TIGUKAT: An Object Model for Query and View Support in Object Database Systems

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  • Technical report TR92-14. Object-oriented computing is influencing many areas of computer science including software engineering, user interfaces, operating systems, programming languages and database systems. The appeal of object-orientation is attributed to its higher levels of abstraction for modeling real world concepts, its support for incremental development and its potential for interoperability. Despite many advances, object-oriented computing is still in its infancy and a universally acceptable definition of an object-oriented data model is virtually nonexistent, although some standardization efforts are underway. This report presents the TIGUKAT(*) object model definition that is the result of an investigation of object-oriented modeling features which are common among earlier proposals, along with some distinctive qualities that extend the power and expressibility of this model beyond others. The literature recognizes two perspectives of an object model: the structural view and the behavioral view. Most object-oriented formalisms have concentrated on one or the other of these two perceptions. The TIGUKAT object model (i) favors formal specifications for both the behavioral and structural components, and (ii) shows an integration of the two components into a complete model definition. Furthermore, the model emphasizes (iii) a clean separation and precise definition of object modeling features which are usually bundled and only intuitively defined in other models, and (iv) a uniform approach to object modeling which encompasses all information, including meta-data, as objects within the primitive definitions. The establishment of a formal object model provides a theoretical foundation from which investigations of other object database features will be pursued. The first of these involves the definition of an object query model with complete calculus and algebra specifications, including an equivalence transformation proof between the two. Based on the query model, object views and view management with update semantics will be examined. The intention is to incorporate very powerful and dynamic object definition and manipulation language features into the model. In parallel with this, a dynamic schema evolution policy will be developed for integrating new types into the model. We are currently in the process of implementing the model presented in this report to establish a workable software base with the long range goal of developing a full-featured object database management system. *TIGUKAT (tee-goo-kat) is a term in the language of the Canadian Inuit people meaning \"objects.\" The Canadian Inuits, commonly known as Eskimos, are native to Canada with an ancestry originating in the Arctic regions of the country. | TRID-ID TR92-14

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    Attribution 3.0 International