{HEAD ~ The preferred embodiment} of the present invention advantageously improves {TAIL ~ the technique} of determining a grid index that is used to locate a geometric shape in a spatial database 
advantageously improves
{ HEAD ~ The preferred embodiment } of the present invention advantageously improves { TAIL ~ the technique } of determining a grid index that is used to locate a geometric shape in a spatial database
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH