the SQL:2011 standard. Microsoft SQL Server introduced Temporal Tables as a feature for SQL Server 2016. The feature is described in a video on Microsoft's "Channel 9" web site. Non-relational, NoSQL database management systems that provide temporal features including the following: TerminusDB is a fully featured open source graph database that natively supports version control, time-travel queries and diffing functions. It has an immutable layer architecture based on delta encoding and succinct data structures. MarkLogic introduced bitemporal data support in version 8.0. Time stamps for Valid and System time are stored in JSON or XML documents. SirixDB stores snapshots of (currently) XML- and JSON-documents very efficiently in a binary format due to a novel versioning algorithm called sliding snapshot, which balances read-/write-performance and never creates write peaks. Time-travel queries are supported natively as well as diffing functions. XTDB (formerly Crux) provides point-in-time bitemporal Datalog queries over transactions and documents ingested from semi-immutable Kafka logs. Documents are automatically indexed to create Entity–attribute–value model indexes without any requirement to define a schema. Transaction operations specify the effective Valid times. Transaction times are assigned by Kafka and enable horizontal scalability via consistent reads. RecallGraph is a point-in-time, unitemporal (transaction time) graph database, built on top of ArangoDB. It runs on ArangoDB's Foxx Microservice sub-system. It features VCS-like semantics in many parts of its interface, and is backed by a transactional event tracker. Bitemporality is listed as one of the items in its development roadmap. Temporal databases were one of the earliest forms of data version control, and influenced the development of modern data versioning systems. Alternatives Slowly changing dimensions can be used to model temporal relations. Further reading C.J. Date, Hugh Darwen, Nikos Lorentzos (2002). Temporal Data & the Relational Model, First Edition (The Morgan Kaufmann Series in Data Management Systems); Morgan Kaufmann; 1st edition; 422 pages. . Joe Celko (2014). Joe Celko's SQL for Smarties: Advanced SQL Programming (The Morgan Kaufmann Series in Data Management); Morgan Kaufmann; 5th edition. .—Chapters 12 and 35 in particular discuss temporal issues. Snodgrass, Richard T. (1999). (Morgan Kaufmann Series in Data Management Systems); Morgan Kaufmann; 504 pages; See also Anchor Modeling Database theory Event store Spatiotemporal database Time series database References External links Temporal Relations in RDF Temporal Scope for RDF Triples IBM DB2 10 for z/OS Time and Time Again series of articles by Randy Weis and Tom Johnston Temporal Patterns by Martin Fowler Database