protect rel_aggr for missing group by's (transplanted from d9fac1bae3a5d63a10927fc2c86d81af0ab7b5a8)
protect rel_aggr for missing group by's
(transplanted from d9fac1bae3a5d63a10927fc2c86d81af0ab7b5a8)

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