Exchanging and integrating data that belong to worlds of different vocabularies are two prominent problems in the database literature. While data coordination deals with managing and integrating data between autonomous yet related sources with possibly distinct vocabularies, data exchange is defined as the problem of extracting data from a source and materializing it in an independent target to conform to the target schema. These two problems, however, have never been studied in a unified setting which allows both the exchange of the data as well as the coordination of different vocabularies between different sources. Our thesis shows that such a unified setting exhibits data integration capabilities that are beyond the ones provided by data exchange and data coordination separately. In this thesis, we propose a new setting – called DSE, for Data Sharing and Exchange – which allows the exchange of data between independent source and target applications that possess independent schemas, as well as independent yet related domains of constants. To facilitate this type of exchange, we extend the source-to-target dependencies used in the ordinary data exchange setting which allow the association between the source and the target at the schema level, with the mapping table construct introduced in the classical data coordination setting which defines the association between the source and the target at the instance level. A mapping table construct defines for each source element, the set of associated (or corresponding) elements in the domain of the target. The semantics of this association relationship between source and target elements change with different requirements of different applications. Ordinary DE settings can represent DSE settings; however, we show that there exist DSE settings with particular semantics of related values in mapping tables where DE is not the best exchange solution to adopt. The thesis introduces two DSE settings with such a property. We call the first DSE with unique identity semantics. The semantics of a mapping table in this DSE setting specifies that each source element should be uniquely mapped to at least one target element that is associated with it in the mapping table. ii In this setting, classical DE is one method to perform a data exchange; however, it is not the best method to adopt, since it can not represent exchange applications, that require – as DC applications – to compute both portions as well as complete sets of certain answers for conjunctive queries. In addition, we show that adopting known DE universal solutions as semantics for such DSE settings is not the best in terms of efficiency when computing certain answers for conjunctive queries. The second DSE setting that the thesis introduces with the same property is called DSE with equality semantics. This setting captures interesting meaning of related data in a mapping table. Such semantics impose that each source element in a mapping table is related to a target element only if both elements are equivalent (i.e they have the same meaning). We show in our thesis that this DSE setting differs from ordinary DE settings in the sense that additional information could be entailed under such interpretation of related data. Also, this added information needs to be augmented to both the source instance and the mapping table in order to generate target instances that correctly reflect both in a DSE scenario. In other words, we can say that in such a DSE setting, a source instance and a mapping table can be incomplete with respect to the semantics of the mapping table. We formally define the two aforementioned semantics of a DSE setting and we distinguish between two types of solutions for this setting, named,universal DSE solutions, which contain the complete set of exchanged information, and universal DSE KB-Solutions, which store a portion of the exchanged information with implicit information in the form of a set of rules over the target. DSEKB-Solutions allow applications to compute on demand both a portion and the complete set of certain answers for conjunctive queries. In addition,we define the semantics of conjunctive query answering, and we distinguish between sound and complete certain answers for conjunctive queries and we define the algorithms to compute these efficiently. Finally, we provide experimental results which compare the run times to generate DSE solutions versus DSE KB-solutions, and compare the performance of computing sound and complete certain answers for conjunctive queries using both types of solutions

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ITC/USA 2005 Conference Proceedings / The Forty-First Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2005 / Riviera Hotel & Convention Center, Las Vegas, Nevada / Creating a generic, multi-vendor data exchange system for transmitting telemetry configurations between various systems is a daunting task. To date many different systems have been proposed including relational databases (RDBMS), TMATS, and several different XML schemas. Although many of these systems have been implemented, a complete, flexible solution has not been developed. This paper describes an implementation that is currently in use for exporting and importing a complete telemetry system via XML. Using this system, an engineer can import an entire telemetry configuration, a partial telemetry configuration, or even just a single measurement (parameter). As a result, the gap between user database systems and the airborne instrumentation vendor’s configuration software (IVCS) is seamlessly bridged. This provides many benefits including: the ability to rapidly change configurations, data entry error avoidance, version control, the protection of sensitive information, and configuration reusability. This system allows for the configuration of all aspects of the telemetry setup including data acquisition hardware, transmitters, ground stations, and recorders. In addition, the recorder settings and the definition of the data that are to be recorded are coupled and linked to the rest of the telemetry configuration, which facilitates future data recovery.

Data Exchange is the problem of transforming data in one format (the source schema) into data in another format (the target schema). Its core component is a schema mapping, which is a high level specification of how such transformation should be done. Relational data exchange has been extensively studied, but exchanging XML data have been paid much less attention. The goal of this thesis is to develop a theory of XML data exchange with expressive schema mappings, extending a previous work using restricted mappings. Our mapping language is based on tree patterns that can use horizontal navigation and data comparison in addition to downward navigation. First we look at static analysis problems concerning a single mapping. More specif- ically, we consider consistency problems with different flavours. One such problem, for instance, asks if any tree has a solution under the given mapping. Then we turn to analyse the complexity of mapping themselves, i.e., recognising pairs of trees such that the one is mapped to the other. For both problems, we provide classifications based on sets of features used in the mappings. Second we investigate the composition of XML schema mappings. Generally it is hard, or rather simply impossible, to achieve closure under composition in XML settings unlike in relational settings. Nevertheless we identify a class of XML schema mappings that is closed under composition. Lastly we consider the problem of query answering. It is important to exchange data so that we can feasibly answer queries while it often leads to intractability. We identify the dividing line between tractable and intractable cases: answering queries with extended features is always intractable while tractability of answering simple queries can be retained in extended mappings.

Scania is a Swedish automotive manufacturer for heavy vehicles and engines. It also offers transport solutions and long term commitment for customers. In today's Scania, a modular system provides a huge variety of specifications to meet varying dramatic needs for different customers. In order to be able to meet the diverse requirements of customers, modular approach with the support of reusable components is used to increase the efficiency of designing different products. To customize both product development and product design, computer aided design(CAD) is used to support the process of design and design documentation. "CATIA" is a multi-platform CAD software and "ENOVIA" is a product modeling product offers product database management for virtual model design into CATIA, both "CATIA" and "ENOVIA" are developed by the French company Dassault Systemes are chosen by Scania to support its product development. The modular system approach requires the system support for product structure, which is managed by a mainframe called SPECTRA. The thesis project is mainly about system designing a new module which takes the responsibility for exchanging information between SPECTRA and ENOVIA. In more detail, the new component is to perform a mapping of data in SPECTRA format into a format which ENOVIA can import. The mapping module has several interfaces with other applications in the system. JavaMigrator provides the environment to import data from the mainframe and transfer the data into the module and finally output the expected data format into ENOVIA. To achieve this purpose, several possible solutions were proposed and several methods were tried. Since an in-house developed CAA-module is highly preferred by Scania, the new mapping component will finally be designed into two separate modules, the first part converts the XML extracted from SPECTRA into an intermediate format and the second part is designed to convert the intermediate file into the expected target file. The intermediate file is required, since the format is independent of changes in both SPECTRA and ENOVIA. Furthermore, it is flexible and less complex to maintain than direct mapping from exported XML to ENOVIA. The report focuses on five parts, background, project specification, methodology, implementation, result and future work.

In recent years, many people use the World Wide Web and Internet to find information that they want. HTML is a document markup language for publishing hypertext on the WWW. HTML has been the target format for content developers around the world. Basically, HTML tags serve the primary purpose of describing how to display a data item. Therefore, HTML documents are difficult to find some useful information. That is because, HTML documents are mixed content with display tags. On the other hand, XML is the another data format for data exchange inter-enterprise applications on the Internet. In order to facilitate data exchange, industry groups define public Document Type Definitions (DTD) that specify the format of the XML documents to be exchanged between their applications. Moreover, WWW/EDI or Electric Commerce is very popular and a lot of business data uses XML to exchange information on the World Wide Web. Basically, XML tags describe the data itself. The contents (meaning) of the XML documents and the display format is separated. It could be easily to find meaningful information of the XML documents and analyze the information. Moreover, when a large volume of business data (XML documents) exists, one way to support the management of the XML documents is to apply the relational databases. For such an approach, we must transform the XML documents to the relational databases. In this thesis, we design and implement the indexing strategies to efficiently access XML documents. XML document is fundamentally different from relational data. XML is a hierarchical and nested document, it is very similar to the semistructured data model. The characteristic of semistructured data is that it may not have a fixed schema and it may be irregular or incomplete. Though, the semistructured data model is flexible in data modeling, it requires a large search space in query processing since there is no schema fixed in advance. Indexing is the way of how to improve query performance efficiently. However, due to the special properties of semistructued data, there are up to five types of queries: (1) complete single path, (2) specified leaf only, (3) specified intrapath, (4) specified attribute/element(value), and (5) multiple paths with the same level. In this thesis, we classify all possible queries into those five query types. Next, we create different indexes for different query types. Moreover, we design and implement the query transformation from XML query statements to SQL statements. Also, we create a user-friendly interface for users to input XML query statements. The whole system is implemented in JAVA and SQL Server 2000. From our experiences, we show that our indexing strategies can improve the XML query processing performance very well.

Thesis (M.S.)--Ohio University, March, 2004. / Includes bibliographical references (p. 70-73).

Thesis (M.S.)--Ohio University, March, 2004. / Title from PDF t.p. Includes bibliographical references (p. 70-73)

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