Defining Logical Joins with the Business Model Diagram

The Business Model Diagram shows logical tables and any defined joins between them. Logical foreign key joins may be needed if the Oracle BI Server is to be used as an ODBC data source for certain third-party query and reporting tools.

NOTE:  It is recommended that you use the Business Model Diagram to define complex joins. It is recommended that you do not use the Diagram to define logical foreign keys.

To display the Business Model Diagram

1. In the Administration Tool, right-click a business model, and then select Business Model Diagram > Whole Diagram.
2. Click one of the following buttons on the Administration Tool toolbar:
   • New complex join (Recommended)
   • New foreign key (Not recommended. This capability exists to provide compatibility with previous releases.)
3. With one of the buttons selected, move the cursor to the first table in the join (the one of the one-to-many join).
4. Left-click and move the cursor to the table to which you want to make the join (the many of the one-to-many join), and then left-click on the second table.
   The Logical Foreign Key or Logical Join dialog box appears.
5. For a logical foreign key, select the joining columns from the left and the right tables.
6. (Optional) To specify a driving table for the key, select a table from the Driving drop-down list, and an applicable cardinality.
   This is for use in optimizing the manner in which the Oracle BI Server processes multi-database inner joins when one table is very small and the other table is very large. Do not select a driving table unless multi-database joins are going to occur. For more information about driving tables, refer to Specifying a Driving Table.
   CAUTION:  Use extreme caution in deciding whether to specify a driving table. Driving tables are used for query optimization only under rare circumstances and when the driving table is extremely small (fewer than 1000 rows). Choosing a driving table incorrectly can lead to severe performance degradation.
7. Select the join type from the Type drop-down list.
8. To open the Expression Builder, click the button to the right of the Expression pane.
   Only columns, designated predicates, and operators are allowed in the expression. For more information, see Expression Builder.
9. Click OK to save your work.