Not sure I’ve got the rest of the post, but really liked these two definitions of big data:
Big data means nothing. It’s a well meaning term for (literally) big piles of data, sitting in various massive balls of infrastructure, randomly scattered around our enterprise. More common terms include data warehouses or decision support systems, etc.
Big data is created by copying transactional data and sticking it on another system. We copy ALL our transactional data and stick it on these systems. Over time, those systems become supersets of our transactional systems. We make lots of copies and put them in lots of big data systems.