I've got a data source that I will need to use as the basis for some 12 to 15 reports and because the table is quite large (several million rows and over 50 columns), I created a SP that given a passed parameter, will return filtered datasets of varying numbers of rows and columns specific to the requirements of each report.
So I thought that for each separate report, I could create a Report Parameter, set it equal to the default value of the result set I wanted to return and then pass that value to a single Shared Dataset.
The problem is that when I create a Shared Dataset in SSRS (R2) and attempt to execute the SP with the passed parameter, I can't seem to get the SP to return the different datasets (it returns the same dataset regardless of what I've set the parameter to), even if I replace the parameter with the actual value of the result set I want returned.
I've set the parameter value every place I can think of (Report Data Parameter, Report Data Dataset, Solution Shared Dataset) but nothing seems to change the dataset that's returned when I refresh the Shared Dataset.
I've also tried using an embedded dataset rather than the Shared Dataset but the same issue persists, I can't get the correct set of fields to return when I refresh the data, even though the SP works without issue when executed in a query window ...
 In a more general sense, I guess I'm asking, "what exactly happens when I hit 'Refresh Fields' in Dataset Properties when I'm using a dynamic SP"?