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XQuery-based application development

Valer, Henrique
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Trabalho de Conclusão de Curso Formato: application/pdf
ENG
Relevância na Pesquisa
38.05%
This thesis evaluates XQuery as a complete solution for data storage and processing, application logic and UI. To this end, I designed and implemented a simpli ed e-Commerce Web Application entirely with XQuery. I used XTC [8], a native XML database management system, as application server. This thesis also describes necessary updates and features related to the server, extending XTC to work as application server. The extension comprises an HTTP infrastructure and XQuery functions for the application development, not supported by the XQuery speci cation. The resulting application has shown that the use of XQuey and XML avoids the impedance mismatch between the data and the application logic and that it simpli es application development.

Executing SQL Queries with an XQuery engine

Rodrigues, Thomas da Silva
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Trabalho de Conclusão de Curso Formato: application/pdf
ENG
Relevância na Pesquisa
38.18%
Nos últimos anos, nós presenciamos o crescimento da XQuery, uma linguagem nativamente projetada para consultas em documentos XML. A Internet, como conhecemos atualmente, faz um uso massivo de documentos XML, mas para intercâmbio de dados, não como uma tecnologia de armazenamento. Bancos de dados relacionais, por outro lado, são dominantes na indústria, para armazenamento. Para prover uma integração entre esses dois mundos, nosso trabalho apresenta uma ferramenta capaz de compilar consultas SQL em operadores XQuery, prontos para serem processados por um motor XQuery. Dessa forma, nós pretendemos dar mais flexibilidade aos programadores, oferecendo independência de linguagem.; In the last years, we witnessed the rise of XQuery, a language natively designed to query over XML documents. The Internet, as we know today, makes a massive use of XML documents, but for data exchange, not as a storage technology. Relational databases, in the other hand, are dominant in the industry, for storage. To provide an integration between these two worlds, our work presents a tool capable of compile SQL queries into XQuery operators ready to be processed by an XQuery engine. In this way, we intend to give more flexibility to developers, offering language independence.

Distributed XQuery-Based Integration and Visualization of Multimodality Brain Mapping Data

Detwiler, Landon T.; Suciu, Dan; Franklin, Joshua D.; Moore, Eider B.; Poliakov, Andrew V.; Lee, Eunjung S.; Corina, David P.; Ojemann, George A.; Brinkley, James F.
Fonte: Frontiers Research Foundation Publicador: Frontiers Research Foundation
Tipo: Artigo de Revista Científica
Publicado em 30/01/2009 EN
Relevância na Pesquisa
27.61%
This paper addresses the need for relatively small groups of collaborating investigators to integrate distributed and heterogeneous data about the brain. Although various national efforts facilitate large-scale data sharing, these approaches are generally too “heavyweight” for individual or small groups of investigators, with the result that most data sharing among collaborators continues to be ad hoc. Our approach to this problem is to create a “lightweight” distributed query architecture, in which data sources are accessible via web services that accept arbitrary query languages but return XML results. A Distributed XQuery Processor (DXQP) accepts distributed XQueries in which subqueries are shipped to the remote data sources to be executed, with the resulting XML integrated by DXQP. A web-based application called DXBrain accesses DXQP, allowing a user to create, save and execute distributed XQueries, and to view the results in various formats including a 3-D brain visualization. Example results are presented using distributed brain mapping data sources obtained in studies of language organization in the brain, but any other XML source could be included. The advantage of this approach is that it is very easy to add and query a new source...

XSimilarity : uma ferramenta para consultas por similaridade embutidas na linguagem XQuery

Silva, Maria Estela Vieira da; Borges, Eduardo Nunes; Galante, Renata de Matos
Fonte: Universidade Federal do Rio Grande Publicador: Universidade Federal do Rio Grande
Tipo: Conferência ou Objeto de Conferência
POR
Relevância na Pesquisa
27.61%
This article presents XSimilarity, a tool for executing similarity queries embedded in XQuery language. Relevant similarity functions for database and information retrieval fields are implemented in the tool. The main contribution of this article is presenting a tool for similarity queries in XML databases. This allows for information retrieval optimization in these databases. Besides that, as many different similarity functions were implemented, the tool allows comparing the effectiveness of these funcions in different contexts. The examples are constructed over Computer Science scientific articles data provided by the DBLP digital library.; Este artigo apresenta o XSimilarity, uma ferramenta para a realiza????o de consultas por similaridade embutidas na linguagem XQuery. S??o implementadas fun????es de similaridade relevantes na ??rea de banco de dados e recupera????o de informa????es. A principal contribui????o desse artigo ?? apresentar uma ferramenta que permite consultas por similaridade em bases de dados no formato XML, possibilitando a melhora da recupera????o de informa????es nessas bases de dados. Al??m disso, como foram implementadas v??rias fun????es de similaridade diferentes, a ferramenta tamb??m permite comparar a efic??cia dessas fun????es para diferentes contextos de utiliza????o. A ferramenta ?? validada atrav??s de experimentos com dados de artigos cient??ficos da ??rea da Ci??ncia da Computa????o oriundos da biblioteca digital DBLP.

ViXQueL: uma ferramenta web para acesso a banco de dados XML nativo

Rangel Bastos, Petrus; Souto Maior de Barros, Roberto (Orientador)
Fonte: Universidade Federal de Pernambuco Publicador: Universidade Federal de Pernambuco
Tipo: Outros
PT_BR
Relevância na Pesquisa
28.05%
XML tornou-se o padrão de fato para troca de informações entre diversas fontes de dados e aplicações. Assim, sistemas de gerenciamento de bancos de dados XML nativos (SGBD XML nativos) têm se tornado peça fundamental na infra-estrutura de empresas que lidam com tal diversidade de fontes de dados e aplicações. Gestores do mundo corporativo estão sempre precisando de informações sobre seus negócios, para que possam tomar decisões de forma rápida e eficiente. Entretanto, as interfaces gráficas disponíveis para recuperar estas informações não demonstram preocupação com esta classe de usuários, disponibilizando apenas interfaces textuais que os obrigam a ter conhecimento nas linguagens de consulta para XML, mais especificamente a XQuery. Visando contribuir para a melhoria desta situação, este trabalho apresenta a ViXQueL, que é uma ferramenta web de abstração para acesso aos SGBD XML nativos, permitindo que usuários não especialistas recuperem informações de bases de dados sem conhecimento na linguagem de consulta XQuery. Esta abstração foi alcançada por meio de uma interface gráfica para criação de consultas visuais, que por sua vez são transformadas em consultas textuais na linguagem XQuery. Devido à extensividade e complexidade...

VISTREE: uma linguagem visual para análise de padrões arborescentes e para especificação de restrições em um ambiente de mineração de árvores

Felício, Crícia Zilda
Fonte: Universidade Federal de Uberlândia Publicador: Universidade Federal de Uberlândia
Tipo: Dissertação
POR
Relevância na Pesquisa
18.12%
A mineração de padrões freqüentes em dados representados por estruturas mais complexas como árvores e grafos vêm crescendo muito nos últimos tempos. Entre as razões para esse crescimento está o fato do padrão arborescente ou em forma de grafo possuir mais informações do que os padrões seqüenciais, e na possibilidade de aplicação desse tipo de mineração em várias áreas como XML Mining, Web Mining e Bioinformática. Um problema que ocorre na mineração de padrões em geral é a grande quantidade de padrões gerados; sendo que muitos deles nem são do interesse do usuário. A diminuição da quantidade de padrões gerados pode ser feita restringido o tipo de padrão produzido através de especificações do usuário. Mesmo incorporando restrições no processo de mineração, a quantidade de padrões arborescentes minerados é grande, o que torna necessário uma ferramenta de análise dos padrões, possibilitando ao usuário especificar consultas para extrair da massa de padrões minerados aqueles que satisfazem os critérios de seleção da consulta. A mineração de padrões com restrição, visa obter como resultado de um processo de mineração apenas os padrões de real interesse do usuário. Uma restrição sobre padrões será representada de acordo com a estrutura dos mesmos. Para a mineração de padrões seqüencias uma forma de representá-la seria através de expressões regulares...

Constructing a Relational Query Optimizer for Non-Relational Languages; Erstellung eines relationalen Anfrageoptimierers für nicht-relationale Sprachen

Rittinger, Jan
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
EN
Relevância na Pesquisa
27.95%
Flat, unordered table data and a declarative query language established today’s success of relational database systems. Provided with the freedom to choose the evaluation order and underlying algorithms, their complex query optimizers are geared to come up with the best execution plan for a given query. With over 30 years of development and research, relational database management systems belong to the most mature and efficient query processors (especially for substantial amounts of data). In contrast, ordered lists of possibly nested data structures are used throughout in programming languages. Most developers handle these constructs on a daily basis and need to change their programming style, when confronted with a relational database system. To leverage the potential of the relational query processing facility in the context of non-relational languages—without the need for a context switch—we provide a query language that copes with order, nesting, and more complex data structures (such as tuples, named records, and XML data). Queries expressed in this language are compiled into relational queries over flat, unordered tables. We take great care in the faithful mapping of the “alien” language constructs. This work describes the Pathfinder compiler achieving the transformation based on the loop lifting compilation strategy. The compiler transforms the input queries into logical algebra plans. The operators of this unordered algebra consist mainly of standard table algebra operators. Additional numbering and XML operators generate surrogate values to ensure an accurate representation of order...

XGI: A Graphical Interface for XQuery Creation

Li, Xiang; Gennari, John H.; Brinkley, James F.;
Fonte: American Medical Informatics Association Publicador: American Medical Informatics Association
Tipo: Artigo de Revista Científica
Publicado em //2007; 2007 EN
Relevância na Pesquisa
27.95%
XML has become the default standard for data exchange among heterogeneous data sources, and in January 2007 XQuery (XML Query language) was recommended by the World Wide Web Consortium as the query language for XML. However, XQuery is a complex language that is difficult for nonprogrammers to learn. We have therefore developed XGI (XQuery Graphical Interface), a visual interface for graphically generating XQuery. In this paper we demonstrate the functionality of XGI through its application to a biomedical XML dataset. We describe the system architecture and the features of XGI in relation to several existing querying systems, we demonstrate the system's usability through a sample query construction, and we discuss a preliminary evaluation of XGI. Finally, we describe some limitations of the system, and our plans for future improvements.

Combinado Indexación y Compresión en Texto Semi-Estructurado

Sologuren Gutiérrez, Felipe Leopoldo
Fonte: Universidad de Chile; Programa Cybertesis Publicador: Universidad de Chile; Programa Cybertesis
Tipo: Tesis
ES
Relevância na Pesquisa
27.28%
El almacenamiento digital de la información debe abordar tanto el problema de la incorporación de datos al sistema como su recuperación, y debe hacer un catálogo acorde con las consultas que sobre ellos quiera hacerse. El espacio ocupado para el almacenamiento y el tiempo necesario para ingresar la información, y para recuperala, depende directamente de la estructura utilizada en el repositorio. De este modo, cuando nos referimos a información que ya cuenta cion un grado de estructuración, la indexación debe ser coherente con la estructuta formal de la misma, para favorecer así la consulta. En el presente estudio se aborda el problema de la compresión estática de información semi-estructurada combinada con una indezación tendiente a soportar uin conjunto de consultas sobre los datos, con un fuerte énfasis en el almacenamiento en memoria secundaria. El ámbito de desarrollo de la aplicación propuesta se enmarca dentro de la documentación XML y su lenguaje de consulta XQuery. El modelo utilizado en la implementación está basado en la propuestas desarrolladas por Baeza-Yates y Navarro en Proximal Nodes. La implementación corresponde a un desarrollo posterior de un procesador destinado a soportar consultas en el lenguaje XPath desarrollado por Manuel Ortega como memoria de Ingeniería. El desarrollo de la capa de almacenamiento del prototipo actual se enfoca en la resolución de problemas en tres áreas: recuperación del archivo fuente...

On the Complexity of Nonrecursive XQuery and Functional Query Languages on Complex Values

Koch, Christoph
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 23/03/2005
Relevância na Pesquisa
28.05%
This paper studies the complexity of evaluating functional query languages for complex values such as monad algebra and the recursion-free fragment of XQuery. We show that monad algebra with equality restricted to atomic values is complete for the class TA[2^{O(n)}, O(n)] of problems solvable in linear exponential time with a linear number of alternations. The monotone fragment of monad algebra with atomic value equality but without negation is complete for nondeterministic exponential time. For monad algebra with deep equality, we establish TA[2^{O(n)}, O(n)] lower and exponential-space upper bounds. Then we study a fragment of XQuery, Core XQuery, that seems to incorporate all the features of a query language on complex values that are traditionally deemed essential. A close connection between monad algebra on lists and Core XQuery (with ``child'' as the only axis) is exhibited, and it is shown that these languages are expressively equivalent up to representation issues. We show that Core XQuery is just as hard as monad algebra w.r.t. combined complexity, and that it is in TC0 if the query is assumed fixed.; Comment: Long version of PODS 2005 paper

XQ2P: Efficient XQuery P2P Time Series Processing

Butnaru, Bogdan; Nguyen, Benjamin; Gardarin, Georges; Yeh, Laurent
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 03/06/2010
Relevância na Pesquisa
27.61%
In this demonstration, we propose a model for the management of XML time series (TS), using the new XQuery 1.1 window operator. We argue that centralized computation is slow, and demonstrate XQ2P, our prototype of efficient XQuery P2P TS computation in the context of financial analysis of large data sets (>1M values).

XQOWL: An Extension of XQuery for OWL Querying and Reasoning

Almendros-Jiménez, Jesús M.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 08/01/2015
Relevância na Pesquisa
28.05%
One of the main aims of the so-called Web of Data is to be able to handle heterogeneous resources where data can be expressed in either XML or RDF. The design of programming languages able to handle both XML and RDF data is a key target in this context. In this paper we present a framework called XQOWL that makes possible to handle XML and RDF/OWL data with XQuery. XQOWL can be considered as an extension of the XQuery language that connects XQuery with SPARQL and OWL reasoners. XQOWL embeds SPARQL queries (via Jena SPARQL engine) in XQuery and enables to make calls to OWL reasoners (HermiT, Pellet and FaCT++) from XQuery. It permits to combine queries against XML and RDF/OWL resources as well as to reason with RDF/OWL data. Therefore input data can be either XML or RDF/OWL and output data can be formatted in XML (also using RDF/OWL XML serialization).; Comment: In Proceedings PROLE 2014, arXiv:1501.01693

Conception et Evaluation de XQuery dans une architecture de m\'ediation "Tout-XML"

Dang-Ngoc, Tuyet-Tram; Gardarin, Georges
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 30/06/2008
Relevância na Pesquisa
27.28%
XML has emerged as the leading language for representing and exchanging data not only on the Web, but also in general in the enterprise. XQuery is emerging as the standard query language for XML. Thus, tools are required to mediate between XML queries and heterogeneous data sources to integrate data in XML. This paper presents the XMedia mediator, a unique tool for integrating and querying disparate heterogeneous information as unified XML views. It describes the mediator architecture and focuses on the unique distributed query processing technology implemented in this component. Query evaluation is based on an original XML algebra simply extending classical operators to process tuples of tree elements. Further, we present a set of performance evaluation on a relational benchmark, which leads to discuss possible performance enhancements.

XQuery Streaming by Forest Transducers

Hakuta, Shizuya; Maneth, Sebastian; Nakano, Keisuke; Iwasaki, Hideya
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
28.18%
Streaming of XML transformations is a challenging task and only very few systems support streaming. Research approaches generally define custom fragments of XQuery and XPath that are amenable to streaming, and then design custom algorithms for each fragment. These languages have several shortcomings. Here we take a more principles approach to the problem of streaming XQuery-based transformations. We start with an elegant transducer model for which many static analysis problems are well-understood: the Macro Forest Transducer (MFT). We show that a large fragment of XQuery can be translated into MFTs --- indeed, a fragment of XQuery, that can express important features that are missing from other XQuery stream engines, such as GCX: our fragment of XQuery supports XPath predicates and let-statements. We then rely on a streaming execution engine for MFTs, one which uses a well-founded set of optimizations from functional programming, such as strictness analysis and deforestation. Our prototype achieves time and memory efficiency comparable to the fastest known engine for XQuery streaming, GCX. This is surprising because our engine relies on the OCaml built in garbage collector and does not use any specialized buffer management, while GCX's efficiency is due to clever and explicit buffer management.; Comment: Full version of the paper in the Proceedings of the 30th IEEE International Conference on Data Engineering (ICDE 2014)

Well-Definedness and Semantic Type-Checking in the Nested Relational Calculus and XQuery

Bussche, Jan Van den; Van Gucht, Dirk; Vansummeren, Stijn
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 29/06/2004
Relevância na Pesquisa
27.81%
Two natural decision problems regarding the XML query language XQuery are well-definedness and semantic type-checking. We study these problems in the setting of a relational fragment of XQuery. We show that well-definedness and semantic type-checking are undecidable, even in the positive-existential case. Nevertheless, for a ``pure'' variant of XQuery, in which no identification is made between an item and the singleton containing that item, the problems become decidable. We also consider the analogous problems in the setting of the nested relational calculus.

XQuery Join Graph Isolation

Grust, T.; Mayr, M.; Rittinger, J.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 27/10/2008
Relevância na Pesquisa
28.05%
A purely relational account of the true XQuery semantics can turn any relational database system into an XQuery processor. Compiling nested expressions of the fully compositional XQuery language, however, yields odd algebraic plan shapes featuring scattered distributions of join operators that currently overwhelm commercial SQL query optimizers. This work rewrites such plans before submission to the relational database back-end. Once cast into the shape of join graphs, we have found off-the-shelf relational query optimizers--the B-tree indexing subsystem and join tree planner, in particular--to cope and even be autonomously capable of "reinventing" advanced processing strategies that have originally been devised specifically for the XQuery domain, e.g., XPath step reordering, axis reversal, and path stitching. Performance assessments provide evidence that relational query engines are among the most versatile and efficient XQuery processors readily available today.; Comment: extended version of a paper published in the ICDE 2009 proceedings (13 pages, 13 figures, 9 tables)

Anatomy of Graph Matching based on an XQuery and RDF Implementation

Rivero, Carlos R.; Jamil, Hasan M.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 10/11/2013
Relevância na Pesquisa
27.28%
Graphs are becoming one of the most popular data modeling paradigms since they are able to model complex relationships that cannot be easily captured using traditional data models. One of the major tasks of graph management is graph matching, which aims to find all of the subgraphs in a data graph that match a query graph. In the literature, proposals in this context are classified into two different categories: graph-at-a-time, which process the whole query graph at the same time, and vertex-at-a-time, which process a single vertex of the query graph at the same time. In this paper, we propose a new vertex-at-a-time proposal that is based on graphlets, each of which comprises a vertex of a graph, all of the immediate neighbors of that vertex, and all of the edges that relate those neighbors. Furthermore, we also use the concept of minimum hub covers, each of which comprises a subset of vertices in the query graph that account for all of the edges in that graph. We present the algorithms of our proposal and describe an implementation based on XQuery and RDF. Our evaluation results show that our proposal is appealing to perform graph matching.; Comment: Technical report

Apache VXQuery: A Scalable XQuery Implementation

Carman Jr., E. Preston; Westmann, Till; Borkar, Vinayak R.; Carey, Michael J.; Tsotras, Vassilis J.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 01/04/2015
Relevância na Pesquisa
27.95%
The wide use of XML for document management and data exchange has created the need to query large repositories of XML data. To efficiently query such large data collections and take advantage of parallelism, we have implemented Apache VXQuery, an open-source scalable XQuery processor. The system builds upon two other open-source frameworks -- Hyracks, a parallel execution engine, and Algebricks, a language agnostic compiler toolbox. Apache VXQuery extends these two frameworks and provides an implementation of the XQuery specifics (data model, data-model dependent functions and optimizations, and a parser). We describe the architecture of Apache VXQuery, its integration with Hyracks and Algebricks, and the XQuery optimization rules applied to the query plan to improve path expression efficiency and to enable query parallelism. An experimental evaluation using a real 500GB dataset with various selection, aggregation and join XML queries shows that Apache VXQuery performs well both in terms of scale-up and speed-up. Our experiments show that it is about 3x faster than Saxon (an open-source and commercial XQuery processor) on a 4-core, single node implementation, and around 2.5x faster than Apache MRQL (a MapReduce-based parallel query processor) on an eight (4-core) node cluster.

An Inflationary Fixed Point Operator in XQuery

Afanasiev, Loredana; Grust, Torsten; Marx, Maarten; Rittinger, Jan; Teubner, Jens
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 21/11/2007
Relevância na Pesquisa
27.95%
We introduce a controlled form of recursion in XQuery, inflationary fixed points, familiar in the context of relational databases. This imposes restrictions on the expressible types of recursion, but we show that inflationary fixed points nevertheless are sufficiently versatile to capture a wide range of interesting use cases, including the semantics of Regular XPath and its core transitive closure construct. While the optimization of general user-defined recursive functions in XQuery appears elusive, we will describe how inflationary fixed points can be efficiently evaluated, provided that the recursive XQuery expressions exhibit a distributivity property. We show how distributivity can be assessed both, syntactically and algebraically, and provide experimental evidence that XQuery processors can substantially benefit during inflationary fixed point evaluation.; Comment: 11 pages, 10 figures, 2 tables

A supply chain collaboration solution using XQuery

Govindasamy, Bharani
Fonte: Rochester Instituto de Tecnologia Publicador: Rochester Instituto de Tecnologia
Tipo: Tese de Doutorado
EN_US
Relevância na Pesquisa
37.81%
Enterprises in a collaborative supply chain share information for quick and intelligent decision making. Collaborative Planning, Forecasting and Replenishment (CPFR), a business model developed by an organization called Voluntary Inter-industry Commerce Standards, defines a set of business processes to collaborate on planning, forecasting and replenishment activities to arrive at a common order. This involves sharing sales forecast, order forecast and promotion information among business partners. The Internet has paved the way for using Web Services to share this information as XML data in real time and to make it available across enterprises. Enterprises need to access this information and integrate it with the information available in their databases, Excel sheets and XML applications. This thesis discusses the development of an information architecture using XQuery (a declarative query language by W3C) for aggregating data from disparate data, and evaluates XQuery as a tool to enable information integration for supply chain collaboration. For this purpose, several CPFR scenarios are identified where two retailers share their sales forecast, order forecast and promotion forecast information with the manufacturer. A prototype application is developed which can fetch data from disparate data sources such as Web Service...