usually, we may have 2 common cases: 1, only have a fact table which has already been joined with lookup tables, take it as a wide table
2, we have star schema data model, and when defining the cube, we define the join with the fact table and lookup tables, currently, to the 1st case, we cannot create derived dimensions based on the fact table which can be created only from the lookup tables, for example, we have fact table: region_id, region_name, province_id, province_name, city_id, city_name, M1, M2, ...Mn, we want to create a hierarchy dimension: region_id->province_id->city_id, and a derived dimenison: (region_name, province_name, city_name) as well, if we can achieve it, there will be no complicated joins at all, and also, the join will take much time in the first step when building the cube~ thus, will we support such demension design? to the 2nd case, even though we make the join, however, if the column names are changed for some reasons, we will have to build the whole cube again instead of only update the dimension data?
