Partenaires
Rechercher
Navigation
Accueil du site > English > Research Topics > Topic 2 - Indexing and Information Search > PYRAMIDE team > Problematics
Problematics
In a large-scale dynamic environment (i.e. grid systems and peer-to-peer systems), management of heterogeneous, persistent and distributed data poses new problems and presents real challenges: discovery and selection of resources (e.g. computational resources, data sources, services), query optimization, cost models, replication, security.... The research activities of the Pyramid Team are centered on resource discovery (data sources) and dynamic distributed query optimization. Efficient discovery of relevant data sources for query execution is a complex problem because of the lack of global schemes and system instability (dynamics). The query optimization process in a large scale environment has to be decentralized in order to prevent bottleneck problems caused by centralized classic optimization techniques. In this context, an interesting approach is to exploit the mobile agent paradigm into the execution models for query optimization. This approach allows a decentralized control and assures scalability. More precisely, the research activities of the team (during the last four years) are focused on the following problems: