Professional SQL Server™ Analysis Services 2005 with MDX

Chapter 11. Updating Your UDM Data

In previous chapters you saw how metadata constituting OLAP databases (the UDM) can be manipulated using the Analysis Services 2005 development environment. You learned that the metadata changes are propagated to Analysis Services instance through Create or Alter statements. Similarly, dimension and fact data within your UDM might have to be updated. For example, change of marital status for an employee, where marital status is an attribute within the employee dimension. Or perhaps an update for next fiscal year's budget based on the current year's revenue where budget is a measure within your UDM. Analysis Services 2005 provides you the ability to update dimension as well as cube data. Data updates within your UDM are referred to as a writeback because you are writing data back into an existing UDM. Updating members within your dimension is referred to as dimension writeback and updating the measure values within your cube is called cell writeback. By the way, don't let the three letter acronym throw you off; a UDM is another way of referring to a cube.

Dimension writeback enables a user to add, update, or delete dimension members; such as when a new employee joins the company, the user can update the employee dimension by adding a new member. Likewise, when an employee changes departments or leaves the company altogether, the user can update or delete relevant dimension members. When you update dimension members, Analysis Services automatically ...