Maybe only an OS can be close to how MUCH deep you can go with a DB engine.
And I bet DB engines can go far than normal OS.
You don't know how much is still waiting for somebody to try, and how much is not applied. And how many of that DBs are not even doing, because all are constrained be being "apps" with so poor interface (sql).
Fun fact: Not exist a viable true relational DBs implemented, neither exist one with a viable programming language AND apis that is for developers.
ZERO.
At the risk of arguing about semantics (and not interesting database semantics) it seems half the commenters here think "deep tech" just means "like, technology you go really super DEEP into, like really dig into that DEEP DEEP HARDCORE TECHNOLOGY"
but that's not what this term has historically meant https://en.wikipedia.org/wiki/Deep_tech
> Deep tech innovations are often radical and may create new markets or disrupt existing ones. Deep tech companies often address big societal and environmental challenges and have potential to impact everyday life. Silicon chips are an example of innovation that enabled calculation at previously unimaginable speed and scale.
Database research is good, important, critical, even! But it's not creating something new that has never existed before. It's not inventing the transistor or the integrated circuit.