It was probably meant as a learning exercise. And for me it is that implementation details of the KV/heap layer with some meaningful transactional properties seem more interesting than how to build SQL/whatever database on top of that, which in comparison looks like mostly obvious but tedious SMOP.
True, I was being somewhat pedantic. Whenever I see the word "db" I can't help but think "DBMS". It's frustrating that "DBMS" is such a mouthful that nobody bothers using it anymore, and that KV store projects choose to (ab)use the DB suffix.
> implementation details of the KV/heap layer with some meaningful transactional properties seem more interesting
There is undoubtedly a real beauty in LMDB's data structures, and it is impressive to see how Rockset have re-engineered RocksDB to become cloud-native …but my own feeling is that the SQL/whatever, distributed consistency and federation layers of a DBMS encompass some seriously hard and fascinating problems. What if the web could behave like a cohesive offline-first database for all of human knowledge after all?
Now I think about it, "interesting" has a pretty loose definition too!
