design of an embedded cost model for mobile queries
In the context of heterogeneous and distributed data sources in large scale, the traditional optimizers generate execution plans can be sub-optimal because: the estimations are inaccurate, the unavailability of data and the execution environment is unstable. To deal with the sub-optimality of an execution plan, an approach consists to execute each relational operator of an execution plan by a mobile agent. This one can migrate from a site to the other one to comply. The information stored in the site, where the agent is situated, can be insufficient to calculate the site of migration of the agent. In this paper, we propose integrating into the mobile agent, executing an operator, a cost model. This last one allows the mobile agent to choose its site of migration the most appropriate.
cost model optimization mobile agents heterogeneous distributed databases