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。