(An) expert system with case-based reasoning for database schema design

Abstract

Case-based reasoning (CBR) has emerged as an alternative to rule-based techniques for the design of expert system. Generally, human designers appear to solve design problems not by reasoning from the primitive components available in the design domain, but by adapting the design cases of previously encountered artifacts. In this thesis, we describe an application of case-based reasoning methodology to the development of an expert system for relational database schema design. Instead of maintaining only domain specific knowledge for vesigning a target application database, the proposed system, Design Expert System for Database Schema (DES-DS), relies on a hybrid case-base that consists of a Domain Dependent Case-Base (DDCB) and a Domain Independent Case-Base (DICB). With user``s requirements, the system searches a DDCB for a similar case. If there is one, the system uses it to design a database schema with minimum user``s interaction. When there is no similar case, the system uses cases in DICB to make a new schema in 3rd normal form with more user``s interaction. Whenever a new schema is designed, it is added to the DDCB. For this approach, we propose a relational conceptual graph (RCG) to represent the design specification of users`` and each case in the case-base. For the design using DICB, we propose nine cases for normalizing the user``s requirements and have shown how the DICB can be used to design a database schema, and can guarantee the schema to be in 3rd normal form. For the design using DDCB, we also explain how the DDCB can be used to design a similar application database. We propose the memory organization of DDCB as an abstraction hierarchy, and we identified cases and their features. The strategies for retrieving the relevant cases, for building a rough solution, for repairing the rough solution, and for learning cases are also described. It is also shown how the system works by using an example in designing for university administration applica...