Learning Apache Apex

State query and data consistency

In Chapter 6, Example Project – Real-Time Aggregation and Visualization, we looked at an example for visualization of streaming computation in Apex. It was based on the idea that since the streaming platform manages the state, it can be accessed directly instead of having to load it to a separate external system first (which also has its own performance constraints).

The idea today is represented under different names such as Queryable State, Interactive Queries, or Stream Processor as Database in a number of ecosystem projects, each with its own implementation flavor and semantics. It will be interesting to see how users will potentially adopt this concept and understand it as true database alternative. There ...