In Business Intelligence Developer Studio, I'm wondering why one would want to create a report model from an OLAP cube.
As far as I understand it, OLAP cubes and report models are both business-oriented views of underlying structures (usually relational databases) that may not mean much to a business user. The cube is a multidimensional view in terms of dimensions and measures, and the report model is... well I'm not sure entirely -- is it a more business-oriented, but still essentially relational view?
Anyway, in Report Builder I can connect directly to both an OLAP cube or a report model. So I don't see why, if I have an OLAP cube which already provides a business-oriented view of the data suitable for end-users, why I would then convert that to a report model and use that in Report Builder instead.
I think I'm obviously missing some fundamental difference between report models and cubes -- any help appreciated!
In SQL Server 2005 you still had to create a report model over a cube to use Report Builder. RB 2.0 will directly open a cube, although not all available features of SSAS are necessarily supported by RB. This blog entry by Teo Lachev discusses it in more detail.