I followed the below-mentioned steps and it worked fine for me:
* I had two stored procedures from two different data sources.
* I created two base views in the Virtual DataPort using the *‘Create from query’* option by invoking the respective stored procedures.
* Now, I created a UNION view of the two base views and published it as a REST web service.
* When I called the web service, the two stored procedures from the respective data sources were executed and the results were retrieved as expected.
For your scenario, you can similarly create a UNION of stored procedures that would hit the respective data sources.
You may refer to [Creating Base Views from a JDBC Data Source](https://community.denodo.com/docs/html/browse/7.0/vdp/administration/creating_data_sources_and_base_views/jdbc_sources/jdbc_sources#creating-base-views-from-a-jdbc-data-source) and [Creating Union Views](https://community.denodo.com/docs/html/browse/7.0/vdp/administration/creating_derived_views/creating_union_views/creating_union_views#creating-union-views) sections of the Virtual DataPort Administration Guide for more information.
Hope this helps!