Oracle PL/SQL Tutorial/System Tables Data Dictionary/rowcache

Query v$rowcache

SQL>
SQL>
SQL> SELECT SUM(gets), SUM(getmisses),
  2         (1 - (SUM(getmisses) / (SUM(gets) +
  3         SUM(getmisses)))) * 100 hitrat
  4  FROM   v$rowcache
  5  where   rownum < 50;
 SUM(GETS) SUM(GETMISSES)     HITRAT
---------- -------------- ----------
     25970           3191 89.0573026
SQL>