显示每个用户的缓存命中率

-- Description  : Displays the Cache Hit Ratio per user.
-- Requirements : Access to the V$ views.
-- Call Syntax  : @user_hit_ratio

SET LINESIZE 500
COLUMN "Hit Ratio %" FORMAT 999.99

SELECT a.username "Username",
       a.sid,
       a.serial#,
       b.consistent_gets "Consistent Gets",
       b.block_gets "DB Block Gets",
       b.physical_reads "Physical Reads",
       Round(100* (b.consistent_gets + b.block_gets - b.physical_reads) /
       (b.consistent_gets + b.block_gets),2) "Hit Ratio %"
FROM   v$session a,
       v$sess_io b
WHERE  a.sid = b.sid
AND    (b.consistent_gets + b.block_gets) > 0
AND    a.username IS NOT NULL;