You can automatically generate a join index for each selected fact table and the dimension tables that it references. The rebuild process only applies to fact tables selected in the Selection tab of the Join Index Rebuild tab.
Each automatically generated join index consists of the references that link a fact table to all the dimension tables located on a single axis proceeding from the fact table.
A reference between two fact tables does not generate any join index.
A join index is constrained and can only be defined for tables that are organized in a connected tree.
Parameter |
Result of selection |
---|---|
Delete and Rebuild |
When selected all existing indexes are deleted before join index rebuild. |
Preserve |
When selected, preserves all existing join indexes in the PDM. |
The same feature applies to Oracle bitmap join indexes (see Automatically creating bitmap join indexes through rebuilding).