TIGUKAT: A Uniform Behavioral Objectbase Management System

  • Author(s) / Creator(s)
  • Technical report TR94-06. Object-oriented computing is influencing many areas of computer science, including database systems. Despite many advances, object-oriented computing is still in its infancy and a universally accepted definition of an object-oriented model is virtually nonexistent. In this thesis, the object model, meta-model, query model, dynamic schema evolution policies, and version control of the TIGUKAT(*) objectbase management system are presented. An identifying characteristic of this system is that all components are uniformly modeled as objects with well-defined behavior. This is an important achievement towards advancing database technology because it unifies the components of a database within a single, clean, underlying semantics that can be easily extended to support other database services. The TIGUKAT object model is purely behavioral, supports full encapsulation of objects, defines a clear separation between primitive components, and incorporates a uniform semantics over objects. A behavioral model definition specifies the semantics of objects and this is integrated with a structural model to form a complete model definition. The meta-model is uniformly represented within the object model, giving rise to reflective capabilities. The query model is uniformly defined as type and behavior extensions to the base model, thus incorporating queries and query processing as extensible parts of the model. The complete query model includes a formal object calculus, formal object algebra, a definition of safety based on the evaluable class of queries (arguably the largest class of \"reasonable\" queries), proofs of completeness, and an effective algorithmic translation from the calculus to algebra. Dynamic schema evolution is a necessary feature that allows for the timely change of information and for restructuring the schema of an objectbase. Since everything is uniform, the schema evolution policies are simply behavior extensions to the base model. Temporality is incorporated to support versioning of objects and of schema. It is also used to maintain the semantic consistency of evolving behaviors. This research leads toward the development of an extensible query optimizer, view manager, and transaction manager as uniformly integrated components of the system. This fulfills the typical gamut of database services. Temporal extensions and a seamlessly integrated database programming language are other components that this research supports. --- *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 TR94-06

  • Date created
  • Subjects / Keywords
  • Type of Item
  • DOI
  • License
    Attribution 3.0 International