通过源关系补偿降低实化视图维护查询代价
Reducing Maintenance Query Cost of Materialized View by Source Relations Compensation
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摘要: 为了解决分布式环境下实化视图维护时基于补偿查询修正维护查询结果所导致的计算及传输代价较高的问题,提出了一个实化视图维护方案:源关系补偿维护(SRCM)方案.它通过补偿并发更新冲突把维护查询涉及的源关系回退到所需状态,然后直接计算并返回正确查询结果.基于代价模型的分析及模拟实验结果表明,SRCM方案与以前的SWEEP和MEDWRAP方案相比,有效地降低了维护查询的整体代价.Abstract: To resolve the problem of the high calculation and transmission cost caused by correcting the maintenance query based on compensation queries when incrementally maintaining materialized view in distributed environments,a view maintenance schema called source relations compensation maintenance(SRCM) was proposed.It pushed back related relations to the required states by compensating concurrent update conflicts,and directly evaluated and returned correct query results.Results of the analysis based on the cost model and imitation experiment show that SRCM effectively reduces the overall cost of maintenance queries compared with previous SWEEP and MEDWRAP compensation solutions.