PostgreSQL Interface for Google Spanner
cloud.google.com
cloud.google.com
Spoiler: no stored procedures or triggers, amongst other stuff.
That means every application that accessed the database will have to use the same, and any migration will be a lot of work.
Then one wouldn't need bespoke features except temporarily or where they are truly necessary for the business.
If this proves successful, there could be other implementations for other vendor dbms dialects.