Professional Microsoft® SQL Server® Analysis Services 2008 with MDX

4.3. Data Source Views in Depth

Data warehouse designs consist of several fact tables and all the associated dimension tables. Small data warehouses are usually comprised of 10 to 20 tables, whereas larger data warehouses can have more than a hundred tables. Even though you have a large number of tables in your data warehouse, you will likely work with a small subset of those tables; each of which has relationships between them. For example, assume you have sales, inventory, and human resources (HR) data to analyze and the HR data is not strongly related to the sales and inventory data but there is a desired linkage. Then you might create two cubes, one for Sales and Inventory information and another one for HR. It is quite possible the Sales, Inventory, and HR information could be stored in a single data source — in the ODS or OLTP system.

Employee information (HR) could be related to the sales and inventory information within the company so far as there is a link between a given sales event and the employee who made the sale. You might want to slice the sales data by a specific employee, but to do so you must access information that is a part of a separate cube only accessible to the HR department (for security reasons). You can get around this problem by making a single DSV containing all the tables that store sales, inventory, and HR information of a company. From that DSV, both cubes can be formulated and permissions set such that only members of the HR group can drill down ...