NuoDB can be categorized as a NewSQL database that retains characteristics of traditional SQL databases while also incorporating features for supporting scale-out processing in cloud computing environments. Application programs communicate with NuoDB with SQL statements, just as they do in a relational database, and the database includes ACID compliance for transaction reliability. But the NuoDB architecture diverges from established relational approaches by using a three-tier structure with administrative, transactional and storage tiers. This layered approach means that NuoDB can work without close coupling an application and its data on a disk drive, which has proved to be an encumbrance in some cloud applications.
NuoDB divides data elements into software objects called "atoms." The database is built around a "durable distributed cache" design that uses a set of in-memory caches to support cloud-style elasticity while ensuring that all of the data objects are safely stored and maintained. It also supports multi-version concurrency control (MVCC) to detect data deadlocks and resolve access conflicts. In addition, it employs elements of object-oriented and message-oriented distributed computing methodologies, principally a peer-to-peer asynchronous communication format.
NuoDB is developed and marketed by software vendor NuoDB Inc., originally formed as NimbusDB in 2008. NuoDB 1.0 was released to general availability in January 2013. At the time of this writing, the software is on Release 2.0.3. The database's original lead architect was Jim Starkey, a database industry veteran responsible for early work on MVCC and blobs at the now-defunct Digital Equipment Corp. Before beginning the effort to create NuoDB, Starkey founded two other database companies. Starkey retired from NuoDB Inc. at the end of 2012 and is now a strategic advisor to the company.