Objected-Oriented View Technology: Challenges and Promises

With object-oriented database (OODB) systems reaching the status of a maturing technology, increased attention has been given in recent years to the realization of view mechanisms in OODBs. Object-oriented views have the potential for achieving important services, including system interoperability, security , heterogeneous systems integration, schema evolution , data warehousing, and workkow management, to just name a few. Given this rising interest, we report on the MultiView project which, now in its middle phase, is a ve-year NSF-funded eeort on exploring object-oriented view foundation and implementation issues as well as on applying view technology to a select subset of problems to evaluate its potential. In this paper, we review our results on designing, implementing , and optimizing object-oriented view mechanisms , which include object-centric view materializa-tion algorithms and view redeenition techniques. In this paper, we also outline three promising directions of applying object-oriented view technology to solve important problems, namely, transparent schema evolution , complex object-based interoperability, and active self-adaptive virtual catalogs for electronic commerce. We not only outline our experiences and results for providing these services but more importantly we point out open problems for future research.