ORACLE 分区表种类以及分区表的创建

分区表，顾名思义。就是将一张大表，按照一定的规则分散成更小型的更容易管理的小片；

每一个小片，对于存储来说，就对应一个段；每个小片，也就是一个分区；

分区表的特点：

每个分区，拥有相同的逻辑结构；

每个分区，拥有不同的物理属性；

每个分区，可以放置到不同的表空间上去；

oracle10g的分区表的分区规则：5种

1.range

2.list

3.hash

4.range list

5.range hash

这里只说明这几种分区表的创建，至于什么时候使用，后续分析

1、RANGE PARTITION

创建：

分区表创建之前，为了后续方便管理数据，建议分区表的各个分区创建在不同的表空间中，如下：

sql>create table obj_range
2  (object_id number,
3   object_name varchar2(128),
4   created date,
5   object_type varchar2(19)
6  )
7  partition by range(object_id)
8  (
9   partition range_p1 values less than(3000) tablespace part1,
10   partition range_p2 values less than(6000) tablespace part2,
11   partition range_p3 values less than(maxvalue) tablespace part3
12  );

Table created.

所以创建这个分区表之前你得创建 part1, part2, part3三个表空间来存储分区表各个分区！这里需要注意一下，建立范围分区的分区表时，一定需要有maxvalue值，否则数据溢出会报错！

插入数据查询数据的方法和普通表一样，如

sql>insert into obj_range
2  select object_id,object_name,created,object_type
3  from obj where object_id < 10000;

9580 rows created.

sql>select count(*) from obj_range partition (range_p1);

COUNT(*)
----------
2953

2、 LIST PARTITION

sql>create table obj_list
2  (object_id number,
3   object_name varchar2(128),
4   created date,
5   object_type varchar2(19)
6  )
7  partition by list(object_type)
8  (
9   partition list_p1 values('TABLE','VIEW') tablespace part1,
10   partition list_p2 values('SEQUENCE','SYNONYM') tablespace part2,
11   partition list_p3 values(default) tablespace part3
12  );

Table created.
sql> insert into obj_list
2  select object_id,object_name,created,object_type
3  from obj where object_id < 10000;

9580 rows created.

PU@orcl10g> commit;

Commit complete.
sql> select count(*) from obj_list partition (list_p1);

COUNT(*)
----------
3734

3、HASH PARTITION

sql>
1  create table obj_hash
2  (object_id number,
3   object_name varchar2(128),
4   created date,
5   object_type varchar2(19)
6  )
7  partition by hash(object_name)
8  (
9   partition hash_p1 tablespace part1,
10   partition hash_p2 tablespace part2,
11   partition hash_p3 tablespace part3
12* )
sql> /

Table created.
sql> insert into obj_hash select object_id,object_name,created,object_type from all_objects where rownum <=10000;

10000 rows created.

SQL> commit;

Commit complete.

sql> select count(*) from obj_hash partition(hash_p1);
COUNT(*)
----------
2430

后面还有2中是前面三种的符合分区，创建比较复杂，实际生产库中可能也比较少用！

4、RANGE、LIST 复合分区

range list分区规则，首先按照range进行分区，然后，每个range里面再作嵌套list分区：

sql>  create table obj_range_list
2  (
3  object_id number,
4  object_name varchar2(128),
5  created date,
6  object_type varchar2(19)
7  )
8  partition by range(object_id) subpartition by list(object_type)
9  (
10   partition range_list_p1 values less than(3000)
11   (
12     subpartition rlp_sub1 values('TABLE','VIEW') tablespace part1,
13     subpartition rlp_sub2 values('SEQUENCE','SYNONYM') tablespace part2,
14     subpartition rlp_sub3 values(default) tablespace part3
15   ),
16   partition range_list_p2 values less than(6000)
17   (
18     subpartition rlp2_sub1 values('TABLE','VIEW') tablespace part1,
19     subpartition rlp2_sub2 values('SEQUENCE','SYNONYM') tablespace part2,
20     subpartition rlp2_sub3 values(default) tablespace part3
21   ),
22   partition range_list_p3 values less than(maxvalue)
23   (
24     subpartition rlp3_sub1 values('TABLE','SYNONYM') tablespace part1,
25     subpartition rlp3_sub2 values(default) tablespace part2
26   )
27* )
sql> /

Table created.

sql> insert into obj_range_list
2  select object_id,object_name,created,object_type
3  from obj where object_id < 10000;

9580 rows created.

PU@orcl10g> commit;

sql> select count(*) from obj_range_list partition(range_list_P1);

COUNT(*)
----------
2953

5、RANG、HASH分区

首先，按照range分区，在每个range范围内，再作hash分区

sql> create table obj_range_hash
2  (
3   object_id number,
4   object_name varchar2(128),
5   created date,
6   object_type varchar2(19)
7  )
8  partition by range(object_id) subpartition by hash(object_name) subpartitions 3 store in(part1,part2,part3)
9  (
10   partition rh_p1 values less than(3000),
11   partition rh_p2 values less than(6000),
12   partition rh_p3 values less than(maxvalue)
13* )
sql> /

Table created.

sql> insert into obj_range_hash
2  select object_id,object_name,created ,object_type
3  from obj where object_id < 10000;

9580 rows created.

sql> commit;

Commit complete.

sql> select count(*) from obj_range_hash;

COUNT(*)
----------
10000

sql> select count(*) from obj_range_hash partition(rh_p1);

COUNT(*)
----------
2952

分区表创建就写那么多了，快去试试创建一个吧！