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
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 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 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 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 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 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!
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