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Article
Publication date: 1 May 2006

Rajugan Rajagopalapillai, Elizabeth Chang, Tharam S. Dillon and Ling Feng

In data engineering, view formalisms are used to provide flexibility to users and user applications by allowing them to extract and elaborate data from the stored data sources…

Abstract

In data engineering, view formalisms are used to provide flexibility to users and user applications by allowing them to extract and elaborate data from the stored data sources. Conversely, since the introduction of EXtensible Markup Language (XML), it is fast emerging as the dominant standard for storing, describing, and interchanging data among various web and heterogeneous data sources. In combination with XML Schema, XML provides rich facilities for defining and constraining user‐defined data semantics and properties, a feature that is unique to XML. In this context, it is interesting to investigate traditional database features, such as view models and view design techniques for XML. However, traditional view formalisms are strongly coupled to the data language and its syntax, thus it proves to be a difficult task to support views in the case of semi‐structured data models. Therefore, in this paper we propose a Layered View Model (LVM) for XML with conceptual and schemata extensions. Here our work is three‐fold; first we propose an approach to separate the implementation and conceptual aspects of the views that provides a clear separation of concerns, thus, allowing analysis and design of views to be separated from their implementation. Secondly, we define representations to express and construct these views at the conceptual level. Thirdly, we define a view transformation methodology for XML views in the LVM, which carries out automated transformation to a view schema and a view query expression in an appropriate query language. Also, to validate and apply the LVM concepts, methods and transformations developed, we propose a viewdriven application development framework with the flexibility to develop web and database applications for XML, at varying levels of abstraction.

Details

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

Keywords

Article
Publication date: 1 November 2005

Joseph Fong, San Kuen Cheung, Herbert Shiu and Chi Chung Cheung

XML Schema Definition (XSD) is in the logical level of XML model and is used in most web applications. At present, there is no standard format for the conceptual level of XML

Abstract

XML Schema Definition (XSD) is in the logical level of XML model and is used in most web applications. At present, there is no standard format for the conceptual level of XML model. Therefore, we introduce an XML Tree Model as an XML conceptual schema for representing and confirming the data semantics according to the user requirements in a diagram. The XML Tree Model consists of nodes representing all elements within the XSD. We apply reverse engineering from an XSD to an XML Tree Model to assist end users in applying an XML database for information highway on the Internet. The data semantics recovered for visualization include root element, weak elements, participation, cardinality, aggregation, generalization, categorization, and n‐ary association, and which can be derived by analyzing the structural constraints of XSD based on its key features such as key, keyref, minOccurs, maxOccurs, Choice, Sequence and extension. We use the Eclipse user interface for generating a graphical view for XML conceptual schema.

Details

International Journal of Web Information Systems, vol. 1 no. 4
Type: Research Article
ISSN: 1744-0084

Keywords

Article
Publication date: 2 September 2019

Zouhaier Brahmia, Fabio Grandi and Rafik Bouaziz

Any XML schema definition can be organized according to one of the following design styles: “Russian Doll”, “Salami Slice”, “Venetian Blind” and “Garden of Eden” (with the…

Abstract

Purpose

Any XML schema definition can be organized according to one of the following design styles: “Russian Doll”, “Salami Slice”, “Venetian Blind” and “Garden of Eden” (with the additional “Bologna” style actually representing absence of style). Conversion from a design style to another can facilitate the reuse and exchange of schema specifications encoded using the XML schema language. Without any computer-aided engineering support, style conversions must be performed very carefully as they are difficult and error-prone operations. The purpose of this paper is to efficiently deal with such XML schema design style conversions.

Design/methodology/approach

A general approach, named StyleVolution, for automatic management of XML schema design style conversions, is proposed. StyleVolution is equipped with a suite of seven procedures: four for converting a valid XML schema from any other design style to the “Garden of Eden” style, which has been chosen as a normalized XML schema format, and three for converting from the “Garden of Eden” style to any of the other desired design styles.

Findings

Procedures, algorithms and methods for XML schema design style conversions are presented. The feasibility of the approach has been shown through the encoding (using the XQuery language) and the testing (with the Altova XMLSpy 2019 tool) of a suite of seven ready-to-use procedures. Moreover, four test procedures are provided for checking the conformance of a given input XML schema to a schema design style.

Originality/value

The proposed approach implements a new technique for efficiently managing XML schema design style conversions, which can be used to make any given XML schema file to conform to a desired design style.

Details

International Journal of Web Information Systems, vol. 16 no. 1
Type: Research Article
ISSN: 1744-0084

Keywords

Article
Publication date: 1 April 2014

I-Ching Hsu, Jang Yang Lee, Der-Chen Huang and Kuan-Yang Lai

XML Schema is used to define schema of XML documents that have become standards for data exchange in various Web-based information applications. The main problem of XML Schema is…

607

Abstract

Purpose

XML Schema is used to define schema of XML documents that have become standards for data exchange in various Web-based information applications. The main problem of XML Schema is that it emphasizes syntax and format rather than semantics and knowledge representation. Hence, even though having the advantage of describing the structure and constraining the contents of XML documents, XML Schema lacks the computer-interpretability to support knowledge representation for existing information systems. The purpose of this study is to propose role-mapping annotations for XML Schema (RMAXS) to integrate Semantic Web with XML Schema, which allows the facilitation interoperability between adjoining layers of the Semantic Web stack.

Design/methodology/approach

The XML, XML Schema, ontology, and rule can be completely integrated into a multi-layered intelligent framework (MIF) for XML-based applications in the current web environment. This work presents a semantic-role-mapping intelligent system, called SRMIS, based on the MIF. SRMIS consists of XML-based document repository, search engine, inference engine and transformation engine, which provides different approaches to present the various metadata and knowledge representations.

Findings

The traditional Semantic Web stack has three gaps between adjoining layers. The first gap, between the XML and XML Schema layers can be bridged with an XMLSchema-instance mechanism. The third gap, between the ontology and rule layers can be connected by building rules on top of ontologies. This study proposes RMAXS to couple the second gap, between the XML schema and ontology layers. The proposed multi-layered intelligent framework (MIF) adopts these coupling technologies to facilitate interoperability between adjoining layers. Therefore, the XML, XML Schema, ontology, and rule can be completely integrated into the MIF for intelligent applications in the web environment.

Practical implications

To demonstrate the SRMIS applications, this work implements a prototype that helps researchers to find interested papers.

Originality/value

This work presents a semantic-role-mapping intelligent system, called SRMIS, based on the MIF. SRMIS consists of XML-based document repository, search engine, inference engine and transformation engine, which provides different approaches to present the various metadata and knowledge representations. The proposed SRMIS can be applied in various application domains.

Details

The Electronic Library, vol. 32 no. 2
Type: Research Article
ISSN: 0264-0473

Keywords

Article
Publication date: 1 August 2005

Nguyen Hong Quang and Wenny Rahayu

This paper presents a systematic XML Schema design approach which conceptually captures semantics of the problem domain at conceptual level and represents such semantics in XML

Abstract

This paper presents a systematic XML Schema design approach which conceptually captures semantics of the problem domain at conceptual level and represents such semantics in XML Schema at schema level. At the conceptual level, objects, their inter‐relationships and constraints are semantically powered by object‐oriented models. At the schema level, these conceptual semantics are comprehensively represented in textbased representation of XML Schema using various schema components and design styles, each of which offers different quality characteristics. Two primary design styles in use are nesting and linking. The nesting design styles are developed based on the choice of schema components and their definition/declaration scopes (global vs. local), whereas the linking design styles use referencing facilities provided by XML Schema and other XML technologies such as XLink and XPointer. With an in‐depth analysis of outstanding problems of existing approaches, the proposed design approach is motivated to help improve the quality and robustness of the XML documents in large‐scale XML‐based applications.

Details

International Journal of Web Information Systems, vol. 1 no. 3
Type: Research Article
ISSN: 1744-0084

Keywords

Article
Publication date: 1 March 2000

Demetrios Ioannides

The flexibility and extensibility of XML have largely contributed to its wide acceptance beyond the traditional realm of SGML. Yet, there is still one more obstacle to be overcome…

615

Abstract

The flexibility and extensibility of XML have largely contributed to its wide acceptance beyond the traditional realm of SGML. Yet, there is still one more obstacle to be overcome before XML is able to become the evangelized universal data/document format. The obstacle is posed by the limitations of the legacy standard for constraining the contents of an XML document. The traditionally used DTD (document type definition) format does not lend itself to be used in the wide variety of applications XML is capable of handling. The World Wide Web Consortium (W3C) has charged the XML schema working group with the task of developing a schema language to replace DTD. This XML schema language is evolving based on early drafts of XML schema languages. Each one of these early efforts adopted a slightly different approach, but all of them were moving in the same direction.

Details

Library Hi Tech, vol. 18 no. 1
Type: Research Article
ISSN: 0737-8831

Keywords

Article
Publication date: 13 April 2010

Bojana Dimić, Branko Milosavljević and Dušan Surla

The purpose of this paper is to create a model for an XML document that will carry information about bibliographic formats. The model will be given in the form of an XML schema

1244

Abstract

Purpose

The purpose of this paper is to create a model for an XML document that will carry information about bibliographic formats. The model will be given in the form of an XML schema describing two bibliographic formats, UNIMARC and MARC 21.

Design/methodology/approach

The description of bibliographic formats using the XML schema language may be discussed in two ways. The first one relates to creating an XML schema in a way that all elements of the bibliographic format are described separately. The second way, used in this paper, is creating an XML schema as a set of elements that presents concepts of bibliographic formats. A schema created in the second way is appropriate for use in implementation of cataloguing software.

Findings

The result is an XML schema that describes MARC 21 and UNIMARC formats. The instance of that schema is an XML document describing a bibliographic format that will be used in software systems for cataloguing. An XML document that is an instance of the proposed XML schema is applied in the development of the editor for cataloguing in the BISIS library information system. This XML document represents input information for that editor. In this way, the implementation of the editor becomes independent of the bibliographic format.

Practical implications

The created XML schema cannot serve as an electronic manual because there is some information about the format that is not included in it. In order to overcome this shortcoming an additional XML schema that will contain remaining format data may be provided.

Originality/value

The originality lies in the idea of creating one XML schema for two bibliographic formats. The schema contains elements that are models for data used in cataloguing tools. On the basis of that XML schema, the object model of bibliographic formats is implemented as well as software component for manipulating format data. This component can be used in development of library software systems.

Details

The Electronic Library, vol. 28 no. 2
Type: Research Article
ISSN: 0264-0473

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: 21 November 2008

Mengchi Liu

The purpose of this paper is to describe a novel XML schema language called DTD Schema that solves major limitations of document type definition (DTD) and supports features that…

Abstract

Purpose

The purpose of this paper is to describe a novel XML schema language called DTD Schema that solves major limitations of document type definition (DTD) and supports features that XML Schema supports in a simple and concise way.

Design/methodology/approach

DTD Schema is designed based on DTD and data definition language of object‐oriented and object‐relational databases. It extends DTD with namespaces, richer built‐in types and user‐defined subtypes, local elements and attributes, complex types with nonmonotonic multiple element and attribute inheritance with overriding, blocking, conflict handling, and polymorphism.

Findings

XML Schema is recommended by W3C as the schema language for XML. It uses a set of predefined XML tags to define the schema, which is often a long, intricate specification, full of details and concepts and its verbose syntax often doubles or triples the document length. It is so complicated that even XML experts do not find it human‐readable, mostly due to the XML‐based syntax.

Research limitations/implications

The only limitation is that DTD Schema is not in XML. But for the same reason, it is simple and concise.

Practical implications

DTD schema is halfway between DTD and XML Schema and thus it is less complex and much easier for human to use than XML Schema.

Originality/value

DTD Schema supports all functionalities of XML Schema and also the best of object‐oriented features including multiple inheritance, overriding, blocking, conflict handling and polymorphism. Therefore, it is much more expressive than XML Schema.

Details

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

Keywords

Article
Publication date: 1 February 2005

Abdelsalam Almarimi and Jaroslav Pokorny

This paper introduces an approach to minimize the total designer effort for building XML data integration systems. Since fully automatic schema mapping generation is infeasible…

Abstract

This paper introduces an approach to minimize the total designer effort for building XML data integration systems. Since fully automatic schema mapping generation is infeasible, in our view such an approach can be used as a semi‐automatic tool for XML schemas mediation. A method is proposed to query XML documents through a mediation layer. Such a layer is introduced to describe the mappings between global XML schema and local heterogeneous XML schemas. It produces a uniform interface over the local XML data sources, and provides the required functionality to query these sources in a uniform way. It involves two important units: the XML Metadata Document (XMD) and the Query Translator. The XMD is an XML document containing metadata, in which the mappings between global and local schemas are defined. The XML Query Translator which is an integral part of the system is introduced to translate a global user query into local queries by using the mappings that are defined in the XMD.

Details

International Journal of Web Information Systems, vol. 1 no. 1
Type: Research Article
ISSN: 1744-0084

Keywords

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