Oracle 分区表创建

分区分类

- 字段范围分区 range `Oracle 8`

- 哈希分区 hash `Oracle 8i`

- 组合分区 range-hash,range-list ... `Oracle 9i`

- 列表分区 list `Oracle 9i`

- 间隔分区 interval `Oracle 11g`

- 系统分区 System `Oracle 11g`

- 引用分区 Reference `Oracle 11g`

 

 

 字段范围 range 

- NUMBER类型字段


CREATE TABLE emp (
   empno NUMBER(4), 
   ename VARCHAR2(30), 
   sal   NUMBER
) 
PARTITION BY RANGE(empno) (
  partition e1 values less than (1000)     tablespace ts1, 
  partition e2 values less than (2000)     tablespace ts2, 
  partition e3 values less than (MAXVALUE) tablespace ts3
); 


- VARCHAR2类型字段


CREATE TABLE emp
( id        NUMBER(5)    PRIMARY KEY,
  name      VARCHAR2(50) NOT NULL,
  phone     VARCHAR2(15),
  email     VARCHAR2(100) )
PARTITION BY RANGE ( name )
     ( PARTITION p1 VALUES LESS THAN ('L')      TABLESPACE ts1,
       PARTITION p2 VALUES LESS THAN (MAXVALUE) TABLESPACE ts2 )


- 基于时间类型字段


CREATE TABLE t1 (id NUMBER, c1 DATE)
PARTITION BY RANGE (c1)
  (PARTITION t1p1 VALUES LESS THAN (TO_DATE('2007-11-01', 'YYYY-MM-DD')),
   PARTITION t1p2 VALUES LESS THAN (TO_DATE('2007-12-01', 'YYYY-MM-DD')),
   PARTITION t1p3 VALUES LESS THAN (TO_DATE('2008-01-01', 'YYYY-MM-DD')),
   PARTITION t1p4 VALUES LESS THAN (MAXVALUE)
  );




### Hash分区

- 两种写法


create table emp2 (
   empno number(4), 
   ename varchar2(30), 
   sal   number
) 
partition by hash(empno) (
  partition e1 tablespace emp1, 
  partition e2 tablespace emp2, 
  partition e3 tablespace emp3,
  partition e4 tablespace emp4
); 
-- tablespace 可以去掉


create table emp2 (
   empno number(4), 
   ename varchar2(30), 
   sal   number
) 
PARTITION BY HASH(empno)
PARTITIONS 3
-- STORE IN (empts1, empts2, empts3);


组合分区

- 8i 之前 只支持 range-hash
- 9i 支持 range-list
- 11g 支持更多 详情看这[http://www.orafaq.com/wiki/Composite_partitioning](http://www.orafaq.com/wiki/Composite_partitioning)


CREATE TABLE orders(
 ord#       NUMBER,
 orderdate  DATE,
 prod#      NUMBER,
 quantity   NUMBER)
PARTITION    BY RANGE(orderdate)
SUBPARTITION BY HASH(prod#) SUBPARTITIONS 4 -- STORE IN(ts1, ts2, ts3, ts4)
( PARTITION q1 VALUES LESS THAN (TO_DATE('01-APR-2009', 'DD-MON-YYYY')),
  PARTITION q2 VALUES LESS THAN (TO_DATE('01-JUL-2009', 'DD-MON-YYYY')),
  PARTITION q3 VALUES LESS THAN (TO_DATE('01-OCT-2009', 'DD-MON-YYYY')),
  PARTITION q4 VALUES LESS THAN (MAXVALUE)
);


List分区


CREATE TABLE myemp_work (
       emp#   NUMBER PRIMARY KEY,
       ename    VARCHAR2(30),
       salary   NUMBER(8,2),
       deptno   NUMBER)
  PARTITION BY LIST (deptno) (  
       PARTITION p10 VALUES (10), 
       PARTITION p20 VALUES (20), 
       PARTITION p30 VALUES (30,40));



间隔分区 Interval

- 11g引入，作为range分区的补充，当插入的值超过所有其他分区的范围时，自动创建分区

- 限制
    - 分区字段必须是NUMBER或者DATE类型
    - 不支持索引组织表 index-organized table 
    - 不能在间隔分区创建域索引domain index 


-- 创建salary有限值的分区
create table test
      (sno number(6),
      last_name varchar2(30),
      salary number(6))
      partition by range(salary)
     (
  partition p1 values less than (5000),
  partition p2 values less than (10000),
  partition p3 values less than (15000),
  partition p4 values less than (20000));

-- 插入一条超过分区区间的记录
insert into test values (1,'Michel',25000);

-- 抛出分区key不能映射到某个分区的错误
ORA-14400:
inserted partition key does not map to any partition

-- interval分区用法
create table test
          (sno number(6),
          last_name varchar2(30),
          salary number(6))
          partition by range(salary)
          Interval  (5000) -- 每5000一个分区
         (
      partition p1 values less than (5000),
      partition p2 values less than (10000),
     partition p3 values less than (15000),
     partition p4 values less than (20000));


系统分区 

- 11g中引入的一种分区方法，它允许应用程序控制分区选择。系统分区不像其他分区模式那样具有分区键。


-- 创建若干分区
CREATE TABLE syspart (c1 NUMBER, c2 NUMBER)
PARTITION BY SYSTEM (
   PARTITION p1 TABLESPACE ts1,
   PARTITION p2 TABLESPACE ts2,
   PARTITION p3 TABLESPACE ts3
);

-- 插入数据时程序选择指定分区
INSERT INTO syspart PARTITION (p1) VALUES (1, 2);
INSERT INTO syspart PARTITION (p2) VALUES (3, 4);



引用分区

- 11g中介绍的一种分区方法。使用引用分区，子表可以从父表继承分区特征。


-- 父表
CREATE TABLE orders (
  order_id    NUMBER PRIMARY KEY,
  order_date  DATE NOT NULL,
  customer_id NUMBER NOT NULL,
  shipper_id  NUMBER)
PARTITION BY RANGE (order_date) (
  PARTITION y1 VALUES LESS THAN (TO_DATE('01-JAN-2006', 'DD-MON-YYYY')),
  PARTITION y2 VALUES LESS THAN (TO_DATE('01-JAN-2007', 'DD-MON-YYYY')),
  PARTITION y3 VALUES LESS THAN (TO_DATE('01-JAN-2008', 'DD-MON-YYYY')));

-- 子表外键继承父表的分区
CREATE TABLE order_items (
  order_id    NUMBER NOT NULL,
  product_id  NUMBER NOT NULL,
  price       NUMBER,
  quantity    NUMBER,
  CONSTRAINT order_items_fk FOREIGN KEY (order_id) REFERENCES orders)
PARTITION BY REFERENCE (order_items_fk);


 分区压缩

- 11g分区可以被单独压缩,10g只支持整表压缩

查看压缩特性


-- 创建分区表，指定分区是否压缩
CREATE TABLE test
           (sno       NUMBER(6),
            last_name VARCHAR2(30),
            salary    NUMBER(6))
          PARTITION BY RANGE (salary)
           INTERVAL  (5000)
          (
     PARTITION p1 VALUES LESS THAN (5000)   COMPRESS,
     PARTITION p2 VALUES LESS THAN (10000)  NOCOMPRESS,
     PARTITION p3 VALUES LESS THAN (15000)  COMPRESS,
     PARTITION p4 VALUES LESS THAN (20000)) NOCOMPRESS;

-- 检查该表的压缩属性
SELECT table_name, partition_name, compression
  FROM user_tab_partitions
  WHERE table_name='TEST';

--单个关键字指定整个表的所有分区可被压缩
CREATE TABLE test
              (sno       NUMBER(6),
               last_name VARCHAR2(30),
               salary    NUMBER(6))
          COMPRESS
             PARTITION BY RANGE (salary)
              INTERVAL (5000)
             (
        PARTITION p1 VALUES LESS THAN (5000) ,
        PARTITION p2 VALUES LESS THAN (10000),
        PARTITION p3 VALUES LESS THAN (15000),
        PARTITION p4 VALUES LESS THAN (20000));