Relational databases are mathematically elegant and useful in certain ways for arbitrary data retrieval and manipulation, but I don't see why they would be the

Relational databases are mathematically elegant and useful in certain ways for arbitrary data retrieval and manipulation, but I don't see why they would be the best fit browser-side for any but the absolute largest and most complicated front-end systems. Is the typical in-browser code really complex enough that one would want to introduce the object-relational mismatch and all of its associated issues? Most in-browser code wants to operate on a limited set of very well-defined tree data structures, which is a bad fit for relational databases because relational databases are designed to represent a generic graph that can be virtualized into a tree arbitrarily and as necessary.