Adapting Materialized Views after Redefinition in Distributed Environments

In this paper, we show how view adaptation can be supported in order to keep views up to date and running after view redefinition. In particular in the area of integrated systems such as Web sites, data warehousing systems and mediator systems, efficient solutions to this task are of most importance. The proposed view adaptation is based on a novel view selection approach that consists in decomposing views into fragments and then merging them into a Multi View Materialization Graph, sharing materialized fragments where possible. The goal is to minimize both communication cost (i.e., accessing the sources) and the cost of adapting the view materialization. In related work, view adaptation is based solely on the old materialization of the same view. Our approach performs view adaptation regarding all the materialized views therefore it optimizes the communication cost.