-- Extend the rank push up phase for rowrank operators: We now also push up    rowrank operators (as long as it is only referenced once).
-- Extend the rank push up phase for rowrank operators: We now also push up
   rowrank operators (as long as it is only referenced once).

   (In comparison to pushing up rank operators the rowrank operators are
    not pushed through selection-like operator as these might prune rows
    necessary to provide the correct rowrank numbers.)

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