Design And Implementation Of A Deductive Object-Oriented Database Language

Deductive database and object-oriented database are two important extensions to the traditional database technology. Both of these approaches have significant advantages. But deductive databases only slightly improve the data modeling capacities of relational model and object-oriented databases lack a mathematical foundation. Since the advantages and disadvantages of these two databases are mutually complementary, the study of putting them together would become a trend of development, that is the study of deductive object-oriented database (abbreviated as deductive object database). Advanced database should be capable of managing data, object and knowledge, and deductive object database can just meet all these requirements.The main tasks of this thesis are to explore the means of combining the object-oriented database and the technology of knowledge base, and study the key technologies of implementing the deductive object database system. The thesis furthers these studies from the following aspects:1. Put forward the concepts involved in the data model of the object in a logical environment, whose essentials are object and relationship.2. Under the direction of the theories of data model, devise a new language of the deductive object database, DOOL, which covers most of the concepts proposed in data model, supports the deductive of complex object, inheritance, methods and sets etc., and improve the capacity of manifesting object identity.3. Design and implement a prototype system of deductive object database, SD-DOOD, which is based on SD-DOOL This system supports the key concepts of object-oriented database such as class, class hierarchies, object, attribute, methods, inheritance and encapsulation etc., and also the concepts of the deductive database such as deductive object etc.. Besides, it provides the graphical user interface (GUI), which facilitates user's operations of creating, query and so on.4. All the final results of the system's query operations are obtained through SD-DDBS. The language of the deductive database, however, is based on Datalog and therefore some transform rules are applied to change DOOL program into Datalog. In this way, the minimum fixpoint of DOOL program (Le. value of this program) will be got, and thus the results of query will be obtained. The specific content of transform rules is introduced in details in the diesis.The design of DOOL, the language of the deductive object database, and the implementation of the prototype system based on DOOL are the keys of this diesis.