Because data is segmented and operated on separately, {HEAD ~ data} from {TAIL ~ multiple sources} may be processed in parallel 
from
Because data is segmented and operated on separately , { HEAD ~ data } from { TAIL ~ multiple sources } may be processed in parallel
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH