http://yangtingkun.itpub.net/post/468/500728

杨老师，我试你这个例子，结果不太一样，不过我是在11G的环境中。

select time,count(*) from test_par where time>to_date('2009-1-1','yyyy-mm-dd')

and time < to_date('2009-1-31','yyyy-mm-dd') group by time;

| Pstart| Pstop |

--------------------------------------------------------------------------------

-------------------

| 0 | SELECT STATEMENT | | 30 | 240 | 71 (2)| 00:00:0

1 | | |

| 1 | PARTITION RANGE SINGLE| | 30 | 240 | 71 (2)| 00:00:0

1 | 3 | 3 |

| 2 | HASH GROUP BY | | 30 | 240 | 71 (2)| 00:00:0

1 | | |

|* 3 | TABLE ACCESS FULL | TEST_PAR | 30 | 240 | 70 (0)| 00:00:0

1 | 3 | 3 |

--------------------------------------------------------------------------------

这个走的都不是物化视图。跨分区了会走物化视图。

select time,count(*) from test_par where time>to_date('2009-1-1','yyyy-mm-dd')

and time < to_date('2010-1-31','yyyy-mm-dd') group by time;

| Time |

--------------------------------------------------------------------------------

------------

| 0 | SELECT STATEMENT | | 395 | 4345 | 126 (3)

| 00:00:02 |

|* 1 | MAT_VIEW REWRITE ACCESS FULL| MV_TEST_PAR | 395 | 4345 | 126 (3)

| 00:00:02 |

--------------------------------------------------------------------------------

------------

为什么？？？？

请杨老师指点。

俺Q273002188.谢谢

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