Siebel Analytics Server Administration Guide > Working in a Repository's Business Model and Mapping Layer >

About Logical Joins

Specifying the logical table joins is required so that the Siebel Analytics Server can have the necessary metadata to translate a logical request against the business model to SQL queries against the physical data sources. The logical join information provides the Analytics server with the many-to-one relationships between the logical tables. This logical join information is used when the Analytics server generates queries against the underlying databases. If the logical joins are the same as in the Physical layer, they will be set up automatically if the logical tables are created by dragging and dropping all of the participating physical tables simultaneously to the Business Model and Mapping layer. However, you should create the logical joins in the Business Model and Mapping layer, because you will rarely drag and drop all physical tables simultaneously except in very simple models. In the Business Model and Mapping layer, you should create complex joins with one-to-many relationships and not key or foreign key joins.

You can create logical foreign keys and logical complex joins using either the Joins Manager or the Business Model Diagram. Complex joins are joins over nonforeign key-primary key columns; that is, the relationship between the tables is arbitrary. When you create a complex join in the Physical layer, you can specify expressions and the specific columns on which to create the join. When you create a complex join in the Business Model and Mapping layer, you cannot specify expressions or columns on which to create the join. A complex join in the Business Model and Mapping layer acts as a placeholder when the business model has no foreign keys but requires a physical join to be created with expression and column information. A complex join in the Physical layer does not require a matching join in the Business Model and Mapping layer.

For information about how to create logical joins, see Defining Logical Joins with the Joins Manager and Defining Logical Joins with the Business Model Diagram.

You can create primary keys for tables using the Key tab of the Logical Table dialog box. For more information, see Using the Logical Table Dialog Box—Key Tab.

You can create primary keys for levels using the Key tab of the Level dialog box. For more information, see Using the Level Dialog Box—Keys Tab.


 Siebel Analytics Server Administration Guide 
 Published: 23 June 2003