cube | 易学教程

What does the SSAS setting None in AggregateFunction do?

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问题 As I understand Microsoft's explanation setting the AggregateFunction of a measure to "None" should null out the value unless you are viewing the data at the lowest possible level. (i.e. the data element is a copy of the value in one exact cell in the cube). I've created a fact table at the grain product id and sales date, and have set AggregateFunction property of a few measures (they are percentages of some sort) to "None", and I nulls at every level in the cube, even the product/sales date

Apache Kylin

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Overview Kylin 的使命是超高速的大数据 OLAP （Online Analytical Processing），也就是要让大数据分析像使用数据库一样简单迅速，用户的查询请求可以在秒内返回。其中的关键就是打破查询时间随着数据量成线性增长的这个规律。解决方案是针对维度聚合的预计算，因为由于业务范围和分析需求是有限的，有意义的维度组合也是相对有限的，一般不会随着数据的膨胀而增长。传统的Hadoop生态提供了大规模并行处理和列式存储两大关键技术，预计算是Kylin提供的第三大关键技术。 Concept MOLAP（Multidimensional Online Analytical Processing）Cube 多维立方体分析 Dimension and Measure（维度和度量）维度是观察数据的角度，度量是被聚合的统计值 Cube and Cuboid N个维度，组合的可能性共有2^N种；对于每一种维度的组合，将度量做聚合运算，然后将运算的结果保存为一个物化视图，称为 Cuboid ;所有维度组合的 Cuboid 作为一个整体，被称为 Cube 。一个 Cube 就是许多按维度聚合的物化视图的集合。 Process Kylin的工作原理就是对数据模型做 Cube 预计算，并利用计算的结果加速查询：指定数据模型，定义维度和度量预计算Cube

Is there a way to simulate GROUP BY WITH CUBE in MySql?

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问题 MySql supports GROUP BY WITH ROLLUP which will return aggregates for the last x of the n columns in the group by but does not support GROUP BY WITH CUBE to take all combinations of the n columns and take aggregates. I can simulate this by doing unions of GROUP BY WITH ROLLUP queries, but MySql is materializing my subquery multiple times. I am using a group by on a large subquery, so this is suboptimal. Is there a way to solve this without temporary tables? 回答1: Short answer: No. Long answer:

Draw OpenGL on the windows desktop without a window

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问题 I've seen things like this and I was wondering if this was possible, say I run my application and it will show the render on whatever is below it. So basically, rendering on the screen without a window. Possible or a lie? Note: Want to do this on windows and in c++. 回答1: It is possible to use your application to draw on other application's windows. Once you have found the window you want, you have it's HWND, you can then use it just like it was your own window for the purposes of drawing. But

SSAS - Facts that happened over a time range

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问题 I don't really know how to handle facts that happened over a period of time. I sually deal with facts that happened on a specific date. In clear, my facts have a start_date and an end_date. So, let's say my start_date is 01/01/2008 and my end_date is 01/01/2011. I need to get the number of those facts that happened in 2009 and those that happened this year. The same fact can have happened on both years. The way to determine a fact is part of 2009 is to check for 12/31/2009. I was thinking

R & COM-Objects: How to connect to a OLAP cube on Windows

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问题 I would like to use a .COM object in R to establish a ADODB.Connection to an OLAP cube. And for that I'm using the rscproxy, rcom and the statconnDCOM packages. However, I am not really successful in finding any useful documentation for the rcom package, and therefore, I am struggling big times with using .COM objects in R. I am able to create a .COM object, but I have no idea about the next steps. What I want to do: set the connection string open the R <-> cube connection execute an mdx

SSAS - Facts that happened over a time range

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I don't really know how to handle facts that happened over a period of time. I sually deal with facts that happened on a specific date. In clear, my facts have a start_date and an end_date. So, let's say my start_date is 01/01/2008 and my end_date is 01/01/2011. I need to get the number of those facts that happened in 2009 and those that happened this year. The same fact can have happened on both years. The way to determine a fact is part of 2009 is to check for 12/31/2009. I was thinking about a StartDate and EndDate dimensions, using date ranges (so from the first date of my StartDate

Calculating the number of days in a time dimension node - with Grand Total

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问题 I need to know the number of days in a time dimension period for calculating weighted averages. I am using the following expression in a calculated measure to obtain the number of days in the current dimension member: Count( Descendants( [Date].[Calendar].CurrentMember, [Date].[Calendar].[Date Key] ) ) This works fine for all drill-down situations, but it does not work for the Grand Total when I have a filter. I suspect that CurrentMember does not work in this situation. It always returns the

Is it possibile to remotely process an SSAS cube throgh script?

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问题 I have an SQL Server Analysis Service ( SSAS ) cube (developed with BIDS 2012 ) and I would like to give the opportunity to the users (that use cube through PowerPivot ) to process the cube in their local machines. I found some material on how to make a scheduled job on the server through Powershell or SQL Agent or SSIS but no material on remotely process the cube. Any advice? 回答1: There are several possibilities to trigger a cube processing. The low level method is issuing an XMLA statement

How to use “cube” only for specific fields on Spark dataframe?

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