On the Efficient Construction of Query Optimizers for Distributed Heterogeneous Information Systems - A Generic Framework
Résumé
It is now common practice to address queries to Distributed Heterogeneous Information Systems (DHIS). In such a setting, the issue of query optimization becomes crucial, and more complex than in centralized homogeneous approaches. Indeed, the optimization processing must be as flexible as possible so as to apply to different database models, and integrate different cost models. In this paper, we present a generic framework for query optimization in the context of DHISs, with the goal of facilitating the implementation of efficient query optimizers. To this end, we identify all necessary components for building such a query optimizer and we define the basic functions that have to be implemented. Moreover, we report on experiments showing that our approach allows for an efficient query optimization in the context of DHISs.