About
A logical join is a join defined in the BMM layer. He is defined between a logical fact table and a logical dimension table.
Two types of logical join exists:
- standard logical join
- logical foreign key join
In the business model, OBI recommends using complex logical joins instead of foreign key logical joins.
When Complex joins are used in the business layer then they are really acting as placeholders. They allow the OBI Server to decide on which are the best joins between fact and dimension logical table source to satisfy the request.
The joins occurs between a fact logical table source and a dimension logical table source when they have the same aggregation grain.
Articles Related
Type Logical join
| 10G | 11G |
|---|---|
 |  |
Standard
In 10g, the standard logical join are defined with the new complex join tool.
In 11g, you have only one choice.
Foreign key
In 10g, The Foreign key logical join are defined with the new foreign key join in the business model.
In 11g, this kind of join is deprecated and if you want to use them, you have to check the preference in the Tools/Options of the administration tool.
