When updating a valid XML Data or Schema, an efficient yet light-weight mechanism is needed to determine if the update would invalidate the document. Towards this goal, we have developed a framework called SAXE. First, we analyzed the constraints expressed in XML schema specifications to establish constraint rules that must be observed when a schema or an XML data conforming to a given XML Schema is altered. We then classify the rules based on their relevancy for a given update case. That is, we show the minimal set of rules that must be checked to guarantee the safety for each update primitive. Next, we illustrate that this set of incremental constraint checks can be specified using generic XQuery expressions composed of three type of components. Safe updates for the XML data have the following components: (1) XML schema meta-queries to retrieve any con-straint knowledge potentially relevant to the given update from the schema or XMl data being altered, (2) retrieval of specific characteristics from the to-be-modified XML, and (3) lastly an analysis of information collected about the XML schema and the affected XML document to determine validity of the update. For the safe schema alteration, the components are: (1) XML schema meta-queries to retrieve relevant information from the schema (2)analysis and usage of retrieved information to update the schema, and lastly to (3) propagate the changes to the XML data when necessary. As a proof of concept, we have established a library of these generic XQuery constraint checks for the type-related XML constraints. The key idea of SAXE is to rewrite each XQuery update into a safe XML Query by extending it with appropriate constraint check subqueries. This en-hanced XML update query can then safely be executed using any existing XQuery engine that supports updates - thus turning any update engine automatically into an incremen-tal constraint-check engine. In order to verify the feasibility of our approach, we have implemented a prototype system SAXE that generates safe XQuery updates. Our experimental evaluation assesses the overhead of rewriting as well as the relative performance of our loosely-coupled incremental constraint check approach against the more traditional first-change-document and then revalidate-it approach.

Recently, plenty of methods dealing with automatic inference of XML schema have been developed, however, most of them utilize XML documents as their only input. In this thesis we focus on extending inference by incorporating XML operations, in particular XQuery queries. We discuss how can XQuery queries help in improving the inference process and we propose an algorithm based on chosen improvements, extending an existing method of a key discovery, that can be integrated to methods inferring so-called initial grammar. By implementing it, we created the first solution of XML schema inference using XML documents along with XML operations.

<p>Research of protein-protein interactions produce vast quantities of data and there exists a large number of databases with data from this research. Many of these databases offers the data for download on the web in a number of different formats, many of them XML-based.</p><p>With the arrival of these XML-based formats, and especially the standardized formats such as PSI-MI, SBML and BioPAX, there is a need for searching in data represented in XML. We wanted to investigate the capabilities of XML query tools when it comes to searching in this data. Due to the large datasets we concentrated on native XML database systems that in addition to search in XML data also offers storage and indexing specially suited for XML documents.</p><p>A number of queries were tested on data exported from the databases IntAct and Reactome using the XQuery language. There were both simple and advanced queries performed. The simpler queries consisted of queries such as listing information on a specified protein or counting the number of reactions.</p><p>One central issue with protein-protein interactions is to find pathways, i.e. series of interconnected chemical reactions between proteins. This problem involve graph searches and since we suspected that the complex queries it required would be slow we also developed a C++ program using a graph toolkit.</p><p>The simpler queries were performed relatively fast. Pathway searches in the native XML databases took long time even for short searches while the C++ program achieved much faster pathway searches.</p>

With the rapid growth of XML documents to serve as a popular and major media for storage and interchange of the data on the Web, there is an increasing interest in using existing traditional relational database techniques to store and/or query XML data. Since XQuery is becoming a standard XML query language, significant effort has been made in developing an efficient and comprehensive XQuery-to-SQL query processor. In this thesis, we design and implement an <em>XQuery-to-SQL Query Processor</em> based on the <em>Dynamic Intervals</em> approach. We also provide a comprehensive translation for XQuery basic operations and FLWR expressions. The query processor is able to translate a complex XQuery query, which might include arbitrarily composed and nested FLWR expressions, basic functions, and element constructors, into a single SQL query for RDBMS and a physical plan for the <em>XQuery-enhanced Relational Engine</em>. In order to produce efficient and concise SQL queries, succinct XQuery to SQL translation templates and the optimization algorithms for the SQL query generation are proposed and implemented. The preferable <em>merge-join</em> approach is also proposed to avoid the inefficient <em>nested-loop</em> evaluation for FLWR expressions. <em>Merge-join</em> patterns and query rewriting rules are designed to identify XQuery fragments that can utilize the efficient <em>merge-join</em> evaluation. Proofs of correctness of the approach are provided in the thesis. Experimental results justify the correctness of our work.

With the rapid growth of XML documents to serve as a popular and major media for storage and interchange of the data on the Web, there is an increasing interest in using existing traditional relational database techniques to store and/or query XML data. Since XQuery is becoming a standard XML query language, significant effort has been made in developing an efficient and comprehensive XQuery-to-SQL query processor. In this thesis, we design and implement an <em>XQuery-to-SQL Query Processor</em> based on the <em>Dynamic Intervals</em> approach. We also provide a comprehensive translation for XQuery basic operations and FLWR expressions. The query processor is able to translate a complex XQuery query, which might include arbitrarily composed and nested FLWR expressions, basic functions, and element constructors, into a single SQL query for RDBMS and a physical plan for the <em>XQuery-enhanced Relational Engine</em>. In order to produce efficient and concise SQL queries, succinct XQuery to SQL translation templates and the optimization algorithms for the SQL query generation are proposed and implemented. The preferable <em>merge-join</em> approach is also proposed to avoid the inefficient <em>nested-loop</em> evaluation for FLWR expressions. <em>Merge-join</em> patterns and query rewriting rules are designed to identify XQuery fragments that can utilize the efficient <em>merge-join</em> evaluation. Proofs of correctness of the approach are provided in the thesis. Experimental results justify the correctness of our work.

Cette thèse propose un cadre d'évaluation pour des requêtes XQuery dans un<br />contexte de médiation de données XML. Un médiateur doit fédérer des sources de données<br />distribuées et hétérogènes. A cette fin, un modèle de représentation des requêtes est néces-<br />saire. Ce modèle doit intégrer les problèmes de médiation et permettre de définir un cadre<br />d'optimisation pour améliorer les performances. Le modèle des motifs d'arbre est souvent<br />utilisé pour représenter les requêtes XQuery, mais il ne reconnaît pas toutes les spécifica-<br />tions du langage. La complexité du langage XQuery fait qu'aucun modèle de représentation<br />complet n'a été proposé pour reconna^³tre toutes les spécifications. Ainsi, nous proposons un<br />nouveau modèle de représentation pour toutes les requêtes XQuery non typées que nous appe-<br />lons TGV. Avant de modéliser une requête, une étape de canonisation permet de produire une<br />forme canonique pour ces requêtes, facilitant l'étape de traduction vers le modèle TGV. Ce<br />modèle prend en compte le contexte de médiation et facilite l'étape d'optimisation. Les TGV<br />définis sous forme de Types Abstraits de Données facilitent l'intégration du modèle dans tout<br />système en fonction du modèle de données. De plus, une algèbre d'évaluation est définie pour<br />les TGV. Grâce µa l'intégration d'annotations et d'un cadre pour règles de transformation, un<br />optimiseur extensible manipule les TGV. Celui-ci repose sur des règles transformations, un<br />modèle de coût générique et une stratégie de recherche. Les TGV et l'optimiseur extensible<br />sont intégrés dans le médiateur XLive, développé au laboratoire PRiSM.

Chemnitz, Techn. Univ., Diplomarb., 2008.

Konstanz, Univ., Bachelorarb., 2004.

Techn. Universiẗat, Diss., 2003--Hamburg.

Submitted by Clebson Anjos (clebson.leandro54@gmail.com) on 2016-02-16T19:48:57Z No. of bitstreams: 1 arquivototal.pdf: 2420194 bytes, checksum: 8e6329082b403c1f41ce1c101f432f96 (MD5) / Made available in DSpace on 2016-02-16T19:48:57Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 2420194 bytes, checksum: 8e6329082b403c1f41ce1c101f432f96 (MD5) Previous issue date: 2015-03-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This work presents an extension of the XQuery query language called XQuery-Pref, to support conditional preferences. In order to make transparent to the user executing queries written in language XQuery-Pref, we use a system called XQPref, which is responsible for elicitation of preferences dynamics and the processing of these custom queries. Restrict the scope of this work to XML documents, essential technology for knowledge management and dissemination of data on the Web, that given the information overload, has aroused concern in personalizing query results according to the needs of each user. / O presente trabalho apresenta uma proposta de extensão da linguagem de consulta XQuery, denominada XQuery-Pref, para suporte a preferências condicionais. Com objetivo de tornar transparente para o usuário a execução de consultas escritas na linguagem XQuery-Pref, utiliza-se um sistema denominado XQPref, que é responsável pela elicitação de preferências dinâmicas e pelo processamento destas consultas personalizadas. Restringimos o escopo deste trabalho a documentos XML, tecnologia essencial para a gestão do conhecimento e divulgação de dados pela web, que diante da sobrecarga da informação, tem despertado a preocupação em personalizar os resultados de consultas de acordo com as necessidades de cada usuário.