Distributed data management in 2020?

Work on distributed data management commenced shortly after the introduction of the relational model in the mid-1970´s. 1970´s and 1980´s were very active periods for the development of distributed relational database technology, and claims were made that in the following ten years centralized databases will be an “antique curiosity” and most organizations will move toward distributed database managers [1]. That prediction has certainly become true, and all commercial DBMSs today are distributed.