Hmm, but the problem with having in-memory objects rather than a db is you end up having to replicate alot of the features of a relational database to get a usable system. And adding all these extra features you want from those dbs end up making a simple solution not very simple at all.
To some extent I think this is an "if all you have is a hammer..." situation. Relational DBs are often not a great fit for how contemporary software manages data in memory (hence the proliferation of ORMs, and adapter layers like graphql). I think it's often easier to write out one's relations in the data structures directly, rather than mapping them to queries and joins
To clarify, as I think some people have misunderstood: we used an existing library called bknr.datastore to handle the "database" part of the in-memory store, so we didn't have to invent too much. Our only innovation here was during the Expand phase, where we put that datastore behind a Raft replication.
