oracle 分区

创建分区

--先声明一下：列表分区不支持多列，但是范围分区和哈希分区支持多列。

create table graderecord
-- 范围分区 根据列的值的范围
(
sno varchar2(10),
sname varchar2(20),
dormitory varchar2(3),
grade int)
partition by range(grade)(
          partition fail values less than(60),
          partition pass values less than(85),
          partition excellent values less than(maxvalue)
)

select * from graderecord

select * from graderecord partition(fail)

-- 散列分区 根据字段的hash分布
partition by hash(sno)(
partition p1,
partition p2,
partition p3
)

-- 列表分区 根据列的值的具体值
partition by list(dormitory)(
partition d229 values('229'),
partition d228 values('228'),
partition d240 values('240')
)

-- 符合分区 范围分区和hash分区
partition by range(grade)
subpartition by hash(sno,sname)(
             partition p1 values less than(75)
             (
             subpartition sp1,subpartition sp2
             ),
             partition p2 values less than(maxvalue)
             (
             subpartition sp3,subpartition sp4
             )
)

 

 

查看分区

select object_name,subobject_name from user_objects

where object_type = 'TABLE PARTITION'

 

删除分区，子分区

alter table [tbname] drop partition [ptname];

alter table [tbname] drop subpartition [ptname];