Agreed. The article looks very weak. Also, it seems like "delta architecture" would be a better name since the "speed layer" is all about updating views with d

Agreed. The article looks very weak. Also, it seems like "delta architecture" would be a better name since the "speed layer" is all about updating views with deltas anyway and the architecture clearly cannot do what it promises. The view update problem is by far not easy even if you take a subset of a well-defined language like SQL. And the article really seems to assume arbitrary queries, i.e. executing even an arbitrary program on the input data. Just a simple example: "If x is there then remove y" and you have other rules inserting and removing x and y. Then you easily run into a query which given the data does not have a single unambiguous solution and in some cases (loops with an odd number of negations) it is not even clear at all what the solution should be and if it can be defined.