With the growing importance of privacy in data access, much research has been done on the privacy protecting technology in the recent years. Developing an access control model and related mechanisms to support a selec...
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With the growing importance of privacy in data access, much research has been done on the privacy protecting technology in the recent years. Developing an access control model and related mechanisms to support a selective access data has become important. The extensible markup language (xml) is rapidly emerging as the new standard language for semi-structured data representation and exchange on the Internet with more and more information being distributed in xml format. In this paper, we present a comprehensive approach for privacy preserving access control based on the notion of purpose. In our model, purpose information associated with a given data element in an xml document specifies the intended use of the data elements. An important issue addressed in this paper is the granularity of data labeling for data elements in xml documents and tree databases with which purposes can be associated. We address this issue in native xml databases and propose different labeling schemes for xml documents. We also propose an approach to represent purpose information to support access control based on purpose information. Our proposed solution relies on usage access control models as well as the components that are based on the notions of the purpose information used in subjects and objects. Finally, comparisons with related works are analysed. Copyright (c) 2011 John Wiley & Sons, Ltd.
The advent of Big Data created a need for out-of-the-box horizontal scalability for data management systems. This ushered in an array of choices for Big Data management under the umbrella term NoSQL. In this paper, we...
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ISBN:
(纸本)9781479950690
The advent of Big Data created a need for out-of-the-box horizontal scalability for data management systems. This ushered in an array of choices for Big Data management under the umbrella term NoSQL. In this paper, we provide a taxonomy and unified perspective on NoSQL systems. Using this perspective, we compare and contrast various NoSQL systems using multiple facets including system architecture, data model, query language, client API, scalability, and availability. We group current NoSQL systems into seven broad categories: Key-Value, Table-type/Column, Document, Graph, nativexml, native Object, and Hybrid databases. We also describe application scenarios for each category to help the reader in choosing an appropriate NoSQL system for a given application. We conclude the paper by indicating future research directions.
native xml databases (NXD) are called to play a crucial role in the near future. The experience with relational databases shows that standard methods for accessing and manipulating databases are necessary if wide acce...
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ISBN:
(纸本)9789898111814
native xml databases (NXD) are called to play a crucial role in the near future. The experience with relational databases shows that standard methods for accessing and manipulating databases are necessary if wide acceptance of these database systems is to be expected in information systems whose applications should access databases preferably through standard APIs. In this paper, the current state of APIs that provide standard access to NXD, standard query languages and standard methods for document update and access control are analyzed from the perspective acquired with our experience using NXD in information systems. Our conclusions show the weak points which still need to be improved as compared with relational databases.
xml fi les are ideal for describing semi structured data. The advent of native xml databases has enhanced storage of a large number of xml fi les preserving the hierarchical format. The challenge is to serve and acces...
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ISBN:
(纸本)9781450314404
xml fi les are ideal for describing semi structured data. The advent of native xml databases has enhanced storage of a large number of xml fi les preserving the hierarchical format. The challenge is to serve and access xml data from geographically distributed native xml databases. In this paper, we discuss the modus operandi for insertion and querying of data in a location transparent manner in decentralised networks. We present the design for a cluster based architecture where query processingF is achieved using distributed hash tables. A bulk insertion method has been employed for insertion of xml data. The proposed design was implemented on eXist-db, a nativexml database engine. Experiments were conducted and the effectiveness of the proposed design was evaluated.
The introduction of native xml databases opens many research questions related to the data models used to represent and manipulate data, including temporal data, in xml. Increasing use of xml for Valid Web pages warra...
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ISBN:
(纸本)9781920682316
The introduction of native xml databases opens many research questions related to the data models used to represent and manipulate data, including temporal data, in xml. Increasing use of xml for Valid Web pages warrants an adequate treatment of now in native xml databases. In this study, we examined how to represent and manipulate now-relative temporal data. We identify different approaches being used to represent current time in xml temporal databases, and introduce the notion of storing variables such as 'now' or 'UC' as strings in xmlnativedatabases. All approaches are empirically evaluated on a query that time-slices the timeline at the current time. The experimental results indicate that the proposed extension offers several advantages over other approaches: better semantics, less storage space and better response time.
Much research work has recently focused on the problem of representing historical information in xml. In this paper, we describe an ongoing work to represent xml changes. Our model is a three-dimensional xml-based mod...
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ISBN:
(数字)9783540775669
ISBN:
(纸本)9783540775652
Much research work has recently focused on the problem of representing historical information in xml. In this paper, we describe an ongoing work to represent xml changes. Our model is a three-dimensional xml-based model (3D_xml in short) for representing and querying histories of xml documents. The proposed model incorporates three time dimensions, valid time, transaction time, and efficacy time without extending the syntax of xml. We use XQuery to express complex temporal queries on the evolution of the document contents. We believe that native xml databases (NXDs) present a viable alternative to relational temporal databases when complex time dependent data has to be manipulated and stored. So NXDs will be our choice.
Real-world information including subjective opinions and judgments need imprecise data to be modeled for representation and querying in databases. The Extensible Markup Language (xml) has become a de-facto standard fo...
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Real-world information including subjective opinions and judgments need imprecise data to be modeled for representation and querying in databases. The Extensible Markup Language (xml) has become a de-facto standard for data modeling and exchange in recent years. Efforts on modeling imprecision and representing such data in xml have not been fully developed. In this paper, an xml based fuzzy data representation and querying system is presented. Complex and imprecise data are represented using a fuzzy extension of xml. The representation forms the basis for a system which enables fuzzy querying on xml documents using XQuery, a xml query language. The system also enables restructuring of xml Schemas through merging of elements of the xml documents. By using this feature of the system, application specific xml Schema and xml documents can be generated from the existing documents.
Program traces can be used to drive visualisations of reusable components, but such traces can be gigabytes in size, are very expensive to generate, and are hard to extract information from. We have developed a soluti...
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ISBN:
(纸本)9781920682170
Program traces can be used to drive visualisations of reusable components, but such traces can be gigabytes in size, are very expensive to generate, and are hard to extract information from. We have developed a solution to this problem, an xml Data Storage Environment (XDSE) for storing xml based program traces in a nativexml database. We use XQuery to extract information from the program traces and the results are then transformed into understandable visualisations.
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