If {HEAD ~ a statement entry} with identical text is found in {TAIL ~ the cache}, then the stored set of compilation environment data for the statement is searched for a match between the stored compilation data and the compilation environment for the statement entry of the new SQL request 
If { HEAD ~ a statement entry } with identical text is found in { TAIL ~ the cache } , then the stored set of compilation environment data for the statement is searched for a match between the stored compilation data and the compilation environment for the statement entry of the new SQL request
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL 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 OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH