When I first read the title I had in my head that it said multi-petabyte. When I think Multi-terabyte, I think 'yea, that is mostly in RAM'. 4TBs of RAM is sort of the new lower norm in DB machines, and GCP and AWS have high RAM machines at 12TB and 24TB. Not that these are not good ideas about scaling to multi-terabytes.. it is just interesting how much data has grown in size.