We have been using SSRS 2008 for several weeks generally connecting to an Oracle database and returning large amounts of data in our reports. The common issue we are seeing is that when switching from preview to design and vice versa after only making layout changes the data is not cached, when switching back to preview. Also there are not and rdl.DATA files being generated. Is there is a switch anywhere in BIDS to turn this on and off or some other reason why the data wouldn't be cached? A size limit perhaps?
-Adam