面向对象数据库设计的研究

结合一个的实例－商业ＭＩＳ框架设计辅助专家系统（ＦＧＳＭ），提出一种面向对象数据库设计的方法。着重介绍了如何利用对象的封装技术和消息。用链表的形式来实现数据库的设计，并在文中按照Ｃ＋＋语法规划给出了具体的实现方法。     

基于面向对象的数据库设计研究

随着科学技术的飞速发展,数据库技术如今已经步入第三代,即面向对象数据库,与前两代数据库相比,面向对象数据库有着非常明显的优势,虽然其并没有非常高深的技术方法,但面向对象数据库的设计方法却很有价值。本文便以数据库设计以及面向对象数据库的概述为研究基点,分析面向对象数据库的主要特点,并研究在数据库中应用面向对象技术的主要方式,最后讨论面向对象数据库的未来发展。     

一种面向对象的数据库设计方法

数据库设计在管理信息系统(MIS)的分析、设计和开发中占据非常重要的地位。本文通过分析大型MIS环境下数据的特点,深入研究国内外有关数据库设计方法,结合铁道部昆明机械厂初步设计和详细设计的工作,提出一种基于面向对象的数据库设计方法。     

一种面向对象数据库应用系统的设计

面向对象方法以其自身清晰，自然的风格在软件开发的各个层次已得到广泛应用，它和数据库的结合是满足数据库系统新需求的有效方法。     

面向对象数据库设计方法

传统需求分析采用数据流图方法,数据库设计则采用Ｅ－Ｒ方法,这两种方法本质上是相分离的。面向对象数据库设计讲在面向对象需求分析基础上将对象模型向数据库结构进行转化的方法。     

基于面向对象数据库模式设计的研究

面向对象数据库系统是为了满足新的数据库应用而产生的新一代数据库系统,通过设计面向对象数据库的理论概念和含义来构建一个面向对象的数据库系统的理论体系,而面向对象数据库的模式设计方法又显得尤为重要,它是在E-R模型的基础上加入面向对象程序设计思想的继承、构成、消息传递、方法等成分后进行的改进,产生了较为规范的根据需求生成扩展的E-R模型和数据结构方法,在设计过程中包括概念提取,概念分析,确定概念模型等,还包括消息传递和联系的实现方法,以及拥有实例的确定法则,实例对方法的可行性检验方法等。     

面向对象理论在PowerBuilderl中的应用

本文概述了面向对象的基本理论,并阐明了它在流行的客户机／服务器开发环境ＰｏｗｅｒＢｕｉｌｄｅｒ中的具体体现和应用情况。     

面向对象数据库原理在工程CAD中的应用

为了解决工程CAD系统中数据处理效率低的问题及方便工程CAD软件的开发维护,本文采用面向对象的编程语言,提出了把不同工程对象定向于面向对象的工程数据库管理系统中,该技术在工程CAD的应用中有很大的实用价值。本文以一个工程CAD系统为例子进行了论述。     

面向对象的视频数据库设计

本文提出了一种面向对象的视频数据建模的新思想，并给出了将该模型映射到关系数据库概念模式的方法。     

Oracle工程数据库中的面向对象设计技术

数据库技术在工程领域的应用越来越广泛。同传统数据库比较，对工程数据库则有许多新的要求，如能够完成强大的建模能力和高效的面向对象的处理能力，能满足网络化和实时分布式处理能力。结合面向对象技术的关系数据库是对传统事务处理数据库的扩展，利用面向对象技术建立数据库的模型。可以在满足工程数据库的要求基础上减少创建应用的过程，是下一代数据库的一个研究方向。以主流数据库Oracle 8i为主，讨论了面向对象的技术特点，最后以实际工程数据库的对象建模为例作了阐述。     

Introduction to object-oriented databases

The object-oriented approach is being used in several areas of computing, including programming, databases, computer-aided design, and office information systems. The paper is a tutorial introduction to object-oriented databases, which is a new application in this field, although object-oriented programming has been under development since the late 1960s. The paper describes the background to object-oriented databases and outlines the rationale for this approach. It concludes with a possible application, in this case a cartographic database, explaining why the object-oriented approach is more appropriate to this application than traditional database approaches, such as the relational approach.     

Approaches to deductive object-oriented databases

The paper is concerned with the problem of combining deductive and object-oriented features to produce a deductive object-oriented database system which is comparable to those currently available under the relational view of data modelling not only in its functionality but also in the techniques employed in its construction and use. Under this assumption, the kinds of issues that have to be tackled for a similar research strategy to produce comparable results are highlighted. The authors motivate their terms of comparison, characterize three broad approaches to deductive object-oriented databases and introduce the notion of language convergence to help in the characterization of some shortcomings that have been perceived in them. Three proposals that have come to light in the past three years are looked into in some detail, in so far as they exemplify some of the positions in the space of choices defined. The main contribution of the paper is towards a characterization of the language convergence property of deductive database languages which has a key role in addressing critiques of the deductive and object-oriented database research enterprise. A basic familiarity with notions from deductive databases and from object-oriented databases is assumed.     

Supporting production rules using ECA rules in an object-oriented context

This paper presents an approach to implementing production rules for object-oriented databases (OODBs). The approach builds upon earlier work on production rule algorithms for relational databases, and exploits fundamental differences in the structuring mechanisms employed by OODBs. An implementation is described whereby the production rules are mapped onto eventcondition action rules for execution. It is shown how the resulting implementation has minimal space overheads, and a time performance close to that of the widely used TREAT algorithm which uses significantly more space.     

面向对象在数据库设计中的应用

主要探索一种将面向对象分析应用到数据库系统设计的方法，利用此方法实现一个管理系统。这一方法是把类的整体与部分关系、一般与特殊关系和实例连接应用到数据库设计中。此方法利用了数据库的基本且简单的功能，因而适应性强，可靠性高。     

A Reasoning Mechanism for DeductiveObject-Oriented Databases

Based on the approach implementing a deductive object-oriented database system through the underlying relational database,this paper presents and object reasoning language O-Datalog,which is the extension of Datalog in form and can deal with object-oriented data.For any O-Datalog program,an dquivalent Datalog program can be built to help evaluate the original program.This paper focuses on the syntax,semantics and evaluation of O-Datalog.     

Views as first-class citizens in object-oriented databases

Extensibility and dynamic schema evolution are among the attractive features that lead to the wide acceptance of the object-oriented paradigm. Not knowing all class hierarchy details should not prevent a user from introducing new classes when necessary. Naive or professional users may define new classes either by using class definition constructs or as views. However, improper placement of such classes leads to a flat hierarchy with many things duplicated. To overcome this problem, we automated the process in order to help the user find the most appropriate position with respect to her class in the hierarchy regardless of her knowledge of the hierarchy. The system must be responsible for the proper placement of new classes because only the system has complete knowledge of the details of the class hierarchy, especially in a dynamic environment where changes are very frequent. In other published work, we proved that to define a view it is enough to have the set of objects that qualify to be in a view in addition to having message expressions (possible paths) that lead to desired values within those objects. Here, we go further to map a view that is intended to be persistent into a class. Then we investigate the proper position of that class in the hierarchy. To achieve this, we consider current characteristics of a new class in order to derive its relationship with other existing classes in the hierarchy. Another advantage of the presented model is that views that generate new objects are still updatable simply because we based the creation of new objects on existing identities. In other words, an object participates inside view objects by its identity regardless of which particular values from that object are of interest to the view. Values are reachable via message expressions, not violating encapsulation. This way, actual values are present in only one place and can be updated.Received: 19 March 1999, Accepted: 26 December 2003, Published online: 8 April 2004Edited by: R. Topor.     

基于并不可约元的面向对象概念格的属性约简

概念格的属性约简是知识处理的重要研究问题之一。提出了一种面向对象概念格的属性约简方法。首先介绍了求面向对象概念格中并不可约元的方法,进而给出了面向对象概念格的并不可约元的外延集与面向对象概念格的协调集和约简集之间的关系,在此基础上,给出面向对象概念格的属性特征、并不可约元的外延集、属性等价类三者间的关系,最后利用这三者间的关系给出了面向对象概念格的约简集的构造。     

Object data MODEL = object-oriented + semantic models

The term ‘object-oriented database’ has been used to refer to different characteristics and mechanisms supported by semantic databases and (behaviorally) object-oriented ones. While this indicates the current confusion due to the lack of a common model, it also suggests the potential desirability of combining these two kinds of modeling facilities into the same nutshell. This paper summarizes from these two paradigms the features common to both, the features influenced/adopted by each other, and the features which are presented in one paradigm but missing from the other. After a brief analysis and discussion of these features, we conclude this paper by proposing our major theme: a complete object data model should take the union of the facilities offered by these two kinds of models.     

A framework for object migration in object-oriented databases

This article presents a framework developed for accomodating various object migrations in ‘statically-typed’ object databases. Requirements for supporting object migrations are stipulated, and a conceptual model for describing and facilitating different kinds of migrations is described. Associated issues of controlling such migrations are then addressed, along with an initial investigation on the interence of implied migration paths and the completeness of migration operators. Some guidelines are then given to help users conduct migrations more effectively. An implementation prototype on top of an object-oriented database system was built, which embodies full support of all migration types specified in the migration model.