Handling Transactional-Level Data - Expert Cube Development with SSAS Multidimensional Models - page 121

At this point, if we close the XML file and return to the Actions pane, we will see the
updated Drillthrough Columns list, as shown in the following screenshot:
The only visible change is that the Category column has been switched with
List Price in the Product dimension. However, the output columns returned
by this drillthrough action will be in the order we specified when we manually
altered the XML file, with columns from different dimensions appearing wherever
we want them to. We have to be careful about making further modifications in
the Drillthrough Columns list. If we don't make any further modifications to the
columns of the dimensions we manually altered in the XML file, we should be able
to keep the order we defined manually. Otherwise, we have to repeat the manual
modification of the XML file to get the desired column order.
Drillthrough and calculated members
We have seen that the drillthrough feature can apparently operate on any cell of the
cube. In particular, we define drillthrough by choosing the measure group on which
the drillthrough action will be active. However, the drillthrough operation works
only on "real" measures. If we have defined calculated measures, drillthrough will
not operate on these cells. Moreover, drillthrough does not operate on any cell that
references any calculated member on any dimension, not just measures.
The rationale behind this is very simple. A calculated member may not have a direct
relationship with a set of rows in the fact table. In reality, that relationship could
be described for many calculated members, but Analysis Services does not offer a
way to define this relationship. For this reason, drillthrough is not supported on
calculated members.