You will need to use the Oracle Native Provider. See Developer's Guide around page 229.
Oracle Stored Procedure Queries
We can map a business object directly to a Microsoft SQL Server stored procedure but we cannot map a business object to an Oracle stored procedure because the Object Mapping tool cannot discover the schema for Oracle stored procedures.
Fortunately, we can use an Oracle stored procedure to return business objects by invoking that procedure in a Stored Procedure Query. The target business object can be any entity resulting from the Object Mapping exercise.
If there is no such entity, we can manufacture a "Fictive Entity Class" as described earlier in this section.
Querying Example
DevForce supports Oracle stored procedures via Oracle Ref Cursors. An example stored procedure and its corresponding DevForce code follow