I think you're missing the massive technical issues that are impeding postgresql from doing efficient sharding. SQL was not designed with distributed systems in

I think you're missing the massive technical issues that are impeding postgresql from doing efficient sharding. SQL was not designed with distributed systems in mind, it has numerous features that can't be done efficiently in a distributed system, and even doing them inefficiently is insanely complicated. The language that Postgresql supports is Huge! The reason nosql databases exist is in recognition of this fact. They jettison features like transactions that can't be done efficiently in a distributed system. If postgresql can implement a fraction of their current functionality in a distributed way, it will be an amazing engineering effort.