Oracle 11g系统分区表中的新功能

在11g有一个新的特点是分区表系统。下面做一个实验：

SQL> select * from v$version;

BANNER

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

Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production

PL/SQL Release 11.2.0.1.0 - Production

CORE    11.2.0.1.0      Production

TNS for Linux: Version 11.2.0.1.0 - Production

NLSRTL Version 11.2.0.1.0 - Production

SQL> drop table S_P_TEST purge;

SQL> CREATE TABLE S_P_TEST

    (

     col1 number,

     name varchar2(100)

    )

    PARTITION BY SYSTEM

    (

      PARTITION p1,

      PARTITION p2,

      PARTITION p3,

      PARTITION p4

   );



--插入时要指明分区

SQL> insert into S_P_TEST select object_id,object_name from dba_objects;

insert into S_P_TEST select object_id,object_name from dba_objects

            *

第 1 行出现错误:

ORA-14701: 对于按“系统”方法进行分区的表, 必须对 DML 使用分区扩展名或绑定变量

SQL> insert into S_P_TEST partition(p1) select object_id,object_name from dba_objects

    where object_type='TABLE';

已创建2115行。

SQL> insert into S_P_TEST partition(p2) select object_id,object_name from dba_objects

    where object_type='INDEX';

已创建2888行。

SQL> commit;

SQL> select count(1) from S_P_TEST;

  COUNT(1)

----------

      5003

SQL> select count(1) from S_P_TEST  partition(p1);

  COUNT(1)

----------

      2115

SQL> select count(1) from S_P_TEST  partition(p2);

  COUNT(1)

----------

      2888

--同样的数据能够插入到不同的分区中，这说明数据和分区没有不论什么关系

SQL> insert into S_P_TEST partition(p3) values(1,'aa');

SQL> insert into S_P_TEST partition(p4) values(1,'aa');

SQL> commit;

SQL> select * from S_P_TEST  partition(p3);

      COL1 NAME

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

         1 aa

SQL> select * from S_P_TEST  partition(p4);



      COL1 NAME

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

         1 aa



--传统的分区裁剪和分区智能关联无效，不能建立本地化的索引

SQL> ALTER TABLE S_P_TEST SPLIT PARTITION p1 at(1000)

     into(partition p3,partition p4);

ALTER TABLE S_P_TEST SPLIT PARTITION p1 at(1000)

            *

第 1 行出现错误:

ORA-14255: 未按范围, 列表, 组合范围或组合列表方法对表进行分区

--假设你知道数据在哪个表里面，做好要制定分区条件

SQL> set autotrace traceonly

SQL> select * from S_P_TEST where col1=1;

运行计划

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

Plan hash value: 2020968526

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

| Id  | Operation            | Name     | Rows  | Bytes | Cost (%CPU)| Time     | Pstart| Pstop |

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

|   0 | SELECT STATEMENT     |          |     2 |   130 |    10   (0)| 00:00:01 |       |       |

|   1 |  PARTITION SYSTEM ALL|          |     2 |   130 |    10   (0)| 00:00:01 |     1 |     4 |

|*  2 |   TABLE ACCESS FULL  | S_P_TEST |     2 |   130 |    10   (0)| 00:00:01 |     1 |     4 |

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

Predicate Information (identified by operation id):

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

   2 - filter("COL1"=1)

Note

-----

   - dynamic sampling used for this statement (level=2)

统计信息

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

          5  recursive calls

          0  db block gets

         70  consistent gets

          0  physical reads

          0  redo size

        414  bytes sent via SQL*Net to client

        338  bytes received via SQL*Net from client

          2  SQL*Net roundtrips to/from client

          0  sorts (memory)

          0  sorts (disk)

          2  rows processed

SQL> select * from S_P_TEST partition(p3) where col1=1;

运行计划

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

Plan hash value: 1626227678

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

| Id  | Operation               | Name     | Rows  | Bytes | Cost (%CPU)| Time     | Pstart| Pstop |

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

|   0 | SELECT STATEMENT        |          |     1 |    65 |     4   (0)| 00:00:01 |       |       |

|   1 |  PARTITION SYSTEM SINGLE|          |     1 |    65 |     4   (0)| 00:00:01 |     3 |     3 |

|*  2 |   TABLE ACCESS FULL     | S_P_TEST |     1 |    65 |     4   (0)| 00:00:01 |     3 |     3 |

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

Predicate Information (identified by operation id):

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

   2 - filter("COL1"=1)

Note

-----

   - dynamic sampling used for this statement (level=2)

统计信息

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

          5  recursive calls

          0  db block gets

         15  consistent gets

          0  physical reads

          0  redo size

        385  bytes sent via SQL*Net to client

        338  bytes received via SQL*Net from client

          2  SQL*Net roundtrips to/from client

          0  sorts (memory)

          0  sorts (disk)

1  rows processed

系统分区表的使用场景我想并不多，假设对传统的分区表数据的特性理解是：1.数据和分区是有联系的； 2.分区就是把非常多的表粘在管理结合起来。

该系统分区表只有第二特征。

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