命中率

Select Sum(Value)/1024/1024 From v$sga
Select  current_size/1024/1024  From v$sga_dynamic_free_memory

Alter System Set statistics_level=typical

show parameter  sga_max_size


--计算库缓冲区的命中率l
Select Sum(pinhits)/Sum(pins)  From v$librarycache

--计算数据字典缓冲区命中率

Select   (Sum(GETS-GETMISSES-FIXED))/Sum(GETS) "ROW CACHE"  From V$ROWCACHE

Select * From  V$SGAINFO

Select *  From v$librarycache

---高速缓冲区的 命中录
Select * From v$sysstat  Where Name In('physiacl read cache','consistent gets from cache','db block gets from cache')
1-(('physiacl read cache')/('consistent gets from cache '+'db block gets from cache'))