The number of {TAIL ~ records} actually retrieved and searched for {HEAD ~ the query sub string} is thereby reduced 
The number of { TAIL ~ records } actually retrieved and searched for { HEAD ~ the query sub string } is thereby reduced
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH