Example - Debugging a Drill-through Definition

Here is an example of debugging a drill-through definition.

Your OLAP source has a Products dimension with the levels Line, Type, and Name. You have defined a parameter in your relational target to match each level of that OLAP source dimension. You can have a situation where you see all target parameters from a single dimension displayed in the View Mapped Target list. This is likely because the individual target parameters are mapped to a single dimension in the drill-through definition, in this case the Products dimension. In your OLAP data source, you have a business key value, or the source value used to create the members, that is duplicated in all three levels, as shown in the following table.

Table 1. Example of problematic parameter mapping for drill-through definition
Parameter Name	Display Value	Use Value
Prod Line Param	Camping Equipment	1
Product Type Param	Cooking Gear	1
Product Name Param	Trail Chef Water Bag	1

Having all three parameters mapped to the Products dimension is correct if the use values are not duplicated in the dimension. In the preceding table, the members from all three levels have the same use value. In this case the drill-through operation cannot determine which level is the correct one because the scenario indicates that all levels are valid. In this situation, the first level encountered with a valid business key or use value is fulfilled by the drill-through definition. This can result in unexpected behavior.

This example shows why it is important to always ensure that your data warehouses and OLAP sources are designed with unique business keys or source values. To correct this situation, the drill-through definition should have each individual target parameter mapped to each associated level in the source metadata rather than in the dimension.