The Experts below are selected from a list of 51 Experts worldwide ranked by ideXlab platform
David Toth - One of the best experts on this subject based on the ideXlab platform.
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Database Engineering from the Category Theory Viewpoint
2009Co-Authors: David TothAbstract:Abstract. This paper gives an overview of XML formal Models, summarizes Database engineering practices, problems and their evolution. We focus on categorical aspects of XML formal Models. Many formal Models such as XML Data Model, Xquery Data Model or Algebra for XML can be described in terms of category theory. This kind of description allows to consider generic properties of these formalisms, e.g. expressive power, optimization, reduction or translation between them, among others. These properties are rather crucial to comparison of different XML formal Models and to consequent decision which formal system should be used to solve a concrete problem. This work aim is to be the basis for further research in the area of XML formal Models where category theory is applied.
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DATESO - Database Engineering from the Category Theory Viewpoint
2008Co-Authors: David TothAbstract:This paper gives an overview of XML formal Models, sum- marizes Database engineering practices, problems and their evolution. We focus on categorical aspects of XML formal Models. Many formal mod- els such as XML Data Model, Xquery Data Model or Algebra for XML can be described in terms of category theory. This kind of description allows to consider generic properties of these formalisms, e.g. expressive power, optimization, reduction or translation between them, among oth- ers. These properties are rather crucial to comparison of dierent XML formal Models and to consequent decision which formal system should be used to solve a concrete problem. This work aim is to be the basis for further research in the area of XML formal Models where category theory is applied.
Ivan Shcheklein - One of the best experts on this subject based on the ideXlab platform.
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Application-Tailored XML Storage
2009Co-Authors: Maxim Grinev, Ivan ShchekleinAbstract:Several native approaches to storing large XML Data sets exist. In all of these approaches the internal Data representation is designed to support any ad-hoc Xquery query. In this paper we argue that Xquery and its Data Model are too universal and any one-size-fits-all XML representation leads to significant overheads in terms of representation size and complexity. Based on the consideration that in many applications queries/updates workload is known in advance and does not change often, we propose an application-tailored XML storage. Elimination of the superfluous Xquery Data Model features and utilization of the various physical Data representations improve performance on the specified workload, while ad-hoc queries support can be limited.
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SYRCoDIS - Application-Tailored XML Storage.
2008Co-Authors: Maxim Grinev, Ivan ShchekleinAbstract:Several native approaches to storing large XML Data sets exist. In all of these approaches the internal Data representation is designed to support any ad-hoc Xquery query. In this paper we argue that Xquery and its Data Model are too universal and any one-size-fits-all XML representation leads to significant overheads in terms of representation size and complexity. Based on the consideration that in many applications queries/updates workload is known in advance and does not change often, we propose an application-tailored XML storage. Elimination of the superfluous Xquery Data Model features and utilization of the various physical Data representations improve performance on the specified workload, while ad-hoc queries support can be limited.
Donald Kossmann - One of the best experts on this subject based on the ideXlab platform.
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VLDB - Extending Xquery with window functions
2007Co-Authors: Irina Botan, Donald Kossmann, Peter M. Fischer, Tim Kraska, Dana Florescu, Rokas TamoseviciusAbstract:This paper presents two extensions for Xquery. The first extension allows the definition and processing of different kinds of windows over an input sequence; i.e., tumbling, sliding, and landmark windows. The second extension extends the Xquery Data Model (XDM) to support infinite sequences. This extension makes it possible to use Xquery as a language for continuous queries. Both extensions have been integrated into a Java-based open source Xquery engine. This paper gives details of this implementation and presents the results of running the Linear Road benchmark on the extended Xquery engine.
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ICDE - XML query processing
Proceedings. 20th International Conference on Data Engineering, 1Co-Authors: Daniela Florescu, Donald KossmannAbstract:Xquery is starting to gain significant traction as a language for querying and transforming XML Data. It is used in a variety of different products. Examples to date include XML Database systems, XML document repositories, XML Data integation, workflow systems, and publish and subscribe systems. In addition, XPath of which Xquery is a superset is used in various products such as Web browsers. Although the W3C Xquery specification has not yet attained Recommendation status, and the definition of the language has not entirely stabilized, a number of alternative proposals to implement and optimize Xquery have appeared both in industry and in the research community. Given the wide range of applications for which Xquery is applicable, a wide spectrum of alternative techniques have been proposed for Xquery processing. Some of these techniques are only useful for certain applications, other techniques are general-purpose. The goal of this seminar is to give an overview of the existing approaches to process Xquery expressions and to give details of the most important techniques. The presenters have experience from designing and building an industrial-strength Xquery engine [1]. The seminar will give details of that Xquery engine, but the seminar will also give extensive coverage of other Xquery engines and of the state of the art in the research community. The agenda for the seminar is as follows: (1) Introduction to Xquery: Motivation, Xquery Data Model, Xquery type system, Basic query language concepts; (2) Internal Representation of XML Data: DOM, SAX Events, TokenStream, Skeleton, Vertical Partitioning; (3) Xquery Algebras: Xquery Core vs. Relational Algebra, Xquery Algebras from Research Projects; (4) XPath Query Processing: Transducers, Automata, etc.; (5) Xquery Optimization: XML query equivalence, Rewrite Rules, Cost Models; (6) Xquery Runtime Systems: Iterator Models, Algorithms for Xquery Operators; (7) XML Indexes: Value and path indexes, others; (8) Xquery Products and Prototypes: XQRL/BEA, Galax, Saxon, etc. (as available); (9) Advanced Query Processing Techniques, Related Topics: Querying compressed XML Data, Multi-Query Optimization, Publish/Subscribe and XML Information Filter, XML Data Integration, XML Updates, XML integrity constraints; (10) Summary.
Maxim Grinev - One of the best experts on this subject based on the ideXlab platform.
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Application-Tailored XML Storage
2009Co-Authors: Maxim Grinev, Ivan ShchekleinAbstract:Several native approaches to storing large XML Data sets exist. In all of these approaches the internal Data representation is designed to support any ad-hoc Xquery query. In this paper we argue that Xquery and its Data Model are too universal and any one-size-fits-all XML representation leads to significant overheads in terms of representation size and complexity. Based on the consideration that in many applications queries/updates workload is known in advance and does not change often, we propose an application-tailored XML storage. Elimination of the superfluous Xquery Data Model features and utilization of the various physical Data representations improve performance on the specified workload, while ad-hoc queries support can be limited.
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SYRCoDIS - Application-Tailored XML Storage.
2008Co-Authors: Maxim Grinev, Ivan ShchekleinAbstract:Several native approaches to storing large XML Data sets exist. In all of these approaches the internal Data representation is designed to support any ad-hoc Xquery query. In this paper we argue that Xquery and its Data Model are too universal and any one-size-fits-all XML representation leads to significant overheads in terms of representation size and complexity. Based on the consideration that in many applications queries/updates workload is known in advance and does not change often, we propose an application-tailored XML storage. Elimination of the superfluous Xquery Data Model features and utilization of the various physical Data representations improve performance on the specified workload, while ad-hoc queries support can be limited.
L I Minqiang - One of the best experts on this subject based on the ideXlab platform.
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definition and implementation of xul language based on Xquery Data Model
Journal of Northeast Normal University, 2008Co-Authors: L I MinqiangAbstract:In order to express Data better and share Data format,the technology of getting XML Data and up-dating XML Data for user must be provided.A language XML-XUL for XML document update is elaborated to the World Wide Web Consortium’s proposed Xquery standard query Data Model,which be described in the form of Xquery syntax.XUL defines the granularity of XML document update,describes six sub-opera-tions:deleting,renaming,inserting before,inserting after,appending,replacing in the form of Xquery syn-tax which takes ordered and unordered document into accounts,and the semantics of update operations are presented by update instances.The implementation framework of XML document update is proposed,which stores XML document in relational Databases,and the XUL update operations are realized based on Kweelt system too.
