Data Exchange with Data-Metadata Translations

Total Page:16

File Type:pdf, Size:1020Kb

Data Exchange with Data-Metadata Translations Data Exchange with Data-Metadata Translations ¤ y z z Mauricio A. Hernandez´ Paolo Papotti Wang-Chiew Tan IBM Almaden Research Center Universita` Roma Tre UC Santa Cruz [email protected] [email protected] [email protected] ABSTRACT of source-to-target tuple generating dependencies (s-t tgds) [6] or Data exchange is the process of converting an instance of one schema (Global-and-Local-As-View) GLAV mappings [7, 12]. They have into an instance of a different schema according to a given speci- also been extended to specify the relation of pairs of instances of fication. Recent data exchange systems have largely dealt with the nested schemas in [8, 18]. case where the schemas are given a priori and transformations can Data exchange systems [9, 13, 14, 21, 22] have been developed only migrate data from the first schema to an instance of the sec- to (semi-) automatically generate the mappings and the transfor- ond schema. In particular, the ability to perform data-metadata mation code in the desired language by mapping schema elements translations, transformation in which data is converted into meta- in a visual interface. These framework alleviate the need to fully data or metadata is converted into data, is largely ignored. This understand the underlying transformation language (e.g. XQuery) paper provides a systematic study of the data exchange problem and language-specific visual editor (e.g. XQuery editor). Further- with data-metadata translation capabilities. We describe the prob- more, some of these systems allow the same visual specification of lem, our solution, implementation and experiments. Our solution is mapping schema elements to be used to generate a skeleton of the a principled and systematic extension of the existing data exchange transformation code in diverse languages (e.g., Java, XSLT). framework; all the way from the constructs required in the visual Past research on data exchange, as well as commercial data ex- interface to specify data-metadata correspondences, which natu- change systems , have largely dealt with the case where the schemas rally extend the traditional value correspondences, to constructs re- are given a priori and transformations can only migrate data from quired for the mapping language to specify data-metadata transla- the first instance to an instance of the second schema. In partic- tions, and algorithms required for generating mappings and queries ular, data-metadata translations are not supported by these sys- that perform the exchange. tems. Data-metadata translations are transformations that convert data/metadata in the source instance or schema to data/metadata in the target instance or schema. Such capabilities are needed in many 1. INTRODUCTION genuine data exchange scenarios that we have encountered, as well Data exchange is the process of converting an instance of one as in data visualization tools, where data are reorganized in differ- schema, called the source schema, into an instance of a different ent ways in order to expose patterns or trends that would be easier schema, called the target schema, according to a given specifica- for subsequent data analysis. tion. This is an old problem that has renewed interests in recent A simple example that is commonly used in the relational setting years. Many data exchange related research problems were inves- to motivate and illustrate data-metadata translations is to “flip” the tigated in the context where the relation between source and target StockTicker(Time, Company, Price) table so that company names instances is described in a high-level declarative formalism called appear as column names of the resulting table [15]. This is akin to schema mappings (or mappings) [10, 16]. A language for map- the pivot operation [23] used in spreadsheets such as Excel. After pings of relational schemas that is widely used in data exchange, as a pivot on the company name and a sort on the time column, it well as data integration and peer data management systems, is that becomes easier to see the variation of a company’s stock prices and also compare against other companies’ performance throughout the ¤Work partly funded by U.S. Air Force Office for Scientific Re- day (see the table on the right below). search under contract FA9550-07-1-0223. y Time Symbol Price Time MSFT IBM Work done while visiting UC Santa Cruz, partly funded by an 0900 MSFT 27.20 0900 27.20 - IBM Faculty Award. 0900 IBM 120.00 0900 - 120.00 zWork partly funded by NSF CAREER Award IIS-0347065 and 0905 MSFT 27.30 0905 27.30 - NSF grant IIS-0430994. Observe that the second schema cannot be determined a priori since it depends on the first instance and the defined transformation. Permission to copy without fee all or part of this material is granted provided Such schemas are called dynamic output schemas in [11]. Con- that the copies are not made or distributed for direct commercial advantage, ceivably, one might also wish to unpivot the right table to obtain the VLDB copyright notice and the title of the publication and its date appear, the left one. Although operations for data-metadata translations and notice is given that copying is by permission of the Very Large Data have been investigated extensively in the relational setting (see, for Base Endowment. To copy otherwise, or to republish, to post on servers instance, [24] for a comprehensive overview of related work), this or to redistribute to lists, requires a fee and/or special permission from the subject is relatively unexplored for data exchange systems in which publisher, ACM. VLDB ‘08, August 24-30, 2008, Auckland, New Zealand source or target instances are no longer “flat” relations and the re- Copyright 2008 VLDB Endowment, ACM 000-0-00000-000-0/00/00. lationship between the schemas is specified with mappings. Extending the data exchange framework with data-metadata trans- Source: Rcd Target: Rcd (a) lation capabilities for hierarchical or XML instances is a highly Sales : SetOf Rcd CountrySales : SetOf Rcd country country non-trivial task. To understand why, we first need to explain the region Sales : SetOf Rcd data exchange framework of [18], which essentially consists of style style three components: shipdate shipdate units units ² A visual interface where value correspondences, i.e., the re- price id lation between elements of the source and target schema can be manually specified or (semi-)automatically derived with a for $s in Source.Sales (b) exists $c in Target.CountrySales, $cs in $c.Sales schema matcher. Value correspondences are depicted as lines where $c.country = $s.country and $cs.style = $s.style and between schema element in the visual interface and it provides $cs.shipdate = $s.shipdate and $cs.units = $s.units and an intuitive description of the underlying mappings. $c.Sales = SK[$s.country] ² A mapping generation algorithm that interprets the schemas “For every Sales tuple, map it to a CountrySales tuple where Sales are grouped by country in that tuple.” and values correspondences into mappings. (c) ² A query generation algorithm that generates a query in some Sales CountrySales country Sales language (e.g., XQuery) from the mappings that are generated country region style shipdate units price USA East Tee 12/07 11 1200 USA style shipdate units id in the previous step. The generated query implements the spec- USA East Elec. 12/07 12 3600 Tee 12/07 11 ID1 ification according to the mappings and is used to derive the USA West Tee 01/08 10 1600 Elec. 12/07 12 ID2 target instance from a given source instance. (Note that the UK West Tee 02/08 12 2000 Tee 01/08 10 ID3 framework of [14] is similar and essentially consists of only the country Sales UK style shipdate units id second and third components.) Tee 02/08 12 ID4 Adding data-metadata translation capabilities to the existing data exchange framework requires a careful and systematic extension to Figure 1: Data-to-Data Exchange all three components described above. The extension must capture traditional data exchange as a special case. It is worth pointing out that the visual interface component described above is not peculiar 2.1 Data-to-Data Translation (Data Exchange) to [18] alone. Relationship-based mapping systems [20] consist of Data-to-data translation corresponds to the traditional data ex- a visual interface in which value correspondences are used to in- change where the goal is to materialize a target instance according tuitively describe the transformation between a source and target to the specified mappings when given a source instance. In data-to- schema and in addition to [18], commercial mapping systems such data translation, the source and target schemas are given a priori. as [13, 21, 22] all fall under this category. Hence, our proposed ex- Figure 1 shows a typical data-to-data translation scenario. Here, tensions to the visual interface could also be applied to these map- users have mapped the source-side schema entities into some tar- ping systems as well. The difference between mapping systems get side entities, which are depicted as lines in the visual interface. such as [13, 21, 22] and [18] is, essentially, the second component The lines are called value correspondences. The schemas are rep- of the data exchange framework described above; these commer- resented using the Nested Relational (NR) Model of [18], where cial systems do not generate mappings, they generate queries (or a relation is modeled as a set of records and relations may be arbi- executable code) directly. trarily nested. In the source schema, Sales is a set of records where Our solution is a principled extension to all the three compo- each record has six atomic elements: country, region, style, ship- nents, from constructs required in the visual interface to depict date, units, and price.
Recommended publications
  • Data Mapping: Definition, Tools, and Techniques
    Data Mapping: Definition, Tools, and Techniques Enterprise data is getting more dispersed and voluminous by the day, and at the same time, it has become more important than ever for businesses to leverage data and transform it into actionable insights. However, enterprises today collect information from an array of data points, and they may not always speak the same language. To integrate this data and make sense of it, data mapping is used which is the process of establishing relationships between separate data models. What is Data Mapping? In simple words, data mapping is the process of mapping data fields from a source file to their related target fields. For example, in Figure 1, ‘Name,’ ‘Email,’ and ‘Phone’ fields from an Excel source are mapped to the relevant fields in a Delimited file, which is our destination. Data mapping tasks vary in complexity, depending on the hierarchy of the data being mapped, as well as the disparity between the structure of the source and the target. Every business application, whether on-premise or cloud, uses metadata to explain the data fields and attributes that constitute the data, as well as semantic rules that govern how data is stored within that application or repository. For example, Microsoft Dynamics CRM contains several data objects, such as Leads, Opportunities, and Competitors. Each of these data objects has several fields like Name, Account Owner, City, Country, Job Title, and more. The application also has a defined schema along with attributes, enumerations, and mapping rules. Therefore, if a new record is to be added to the schema of a data object, a data map needs to be created from the data source to the Microsoft Dynamics CRM account.
    [Show full text]
  • Managing Data in Motion This Page Intentionally Left Blank Managing Data in Motion Data Integration Best Practice Techniques and Technologies
    Managing Data in Motion This page intentionally left blank Managing Data in Motion Data Integration Best Practice Techniques and Technologies April Reeve AMSTERDAM • BOSTON • HEIDELBERG • LONDON NEW YORK • OXFORD • PARIS • SAN DIEGO SAN FRANCISCO • SINGAPORE • SYDNEY • TOKYO Morgan Kaufmann is an imprint of Elsevier Acquiring Editor: Andrea Dierna Development Editor: Heather Scherer Project Manager: Mohanambal Natarajan Designer: Russell Purdy Morgan Kaufmann is an imprint of Elsevier 225 Wyman Street, Waltham, MA 02451, USA Copyright r 2013 Elsevier Inc. All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Details on how to seek permission, further information about the Publisher’s permissions policies and our arrangements with organizations such as the Copyright Clearance Center and the Copyright Licensing Agency, can be found at our website: www.elsevier.com/permissions. This book and the individual contributions contained in it are protected under copyright by the Publisher (other than as may be noted herein). Notices Knowledge and best practice in this field are constantly changing. As new research and experience broaden our understanding, changes in research methods or professional practices, may become necessary. Practitioners and researchers must always rely on their own experience and knowledge in evaluating and using any information or methods described herein. In using such information or methods they should be mindful of their own safety and the safety of others, including parties for whom they have a professional responsibility.
    [Show full text]
  • Transforming MARCXML Records Using XSLT
    Transforming MARCXML Records Using XSLT Violeta Ilik Head, Digital Systems & Collection Services Digital Innovations Librarian Galter Health Sciences Library Northwestern University Clinical and Translational Sciences Institute Chicago, IL March 4, 2015 Teun Hocks Violeta Ilik vivoweb.org Hosted by ALCTS, Association for Library Collections and Technical Services + ALCTS - Library Resources & Technical Services n Ilik, V., Storlien, J., and Olivarez, J. (2014). “Metadata Makeover: Transforming MARC Records Using XSLT.” Library Resources and Technical Services 58 (3): 187-208. “The knowledge gained from learning information technology can be used to experiment with methods of transforming one metadata schema into another using various software solutions” Violeta Ilik vivoweb.org Hosted by ALCTS, Association for Library Collections and Technical Services + Why Catalogers? n Survey conducted by Ma in 2007 revealed that the metadata qualifications and responsibilities required knowledge of MARC, crosswalks, XML, OAI … n Analysis of cataloging position description performed by Park, Lu, and Marion reveal that advances in technology have created a new realm of desired skills, qualifications and responsibilities for catalogers. n Terry Reese’s MarcEdit is a best friend to everyone in technical services n Tosaka stresses the importance of metadata transformation to enable reuse Violeta Ilik vivoweb.org Hosted by ALCTS, Association for Library Collections and Technical Services + Recommendations: n Cataloging departments need to be proactive in
    [Show full text]
  • X3ML Mapping Framework for Information Integration in Cultural Heritage and Beyond
    Int J Digit Libr (2017) 18:301–319 DOI 10.1007/s00799-016-0179-1 X3ML mapping framework for information integration in cultural heritage and beyond Yannis Marketakis1 · Nikos Minadakis1 · Haridimos Kondylakis1 · Konstantina Konsolaki1 · Georgios Samaritakis1 · Maria Theodoridou1 · Giorgos Flouris1 · Martin Doerr1 Received: 28 December 2015 / Revised: 20 May 2016 / Accepted: 25 May 2016 / Published online: 6 June 2016 © Springer-Verlag Berlin Heidelberg 2016 Abstract The aggregation of heterogeneous data from dif- verified via the increasing number of international projects ferent institutions in cultural heritage and e-science has the that adopt and use this framework. potential to create rich data resources useful for a range of different purposes, from research to education and public Keywords Data mappings · Schema matching · Data interests. In this paper, we present the X3ML framework, aggregation · URI generation · Information integration a framework for information integration that handles effec- tively and efficiently the steps involved in schema mapping, uniform resource identifier (URI) definition and generation, 1 Introduction data transformation, provision and aggregation. The frame- work is based on the X3ML mapping definition language Managing heterogeneous data is a challenge for cultural her- for describing both schema mappings and URI generation itage institutions, such as archives, libraries and museums, policies and has a lot of advantages when compared with but equally for research institutes of descriptive sciences such other relevant frameworks. We describe the architecture of as earth sciences [1], biodiversity [2,3], clinical studies and the framework as well as details on the various available com- e-health [4,5]. These institutions host and maintain various ponents.
    [Show full text]
  • The Value of Automated Data Preparation & Mapping for the Data
    Solution Brief: erwin Data Catalog (DC) The Value of Automated Data Preparation & Mapping for the Data-Driven Enterprise Creating a sustainable bond between data management and data governance to accelerate actionable insights and mitigate data-related risks Data Preparation & Mapping: Why It Matters Business and IT leaders know that their of unharvested, undocumented databases, organisations can’t be truly and holistically data- applications, ETL processes and procedural driven without a strong data management and code. Consider the problematic issue of manually governance backbone. mapping source system fields (typically source files or database tables) to target system fields But they’ve also learned getting to that point is (such as different tables in target data warehouses frustrating. They’ve probably spent a lot of time or data marts). These source mappings generally and money trying to harmonise data across diverse are documented across a slew of unwieldy platforms, including cleansing, uploading metadata, spreadsheets in their “pre-ETL” stage as the input code conversions, defining business glossaries, for ETL development and testing. However, the ETL tracking data transformations and so on. But the design process often suffers as it evolves because attempts to standardise data across the entire spreadsheet mapping data isn’t updated or may enterprise haven’t produced the hoped-for results. be incorrectly updated thanks to human error. So How, then, can a company effectively implement questions linger about whether transformed data data governance—documenting and applying can be trusted. business rules and processes, analysing the impact of changes and conducting audits—when it fails at The sad truth is that high-paid knowledge workers data management? like data scientists spend up to 80 percent of their time finding and understanding source data and In most cases, the problem starts by relying on resolving errors or inconsistencies, rather than manual integration methods for data preparation analysing it for real value.
    [Show full text]
  • Integrated Data Mapping for a Software Meta-Tool
    2009 Australian Software Engineering Conference Integrated data mapping for a software meta-tool Jun Huh1, John Grundy1,2, John Hosking1, Karen Liu1, Robert Amor1 1Department of Computer Science and 2Department of Electrical and Computer Engineering University of Auckland Private Bag 92019, Auckland 1142 New Zealand [email protected],{john-g,john,karen,trebor}@cs.auckland.ac.nz Abstract Using high-level specification tools that generate high quality translators is the preferred approach [1] Complex data mapping tasks often arise in [27][13]. This makes complex translator development software engineering, particularly in code generation faster, more scalable and maintainable, and results in and model transformation. We describe Marama higher quality translators than ad-hoc coding or reuse Torua, a tool supporting high-level specification and of less appropriate existing translators. Toolsets to implementation of complex data mappings. Marama generate such translators are typically either general- Torua is embedded in, and provides model purpose, supporting specification of mappings between transformation support for, our Eclipse-based Marama a wide range of models, or domain-specific and limited domain-specific language meta-tool. Developers can to a small range of source models and target formats. quickly develop stand alone data mappers and model General-purpose toolsets usually provide only low- translation and code import-export components for level modeling support and limited extensibility. their tools. Complex data schema and mapping Domain-specific translator generators provide higher- relationships are represented in multiple, high-level level abstractions but are often inflexible and do not notational forms and users are provided semi- support modifying built-in data mapping automated mapping assistance for large models.
    [Show full text]
  • Excel Xml Mapping Schema
    Excel Xml Mapping Schema Is Hiram sprightly or agnostic after supersensual Shepard outthinks so unthinking? If factual or unciform Taddeo usually buy-ins his straightness embrute imbricately or restock threefold and pivotally, how backstage is Gilbert? Overgrown Norwood polarizes, his afternoons entwining embrangles dam. Office Open XML text import filter. One or more repeating elements or attributes are mapped to the spreadsheet. And all the code used in the book is available to customers in a downloadalbe archive. Please copy any unsaved content to a safe place, only the address of the topmost cell appears, and exchanged. For the file named in time title age of the dialog box, so you purchase already using be it. This menu items from any other site currently excel is focused on a check box will be able only used for? Input schema mapping operation with existing schema? You select use memories to open XML files as current, if you reimport the XML data file, we may seize to do handle several times. The Windows versions of Microsoft Excel 2007 2010 and 2013 allow columns in spreadsheets to be mapped to an XML structure defined in an XML Schema file. The mappings that text, i did you want to hear the developer tab click xml excel schema mapping. Thread is defined in schema, schemas with xpath in onedrive than referencing an editor. Asking for help, it may be impractical to use a Website to validate your XML because of issues relating to connectivity, and then go to your pc? XML Syntax. When you take a schema and map it has Excel using the XML Source task pane you taunt the exporting and importing of XML data implement the spreadsheet We are.
    [Show full text]
  • Semantic Data Mapping Technology to Solve Semantic Data Problem on Heterogeneity Aspect
    International Journal of Advances in Intelligent Informatics ISSN: 2442-6571 Vol. 3, No 3, November 2017, pp. 161-172 161 Semantic data mapping technology to solve semantic data problem on heterogeneity aspect Arda Yunianta a,b,1,*, Omar Mohammed Barukab a,2, Norazah Yusof a,3, Nataniel Dengen b,4, Haviluddin b,5, Mohd Shahizan Othman c,6 a Faculty of Computing and Information Technology, King Abdul Aziz University, Rabigh, Saudi Arabia b Faculty of Computer Science and Information Technology, Mulawarman University, Indonesia c Faculty of Computing, University Teknologi Malaysia, Malaysia 1 [email protected] *; [email protected]; 3 [email protected]; 4 [email protected]; 5 [email protected]; 6 [email protected]; * corresponding author ARTICLE INFO ABSTRACT Article history: The diversity of applications developed with different programming Received November 15, 2017 languages, application/data architectures, database systems and Revised December 17, 2017 representation of data/information leads to heterogeneity issues. One Accepted December 18, 2017 of the problem challenges in the problem of heterogeneity is about heterogeneity data in term of semantic aspect. The semantic aspect is about data that has the same name with different meaning or data Keywords: that has a different name with the same meaning. The semantic data Ontology mapping process is the best solution in the current days to solve Education domain semantic data problem. There are many semantic data mapping Semantic approach technologies that have been used in recent years. This research aims Heterogeneity aspect to compare and analyze existing semantic data mapping technology Mapping technology using five criteria’s. After comparative and analytical process, this research provides recommendations of appropriate semantic data mapping technology based on several criteria’s.
    [Show full text]
  • Clio: Schema Mapping Creation and Data Exchange
    Clio: Schema Mapping Creation and Data Exchange Ronald Fagin1, Laura M. Haas1, Mauricio Hern´andez1, Ren´eeJ. Miller2, Lucian Popa1, and Yannis Velegrakis3 1 IBM Almaden Research Center, San Jose, CA 95120, USA 2 University of Toronto, Toronto ON M5S2E4, Canada 3 University of Trento, 38100 Trento, Italy [email protected], [email protected], [email protected], [email protected], [email protected], [email protected] Abstract. The Clio project provides tools that vastly simplify infor- mation integration. Information integration requires data conversions to bring data in different representations into a common form. Key con- tributions of Clio are the definition of non-procedural schema mappings to describe the relationship between data in heterogeneous schemas, a new paradigm in which we view the mapping creation process as one of query discovery, and algorithms for automatically generating queries for data transformation from the mappings. Clio provides algortihms to ad- dress the needs of two major information integration problems, namely, data integration and data exchange. In this chapter, we present our al- gorithms for both schema mapping creation via query discovery, and for query generation for data exchange. These algorithms can be used in pure relational, pure XML, nested relational, or mixed relational and nested contexts. 1 Introduction We present a retrospective on key contributions of the Clio project, a joint project between the IBM Almaden Research Center and the University of Toronto begun in 1999. Clio’s goal is to radically simplify information inte- gration, by providing tools that help in automating and managing one chal- lenging piece of that problem: the conversion of data between representations.
    [Show full text]
  • Etl User Guide
    eTL Integrator User Guide Release 5.0 SeeBeyond Proprietary and Confidential The information contained in this document is subject to change and is updated periodically to reflect changes to the applicable software. Although every effort has been made to ensure the accuracy of this document, SeeBeyond Technology Corporation (SeeBeyond) assumes no responsibility for any errors that may appear herein. The software described in this document is furnished under a License Agreement and may be used or copied only in accordance with the terms of such License Agreement. Printing, copying, or reproducing this document in any fashion is prohibited except in accordance with the License Agreement. The contents of this document are designated as being confidential and proprietary; are considered to be trade secrets of SeeBeyond; and may be used only in accordance with the License Agreement, as protected and enforceable by law. SeeBeyond assumes no responsibility for the use or reliability of its software on platforms that are not supported by SeeBeyond. SeeBeyond, e*Gate, and e*Way are the registered trademarks of SeeBeyond Technology Corporation in the United States and select foreign countries; the SeeBeyond logo, e*Insight, and e*Xchange are trademarks of SeeBeyond Technology Corporation. The absence of a trademark from this list does not constitute a waiver of SeeBeyond Technology Corporation's intellectual property rights concerning that trademark. This document may contain references to other company, brand, and product names. These company, brand, and product names are used herein for identification purposes only and may be the trademarks of their respective owners. © 2003 by SeeBeyond Technology Corporation.
    [Show full text]
  • Improving the Usability of Heterogeneous Data Mapping Languages for First-Time Users
    ShExML: improving the usability of heterogeneous data mapping languages for first-time users Herminio García-González1, Iovka Boneva2, Sªawek Staworko2, José Emilio Labra-Gayo1 and Juan Manuel Cueva Lovelle1 1 Deparment of Computer Science, University of Oviedo, Oviedo, Asturias, Spain 2 University of Lille, INRIA, Lille, Nord-Pas-de-Calais, France ABSTRACT Integration of heterogeneous data sources in a single representation is an active field with many different tools and techniques. In the case of text-based approaches— those that base the definition of the mappings and the integration on a DSL—there is a lack of usability studies. In this work we have conducted a usability experiment (n D 17) on three different languages: ShExML (our own language), YARRRML and SPARQL-Generate. Results show that ShExML users tend to perform better than those of YARRRML and SPARQL-Generate. This study sheds light on usability aspects of these languages design and remarks some aspects of improvement. Subjects Human-Computer Interaction, Artificial Intelligence, World Wide Web and Web Science, Programming Languages Keywords Data integration, Data mapping, ShExML, YARRRML, Usability, SPARQL-Generate INTRODUCTION Data integration is the problem of mapping data from different sources so that they can be used through a single interface (Halevy, 2001). In particular, data exchange is the process Submitted 26 May 2020 of transforming source data to a target data model, so that it can be integrated in existing Accepted 25 October 2020 Published 23 November 2020 applications (Fagin et al., 2005). Modern data exchange solutions require from the user to Corresponding author define a mapping from the source data model to the target data model, which is then used Herminio García-González, garciaher- by the system to perform the actual data transformation.
    [Show full text]
  • Specification of Data Schema Mappings Using Weaving Models
    DOI: 10.2298/CSIS110823010A Specification of Data Schema Mappings using Weaving Models Nenad Aničić1, Siniša Nešković1, Milica Vučković1 and Radovan Cvetković2 1Faculty of Organizational Sciences, Jove Ilića 154, 11000 Belgrade, Serbia {nenad.anicic, sinisa.neskovic, milica.vuckovic}@fon.bg.ac.rs 2Telekom Srbije A.D., Technical Affairs Division Bulevar umetnosti 16a, 11000 Belgrade, Serbia [email protected] Abstract. Weaving models are used in the model driven engineering (MDE) community for various application scenarios related to model mappings. However, an analysis of its suitability for specification of heterogeneous schema mappings reveals that weaving models lack support for mapping rules and, therefore, cannot prevent mapping specifications which are semantically meaningless, wrong or disallowed. This paper proposes a solution which overcomes the identified open issue by providing the explicit support for semantic mapping rules. It is based on introduction of weaving metamodels augmented with constraints written in OCL. The role of OCL constraints is to restrict mapping specifications to only those which are semantically meaningful. Using well known MDE technologies, such as EMF and QVT, an existing tool is used to validate the presented solution. This solution is also successfully evaluated in practice. Keywords: schema mappings, weaving models, model transformations 1. Introduction Specification of mappings among heterogeneous schemas1 has been studied in many different research areas, such as distributed databases [1], data warehouses [2], ontologies [3], model driven development [4], [5], [6], etc. According to specific needs and characteristics of a particular problem domain, researchers have proposed different approaches and techniques that can be used to specify schema mappings. Without diving into details of each particular approach, it can be generally concluded that most of them rely on a mapping specification formalism, 1 The term schema is used in a broader sense and includes database schemas, ontologies, or generic models.
    [Show full text]