By virtualization I meant also not loading entire dataset to memory, but being able to work only on a constrained view of the data. For example, database has 1TB dataset, I only view 100 MB, further columns/sections are loaded when I scroll.
Though, we have quite alot of experience doing this in the past - and the design of Perspective is very much a reaction to what we learned, at lesat in regards to the typical financial dataset which is much smaller than 1TB.