Jepsen Distributed Systems Safety Analysis

http://jepsen.io

The Jepsen site is an essential resource for anyone thinking seriously about building software deployments at scale. Run by Kyle Kingsbury, he tests clusters of datastore-type systems by firing data at them, introducing internal partitions and failures, and comparing what the system told the clients that it had stored with what it had actually persisted.

DB Engines Ranking

http://db-engines.com/en/ranking

Provides an insight into which databases have momentum (and which ones don’t!). Methodology focusses more on “buzz” than actual users. Conveniently categorised by type of database.