[chad_walters]

"After extensive experience working with Bigtable and other eventually consistent systems..."

This is not accurate -- Bigtable is not eventually consistent. The scope of transactions supported by a system is a different set of considerations from the level of consistency it provides. Bigtable is consistent but only allows for transactionality at the row level.

Optimistic concurrency control is nothing new and Percolator layered transactions on top of Bigtable years back. Furthermore, TrueTime -- allowing for comparatively low-latency update across a globally distributed set of DCs -- is the real innovation in Spanner, not the use of optimistic concurrency control.

Honestly, I am not sure what this article is trying to claim, except perhaps that per-node performance has been improved. AFAICT, most of this is due to the fact that RAM is cheaper than it was, SSDs have reached commoditization, and networks in the DC are faster than they used to be.