when clicking on the Essbase datasource, the "extract data" button is not available (not even grayed out). Any idea, why? This would be a great feature, since often the OLAP structure is counterproductive for visualization, and normalizing the data in form of an extract would be very helpful.
It is not possible to take an extract of a cube data source. This is by design: You cannot take an OLAP cube "offline" and all analysis must occur directly against the cube data source.