The MultiDimensional eXpressions, or MDX, language is used to query the data in a multidimensional in an OLAP database. In the case of examples here, SQL Server Analysis Services. This example uses the Contoso demo cube available for download here: http://www.microsoft.com/download/en/details.aspx?displaylang=en&id=18279
Function Name: BottomCount
Use Case: Brings back the lowest X number of values from a set
MSDN Link: http://msdn.microsoft.com/en-us/library/ms144864.aspx
Notes: Always breaks a hierarchy
Syntax: BOTTOMCOUNT(<<MDX Set>>, Number of Tuples to return, <<Measure>>)
Sample Query:
SELECT
[Measures].[Online Sales Amount]
ON COLUMNS,
BOTTOMCOUNT(
[Product].[Product Category].CHILDREN,
2,
[Measures].[Online Sales Amount]
)
ON ROWS
FROM [Contoso]
Sample Results: