查看oracle命中率

SELECT SubStr((1 - (phy.value - lob.value - dir.value) / ses.value) * 100,1,4) || '%' AS buffer_cache_hit_ratio
  FROM v$sysstat ses, v$sysstat lob, v$sysstat dir, v$sysstat phy
 WHERE ses.name = 'session logical reads'
   AND dir.name = 'physical reads direct'
   AND lob.name = 'physical reads direct (lob)'
   AND phy.name = 'physical reads';

SELECT SubStr(SUM(PINS - RELOADS) / SUM(PINS) * 100,1,4) || '%' AS library_cache_hit_ratio
  FROM v$librarycache;

SELECT SubStr((SUM(GETS - GETMISSES) / SUM(GETS)) * 100,1,4) || '%' AS dictionary_cache_hit_ratio
  FROM v$rowcache;


Select SubStr(Sum(V$LibraryCache.PINS) /(Sum(V$LibraryCache.PINS) + Sum(V$LibraryCache.RELOADS)) * 100,1,4) || '%' "Hit Ratio"
  From V$LibraryCache;

–合

select a.                        buffer_cache_hit_ratio,
       b.library_cache_hit_ratio,
       c.                        dictionary_cache_hit_ratio
  from (SELECT SubStr((1 - (phy.value - lob.value - dir.value) / ses.value) * 100,
                      1,
                      4) || '%' AS buffer_cache_hit_ratio
          FROM v$sysstat ses, v$sysstat lob, v$sysstat dir, v$sysstat phy
         WHERE ses.name = 'session logical reads'
           AND dir.name = 'physical reads direct'
           AND lob.name = 'physical reads direct (lob)'
           AND phy.name = 'physical reads') a,
       (SELECT SubStr(SUM(PINS - RELOADS) / SUM(PINS) * 100, 1, 4) || '%' AS library_cache_hit_ratio
          FROM v$librarycache) b,
       (SELECT SubStr((SUM(GETS - GETMISSES) / SUM(GETS)) * 100, 1, 4) || '%' AS dictionary_cache_hit_ratio
          FROM v$rowcache) c;