Nested historical relations

Abstract

The paper extends nested relations for managing temporal variation of complex objects. It combines the research in temporal databases and nested relations for nontraditional database applications. The basic modelling construct is a temporal atom as an attribute value. A temporal atom consists of two components, a value and temporal set which is a set of times denoting the validity period of the value. We define algebra operations for nested historical relations. Data redundancy in nested historical relations is also discussed and criteria for well-structured nested relations are established.