The views created here were created to serve various queries and to produce desired outputs. There are some other classes of data processing applications that are often developed to implement real-world use cases. From the Lambda Architecture perspective, this also falls into the serving layer. The reason why these custom data processes fall into the serving layer is mainly because most of these use or process data from the master dataset and create views or outputs. It is also very possible for the custom processed data to remain as a view, and the following use case is one of such cases.
In the SfbMicroBlog microblogging application, it is a very common requirement to see whether a given user A is in some way connected to user B in a direct follower relationship or in a transitive way. This use case can be implemented using a graph data structure to see whether the two users in question are in the same connected component, whether they are connected in...