-- Move cross product up the DAG trough a union operator in some special    cases (that appear quite often).
-- Move cross product up the DAG trough a union operator in some special
   cases (that appear quite often).

zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb