> That depends on the functionality requirements of noSQL customers. I posit that writing a new, indepedent RDBMS that implements the latest SQL spec with the same maganement and replication capabilities as the incumbents is on-par with trying to compete with WebKit and Gecko. The SQL Server engineering team at Microsoft is about 1,000 people according to my friends on campus.

CockroachDB is the newest from-scratch SQL engine that I am aware of: https://www.cockroachlabs.com/

They re-use the RocksDB K/V store maintained by Facebook (in C++) as the storage layer, and their own code is written in Go, so I suspect that their development work is probably a lot less time-expensive than the teams working on older SQL databases.