unprocessed data is proprietary - I am only allowed to distribute summary statistics.  And I would rather not do option 2 because it seems like an ordeal and there is no need to keep the data around once the user is finished making requests.  What I want is a third option which allows me to keep the data in the first request around for subsequent requests (until, say, the user is inactive for 5 minutes or something).  Does this sort of system exist?  Or is there a reason why it is a bad idea?
Web applications: is there such a thing as semi-stateful?
web applications