Bitemporal Databases

All mainstream database systems lack support fortemporal metadata and instead store only the mostrecent data. Consequently they can only managetemporal data in an ad hoc manner -- oftentimes noteffectively. Yet there are countless applicationdomains that need temporal data. This book offers amuch-needed solution: It includes a bitemporalrelational data model based on nested relations aswell as its algebra and calculus languages forexpressing queries. The fundamental construct forrepresenting temporal data is a bitemporal atom; avalue its validity period and the time this datawas recorded in the database. The concept of'context' defines different views of bitemporal data.BtSQL a simple bitemporal variation of the SQL isintroduced. The book also provides a prototypeimplementation which demonstrates the feasibility ofthe proposed approach in an object-relationaldatabase system. Researchers and practitioners indatabase development will find this book useful. Itcan be used as a textbook in advanced databasecourses -- particularly in application domains wheretemporal metadata can greatly leverage the value ofthe data as it is stored and utilized.