Fact load parameters

Parameters can be set up to allow flexibility in choosing column names and to avoid superfluous columns in the fact table. These are set in the _FactLoadParameters metadata table.

The fact load parameters match each dimension with one of:

• A column in the fact table.
• A single element of that dimension (the target element). All cells loaded have this element as a coordinate in this dimension.

The simplest scenario is with all the dimensions of the cube matching all the columns of its source fact table.

Another scenario is one dimension matching a target element instead of a column. Here, the dimension does not need a matching column in the fact table. All data go to cells with the target element as a coordinate of that dimension. The fact table has one column less than the cube has dimensions. There can be any number of dimensions with target elements in place of columns.

There is also a possibility that elements in the fact load are not recognized, that is to say, they do not exist on their dimensions. Or, that there are blanks (NULLs) in the fact table where there should be elements. To prevent outright rejection of those rows, the fact load parameters table allows replacement elements on their dimension. These are referred to as Target Element Unknown and Target Element Missing respectively. An error element in a row results in the data being sent to the cell with coordinate Target Element Unknown of its dimension, and a missing element to the cell with coordinate Target Element Missing.