$$
$$
So far on the blog we have motivated 
-sets mainly as a unifying abstraction that encompasses graphs, wiring diagrams, Petri nets, and other graph-like objects. But what makes attributed -sets so useful is that they are a joint generalization of two essential data structures in computer science: graphs, as we have seen, but also data frames, a mainstay in any modern environment for data analysis.
This is a companion discussion topic for the original entry at https://blog.algebraicjulia.org/post/2020/12/cset-conjunctive-queries/