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