About Joins to Tables in External Data Sources

Joins from business components, based on the default data source to a table in an external data source, are supported in the Siebel application.

Like other joined fields, the fields based on the join to the EBC are read-only.

The limitations for joining business components to tables in an external data source are as follows:

The source field for the join must be based on a table in the default data source.
The destination column of the join must be the column mapped to System Field Id.
Multiple single join specifications are not supported for the join to the external table.
Reverse navigation (for example, a call to go to the last record) is not supported when fields from multiple data sources are active.

Join Constraints are supported. Joins to more than one external table might be specified. However, increasing the number of external joined data sources can cause degradation in performance.