The term volume describes the quantity of generated and stored data. The size of the data determines the value of a dataset and whether or not a dataset can be considered as big data.

To meet our original objective, this means you must answer the following questions:

• How large is the data you need to store?
• Entities should be maintained as a single document or multiple documents?

Where do we go next? We will leave the list of big Vs and deal now with a few rather specific factors. I will start with the factors, concurrency and consistency.