Adding limit parameters to bar charts in Pentaho Report Designer

Question

I am using Pentaho Report Designer to generate reports from my olap cube using mdx. I want to generate bar chart reports from Pentaho Report Designer. I have 50000 records and writing a MDX query to display keywords along with their count. Problem is bar chart that is created is of 50000 records, but I want to pass two parameters that act as start and end value to display i.e user is prompted to enter starting and ending parameters (suppose he enters 1 and 10) so 10 records should be displayed.

Answer 1

I do not know the specifics of Pentaho MDX, but in general, I would use the following approach, assuming the 50000 records are in hierarchy [DimA].[Record]:

WITH SET [Selected Records] AS
     SubSet([DimA].[Record].[Record].Members,
            ParamRef('start') - 1, 
            ParamRef('end') - ParamRef('start') + 1
           )
SELECT { [Measures].[Count] }
       ON COLUMNS,
       [Selected Records]
       ON ROWS
FROM [MyCube]

I am a bit guessing about the use of ParamRef in Mondrian MDX here. The SubSet function is described for Analysis Services here: http://msdn.microsoft.com/en-us/library/ms144767.aspx