Temporal Data Models
Bitemporal data model; Historical data model; Transaction-time data model; Valid-time data model
A “data model” consists of two components, namely a set of objects and a language for querying those objects . In a temporal data model the objects vary over time, and the operations in some sense “know” about time. Focus has been on the design of data models where the time references capture valid time, or transaction time, or a combination of both (for bitemporal data).
Almost all real-world databases contain time-referenced data. Few interesting databases are entirely stagnant, and when the modeled reality changes, the database must be updated. Usually at least the start time of currently valid data are captured, though most databases also retain previous data.
Two decades of research into temporal databases have unequivocally shown that a time-referencing table, containing certain kinds of time-valued columns that capture one or more...