Thank you for replies!
So far we have ended up with the solution based on VDS provisioning data source:
- Created two single data sources that refer to two different databases containing the same identical table.
- Created a group Provisioning data source that unites these both single data sources.
- Re-pointed our virtual tree to the group provisioning data source instead of a single data source as it was before.
Now if new ADD request coming to the virtual tree it's automatically transitioned to the both single data-sources and finally drops to both tables in the two different databases. Not tested yet this solution on big data volume, but with it works fine in our sandbox.
Siarhei