Nicolas Travers

Position

• Assistant Professor in Computer Science at CNAM Paris
• Member of the Vertigo database team, component of the CEDRIC research laboratory and of the Wisdom database PPF

Research

Extensible optimization in a distributed context

XQuery is the emerging standard for querying XML data sources. XLive is a light XML/XQuery mediator developed at University of Versailles whose engine processes an XML algebra derived from the relational one extended to process in dataflow XML trees. The query optimizer translates a subset of XQuery in this algebra. To extend the optimizer’s coverage of XQuery and better optimize query plans, we propose a representation of queries as graphs of trees, more precisely as tree pattern graphs interconnected by hyperlinks. Our structure called Tree Graph View (TGV) is an extension of the Generalized Tree Pattern graph as a concise and practical representation of an XQuery request. It is designed to be a more intuitive model of queries and to allow direct optimization before generating the physical execution plan. TGV lends itself to simple algorithms to generate efficient algebraic execution plans. Moreover, it is effective for view translation and query simplification, and for taking into account source capabilities. We are currently implementing it to support the new XLive optimizer.

Projects and Softwares

• RoSeS - Really Open and Simple Web Syndication (ANR)
• XLive : An XML Light Integration Virtual Engine (software)
• Tree Graph Views (TGV) (Representation model for XQuery)
• Sem Web : Interrogation du Web Sémantique avec XQuery (ACI MD)
• WebContent (RNTL)
• PADAWAN (ANR)

Publications

All publications

Last publications :

Authors	Title	Proceedings	Place	Type	Date	Show
Serge Abiteboul, T. Allard, Philippe Chatalic, Georges Gardarin, A. Ghitescu, François Goasdoué, Ioana Manolescu, Benjamin Nguyen, M. Ouazara, A. Somani, Nicolas Travers, Gabriel Vasile, Spyros Zoupanos	WebContent: efficient P2P Warehousing of web data	PVLDB	Auckland - New-Zealand	Int. Conference	Jul 2008
Tuyêt Trâm Dang-Ngoc, Nicolas Travers	Tree Graph Views for a Distributed Pervasive Environment	NBIS, issue 1, IEEE & DEXA Conference	Regensburg, Germany	Int. Conference	Sep 2007
Nicolas Travers, Tuyêt Trâm Dang-Ngoc, Tianxao Liu	Untyped XQuery Canonization	WebEtrends, APWeb-WAIM	HuangShan, China	Int. Workshop	Jun 2007	x
Nicolas Travers, Tuyêt Trâm Dang-Ngoc	An Extensible Rule Transformation Model for XQuery Optimization	ICEIS, issue 9	Madeira,Portugal	Int. Conference	Jun 2007	x
Nicolas Travers, Tuyêt Trâm Dang-Ngoc, Tianxao Liu	TGV : a Tree Graph View for Modelling untyped XQuery	DASFAA, Issue 12	Bangkok, Thailand	Int. Conference	Apr 2007	x

Teaching

My academic teaching activities concern relational databases, XML data management and Web technologies.

• Databases :
  • Systèmes de gestion de bases de données (NFP107)
  • Bases de données avancées (NFE204)
  • Ingénierie des bases de données (NFE106)
• Web technologies :
  • Infrastructures technologiques pour le commerce électronique (NFE102)

Last update: 19/07/2007