SSAS Series--"07" Multidimensional data (query cube)

Original: SSAS Series-"07" Multidimensional data (query cube)

1. What is MDX?

MDX, called Multidimensional Expressions , is a query language, a query language similar to SQL, based on the XML for Analysis (XMLA) specification, with extensions specific to SQL Server analysis Services.

2. What is the difference between MDX and SQL?

Learning things, always like "preconceived", when learning MDX, my first idea is: what is the difference between MDX and SQL? In fact, after figuring out the problem, MDX is even clearer. SQL is OLTP-based, and MDX is OLAP-based, which means that MDX is querying multidimensional data. MDX, like SQL, also has a number of different functionality APIs to support MDX. These include object linking and inline data functions for online analysis (that is, Ole DB for OLAP), ADO MD, Adomd.net, XMLA (XML for analyses), and so on. The specification of OLE DB for OLAP describes the complete relationship between the MDX query and the data structure to which the queried information is sent to the client.

3. What can MDX do?

Returns data from an SSAS cube to a client application, formats query results, and performs cube design tasks, including defining calculated members, named sets, range assignments, and key performance indicators (KPIs), and performing administrative tasks, including dimension and cell security.

4, the first multidimensional query?

Query 1965 China's oil storage (data virtual)?

Figure Query

   Select {[Measures]. [Oil proved reserves]}  on Columns
,{[Dim time]. [Year].&[19]}  on rows  from [BPDW]
where [Dim Geography]. [Country name].&[total Asia Pacific]&[china]

Figure MDX Query Results

Haha, to this step will generally small have a sense of accomplishment, in fact, it is so simple, a few to come out, the following questions, I have to introduce the more important in the MDX knowledge, those who need to commonly used east to like their own name as deep into the mind.

SSAS Series--"07" Multidimensional data (query cube)