聚合在SQL 2008

在最近的一次商业智能类,我们钻研设计聚合在多维数据集的概念。在多维数据库中,预处理聚合提供了我们所需要的性能执行专用查询时一个巨大的数据库包含业务趋势信息。关系数据仓库包含相同的数据,但遭受属性,因为SQL引擎预计插入、更新和删除发生。执行复杂的数据重复也许数十亿行数据。这将使您的查询缓慢。分析服务引擎利用这一事实我们只加载数据通常一天一次,其余的时间数据是只读的。它可以预处理这些聚合。额外的存储成本,但这是一个公平的权衡性能。您可以允许介绍计算默认聚合,你可以添加自己的。有聚合设计向导,您可以使用当你构建多维数据集。 Then once you have started using the cube with your users you can then use the Usage-based Aggregation wizard that will take into account the actual queries submitted previously to the cube. In SSAS 2008 there is a new tab in the Cube Designer, entitled appropriately: Aggregations. This tab helps identify the aggregations currently in the cube and has a new Advanced view to keep track of the individual aggregations. Here's a great article that summarizes the options available in 2008 including the extra add-in "Aggregations Manager": (scroll down to the bottom of the article for the good stuff): Recommended practices for SQL Server Analysis Services aggregations, by By Baya Dewald http://searchsqlserver.techtarget.com/tip/0,289483,sid87_gci1365109,00.html cheers Brian