The cache processing section performs {HEAD ~ a cache process} composed of two stage processes, {TAIL ~ a query process} and a subsequent process  
composed of
The cache processing section performs { HEAD ~ a cache process } composed of two stage processes , { TAIL ~ a query process } and a subsequent process
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH