Optimisation Extensible dans un Mediateur de Données Semi-Structurées

Abstract : This thesis proposes to evaluate XQuery queries into a mediation context.
This mediator must federate several heterogeneous data sources with an appropriate query
model. On this model, an optimization framework must be defined to increase performance.
The well-known Tree Pattern model can represent a subset of XPath queries in a tree form.
Because of the complexity of XQuery, no model has been proposed that is able to represent all
the structural components of the language. Then, we propose a new logical model for XQuery
queries called TGV. It aims at supporting the whole XQuery specification for un-typed que-
ries. Before modelling, a canonization step transforms XQuery queries into a canonical form
in order to check more XQuery specifications. This form allows us to translate in a unique
way queries into our TGV model. This model takes into account a distributed heteroge-
neous context and eases the optimization process. It integrates transformation rules, cost
evaluation, and therefore, execution of XQuery queries. The TGV can be used as a basis
for processing XQuery queries, since it is °exible, it provides abstracts data types which can
be implemented according to the underneath data model. Moreover, it allows user-defined
annotating and also cost-related annotating for cost estimation. Although the model will be
useful, it relies on XQuery complicated specifications. TGV are illustrated in this thesis with
several figures on W3C's use-cases. Finally, a framework to define transformation rules is
added to the extensible optimizer to increase the XLive mediator performances. The XLive
mediation system has been developed at the PRiSM Laboratory.
Document type :
Theses
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https://tel.archives-ouvertes.fr/tel-00131338
Contributor : Nicolas Travers <>
Submitted on : Friday, February 16, 2007 - 9:55:11 AM
Last modification on : Thursday, January 11, 2018 - 6:21:30 AM
Long-term archiving on : Friday, September 21, 2012 - 11:31:38 AM

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Nicolas Travers. Optimisation Extensible dans un Mediateur de Données Semi-Structurées. Autre [cs.OH]. Université de Versailles-Saint Quentin en Yvelines, 2006. Français. ⟨tel-00131338⟩

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