2DCMA: An Effective Maintenance Algorithm of Materialized Views in Peer Data Management Systems

Update management is very important for data integration systems. Soupdate management in peer data management systems (PDMSs) is a hotresearch area. This paper researches on view maintenance in PDMSs.First, the definition of view is extended and the peer view, localview and global view are proposed according to the requirements of applications.There are two main factors to influence materialized views in PDMSs. Oneis that schema mappings between peers are changed, and the other is thatpeers update their data. Based on the requirements, this paper proposesan algorithm called 2DCMA, which includes two sub-algorithms: data anddefinition consistency maintenance algorithms, to effectively maintainviews. For data consistency maintenance, Mork's rules are extended forgoverning the use of updategrams and boosters. The new rule system canbe used to optimize the execution plan. And are extended for the data consistencymaintenance algorithm is based on the new rule system. Furthermore, anECA rule is adopted for definition consistency maintenance.Finally, extensive simulation experiments are conducted in SPDMS. Thesimulation results show that the 2DCMA algorithm has better performancethan that of Mork's when maintaining data consistency. And the 2DCMAalgorithm has better performance than that of centralized viewmaintenance algorithm when maintaining definition consistency.