There needs to be a time-dependent definition of "Big Data", because this term is frequently abused and results in confusion all around. In my view there has a

There needs to be a time-dependent definition of "Big Data", because this term is frequently abused and results in confusion all around. In my view there has always been "big" data. As others have pointed out, none of this is really any different from the data warehousing days. How much data you can store is a function of how much money you are willing to spend, and all that has changed is the amount of disk storage you get per dollar. I would propose a definition as follows: S_t > N * H_t Where S_t is "big" data when it is greater than some constant # of hard drives N and H is the size of the average consumer HDD at time t. So if we assume that today the average HDD is 2TB and we define C as say 200, big data is 400TB. 10 years ago "big data" would have been say 20TB. Simple.