EdgeDB is trying to improve upon SQL databases. It is built on top of Postgres; But you can do join-less nested queries, schema introspection with GrapQL and more.
They have recently reached Release Candidate - RC1, after more than 5 years of development.
Someone has been kind enough to work on an Elixir driver here - GitHub - nsidnev/edgedb-elixir: WIP: Elixir driver for EdgeDB