Understanding Dimensional Queries

The basic goals of multiple-fact querying are:

• Preserve data when fact data does not perfectly align across common dimensions, such as when there are more rows in the facts than in the dimensions.
• Prevent double-counting when fact data exists at different levels of granularity by ensuring that each fact is represented in a single query with appropriate grouping. Determinants may need to be created for the underlying query subjects in some cases.