问题
I have Dimension "Customer". Each Customer can have some buisness units and some departmens. I should bild 2 hierarchies: Customer->Department and Customer->Buisness Unit. So, I also need to set key attribute. This is my question: What should be use as key attribute? May be I do this wrong? Could you help?
回答1:
To define hierarchies, you should ask the following questions:
If I group the departments, I have a consumer? If I group the business, I have a consumer? If I group the departments and business, I have a consumer?
If grouping the departments get a consumer, so the hierarchy is: Consumer > Department. Similarly with the other. If grouping the department and business (an attribute in dimension that contains two pieces of information, for example, DPT1-BUS1) obtains a consumer, the hierarchy is: Consumer > Department_Business.
It is not recommended to have null attributes in a dimension. So make sure that the consumer needs to have a business and a department. Otherwise, rephrase the modeling of the data warehouse. Generally, a key dimension is a artificial key auto-increment...
I recommend that read Kimball
Hope this help.
来源：https://stackoverflow.com/questions/8490657/olap-dimension-structure