This site is underweighted on OLAP. Columnstores were invented for precisely this use case; nobody in the field wants to normalize everything.
Which brings me to the question, why a rowstore? Are Z-sets hard to manage otherwise?
Another aspect of wide tables is that they tend to have a lot of dependencies, ie different columns come from different aggregations, and the whole table gets held up if one of them is late. IVM seems like a good solution for that problem.
Good questions!
Feldera tries to be row- and column-oriented in the respective parts that matter. E.g. our LSM trees only store the set of columns that are needed, and we need to be able to pick up individual rows from within those columns for the different operators.
I don't think we've converged on the best design yet here though. We're constantly experimenting with different layouts to see what performs best based on customer workloads.