In traditional relational database management systems, data was often moved to computational space for processing. In Big Data space bringing the computation to where data is located. So, everything is real-time.
A key feature of these types of real-time notifications is that they enable real-time actions. However, using such a capability would require you to approach your application and your work differently.
Most Big Data companies have updated their culture to be more real-time action oriented, refining real-time processes to handle anything from customer relations and fraud detection, to system monitoring and control.
Such volumes of real-time data and analytical operations that need to take place requires an increased use of scalable computing systems, which need to be a part of the planning for an organisational Big Data strategy.