四， DBMS_RESULT_CACHE管理包  
使用DBMS_RESULT_CACHE包管理shared pool中的result cache区
The DBMS_RESULT_CACHE package provides an interface to allow the DBA to administer that part of the shared pool that is used by the SQL result cache and the PL/SQL function result cache. Both these caches use the same infrastructure. Therefore, for example, DBMS_RESULT_CACHE.BYPASS determines whether both caches are bypassed or both caches are used, and DBMS_RESULT_CACHE.FLUSH flushes both all the cached results for SQL queries and all the cached results for PL/SQL functions.

BYPASS
    Sets the bypass mode for the Result Cache, When bypass mode is turned on, it implies that cached results are no longer used and that no new results are saved in the cache
FLUSH
   Flushes all objects from result cache
   Note: flushing shared pool has no affect
MEMORY_REPORT
    Nice report that shows usage of result cache
STATUS
    ENABLED or NOT ENABLED
INVALIDATE
    Invalidate contents of the result cache
INVALIDATE_OBJECT
    Invalidates contents that rely on object passed in

常见用法： 
BEGIN
   DBMS_RESULT_CACHE.BYPASS(TRUE);
   DBMS_RESULT_CACHE.FLUSH;
END;
/

BEGIN
   DBMS_RESULT_CACHE.BYPASS(FALSE);
END;
/

BEGIN
   DBMS_RESULT_CACHE.INVALIDATE('HR','EMP');
END;
/