检索结果-内蒙古大学图书馆

ZENITH SYSTEM FOR object MANAGEMENT IN DISTRIBUTED MULTIMEDIA DESIGN ENVIRONMENTS

INFORMATION AND SOFTWARE TECHNOLOGY 1992年第7期34卷 427-436页

作者： KEMP, ZP OXBORROW, EA DAVY, MJ LININGTON, PF THEARLE, R BLAIR, GS DARK, P DAVIES, NA MARIANI, JA SNAPE, C UNIV LANCASTER DEPT COMPLANCASTER LA1 4YRENGLAND

The paper describes the Zenith research project, which is being carried out at the Universities of Kent and Lancaster, UK. It is a research prototype of an object management system that is intended to meet the data-management requirements of the next generation of application domains, such as office information systems, integrated project support environments, and geographical information systems. Zenith is designed to provide a flexible and adaptable platform for the management of distributed multimedia objects, on top of which specialized applications can easily be built. The design of the system reflects this goal. The object-management layer provides the high-level abstractions required for managing complex objects, and the base-services layer is responsible for the management of primitive entities stored on conventional and specialized devices, while maintaining appropriate location, media, and other transparencies. The earlier sections of the paper briefly discuss the background to the project, including the context of the Zenith environment and the philosophy that underlies its design. Subsequent sections concentrate on the object model and the object-oriented design of the prototype system architecture. Finally, the current status and implementation issues are presented, followed by some brief concluding remarks.

关键词： DATA MANAGEMENT MULTIMEDIA object MANAGEMENT object MODELS object-oriented database systems DISTRIBUTED systems

来源：评论

学校读者我要写书评

暂无评论

Formal approach to object-oriented databases

引用

Data & Knowledge Engineering 1990年第4期5卷 353-382页

作者： Beeri, Catriel Department of Computer Science The Hebrew University Jerusalem 91904 Israel

object-oriented database systems are the focus of current research and development efforts. Yet, there is no commonly accepted object model, nor is it clear whether such a model can be developed. This paper reports on efforts to develop a formal framework that contains most features found in current object oriented database systems. The framework contains two parts. The first is a structural object model, including concepts such as structured objects, identity, and some form of inheritance. For this model, we explain the distinction between values and (abstracts) objects, describe a system as a directed graph, and discuss declarative languages. The second part deals with higher-order concepts, such as classes and functions as data, methods, and inheritance. This part is a sketch, and leaves many issues unresolved. Throughout the paper, the emphasis is on logic-oriented modeling.

关键词： object-oriented database systems Formal model Declarative languages Higher-order logic Methods

来源：评论

学校读者我要写书评

暂无评论

ON RULES AND INTEGRITY CONSTRAINTS IN database-systems

引用

INFORMATION AND SOFTWARE TECHNOLOGY 1992年第3期34卷 147-158页

作者： LING, TW TEO, PK Department of Information Systems and Computer Science National University of Singapore Lower Kent Ridge Road Singapore 0511

Recently, several researchers have proposed incorporating rules into database systems. These rules typically embody several diverse concepts, e.g., deductive rules, production rules, and authorization rules. However, most systems treat these diverse concepts homogeneously. Their roles are often misunderstood because of this lack of distinction. The paper clarifies the concepts of deductive rules, production rules, authorization rules, and integrity constraints and points out the essential differences between them. A framework for comparison is established. Several problems with current implementations of the rule mechanisms are highlighted. The advantages and disadvantages of each of these concepts and the domains for which they are suitable are also described.

关键词： databaseS database systems RULES CONSTRAINTS object-oriented database systems

来源：评论

学校读者我要写书评

暂无评论

ACCESS SUPPORT RELATIONS - AN INDEXING METHOD FOR object BASES

引用

INFORMATION systems 1992年第2期17卷 117-145页

作者： KEMPER, A MOERKOTTE, G UNIV KARLSRUHE FAK INFORMATW-7500 KARLSRUHEGERMANY

In this work access support relations are introduced as a means for optimizing query processing in object-oriented database systems. The general idea is to maintain separate structures (dissociated from the object representation) to redundantly store those object references that are frequently traversed in database queries. The proposed access support relation technique is no longer restricted to relate an object (tuple) to an atomic value (attribute value) as in conventional indexing. Rather, access support relations relate objects with each other and can span over reference chains which may contain collection-valued components in order to support queries involving path expressions. We present several alternative extensions and decompositions of access support relations for a given path expression, the best of which has to be determined according to the application-specific database usage profile. An analytical performance analysis of access support relations is developed. This analytical cost model is, in particular, used to determine the best access support relation extension and decomposition with respect to specific database configuration and usage characteristics.

关键词： INDEXING ACCESS METHODS ACCESS COST MODEL QUERY OPTIMIZATION object-oriented database systems

来源：评论

学校读者我要写书评

暂无评论

Adaptable pointer swizzling strategies in object bases: design, realization, and quantitative analysis

引用

The VLDB Journal 1995年第3期4.0卷 519-566页

作者： Kemper, Alfons Kossmann, Donald University of Passau Passau D-94030 Germany Department of Computer Science University of Maryland College Park 20742 MD United States

In this article, different techniques for "pointer swizzling" are classified and evaluated for optimizing the access to main-memory resident persistent objects. To speed up the access along inter-object references, the persistent pointers in the form of unique object identifiers (OIDs) are transformed (swizzled) into main-memory pointers (addresses). Pointer swizzling techniques can be divided into two classes: (1) those that allow replacement of swizzled objects from the buffer before the end of an application program, and (2) those that rule out the displacement of swizzled objects. The first class (i.e., techniques that take "precautions" for the replacement of swizzled objects) has not yet been thoroughly investigated. Four different pointer swizzling techniques allowing object replacement are investigated and compared with the performance of an object manager employing no pointer swizzling. The extensive qualitative and quantitative evaluation-only part of which could be presented in this article-demonstrate that there is no one superior pointer swizzling strategy for all application profiles. Therefore, an adaptable object base run-time system is devised that employs the full range of pointer swizzling strategies, depending on the application profile characteristics that are determined by, for example, monitoring in combination with sampling, user specifications, and/or program analysis. © 1995 VLDB Endowment.

关键词： object-oriented database systems performance evaluation Pointer swizzling

来源：评论

学校读者我要写书评

暂无评论

Design, implementation and management of rules in an active database system

Design, implementation and management of rules in an active ...

引用

7th International Conference on database and Expert systems Applications (DEXA 96)

作者： Zimmermann, J Branding, H Buchmann, AP Deutsch, A Geppert, A UNIV ZURICH CH-8057 ZURICH SWITZERLAND

ISBN: (纸本)354061656X

Active database systems must provide efficient support for event detection and rule execution. Large applications that benefit from facilities offered by active database systems require tools for their whole life cycle - otherwise there will be no acceptance of this new database technology. Therefore, we propose to extend the well-known and broadly accepted OMT design methodology to model classes and rules which have to be mapped onto a rule language. Then we present the rule languages of NAGS, SAMOS and REACH and compare them from a user's point of view. To improve the rule management REACH offers the facility to organize rules in so-called rule directories which provide a structured name space like UNIX directories for the storage of files. Then we describe a comprehensive set of commands for rules and rule directories, especially an access control mechanism for rules. Additionally browsers for the rules, the rule triggering graph, and the event history are presented, and finally we show how the triggering of rules within applications can be visualised online in a trace mode.

关键词： active database systems object-oriented database systems modelling of rules software life cycle rule languages tools for rule management access control of rules

来源：评论

学校读者我要写书评

暂无评论

A framework for constraint management in VLSI design database applications

A framework for constraint management in VLSI design databas...

引用

International Conference on Information and Knowledge Engineering (IKE 04)

作者： Asatryan, A Natl Acad Sci Armenia P Sevak 1 Inst Informat & Automat Problems UNICAD CJSC Yerevan Armenia

ISBN: (纸本)1932415270

The paper presents concepts and ideas underlying an approach for constraint management in VLSI design database applications and designs flows. In this approach constraints are defined as scripts of EVA strongly typed scripting language and stored in meta-databases called check catalogue. Interaction of applications with check catalogue is supported by subsystem of DBMS called Checker Frame-work. Checker Frame-work provides facilities for creation, modification and deletion of the constraints and has a several features that enhance the constraint management in database applications.

关键词： consistency constraints object-oriented database systems scripting

来源：评论

学校读者我要写书评

暂无评论

Um modelo para representação de atividades em aplicações de escritórios

Um modelo para representação de atividades em aplicações...

引用

作者： Ruiz, Duncan Dubugras Alcoba

This thesis presents a model for representing activities in office applications that is adequate for the description of the dynamic aspects of such applications. This model has two fundamental concepts, namely activities and office objects. Activity diagrams are used to model office application activities, depicting the flow of office objects, the transformations performed by office agents on those objects, and the decision making eventually involved on these activities. By modeling activities in this way, the dynamics of an application is described respecting the organizational and functional solutions adopted by an enterprise, as well as the assignments and responsibilities of the agents working in the organization. Office objects are complex and may present multimedia characteristics. However, the most striking peculiarity of these objects is the massive standardization of their descriptions, due to either legal or commercial reasons. It is this particularity that distinguishes office objects from objects belonging to other non-conventional application domains. As a consequence, office objects constitute a domain allowing intensive class reuse for modeling office applications. This work assumes that models targeted at representing office applications should have the reuse of office classes as one of their goals. In this thesis, it is considered that the office class library must be supported by an OODBMS and its description environment, independently of the specificity of office applications. Such OODBMS must support multiple inheritance as a description resource. Activity is the main component of the model proposed here. An activity represents the interaction of an agent with an application where office objects can be either created, queried, updated or destroyed, and additionaly be sent to other agents. This interaction between the agent and an application activity is performed in the agent workplace, i.e., in its workstation. The flow of office objects is the

关键词： Automação : Escritórios Information systems Sistemas : Informacao : Escritorios Office information systems Banco : Dados orientados : Objetos Activities Reuse object-oriented database systems Tese

来源：评论

学校读者我要写书评

暂无评论

Extending the ODMG object model with composite objects

引用

ACM SIGPLAN NOTICES 1998年第10期33卷 259-270页

作者： Bertino, E Guerrini, G Univ Milan Dipartimento Sci Informaz I-20135 Milan Italy Univ Genoa Dipartimento Informat & Sci Informaz I-16146 Genoa Italy

In this paper we extend the ODMG object data model with composite objects. A composite object is an object built by aggregating other component objects. Exclusiveness and dependency constraints, as well as referential integrity, can be associated with composition relationships among objects. Our composite object model is developed in the framework of the ODMG object database standard data model, but can be used in both object-oriented and object-relational database systems. In the paper, we propose a language for defining composite objects and we define the semantics of update operations on composite objects.

关键词： object-oriented database systems composite objects integrity constraints data models

来源：评论

学校读者我要写书评

暂无评论

THE O2 SYSTEM

引用

COMMUNICATIONS OF THE ACM 1991年第10期34卷 34-48页

作者： DEUX, O O2 Technology Cedex France

This paper examines the O2 system, an object-oriented database management system with a complete development environment and a set of user interface tools. Three principal objectives of O2 are reviewed: increased productivity of application development, improved quality of the final applications, and availability of better tools to serve the development of new applications. The three main features of O2 are studied as well, the merger of user interfaces, the use of object-oriented technology, and the conformance to standards. The three interfaces, C, C++, and O2 are reviewed. The O2 Look user interface generator, the programming environment, and the O2 engine are also examined.

关键词： object-oriented database systems O2

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：