Efficient view maintenance using version numbers

Maintaining a materialized view in an environment of multiple, distributed, autonomous data sources is a challenging issue. The results of incremental computation are effected by interfering updates and compensation is required. In this paper, we improve the incremental computation proposed in our previous work by making it more efficient through the use of data source and refreshed version numbers. This is achieved by cutting down unnecessary maintenance queries and thus their corresponding query results. The number of times of sending subqueries to a data source with multiple base relations are also reduced, as well as avoiding the execution of cartesian products. Updates that will not affect the view are detected and incremental computation is not applied on them. We also provide a compensation algorithm that resolve the anomalies caused by using the view in the incremental computation.