Hi Nils,

Thanks for being patient.  From what I've seen, the short term query cache is just another cache for database data, so any call that is looking for something that lives in the database will check the short term query cache first, fall through to the regular query cache, and then go to the database if it doesn't find the data in either of them.  The reason for the short term query cache is this:  we keep many lists.  And caches are helpful for that.  Problem is that the list is often edited while a copy of it is in the cache.  So an item somewhere down the list goes to the top.  So we nuke the whole copy of the list in the cache, and get it back from the db.  That can suck for the user.  The short term query cache helps with that problem like so:  when a list is invalidated in the regular query cache, the short term query cache spawns a background thread to get that data and load it before you have to call for it again.  That way we try not to spend as much time waiting for the newest version of the list.  A forum thread as it is so far in the conversation can be seen as a list, and the short term query cache can help get a copy of the thread if it has been edited and dropped from the regular query cache at some point while you were viewing/editing/adding to it.  The reason you're seeing it work so quickly is most likely because your copy of the forum thread is current with the actual thread when you edit, so it isn't a big deal.  And honestly, I think the problem is load based.  I don't think you'll be able to really reproduce the behavior for this cache to really take effect unless your system is under some serious load from users.  Let me know if you have any other questions.

Thanks,
Kevin