Big data consists of huge modules, difficult, growing data sets with numerous and, independent sources. With the fast development of networking, storage of data, and the data gathering capacity, big data are now quickly increasing in all science and engineering domains, as well as animal, genetic and biomedical sciences. This paper elaborates a HACE theorem that states the characteristics of the big data revolution, and proposes a big data processing model from the data mining view. This data-oriented model contains demand-driven aggregation of data sources, mining and study, user knowledge modeling, and security and privacy issues.