Cubes can be very complex objects for users to explore in Microsoft SQL Server 2005 Analysis Services. A single cube can represent the contents of a complete data warehouse, with multiple measure groups in a cube representing multiple fact tables, and multiple dimensions based on multiple dimension tables. Such a cube can be very complex and powerful, but daunting to users who may only need to interact with a small part of the cube in order to satisfy their business intelligence and reporting requirements.
In Microsoft SQL Server 2005 Analysis Services (SSAS), you can use a perspective to reduce the perceived complexity of a cube in Analysis Services. A perspective defines a viewable subset of a cube that provides focused, business-specific or application-specific viewpoints on the cube. The perspective controls the visibility of objects that are contained by a cube. The following objects can be displayed or hidden in a perspective:
- Measure groups
- Key Performance Indicators (KPIs)
- Calculations (calculated members, named sets, and script commands)
For example, the Adventure Works cube in the Adventure Works DW sample Analysis Services database contains eleven measure groups and twenty-one different cube dimensions, representing sales, sales forecasting, and financial data. A client application can directly reference the complete cube, but this viewpoint may be overwhelming to a user trying to extract basic sales forecasting information. Instead, the same user can use the Sales Targets perspective to limit the view of the Adventure Works cube to only those objects relevant to sales forecasting.
Objects in a cube that are not visible to the user through a perspective can still be directly referenced and retrieved using XML for Analysis (XMLA), Multidimensional Expressions (MDX), or Data Mining Extensions (DMX) statements. Perspectives do not restrict access to objects in a cube and should not be used as such; instead, perspectives are used to provide a better user experience while accessing a cube.
A perspective is a read-only view of the cube; objects in the cube cannot be renamed or changed by using a perspective. Similarly, the behavior or features of a cube, such as the use of visual totals, cannot be changed by using a perspective.
Perspectives are not meant to be used as a security mechanism, but as a tool for providing a better user experience in business intelligence applications. All security for a particular perspective is inherited from the underlying cube. For example, perspectives cannot provide access to objects in a cube to which a user does not already have access. - Security for the cube must be resolved before access to objects in the cube can be provided through a perspective. Related topic:Securing Analysis Services