MongoDB translator throws java.lang.IndexOutOfBoundsException when GROUP BY is used in SELECT. This bug is fixed in community, but probably it is not back ported.
Filip, Can you attach the VDB and the query that you ran?
Van, VDB and server log are in the attachment. Queries: SELECT IntKey, SUM(IntNum) FROM BQT1.SmallA GROUP BY intKey SELECT IntKey, IntNum FROM BQT1.SmallA GROUP BY IntKey, IntNum