I recently took the opportunity to sit through a SAS e-Learning course titled Creating OLAP Cubes. It was a pretty detailed walkthrough for individuals creating OLAP cubes using SAS OLAP Cube Studio or Data Integration Studio. Dimensions, levels, and hierarchies were described thoroughly, but measures were inadequately addressed. Overall, it was a fine course for staff preparing to develop their first cube, particularly for small course fee.
There were a few takeaway points from the course that were worth sharing, particularly the last one, which I learned the hard way:
- Every cube must have at least one dimension.
- You can have only one TIME dimension per cube.
- In a TIME dimension, you must order levels from the most general time period to the most specific with regard to the drill path.
- You can specify a maximum of 1,024 measures per cube.
- If you are creating a cube from a detail table or a star schema and you are including aggregated data from tables other than the input data source, then you must include measures for the stored statistics that are required for each derived statistic that you want to create for the new cube.
- When you edit the definition of a cube, any existing physical cube is deleted.
- To perform tasks on a physical cube (such as deleting, rebuilding, and tuning), you must have the appropriate file access permissions at the operating system level. If you do not have access, contact your system administrator for more information.