While I suspect it is better to refer to column(3), I don't know for sure. What should tell you for sure is sheet properties -> objects -> calc time. Try it both ways and see if there is any noticeable difference in calc time. For memory usage, I doubt there is any noticeable difference. You could check the size of the file and also the memory usage in task manager (processes -> mem usage -> Qv.exe). I'd bring up a fresh copy of QlikView each time. I'm not convinced there aren't memory leaks.