Management of interdependent data: specifying dependency and consistency requirements

Multiple databases that serve the needs of various application systems are considered. One of the significant problems in managing these databases is to maintain the related data items consistent to the required degree. This problem is frequently referred to as `redundant data management´. Since the term `redundancy´ tends to imply that the data is unwanted or superfluous, the authors use the more general term `management of interdependent data´. Some preliminary ideas in this area are discussed. The problem of managing interdependent data is characterized, and some important types of interdatabase dependency are identified. The types of consistency requirements which can exist among the interdependent data are defined