CAD^2B—一个计算机辅助数据库设计系统

本文介绍了一个用Ｔｕｒｂｏ Ｃ语言在ＡＳＴ－２８６机器上实现的计算机辅助数据库设计系统ＣＡＤ＾２Ｂ。该系统提供了人机交互的环境，供设计者进行概念模型设计，并自动完成从概念模型逻辑模型的映射，创建满足规范化要求的关系表。该系统采用的概念模型是引入了事件和时间的扩展了的实体关系模型。该模型既能充分反映应用环境的静态和动态语义，又是向关系模式转化的基础。     

A conceptual schema-based temporal meta database schemas generation technique for 3D objects

In this paper, a temporal meta database for three-dimensional (3D) objects whose properties and relationships are supported by valid time is introduced. Based on our proposed temporal object-oriented conceptual schema model, a conceptual schema of the temporal meta database can be generated from a 3D graphical data source and other particular application requirements. Based on our proposed temporal object relational data model with attribute timestamping, logical schemas of the temporal meta database can be systematically and automatically generated from the conceptual schema. From the temporal meta database, non-temporal/temporal metadata about temporal 3D objects are available for temporal information system users. Convenient access using database languages such as SQL can be performed. Queries over 3D objects using a temporal object relational SQL are demonstrated.     

The MIEL system: Uniform interrogation of structured and weakly-structured imprecise data

We present an information system developed to help assessing the microbiological risk in food. That information system contains experimental results in microbiology, mainly extracted from scientific publications. The increasing amount of the experimental results available and the difficulty to integrate them into a classic relational database schema led us to design a system composed of two distinct subsystems queried through a common interface. The first subsystem is a classic relational database. The second subsystem is a database containing weakly-structured pieces of information expressed in terms of conceptual graphs. The data stored in both bases can be fuzzy ones in order to take into account the specificities of the biological information. The uniform query language used on both relational database and conceptual graph database allows the users to express preferences by using fuzzy sets in their queries. The MIEL system is now operational and used by the microbiologists involved in the Sym’Previus French project.     

Mapping Considerations in the Design of Schemas for the Relational Model

The typical design process for the relational database model develops the conceptual schema and each of the external schemas separately and independently from each other. This paper proposes a new design methodology that constructs the conceptual schema in such a way that overlappings among external schemas are reflected. If the overlappings of external schemas do not produce transitivity at the conceptual level, then with our design method, the relations in the external schemas can be realized as a join over independent components. Thus, a one-to-one function can be defined for the mapping between tuples in the external schemas to tuples in the conceptual schema. If transitivity is produced, then we show that no such function is possible and a new technique is introduced to handle this special case.     

Translation of fuzzy queries for relational database system

The concept of a database skeleton which reflects both the user's conception of the real world and the system's understanding of the interrelationships among database entities is described. It consists of a conceptual schema (conceptual graphs) and a relational schema (information graph). With the aid of the database skeleton, fuzzy queries can be translated and disambiguated by analyzing the queries using the conceptual graphs of a database skeleton. The query language XQL is introduced, and the XQL translator is described in some detail.     

Translating relational schema into XML schema definition with data semantic preservation and XSD graph

Many legacy systems have been created by using relational database operating not for the Internet expression. Since the relational database is not an efficient way for data explosion, electronic transfer of data, and electronic business on the Web, we introduce a methodology in which a relational schema will be translated to an Extensible Markup Language (XML) schema definition for creating an XML database that is a simple and efficient format on the Web. We apply the Indirect Schema Translation Method that is a semantic-based methodology in this project. The mechanism is that the Relational Schema will be translated into the conceptual model, an Extended Entity Relationship (EER) Model using Reverse Engineering. Afterward, the EER model will be mapped to an XML Schema Definition Language (XSD) Graph as an XML conceptual schema using Semantic Transformation. Finally, the XSD Graph will be mapped into the XSD as an XML logical schema in the process of Forward Engineering, and the data semantics of participation, cardinality, generalization, aggregation, categorization, N-ary and U-ary relationship are preserved in the translated XML schema definition.     

数据库逻辑设计中消除规范化处理问题

关系数据库设计要求规范化处理的过程以消除数据冗余和更新异常问题. 范式化理论的算法与数据依赖有着直接的联系, 数据依赖中最重要的是函数依赖, 识别该依赖既耗时又复杂. 讨论如何在采用ER模型的数据库逻辑设计步骤中消除规范化处理过程, 在概念结构设计过程中遵循一组规则将产生满足3NF范式的初始关系模式集, 以节省数据库设计者在导出初始关系模式集后的规范化处理步骤.     

Database reverse engineering: From the relational to the binary relationship model

This paper describes an algorithmic method for transforming a relational database schema to a binary-relationship one. The source schema may consist of relations that are at any level of normalization, and the designer may add semantic information on the source schema, such as the definition of candidate keys, foreign keys, functional dependencies of various types, multi-valued dependencies, many-to-many constraints, inclusion dependencies, and others. Based on this information, the multi-stage transformation algorithm applies mapping rules to generate object-types, binary-relationships and constraints in the target conceptual schema. The method is implemented as a PC-based tool, utilizing Ingres, SQL and C, and is part of a comprehensive database design tool for both forward and reverse engineering.     

A Methodological Approach for Object-Relational Database Design using UML

The most common way of designing databases is by means of a conceptual model, such as E/R, without taking into account other views of the system. New object-oriented design languages, such as UML (Unified Modelling Language), allow the whole system, including the database schema, to be modelled in a uniform way. Moreover, as UML is an extendable language, it allows for any necessary introduction of new stereotypes for specific applications. Proposals exist to extend UML with stereotypes for database design but, unfortunately, they are focused on relational databases. However, new applications require complex objects to be represented in complex relationships, object-relational databases being more appropriate for these requirements. The framework of this paper is an Object-Relational Database Design Methodology, which defines new UML stereotypes for Object-Relational Database Design and proposes some guidelines to translate a UML conceptual schema into an object-relational schema. The guidelines are based on the SQL:1999 object-relational model and on Oracle8i as a product example. Initial submission: 22 January 2002 / Revised submission: 10 June 2002 Published online: 7 January 2003 This paper is a revised and extended version of Extending UML for Object-Relational Database Design, presented in the UML’2001 conference [17].     

智能化图象数据库系统的GBASE的模式设计

知识化图象数据库系统近年来引起了人们的研究兴趣,表现出了广泛的应用前景.本文 介绍一种知识化图象数据库管理系统GBASE的模式设计,它将传统的关系模式加以扩充,使 之能容许框架知识表达的抽象数据类型(ADTs),增强了关系数据库系统的语义描述能力,有 助于表达有关图象实体以及它们之间的空间关系等有关知识.利用ADT我们可以进行知识 引导下的数据库查询、图象实体空间关系的推理以及基于应用模型的辅助设计和规划.GBASE 系统是在VAX11/750机上在VMS操作系统下,以C语言完成的.它统一管理着多种类型 的信息,即关系数据、图形、图象数据、知识以及过程等,是一个综合的图象数据库管理系统. 目前正应用于林业资源的管理和规划.     

ADDS: A system for automatic database schema design based on the binary-relationship model

This paper presents the system ADDS that has been developed to assist the database designer designing a database schema. A distinction is made between the stage of information structure analysis in which the information structure of the system is defined according to its user information needs, and the stage of database schema design in which the record types of the database and the relationships between them are defined. In the first stage a conceptual schema is obtained, represented as an information structure diagram (ISD), and in the later stage the ISD is used to derive the database schema in the form of a data structure diagram (DSD).ADDS automatically creates the database schema out of a conceptual schema which is expressed as an ISD of the binary-relationship data mode. The resulting schema consists of normalized record types, according to the relation model, along with hierarchical/set relationships between ‘owner’ and ‘member’ record types, as in the CODASYL/Network model. ADDS applies algorithms to convert the conceptual schema into the database schema. It is implemented on a micro-computer under MS-DOS using dBASE III.     

SEAM: A state-entity-activity-model for a well-defined workflowdevelopment methodology

Current conceptual workflow models use either informally defined conceptual models or several formally defined conceptual models that capture different aspects of the workflow, e.g., the data, process, and organizational aspects of the workflow. To the best of our knowledge, there are no algorithms that can amalgamate these models to yield a single view of reality. A fragmented conceptual view is useful for systems analysis and documentation. However, it fails to realize the potential of conceptual models to provide a convenient interface to automate the design and management of workflows. First, as a step toward accomplishing this objective, we propose SEAM (State-Entity-Activity-Model), a conceptual workflow model defined in terms of set theory. Second, no attempt has been made, to the best of our knowledge, to incorporate time into a conceptual workflow model. SEAM incorporates the temporal aspect of workflows. Third, we apply SEAM to a real-life organizational unit's workflows. In this work, we show a subset of the workflows modeled for this organization using SEAM. We also demonstrate, via a prototype application, how the SEAM schema can be implemented on a relational database management system. We present the lessons we learned about the advantages obtained for the organization and, for developers who choose to use SEAM, we also present potential pitfalls in using the SEAM methodology to build workflow systems on relational platforms. The information contained in this work is sufficient enough to allow application developers to utilize SEAM as a methodology to analyze, design, and construct workflow applications on current relational database management systems. The definition of SEAM as a context-free grammar, definition of its semantics, and its mapping to relational platforms should be sufficient also, to allow the construction of an automated workflow design and construction tool with SEAM as the user interface     

一种关系模式到OWL DL本体的翻译方法

本体技术是数据可以达到语义层次交换的关键,如何将当前各类数据形成本体知识库表示是一个非常重要的问题。针对这个问题,以一种关系模式到一种语义扩展ER模型的正确性可满足转换算法为基础,提出了一种通过数据库反向工程到OWL DL本体的翻译算法,说明了该算法使得转换是正确性可满足的,并实验实现验证了算法。     

Automated Query Formulation Using an Entity–Relationship Conceptual Schema

Significant effort is expended in developing a high-level conceptual schema for a relational database. However, criticalknowledge is often discarded when the conceptual schema is mapped to aset of relation schemas. As a result, designers and users must employsparser logical-level knowledge to access data. Unfortunately, naiveusers do not possess the detailed logical-level knowledge required toformulate queries corresponding to ad hoc requests. Auniversal relation interface can shield users from underlyingdesign details. However, most universal relation systems have beenbased on abstractions not typically used by database designers.Consequently, the usefulness of these interfaces has been limited.This article demonstrates how an Entity-Relationship (ER) conceptualschema can be used by a high-level interface to formulate queriesautomatically. The notion of contextsis introduced to describethe segmentation of an ER conceptual schema into overlapping subgraphsthat correspond to sets of relations that can be joined in a losslessmanner. Given a set of contexts, natural join query formulation isstraightforward. As demonstrated with a case study using theprototype QUICK system, the techniques presented facilitate theconstruction of high-level, intelligent interfaces.     

An approach to developing complex database schemas using form types

In this paper we consider an approach to developing complex database schemas. Apart from the theoretical model of the approach, we also developed a CASE tool named Integrated Information Systems*Case, R.6.2 (IIS*Case) that supports the practical application of the approach. In this paper the basis of our approach to the design and integration of database schemas and ways of using IIS*Case is outlined. The main features of a new version of IIS*Case, developed in Java, are described. IIS*Case is based on the concept of ‘form type’ and supports the conceptual modelling of a database schema, generating subschemas and integrating them into a relational database schema in 3NF. IIS*Case provides an intelligent support for complex and highly formalized design and programming tasks. Having an advanced knowledge of information systems and database design is not a compulsory prerequisite for using IIS*Case. IIS*Case is based on a methodology of gradual integration of independently designed subschemas into a database schema. The process of independent subschema design may lead to collisions in expressing real‐world constraints. IIS*Case uses specialized algorithms for checking the consistency of constraints embedded in a database schema and its subschemas. This paper briefly outlines the application of the process of detecting collisions, and actions the designer may take to resolve them. Copyright © 2007 John Wiley & Sons, Ltd.     

Constraint Preserving Transformation from Relational Schema to XML Schema

XML has become the standard for publishing and exchanging data on the Web. However, most business data is managed and will remain to be managed by relational database management systems. As such, there is an increasing need to efficiently and accurately publish relational data as XML documents for Internet-based applications. One way to publish relational data is to provide virtual XML documents for relational data via an XML schema which is transformed from the underlying relational database schema such that users can access the relational database through the XML schema. In this paper, we discuss issues in transforming a relational database schema into the corresponding XML schema. We aim to preserve all integrity constraints defined in a relational database schema, to achieve high level of nesting and to avoid introducing data redundancy in the transformed XML schema. In the paper, we first propose a basic transformation algorithm which introduces no data redundancy, then we improve the algorithm by exploring further nesting of the transformed XML schema.     

OWL本体到关系数据库模式的映射

通过对现有本体存储模式的分析,以及对OWl本体和关系数据库模式之间的概念对应关系的分析,定义了从OWL本体到关系数据库模式的转换规则,给出了OWL本体存储模式的设计原则,并基于该原则提出了一种新的本体存储模式.针对本体描述语言OWL的构词特点,该模式提出将本体中的语义信息存放在不同的表中,以达到方便理解、结构稳定和提高效率的目的,适应于多数中小型本体的存储.     

UML动态模型在关系数据库操作中的应用

UML作为一种面向对象的标准建模语言,在关系数据库系统的建模领域也得到了广泛的应用.用UML为关系数据库模式建立的模型比ER模型表达力更强,但目前的UML数据库建模技术主要强调静态模型.概述了如何使用UML动态建模方法为关系数据库操作建模.在建立的框架的基础上可为原子数据库操作建模,进而为更复杂的数据库操作建模.这种方法将为用户和开发者提供对整个系统的一个统一视角,将UML的强大功能扩展到数据库领域.