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1.
基于Schema路径分析的XML数据库存储策略   总被引:2,自引:0,他引:2  
朱震  左春 《计算机科学》2003,30(8):69-72
With XML standards playing more and more important role at information exchanges in data management,the XML database storing strategy which supports huge amount XML data control from bottom layer of database has become the key part of fields such as content management. This article proposes an efficiently XML storing strategy from the perspective of constraint schema of XML instance based on XML Schema path analysis.  相似文献   

2.
Secure XML query answering to protect data privacy and semantic cache to speed up XML query answering are two hot spots in current research areas of XML database systems. While both issues are explored respectively in depth,they have not been studied together,that is,the problem of semantic cache for secure XML query answering has not been addressed yet. In this paper,we present an interesting joint of these two aspects and propose an efficient framework of semantic cache for secure XML query answering,which can improve the performance of XML database systems under secure circumstances. Our framework combines access control,user privilege management over XML data and the state-of-the-art semantic XML query cache techniques,to ensure that data are presented only to authorized users in an efficient way. To the best of our knowledge,the approach we propose here is among the first beneficial efforts in a novel perspective of combining caching and security for XML database to improve system performance. The efficiency of our framework is verified by comprehensive experiments.  相似文献   

3.
For a large-scale palmprint identification system,it is necessary to speed up the identification process to reduce the response time and also to have a high rate of identification accuracy.In this paper,we propose a novel hashing-based technique called orientation field code hashing for fast palmprint identification.By investigating hashing-based algorithms,we first propose a double-orientation encoding method to eliminate the instability of orientation codes and make the orientation codes more reasonable.Secondly,we propose a window-based feature measurement for rapid searching of the target.We explore the influence of parameters related to hashing-based palmprint identification.We have carried out a number of experiments on the Hong Kong Poly U large-scale database and the CASIA palmprint database plus a synthetic database.The results show that on the Hong Kong Poly U large-scale database,the proposed method is about 1.5 times faster than the state-of-the-art ones,while achieves the comparable identification accuracy.On the CASIA database plus the synthetic database,the proposed method also achieves a better performance on identification speed.  相似文献   

4.
Preface          下载免费PDF全文
Recent advances in database related applications propose many new challenges and have inspired database researchers and practitioners to further make their efforts on new database technologies. Currently, there are many related ongoing research fields, such as XML databases, data mining, data warehouses, data streams, database integration, moving object management, bioinformatics, peer-to-peer data systems and so on. In order to promptly reflect the advances and trends in the emerging fields, the Journal of Computer Science and Technology (JCST) decided to publish a special issue on new database technologies.  相似文献   

5.
Accomplishing Deterministic XML Query Optimization   总被引:1,自引:1,他引:0       下载免费PDF全文
As the popularity of XML (extensible Markup Language) keeps growing rapidly, the management of XML compliant structured-document databases has become a very interesting and compelling research area. Query optimization for XML structured-documents stands out as one of the most challenging research issues in this area because of the much enlarged optimization (search) space, which is a consequence of the intrinsic complexity of the underlying data model of XML data. We therefore propose to apply deterministic transformations on query expressions to most aggressively prune the search space and fast achieve a sufficiently improved alternative (if not the optimal) for each incoming query expression. This idea is not just exciting but practically attainable. This paper first provides an overview of our optimization strategy, and then focuses on the key implementation issues of our rule-based transformation system for XML query optimization in a database environment. The performance results we obtained from experimentation show that our approach is a valid and effective one.  相似文献   

6.
Fundamentally, semantic grid database is about bringing globally distributed databases together in order to coordinate resource sharing and problem solving in which information is given well-defined meaning, and DartGrid II is the implemented database gird system whose goal is to provide a semantic solution for integrating database resources on the Web. Although many algorithms have been proposed for optimizing query-processing in order to minimize costs and/or response time, associated with obtaining the answer to query in a distributed database system, database grid query optimization problem is fundamentally different from traditional distributed query optimization. These differences are shown to be the consequences of autonomy and heterogeneity of database nodes in database grid. Therefore, more challenges have arisen for query optimization in database grid than traditional distributed database. Following this observation, the design of a query optimizer in DartGrid II is presented, and a heuristic, dynamic and parallel query optimization approach to processing query in database grid is proposed. A set of semantic tools supporting relational database integration and semantic-based information browsing has also been implemented to realize the above vision.  相似文献   

7.
The disk manager of spatial database provides uniform storage and management for spatial data and attribute data in GIS applications.To investigate it will have effect on creating storage manager of spatial database and SDBMS with lore‘‘s property right for our country.This paper investigates and analyzes the Oracele‘‘s spatial data model,and on the basis of it,it puts forward a new method about disk storage of spatial data and has it designed.  相似文献   

8.
郭平  程代杰 《计算机科学》2003,30(11):40-43
As the base of intelligent system, it is very important to guarantee the consistency and non-redundancy of knowledge in knowledge database. Since the variety of knowledge sources, it is necessary to dispose knowledge with redundancy, inclusion and even contradiction during the integration of knowledge database. This paper researches the integration method based on the multi-knowledge database. Firstly, it finds out the inconsistent knowledge sets between the knowledge databases by rough set classification and presents one method eliminating the inconsistency by test data. Then, it regards consistent knowledge sets as the initial population of genetic calculation and constructs a genetic adaptive function based on accuracy, practicability and spreadability of knowledge representation to carry on the genetic calculation. Lastly, classifying the results of genetic calculation reduces the knowledge redundancy of knowledge database. This paper also presents a frameworkfor knowledge database integration based on the rough set classification and genetic algorithm.  相似文献   

9.
A fast face recognition system is proposed in this paper. It implements the feature location and extraction according to the gray-scale characteristic and geometric features of face image, and based on the projection and the proportion relationship of facial features, and implements direct inquiry about face photos in the multimedia database.  相似文献   

10.
软件脆弱性分析   总被引:3,自引:0,他引:3  
Software vulnerability is the root reason that cause computer system security problem. It's a new researchtopic to analyze vulnerability based on the essence of software vulnerability. This paper analyzes the main definitions and taxonomies of vulnerability,studies vulnerability database and tools for vulnerability analysis and detection, and gives the details about what caused the most common vnlnerabilities in the LINUX/UNIX operating systems.  相似文献   

11.
二进制XML浅析   总被引:1,自引:0,他引:1  
随着XML作为数据交换通用语言的成功,关于它能否在注重性能的应用上占有一凡;艺地引起了广泛的关注。首先,比较了文本XML与二进制XML特征,接着比较三种二进制XML编码方式,最后指出进一步的研究方向。  相似文献   

12.
基于XML的中间层交互技术的研究   总被引:1,自引:0,他引:1  
陆剑江 《微机发展》2004,14(8):30-33
由于HTML自身的不足.所以无法适应Web发展的复杂性和多变性,也不利于机器之间的数据交换和信息传递,通过对XML和HTML作多个角度的对比,文中提出将XML作为载体实现Web上的动态交互。首先从XML的自身特点出发,分析了XML驱动下的Web体系结构,从而得出基于XML的中间层交互技术的实现原理.重点研究了如何设计与XML相匹配的Web数据库,用XML查询数据库的实现方法,以及如何构造从XML到数据库的映射关系,具体包括从XIviL的DTD或者Schema出发来设计数据库的结构或者从数据库本身出发来构造与之相适应的DTD或Schema,最后分析了浏览XML格式信息的诸多策略。  相似文献   

13.
首先阐述了由于数据表示方式上的差异,为了使XML和传统数据库之间能够互通信息,必须在XML文档和传统数据库之间建立数据转换机制。然后提出在XML中使用ID/IDREF/IDREFS属性类型针对多元复杂联系的关系数据进行建模的方法。  相似文献   

14.
XML数据库及其应用研究   总被引:32,自引:2,他引:32  
XML正在成为Internet上数据描述和交换的标准,它将代替HTML而成为Web上存放数据的主要格式。XML及其一系列相关的标准已广为接受和使用,为XML成为数据库奠定了基础。文章针对XML数据库研究的现状,介绍了XML数据库的基本概念和相关技术,并对其应用领域和使用方法进行了分析和研究。  相似文献   

15.
汪立  杨华  孙莉 《计算机工程》2002,28(3):99-100,191
围绕怎样实现数据从面向对象数据库(OODB)到XML格式的移植这一问题,介绍了面向对象数据库Jasmine,可扩展标记语言XML和Java,分析了现有的数据从关系数据库到XML的移植机制,并在此基础上提出了详细的Jasmine到XML的解决方法。  相似文献   

16.
黄寿孟 《计算机科学》2016,43(Z11):529-531
随着XML数据库技术研究的深入,关于XML查询优化的研究日益增多,但至今其仍是XML数据库的薄弱环节。从传统的查询估算模型中找出原子操作,在物理优化时通过分析估算操作,采用基于统计学习的方法找出操作代价和这些影响因素之间的函数关系,从而建立起基于代价的操作模型。  相似文献   

17.
XML是连接Web与数据库的桥梁,针对B/S模型的Web数据库存在的不足,提出并构造了基于XML的Web数据库三层体系结构模型,重点介绍中间件的主要代码。  相似文献   

18.
基于RDBMS的XML数据管理技术研究   总被引:1,自引:0,他引:1  
李黎  杨春  吴微 《计算机工程与设计》2007,28(24):6008-6011
XML是一种专门为Internet所设计的标记语言,但是它已逐渐成为Internet上数据表示以及数据交换的标准,是一种发展势头良好的新兴数据管理手段.关系数据库管理系统(RDBMS)是一种技术成熟、应用十分广泛的系统.在数据管理上,XML技术和数据库技术各有优势和不足,XML和数据库结合技术成为学术界的研究热点.在对XML和数据库结合技术进行了研究的基础上一个基于RDBMS的XML数据管理的实现框架(XRM)被提出,该框架依据不同的映射策略,解析Schema文件或DTD,生成对应的关系模式,利用RDBMS存储中间件,使用户能透明地通过RDBMS来管理XML数据.该框架充分考虑了结构的灵活性和扩展性.  相似文献   

19.
路径表达式查询是XML数据查询处理的核心研究问题之一,研究者开展了大量的研究工作.但这些研究更多关注XML数据上路径表达式的匹配,忽略了谓词"包含".研究XML查询处理中谓词"包含"的查询处理方法.采用了两种方法,第一种是采用跳跃表的方法,在XML分枝模式匹配时动态地对结点数据进行读取和关键字匹配.第二种是为XML文档中的词语建立倒排索引,来实现关键字的匹配.并从分枝模式路径长度、查询关键的数量和"包含"谓词判断结点的类型,对两种方法进行了分析和比较.  相似文献   

20.
XML数据存储模式的研究   总被引:5,自引:0,他引:5  
比较和分析了XML数据的逻辑结构以及现有的XML数据存储方式,重点突出了XML数据在数据库中的存储,并分析了这种存储模式的优缺点。  相似文献   

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