DB_composed_op - optimize for empty n_add, l_add sets
DB_composed_op - optimize for empty n_add, l_add sets

yuvadm/rhizi,Rhizi/rhizi,cben/rhizi,yuvadm/rhizi,ozFri/rhizi,tlevine/rhizi,ozFri/rhizi,tlevine/rhizi,yuvadm/rhizi,shlomif/rhizi,cben/rhizi,tlevine/rhizi,ozFri/rhizi,ozFri/rhizi,yuvadm/rhizi,shlomif/rhizi,shlomif/rhizi,cben/rhizi,Rhizi/rhizi,cben/rhizi,Rhizi/rhizi,tlevine/rhizi,Rhizi/rhizi,shlomif/rhizi