Structure of a Fact Table
A fact table typically has one record for each record of the base table; this row is a fact. The fact contains one field for each level and one field for each measure. The following shows a sketch:
The field for a given level might contain no values, a single value, or multiple values. Each distinct value corresponds to a member of this level. The field for any given measure contains either null or a single value.
When the system builds this fact table, it also generates indexes for it.
The fact table does not contain information about hierarchies and dimensions. In the fact table, regardless of relationships among levels, each level is treated in the same way: the fact table contains one column for each level, and that column contains the value or values that apply to each source record.
Tip:
By default, the fact table has the same number of rows as the base table. When you edit a cube class in Studio, you can override its OnProcessFact() callback, which enables you to ignore selected rows of the base table. If you do so, the fact table has fewer rows than the base table.
