Data warehouses can be considered as materialized views which maintain the online analytical information extracted from distributed data sources. When data sources are changed, materialized views should be maintained correspondingly to keep the consistency between data sources and materialized views. If a view is defined through joining several source relations, an update in one source relation invokes a set of join subqueries thus the view maintenance takes much time of processing. In this paper, we propose a view maintenance algorithm processing these join subqueries in parallel by using referential integrity constraints over source relations. A relation which has several foreign keys can be joined with referenced relations independently. The proposed algorithm processes these join operations in parallel then it merges their results. With the parallel processing, the algorithm can maintain materialized views efficiently. We show the superiority of the proposed algorithm using an analytical cost model.
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