Design and Implementation of the Nested Relational Data Model under the Exodus Extensible Database System.

摘要

The problem addressed in this thesis effort concerns the design and implementation of the nested relational data model. The data model is designed within the Exodus extensible architecture. Although a large amount of theory exists with the model, no vehicle has been available to implement the concepts. The objective of the model is to increase performance of non-traditional databases by modeling real-world objects in the problem domain into nested relations within the software domain of Exodus. Exodus is used to implement several components essential to the data model. First, the concept of nested relations is realized, and then a parser is developed to create and maintain a data dictionary. The Colby relational algebra is used to form the query tree for the query optimizer, and a plan tree permits the code to be generated for the query. Operator methods are developed for the query to be subsequently executed. The nested relational data model was implemented using the Exodus architecture. The query tree was built and the code generated for the architecture's compiler. Operator methods were implemented for the project, select, and natural join operators. Because the data model can be implemented, more non-traditional databases can be developed with efficient components. (KT)