I think the major contribution in this paper is how to do consistent snapshot reads in a distributed system without a common reference clock, i.e. the use of Tr

I think the major contribution in this paper is how to do consistent snapshot reads in a distributed system without a common reference clock, i.e. the use of True Time. Many databases use some sort of MVCC, but they operate on a single node or in a closely connected cluster. This paper shows how to achieve the same properties in a system spanning continents.