1. A computer-implemented method to generate an online analytical processing (OLAP) query for data aggregated in a cube, the cube having a plurality of dimensions, each including a hierarchy of members, the method comprising: receiving a report specification against a hierarchy of the cube, wherein the hierarchy is a balanced hierarchy having a level with an unbalanced characteristic; identifying a first set and a second set among the members of the hierarchy, the first set comprising members projected by the report specification that have a descendant at a lowest level of the hierarchy; the second set comprising members projected by the report specification that do not have any descendant at the lowest level of the hierarchy; and generating the OLAP query from the report specification and by operation of one or more computer processors, wherein the OLAP query joins the first set with the second set, wherein the OLAP query is executed to produce results responsive to the report specification.