You could try and perform a oql query in java with a select distinct.
Then from the resulting IDataTable get the Id's of the objects in an ArrayList.
The perform a Core.retrieveIdList with the arraylist as input and return the list.
This will provide the microflow with the needed distinct list of objects.
There is even a native Mx solution without having to know OQL or other technologies that I would try myself:
- copy the list (1) to list (2)
- loop through list (1)
START LOOP
- create a list (3) of all objects in list (2) with the same i as the (list (1)) iterator
- subtract list (3) from list (2)
- if list (3) = empty then the iterator is a duplicate
- if list (3) != empty remove the iterator from list (1)
END LOOP
Now list(1) contains only the duplicates!