%0 Journal Article
%T What-If Query Processing Policy of Main-Memory OLAP System<br>主存OLAP系统中what-if查询处理策略
%A ZHANG Yan-Song
%A XIAO Yan-Qin
%A WANG Shan
%A CHEN Hong
%A <br>张延松
%A 肖艳芹
%A 王珊
%A 陈红
%J 软件学报
%D 2010
%I 
%X A what-if analysis can provide a more meaningful information than classical OLAP (on-line analysis processing). Multi-Scenario hypothesis upon historical data needs efficient what-if data view support. Two novel algorithms of deltaMap and pre-merge, which can greatly improve the performance of delta table algorithm with set operations, are proposed. To analyze the performance of query re-writing algorithm and delta cube algorithm under different what-if update conditions, a global performance analysis and comparison are presented in the experiment section. This paper proposes a cost model for a what-if analysis processing engine, based on different algorithms with parameters such as application scenario, what-if update rate, complexity of what-if updates, memory storage policy, cardinality of query result set etc, that can be used as a practical framework in a what-if analysis system.
%K what-if analysis
%K main-memory database
%K delta table
%K query re-writing
%K deltaMap index
%K pre-merge algorithm<br>what-if分析
%K 内存数据库
%K delta表
%K 查询重写
%K deltaMap索引
%K pre-merge算法
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=5B3AB970F71A803DEACDC0559115BFCF0A068CD97DD29835&cid=8240383F08CE46C8B05036380D75B607&jid=7735F413D429542E610B3D6AC0D5EC59&aid=3590E05B19457813EB1CEFDF0483A6A6&yid=140ECF96957D60B2&vid=659D3B06EBF534A7&iid=F3090AE9B60B7ED1&sid=B69FEB12D9A4855D&eid=8BBC50AE1A1F67D9&journal_id=1000-9825&journal_name=软件学报&referenced_num=0&reference_num=15