第二个特点，CACHE存储参数无效：
SQL> CREATE TABLE T3 STORAGE(BUFFER_POOL KEEP) AS SELECT * FROM T2;
Table created.
SQL> ALTER TABLE T2 CACHE;
Table altered.
SQL> SELECT COUNT(*) FROM T;
COUNT(*)
----------
334022
SQL> SELECT OBJECT_NAME, A.STATUS, COUNT(*)
2 FROM V$BH A, USER_OBJECTS B
3 WHERE A.OBJD = B.OBJECT_ID
4 AND OBJECT_NAME IN ('T', 'T2', 'T3')
5 GROUP BY OBJECT_NAME, A.STATUS;
OBJECT_NAME STATU COUNT(*)
--------------------------
T xcur 8096
SQL> SELECT COUNT(*) FROM T2;
COUNT(*)
----------
167011
SQL> SELECT OBJECT_NAME, A.STATUS, COUNT(*)
2 FROM V$BH A, USER_OBJECTS B
3 WHERE A.OBJD = B.OBJECT_ID
4 AND OBJECT_NAME IN ('T', 'T2', 'T3')
5 GROUP BY OBJECT_NAME, A.STATUS;
OBJECT_NAME STATU COUNT(*)
---------------------------
T xcur 3267
T2 xcur 4829

SQL> SELECT COUNT(*) FROM T3;
COUNT(*)
----------
167011
SQL> SELECT OBJECT_NAME, A.STATUS, COUNT(*)
2 FROM V$BH A, USER_OBJECTS B
3 WHERE A.OBJD = B.OBJECT_ID
4 AND OBJECT_NAME IN ('T', 'T2', 'T3')
5 GROUP BY OBJECT_NAME, A.STATUS;

OBJECT_NAME STATU COUNT(*)
--------------------------
T2 xcur 3267
T3 xcur 4829
SQL> SELECT COUNT(*) FROM T WHERE ROWNUM < 100000;
COUNT(*)
----------
99999
SQL> SELECT OBJECT_NAME, A.STATUS, COUNT(*)
2 FROM V$BH A, USER_OBJECTS B
3 WHERE A.OBJD = B.OBJECT_ID
4 AND OBJECT_NAME IN ('T', 'T2', 'T3')
5 GROUP BY OBJECT_NAME, A.STATUS;

OBJECT_NAME STATU COUNT(*)
------------------------------
T xcur 3696
T3 xcur 4400

通过测试可以发现，CACHE选项没有起作用，其实这也不难理解，既然放到单独的KEEP池中，那么必然打
算将这个对象缓存，因此Oracle对所有KEEP池中的对象采用了默认CACHE的方式。而忽略对象本身的CACHE和NOCACHE选项[@more@]

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oracle cache table(6)

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