http://www.perlmonks.org?node_id=447365


in reply to Re^3: Tracking down memory leaks
in thread Tracking down memory leaks

So basicly if one has a large variable, which should be removed by scoping (not counting the speed usage but memory in should word), one should do manually. But if the large variable is within sub and that sub is used again (eg from a loop structure), then all the variables within it is automatically reused.