摘要
针对含聚集物化视图的增量维护问题,提出了一种基于逐步更新思想的增量维护模型和方法。该方法建立了聚集函数计算前查询结果与基表记录之间的映射关系表,并根据映射关系表的增量变化更新物化视图的聚集函数。针对之前方法对于MAX/MIN聚集函数增量更新的不足,在仅利用增量数据不能更新聚集函数值时,采用仅重新计算映射关系表中相关行的MAX/MIN函数值的方法,极大地减小了更新MAX/MIN聚集函数的计算量。在OSCAR数据库的应用表明了该方法的有效性和高效性。
To solve the incremental maintenance problem of materialized views with aggregation, a model based on progressive updating is proposed.In this model, a mapping table between base relations and the query result before aggregation evaluation is built.And aggregation values of the materialized view are evaluated in terms of the increment changes of the mapping table.To overcome the shortcomings of previous methods about the updating of MAX/MIN aggregations, this model only recalculates MAX/MIN values of related rows of the mapping table, and the computational complexity is reduced significantly.The effectivity and efficiency of this model is demonstrated in Shenzhou OSCAR database.
出处
《计算机工程与设计》
CSCD
北大核心
2009年第23期5419-5423,共5页
Computer Engineering and Design
基金
国家863高技术研究发展计划基金项目(2005AA4Z3020)
