/*
Library Cache Hit Ratio.
*/
select sum(pins) Executions, sum(pinhits) "Execution Hits", 
       	((sum(pinhits) / sum(pins)) * 100) phitrat,
       	sum(reloads) Misses,
       	((sum(pins) / (sum(pins) + sum(reloads))) * 100)  hitrat
from	v$librarycache;