In some embodiments, the sub strings associated with the indices are created based on {HEAD ~ a historical analysis} of {TAIL ~ queries} received from database users 
of
In some embodiments , the sub strings associated with the indices are created based on { HEAD ~ a historical analysis } of { TAIL ~ queries } received from database users
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH