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Article
Publication date: 6 November 2017

Hind Hamrouni, Fabio Grandi and Zouhaier Brahmia

A temporal XML database could become an inconsistent model of the represented reality after a retroactive update. Such an inconsistency state must be repaired by…

96

Abstract

Purpose

A temporal XML database could become an inconsistent model of the represented reality after a retroactive update. Such an inconsistency state must be repaired by performing corrective actions (e.g. payment of arrears after a retroactive salary increase) either immediately (i.e. at inconsistency detection time) or in a deferred manner, at one or several chosen repair times according to application requirements. The purpose of this work is to deal with deferred and multi-step repair of detected data inconsistencies.

Design/methodology/approach

A general approach for deferred and stepwise repair of inconsistencies that result from retroactive updates of currency data (e.g. the salary of an employee) in a valid-time or bitemporal XML database is proposed. The approach separates the inconsistency repairs from the inconsistency detection phase and deals with the execution of corrective actions, which also take into account enterprise’s business rules that define some relationships between data.

Findings

Algorithms, methods and support data structures for deferred and multi-step inconsistency repair of currency data are presented. The feasibility of the approach has been shown through the development and testing of a system prototype, named Deferred-Repair Manager.

Originality/value

The proposed approach implements a new general and flexible strategy for repairing detected inconsistencies in a deferred manner and possibly in multiple steps, according to varying user’s requirements and to specifications which are customary in the real world.

Details

International Journal of Web Information Systems, vol. 13 no. 4
Type: Research Article
ISSN: 1744-0084

Keywords

Article
Publication date: 18 November 2013

Jaroslav Pokorný

This paper considers schemaless XML data stored in a column-oriented storage, particularly in C-store. Axes of the XPath language are studied and a design and analysis of…

Abstract

Purpose

This paper considers schemaless XML data stored in a column-oriented storage, particularly in C-store. Axes of the XPath language are studied and a design and analysis of algorithms for processing the XPath fragment XP{*, //, /} are described in detail. The paper aims to discuss these issues.

Design/methodology/approach

A two-level model of C-store based on XML-enabled relational databases is supposed. The axes of XPath language in this environment have been studied by Cástková and Pokorný. The associated algorithms have been used for the implementation of the XPath fragment XP{*, //, /}.

Findings

The main advantage of this approach is algorithms implementing axes evaluations that are mostly of logarithmic complexity in n, where n is the number of nodes of XML tree associated with an XML document. A low-level memory system enables the estimation of the number of two abstract operations providing an interface to an external memory. The algorithms developed are mostly of logarithmic complexity in n, where n is the number of nodes of XML tree associated with an XML document.

Originality/value

The paper extends the approach of querying XML data stored in a column-oriented storage to the XPath fragment using only child and descendant axes and estimates the complexity of evaluating its queries.

Details

International Journal of Web Information Systems, vol. 9 no. 4
Type: Research Article
ISSN: 1744-0084

Keywords

Article
Publication date: 1 September 2001

James R. Otto, James H. Cook and Q.B. Chung

Explores the use of extensible markup language (XML) to both store and enforce organizational data definitions, thus providing a synergetic framework for leveraging the…

1157

Abstract

Explores the use of extensible markup language (XML) to both store and enforce organizational data definitions, thus providing a synergetic framework for leveraging the potential of knowledge management (KM) tools. XML provides a flexible markup standard for representing data models. KM provides IT processes for capturing, maintaining, and using information. While the processes that comprise KM and the mechanisms that form XML differ greatly in concept, they both deal in a fundamental way with information. XML maintains the context of data (i.e. data model) which enables data to represent information. KM provides the framework for managing this information. Explores the vital role that XML can play to support an efficient corporate KM strategy.

Details

Journal of Knowledge Management, vol. 5 no. 3
Type: Research Article
ISSN: 1367-3270

Keywords

Article
Publication date: 29 August 2008

Darius Hedgebeth

The purpose of this paper is to provide information about the extensible markup language (XML) – its history, function, legacy, and contribution to the world wide web and

Abstract

Purpose

The purpose of this paper is to provide information about the extensible markup language (XML) – its history, function, legacy, and contribution to the world wide web and to the discipline of knowledge management. The knowledge worker will better understand how XML supports the codification aspect of the technology pillar of knowledge management.

Design/methodology/approach

The author gives an overview of markup languages, which preceded XML, details XML syntax structure, and discusses techniques for processing XML data. Derivative markup languages which use XML's syntactical structure are listed, and an exercise explaining the process behind generating XML documents from spreadsheets is provided.

Findings

XML has served as an integral part of the world wide web for over a decade, and enables internet applications to transform and exchange data in a very efficient manner. The codification of knowledge is germane to the KM process, and XML provides a very capable means for warehousing knowledge that can later be retrieved from knowledge repositories and relational databases. Additionally, XML‐like markup languages such as ebXML (electronic business for XML) help improve the effectiveness and efficiency of knowledge organizations.

Originality/value

The paper hightlights how the management and valuation of knowledge assets are greatly facilitated by the functionality offered by XML, which enables a knowledge worker to store and retrieve knowledge artifacts in the form of structured data.

Details

VINE, vol. 38 no. 3
Type: Research Article
ISSN: 0305-5728

Keywords

Article
Publication date: 27 August 2014

Paolo Manghi, Michele Artini, Claudio Atzori, Alessia Bardi, Andrea Mannocci, Sandro La Bruzzo, Leonardo Candela, Donatella Castelli and Pasquale Pagano

The purpose of this paper is to present the architectural principles and the services of the D-NET software toolkit. D-NET is a framework where designers and developers…

Abstract

Purpose

The purpose of this paper is to present the architectural principles and the services of the D-NET software toolkit. D-NET is a framework where designers and developers find the tools for constructing and operating aggregative infrastructures (systems for aggregating data sources with heterogeneous data models and technologies) in a cost-effective way. Designers and developers can select from a variety of D-NET data management services, can configure them to handle data according to given data models, and can construct autonomic workflows to obtain personalized aggregative infrastructures.

Design/methodology/approach

The paper provides a definition of aggregative infrastructures, sketching architecture, and components, as inspired by real-case examples. It then describes the limits of current solutions, which find their lacks in the realization and maintenance costs of such complex software. Finally, it proposes D-NET as an optimal solution for designers and developers willing to realize aggregative infrastructures. The D-NET architecture and services are presented, drawing a parallel with the ones of aggregative infrastructures. Finally, real-cases of D-NET are presented, to show-case the statement above.

Findings

The D-NET software toolkit is a general-purpose service-oriented framework where designers can construct customized, robust, scalable, autonomic aggregative infrastructures in a cost-effective way. D-NET is today adopted by several EC projects, national consortia and communities to create customized infrastructures under diverse application domains, and other organizations are enquiring for or are experimenting its adoption. Its customizability and extendibility make D-NET a suitable candidate for creating aggregative infrastructures mediating between different scientific domains and therefore supporting multi-disciplinary research.

Originality/value

D-NET is the first general-purpose framework of this kind. Other solutions are available in the literature but focus on specific use-cases and therefore suffer from the limited re-use in different contexts. Due to its maturity, D-NET can also be used by third-party organizations, not necessarily involved in the software design and maintenance.

Details

Program, vol. 48 no. 4
Type: Research Article
ISSN: 0033-0337

Keywords

Article
Publication date: 1 June 2002

Art Rhyno

Relational Database Management Systems (RDBMS) have a proven track record for storing and managing many different forms of digital content, and new strategies have been…

1206

Abstract

Relational Database Management Systems (RDBMS) have a proven track record for storing and managing many different forms of digital content, and new strategies have been defined to provide RDBMS‐based solutions for XML. Some relational databases now offer special mechanisms to accommodate XML while several technologies have emerged to facilitate the use of XML representations of data housed within an RDBMS. In addition to presenting challenges and opportunities to RDBMS developers, XML and XML‐enabled technologies may find new application for libraries by combining RDBMS concepts with Web‐based services.

Details

OCLC Systems & Services: International digital library perspectives, vol. 18 no. 2
Type: Research Article
ISSN: 1065-075X

Keywords

Article
Publication date: 1 September 2002

Ioannis Papadakis, Vassileios Karakoidas and Vassileios Chrissikopoulos

This paper presents DocML, a Web‐based digital library of university data. The goal is to build a system capable of preserving and managing student assignments efficiently…

1350

Abstract

This paper presents DocML, a Web‐based digital library of university data. The goal is to build a system capable of preserving and managing student assignments efficiently in a university environment. It is based on a three‐tier architecture that is typical for distributed Web applications. Communication between the layers of the digital library and the architectural components that reside in the middle layer is facilitated through an XML standard. XML is also used for the development of a distributed metadata management system that describes the location and content of the digital library’s documents.

Details

Library Hi Tech, vol. 20 no. 3
Type: Research Article
ISSN: 0737-8831

Keywords

Article
Publication date: 28 August 2009

Jun Wu and Shang‐Yi Huang

The purpose of this paper is to reduce the number of join operations for retrieving Extensible Markup Language (XML) data from a relational database.

Abstract

Purpose

The purpose of this paper is to reduce the number of join operations for retrieving Extensible Markup Language (XML) data from a relational database.

Design/methodology/approach

The paper proposes a new approach to eliminate the join operations for parent‐child traversing and/or sibling searching such that the performance of query processing could be improved. The rationale behind the design of the proposed approach is to distribute the structural information into relational databases.

Findings

The paper finds that the number of join operations which are needed for processing parent‐child traversal and sibling search can be bounded under the proposed approach. It also verifies the capability of the proposed approach by a series of experiments based on the XMark benchmark, for which it has encouraging results.

Research limitations/implications

Compared with previous approaches based on the structure encoding method, the proposed approach needs more space to store additional immediate predecessor's IDs. However, the approach has similar performance to others and it is much easier to implement.

Practical implications

The experimental results show that the performance of the proposed approach is less than 3 per cent of the well‐known MonetDB approach for processing benchmark queries. Moreover, its bulkloading time is much less than that for the MonetDB. There is no doubt that the approach is efficient for accessing XML data with acceptable overheads.

Originality/value

This paper contributes to the implementations of XML database systems.

Details

International Journal of Web Information Systems, vol. 5 no. 3
Type: Research Article
ISSN: 1744-0084

Keywords

Article
Publication date: 23 November 2010

Nils Hoeller, Christoph Reinke, Jana Neumann, Sven Groppe, Christian Werner and Volker Linnemann

In the last decade, XML has become the de facto standard for data exchange in the world wide web (WWW). The positive benefits of data exchangeability to support system and

Abstract

Purpose

In the last decade, XML has become the de facto standard for data exchange in the world wide web (WWW). The positive benefits of data exchangeability to support system and software heterogeneity on application level and easy WWW integration make XML an ideal data format for many other application and network scenarios like wireless sensor networks (WSNs). Moreover, the usage of XML encourages using standardized techniques like SOAP to adapt the service‐oriented paradigm to sensor network engineering. Nevertheless, integrating XML usage in WSN data management is limited by the low hardware resources that require efficient XML data management strategies suitable to bridge the general resource gap. The purpose of this paper is to present two separate strategies on integrating XML data management in WSNs.

Design/methodology/approach

The paper presents two separate strategies on integrating XML data management in WSNs that have been implemented and are running on today's sensor node platforms. The paper shows how XML data can be processed and how XPath queries can be evaluated dynamically. In an extended evaluation, the performance of both strategies concerning the memory and energy efficiency are compared and both solutions are shown to have application domains fully applicable on today's sensor node products.

Findings

This work shows that dynamic XML data management and query evaluation is possible on sensor nodes with strict limitations in terms of memory, processing power and energy supply.

Originality/value

The paper presents an optimized stream‐based XML compression technique and shows how XML queries can be evaluated on compressed XML bit streams using generic pushdown automata. To the best of the authors' knowledge, this is the first complete approach on integrating dynamic XML data management into WSNs.

Details

International Journal of Web Information Systems, vol. 6 no. 4
Type: Research Article
ISSN: 1744-0084

Keywords

Article
Publication date: 19 June 2009

Imam Machdi, Toshiyuki Amagasa and Hiroyuki Kitagawa

The purpose of this paper is to propose Extensible Markup Language (XML) data partitioning schemes that can cope with static and dynamic allocation for parallel holistic…

Abstract

Purpose

The purpose of this paper is to propose Extensible Markup Language (XML) data partitioning schemes that can cope with static and dynamic allocation for parallel holistic twig joins: grid metadata model for XML (GMX) and streams‐based partitioning method for XML (SPX).

Design/methodology/approach

GMX exploits the relationships between XML documents and query patterns to perform workload‐aware partitioning of XML data. Specifically, the paper constructs a two‐dimensional model with a document dimension and a query dimension in which each object in a dimension is composed from XML metadata related to the dimension. GMX provides a set of XML data partitioning methods that include document clustering, query clustering, document‐based refinement, query‐based refinement, and query‐path refinement, thereby enabling XML data partitioning based on the static information of XML metadata. In contrast, SPX explores the structural relationships of query elements and a range‐containment property of XML streams to generate partitions and allocate them to cluster nodes on‐the‐fly.

Findings

GMX provides several salient features: a set of partition granularities that balance workloads of query processing costs among cluster nodes statically; inter‐query parallelism as well as intra‐query parallelism at multiple extents; and better parallel query performance when all estimated queries are executed simultaneously to meet their probability of query occurrences in the system. SPX also offers the following features: minimal computation time to generate partitions; balancing skewed workloads dynamically on the system; producing higher intra‐query parallelism; and gaining better parallel query performance.

Research limitations/implications

The current status of the proposed XML data partitioning schemes does not take into account XML data updates, e.g. new XML documents and query pattern changes submitted by users on the system.

Practical implications

Note that effectiveness of the XML data partitioning schemes mainly relies on the accuracy of the cost model to estimate query processing costs. The cost model must be adjusted to reflect characteristics of a system platform used in the implementation.

Originality/value

This paper proposes novel schemes of conducting XML data partitioning to achieve both static and dynamic workload balance.

Details

International Journal of Web Information Systems, vol. 5 no. 2
Type: Research Article
ISSN: 1744-0084

Keywords

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