数据库概念设计自动化工具研究

A Research on Automatic Tool for Conceptual Design of Database

本文介绍了在 IBM-PC 上用 Tubo-Prolog 语言实现的数据库慨念设计的一个自动化工具。该系统根据 D.R.Howe 的数据库慨念设计方法学,通过与用户交互有关数据库概念设计所必需的信息、属性表及受限自然语言表示的企业规则,成功地识别和解决了设计中遇到的联结陷阱危害及语义闭链冗余信息,最终产生出关系数据库的规范表。本系统结合 Prolog 的强有力的知识表达与推理能力,采用一定的专家系统现有技术,较好地解决了设计知识与控制知识的表示和处理,并优化地识别和处理了子类联系与递归类联系的问题。系统中采用扩展的 E—R 模型作为联系现实世界与关系模型的纽带。用户接口采用受控自然语言集合,便于用户使用及描述现实世界的语义信息。使得该工具既是用户友好的,又有很高的自动化程度。文中对自然语言理解作了一点探讨,重点放在受控自然语言理解及概念设计的应用上。

The article features an automatic tool,which is employed to implement the conceptual design of database in Tubo—Prolog language on IBM—PC.It is based on the methodology of the con- ceptual design by D.R.Howe.Using interactive ability with users,it can receive and analyze informa- tion such as lists of attributes and enterprise rules which are expressed by limited natural language. From the information,fan traps and sementic closing chains are sucessful identified and overcome.At last the nomaliged table in BCNF is obtained. With advantages of powerful knowledge expression and reasoning,adaptiog the existed tecknique of expert systems,the tool has solved the problem of expression and manipulation of designing and con- trolling knowledge.The problem of subset and recursive relationship is also solved optionally.In this system,the extend E—R model is used as an association between the real world and relational models. On the other hand,the limited natural language is used as an interface for the user that makes it easier for users to describe the sementic information of the real world.So the tool is friendly with user,and has also a high level of automation. The article puts stress on understanding of the limited nature language and applications of concep- tual design.As for understanding of nature languge a brief discussion has been made only in it.