have become interesting and attractive in the last decade, as companies with world-wide operations require transactional databases with horizontal scalability and global reach. There’s an essential tension between geographic distribution and low transaction latency, however: The speed of light limits the transmission time between distant nodes.
To allow for high throughput on write transactions, many have weakened their transaction support, either by prohibiting cross-partition transactions, or by downgrading their consistency guarantees from strong (synchronous transactions) to eventual (asynchronous transactions). Most databases use a two-phase commit scheme for transactions, which drives up the transaction latency when there is geographic distribution of nodes. However, many recent distributed databases use either a Paxos or Raft scheme for quorum-based transaction consensus, which lowers the transaction latency.
FaunaDB is a distributed, strongly consistent OLTP NoSQL database that is ACID compliant and offers a multi-model interface. It has an active-active architecture and can span clouds as well as continents. FaunaDB supports document, relational, graph, and temporal data sets from a single query. In addition to its own FQL query language, the product supports GraphQL, with SQL planned for the future.