• Title/Summary/Keyword: Relational schema

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Database Design Methodology : Converting a Relational Schema into an Object-Relational Schema

  • Sunit Gala;Kim, Won
    • The Journal of Information Technology and Database
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    • v.1 no.1
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    • pp.9-30
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    • 1994
  • The objective of this paper is to give a brief review of relational design methodology, and show how a relational schema can be converted into an object-relational schema. We first introduce relational terminology and describe the relational design process along with its limitations. Next we show how the relational model can be extended to overcome these limitations : these extensions form the core of an object-relational data model ; we use the UniSQL/X data model as an example. We illustrate the process or converting a relational schema into an object-relational schema, and show the benefits of this conversion with respect to queries. The conversion process is then summarized as a set of guidelines. Finally, we make our conclusions.

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An Automatic Relational Schema Generating System for an XML Schema (XML Schema에 대한 관계형 스키마 자동 생성 시스템)

  • 김정섭;박창원;정진완
    • Journal of KIISE:Databases
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    • v.31 no.5
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    • pp.527-539
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    • 2004
  • As more and more documents are published in XML, generating relational schemas to store XML documents in a relational database is also getting important. This paper describes a technique as well as its implementation to produce a relational schema from the XML Schema, a standard recently recommended by W3C. The DTD-based inlining technique cannot be applied to the XML Schema, because the XML Schema has many new features, which don't exist in the DTD. Various built-in data types, inheritance, and polymorphism, for example, strengthen the XML Schema, but make the generation of a relational schema from an XML Schema more difficult. We propose an XML Schema Inlining Technique, based on the previous work. The technique first maps various data types in the XML Schema to those of the relational database. After that, it construct the schema graph and the type graph from types and elements defined in the XML Schema. The relational schema is generated while traversing the type graphs. Besides, we describe techniques for handling xsi:type, used for the polymorphism, and the anon#moos type. We also propose a couple of heuristic methods for enhancing the performance of the system. Finally, we conducted experiments to show that our technique is better than the binary table approach.

A Design Methodology of Relational Database Schema Without the Conceptual Design Step (개념적 설계를 배제한 관계형 데이터베이스 스키마의 설계)

  • Um Yoon-Sup
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.9 no.2
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    • pp.445-453
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    • 2005
  • The design process of a relational database system consists of requirement analysis, conceptual design using ER diagram, logical design, and physical design. In logical design process, the conceptual schema is transformed to relational schema, and relational schema is normalized. This traditional design process is hard to applied in real database design process, since there is an ambiguity in conceptual design process. In this paper, we suggest a new design process, which provides more structural design steps by removing the conceptual design process. In new approach, we produce the data flow diagram by the structural methodology. From the attributes in the data store of data flow diagram, we construct relational table schema, and we normalize relational schema. Finally we produced table relationship diagram in order to figure out relationships between tables.

An Efficient Transformation Technique from Relational Schema to Redundancy Free XML Schema (관계형 스키마로부터 중복성이 없는 XML 스키마로의 효율적인 변환 기법)

  • Cho, Jung-Gil
    • Journal of Internet Computing and Services
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    • v.11 no.6
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    • pp.123-133
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    • 2010
  • XML has been become the new standard for publishing and exchanging data on the Web. However, most business data is still stored and maintained in relational database management systems. As such, there is an increasing need to efficiently publish relational data as XML data for Internet-based applications. The most important issue in the transformation is to reflect structural and semantic relations of RDB to XML schema exactly. Most transformation approaches have been done to resolve the issue, but those methods have several problems. In this paper, we discuss algorithm in transforming a relational database schema into corresponding XML schema in XML Schema. We aim to achieve not only explicit/implicit referential integrity relation information but also high level of nested structure while introducing no data redundancy for the transformed XML schema. To achieve these goals, we propose a transformation model which is redundancy free and then we improve the XML Schema structure by exploring more nested structure.

A Transformation of XML DTD to Relational Database Schema Using Functional Dependency (함수적 종속관계를 이용한 XML DTD의 관계형 스키마 변환)

  • Lee Jung-hwa;Lee Man-sik;Yun Hong-won
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.8 no.7
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    • pp.1604-1609
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    • 2004
  • We have to convert XML DTD into relational database schema for storing XML Document at relational database. Hybrid inlining algorithm are used for converting XML DTD to relational database schema. But this method have some problem. That is the relational database schema have N:N relationship are created according this method are not satisfied with third normal from. Therefore, We proposed Extended Hybrid inlining algorithm for solving this problem in this paper.

A Unified Design Methodology Development For XML Application based on Relational Database using UML Class (UML 클래스를 이용한, 관계형 데이터베이스 기반의 XML 응용을 위한 통합 설계 방법론 개발)

  • 방승윤;주경수
    • The Journal of Society for e-Business Studies
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    • v.8 no.1
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    • pp.85-102
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    • 2003
  • Nowadays an information exchange on XML such as B2B electronic commerce is spreading. Therefore the systematic and stable management mechanism for storing the exchanged information is needed. For this goal there are many research activities for connection between XML application and relational database. But because XML data have hierarchical structures and relational database can store only flat-structured data, we need to make the conversion rule which changes the hierarchical architecture to 2-dimensional information. Accordingly the modeling methodology for storing each structured information in relational database is needed. In this paper, we introduce a XML modeling methodology to design W3C XML schema using UML and we propose a unified design methodology for relational database schema to store XML data efficiently in relational databases. In the second place, in order to verify objectivity of a unified design methodology. By the way of Ronald Bourret, First we introduce the method of the transformation from XML schema to object model and second we translate object model into relational database schema. Therefore we show the mutual consistency between those consequence, and so can verify a unified design methodology.

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A Transformation Military Databases based on the Relational Data model into XML Databases (관계형 데이터 모델 기반 군사용 데이터베이스의 XML 데이터베이스로의 변환)

  • Kim, Chang-Seok;Kim, Eong-Su
    • Journal of National Security and Military Science
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    • s.1
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    • pp.269-310
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    • 2003
  • AS Extensible Markup Language(XML) is emerging as the data format of the Internet era, there are increasing needs to efficiently transform between database and XML documents. In this paper, we propose a schema transformation method from relational database to XML database. To transform the schema, we represent input schema as Entity-Relationship diagram. Entity-Relationship model translator scans the input Entity-Relationship diagram using BFS (breadth First Search) and translates the diagram into hierarchical structure model. The XML Schema generator produces XML Scema code using the transformed hierarchical structure model. The proposed method has a merit that having reusability facility of XML Schema property in comparison with existing researches.

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Performance Evaluation about Implicit Referential Integrities Extraction Algorithm of RDB (RDB의 묵시적 참조 무결성 추출 알고리즘에 대한 성능 평가)

  • Kim, Jin-Hyung;Jeong, Dong-Won
    • Proceedings of the Korea Society for Simulation Conference
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    • 2005.11a
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    • pp.71-76
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    • 2005
  • XML is rapidly becoming one of the most widely adopted technologies for information exchange and representation on the World Wide Web. However, the large part of data is still stored in a relational database. Hence, we need to convert relational data into XML documents. The most important point of the conversion is to reflect referential integrities In relational schema model to XML schema model exactly. Until now, FT, NeT and CoT are suggested as existing approaches for conversion from the relational schema model to the XML schema model but these approaches only reflect referential integrities which are defined explicitly for conversion. In this paper, we suggest an algorithm for automatic extraction of implicit referential integrities such as foreign key constraints which is not defined explicitly in the initial relational schema model. We present translated XML documents by existing algorithms and suggested algorithms as comparison evaluation. We also compare suggested algorithm and conventional algorithms by simluation in accuracy part.

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An XML Data Management System Using an Object-Relational Database

  • Nam, S.H.;Jung, T.S.;Kim, T.K.;Kim, K.R.;Zahng, H.K.;Yoo, J.S.;Cho, W.S.
    • Proceedings of the Korea Society for Industrial Systems Conference
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    • 2007.02a
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    • pp.163-167
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    • 2007
  • We propose an XML document storage system, called XDMS (XML Document Management System), by using an object-relational DBMS. XDMS generates object database schema from XML Schema and stores the XML documents in an object-relational database. SAX parser is used for understanding the structure of the XML documents, and XDMS transforms the documents into objects in the database. Experiment shows that object-relational databases provide more efficient storage and query model compared with relational databases.

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Developing a Design Support System for Database Distribution : Relational Schema as an Input (데이터베이스 분산 설계 지원 시스템 개발: 관계형 스키마를 입력으로)

  • Lee, Hui-Seok;Ji, Jeong-Kang;Kim, Tae-Hun;Yeo, Ji-Yeong
    • Asia pacific journal of information systems
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    • v.6 no.1
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    • pp.165-194
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    • 1996
  • Data distribution is one of the most important steps in distributed database design. This paper proposes a methodology for distributing database by using a relational schema as an input. A design support system called DBDD (Database Distribution Design) is implemented within the framework of this methodology. The methodology consists of three phases such as (i) schema analysis, (ii) fragmentation, and (iii) allocation. In the schema analysis phase, all the table names are acquired from a global relational schema. In the fragmentation phase, fragments are generated according to transaction retrieval patterns. Furthermore, DBDD enhances the design quality by allocating fragments in a progressive manner. A real-life case is illustrated to demonstrate the practical usefulness of the DBDD.

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