ALTER TABLE…SPLIT PARTITION命令将一个分区划分为两个分区,并重新分配新分区的内容。
语法介绍
ALTER TABLE…SPLIT PARTITION命令的语法有两种形式:
ALTER TABLE table_name SPLIT PARTITION partition_name
AT (range_part_value)
INTO
(
PARTITION new_part1
[TABLESPACE tablespace_name],
PARTITION new_part2
[TABLESPACE tablespace_name]
);
ALTER TABLE table_name SPLIT PARTITION partition_name
VALUES (value[, value]...)
INTO
(
PARTITION new_part1
[TABLESPACE tablespace_name],
PARTITION new_part2
[TABLESPACE tablespace_name]
);
描述
ALTER TABLE…SPLIT PARTITION命令用于将分区添加到现有的分区表中。在分区表中对于分区数量没有上限要求。
当您执行ALTER TABLE…SPLIT PARTITION命令时,PolarDB就会创建两个新分区,并在这两个新分区之间(如分区规则约束的一样)重新分配旧分区中的内容。
包括TABLESPACE子句指定新分区要所属的表空间。如果您没有指定表空间, 那么分区将所属于缺省表空间。
如果对表进行了索引设置, 那么索引将创建在新分区上。
要使用ALTER TABLE…SPLIT PARTITION命令,您必须是表的拥有者或有超级用户(或管理员)的权限。
参数
参数 | 参数说明 |
---|---|
table name | 分区表的名称(可以采用模式限定的方式引用)。 |
partition name | 要划分的分区名称。 |
new_part1 |
要创建的第一个新分区的名称。在所有分区和子分区当中,分区名称必须是唯一的,且必须遵循给对象标识符命名的惯例。
|
new_part2 |
要创建的第二个新分区的名称。在所有分区和子分区当中,分区名称必须是唯一的,且必须遵循给对象标识符命名的惯例。
|
range part value | 使用range_part_value 指定边界规则来创建新分区。分区规则必须至少包含一列有两个运算符的数据类型(例如,一个大于等于运算符和一个小于运算符)。范围边界的评估是依据less than 子句进行的,且范围边界是非包容性的。2010年1月1日这个日期边界只会包括那些在2009年12月31日当天或之前的日期值。
|
(value[, value]...) |
使用 更多关于创建 |
tablespace name | 分区或子分区所属的表空间名称。 |
划分LIST分区示例
CREATE TABLE sales
(
dept_no number,
part_no varchar2,
country varchar2(20),
date date,
amount number
)
PARTITION BY LIST(country)
(
PARTITION europe VALUES('FRANCE', 'ITALY'),
PARTITION asia VALUES('INDIA', 'PAKISTAN'),
PARTITION americas VALUES('US', 'CANADA')
);
INSERT INTO sales VALUES
(10, '4519b', 'FRANCE', '17-Jan-2012', '45000'),
(20, '3788a', 'INDIA', '01-Mar-2012', '75000'),
(40, '9519b', 'US', '12-Apr-2012', '145000'),
(20, '3788a', 'PAKISTAN', '04-Jun-2012', '37500'),
(40, '4577b', 'US', '11-Nov-2012', '25000'),
(30, '7588b', 'CANADA', '14-Dec-2012', '50000'),
(30, '9519b', 'CANADA', '01-Feb-2012', '75000'),
(30, '4519b', 'CANADA', '08-Apr-2012', '120000'),
(40, '3788a', 'US', '12-May-2012', '4950'),
(10, '9519b', 'ITALY', '07-Jul-2012', '15000'),
(10, '9519a', 'FRANCE', '18-Aug-2012', '650000'),
(10, '9519b', 'FRANCE', '18-Aug-2012', '650000'),
(20, '3788b', 'INDIA', '21-Sept-2012', '5090'),
(40, '4788a', 'US', '23-Sept-2012', '4950'),
(40, '4788b', 'US', '09-Oct-2012', '15000'),
(20, '4519a', 'INDIA', '18-Oct-2012', '650000'),
(20, '4519b', 'INDIA', '2-Dec-2012', '5090');
acctg=# SELECT tableoid::regclass, * FROM sales;
tableoid | dept_no | part_no | country | date | amount
----------------+---------+---------+----------+--------------------+-------
sales_europe | 10 | 4519b | FRANCE | 17-JAN-12 00:00:00 | 45000
sales_europe | 10 | 9519b | ITALY | 07-JUL-12 00:00:00 | 15000
sales_europe | 10 | 9519a | FRANCE | 18-AUG-12 00:00:00 | 650000
sales_europe | 10 | 9519b | FRANCE | 18-AUG-12 00:00:00 | 650000
sales_asia | 20 | 3788a | INDIA | 01-MAR-12 00:00:00 | 75000
sales_asia | 20 | 3788a | PAKISTAN | 04-JUN-12 00:00:00 | 37500
sales_asia | 20 | 3788b | INDIA | 21-SEP-12 00:00:00 | 5090
sales_asia | 20 | 4519a | INDIA | 18-OCT-12 00:00:00 | 650000
sales_asia | 20 | 4519b | INDIA | 02-DEC-12 00:00:00 | 5090
sales_americas | 40 | 9519b | US | 12-APR-12 00:00:00 | 145000
sales_americas | 40 | 4577b | US | 11-NOV-12 00:00:00 | 25000
sales_americas | 30 | 7588b | CANADA | 14-DEC-12 00:00:00 | 50000
sales_americas | 30 | 9519b | CANADA | 01-FEB-12 00:00:00 | 75000
sales_americas | 30 | 4519b | CANADA | 08-APR-12 00:00:00 | 120000
sales_americas | 40 | 3788a | US | 12-MAY-12 00:00:00 | 4950
sales_americas | 40 | 4788a | US | 23-SEP-12 00:00:00 | 4950
sales_americas | 40 | 4788b | US | 09-OCT-12 00:00:00 | 15000
(17 rows)
ALTER TABLE sales SPLIT PARTITION americas
VALUES ('US')
INTO (PARTITION us, PARTITION canada);
acctg=# SELECT tableoid::regclass, * FROM sales;
tableoid | dept_no | part_no | country | date | amount
--------------+---------+---------+----------+--------------------+--------
sales_europe | 10 | 4519b | FRANCE | 17-JAN-12 00:00:00 | 45000
sales_europe | 10 | 9519b | ITALY | 07-JUL-12 00:00:00 | 15000
sales_europe | 10 | 9519a | FRANCE | 18-AUG-12 00:00:00 | 650000
sales_europe | 10 | 9519b | FRANCE | 18-AUG-12 00:00:00 | 650000
sales_asia | 20 | 3788a | INDIA | 01-MAR-12 00:00:00 | 75000
sales_asia | 20 | 3788a | PAKISTAN | 04-JUN-12 00:00:00 | 37500
sales_asia | 20 | 3788b | INDIA | 21-SEP-12 00:00:00 | 5090
sales_asia | 20 | 4519a | INDIA | 18-OCT-12 00:00:00 | 650000
sales_asia | 20 | 4519b | INDIA | 02-DEC-12 00:00:00 | 5090
sales_us | 40 | 9519b | US | 12-APR-12 00:00:00 | 145000
sales_us | 40 | 4577b | US | 11-NOV-12 00:00:00 | 25000
sales_us | 40 | 3788a | US | 12-MAY-12 00:00:00 | 4950
sales_us | 40 | 4788a | US | 23-SEP-12 00:00:00 | 4950
sales_us | 40 | 4788b | US | 09-OCT-12 00:00:00 | 15000
sales_canada | 30 | 7588b | CANADA | 14-DEC-12 00:00:00 | 50000
sales_canada | 30 | 9519b | CANADA | 01-FEB-12 00:00:00 | 75000
sales_canada | 30 | 4519b | CANADA | 08-APR-12 00:00:00 | 120000
(17 rows)
划分RANGE分区示例
CREATE TABLE sales
(
dept_no number,
part_no varchar2,
country varchar2(20),
date date,
amount number
)
PARTITION BY RANGE(date)
(
PARTITION q1_2012
VALUES LESS THAN('2012-Apr-01'),
PARTITION q2_2012
VALUES LESS THAN('2012-Jul-01'),
PARTITION q3_2012
VALUES LESS THAN('2012-Oct-01'),
PARTITION q4_2012
VALUES LESS THAN('2013-Jan-01')
);
INSERT INTO sales VALUES
(10, '4519b', 'FRANCE', '17-Jan-2012', '45000'),
(20, '3788a', 'INDIA', '01-Mar-2012', '75000'),
(40, '9519b', 'US', '12-Apr-2012', '145000'),
(20, '3788a', 'PAKISTAN', '04-Jun-2012', '37500'),
(40, '4577b', 'US', '11-Nov-2012', '25000'),
(30, '7588b', 'CANADA', '14-Dec-2012', '50000'),
(30, '9519b', 'CANADA', '01-Feb-2012', '75000'),
(30, '4519b', 'CANADA', '08-Apr-2012', '120000'),
(40, '3788a', 'US', '12-May-2012', '4950'),
(10, '9519b', 'ITALY', '07-Jul-2012', '15000'),
(10, '9519a', 'FRANCE', '18-Aug-2012', '650000'),
(10, '9519b', 'FRANCE', '18-Aug-2012', '650000'),
(20, '3788b', 'INDIA', '21-Sept-2012', '5090'),
(40, '4788a', 'US', '23-Sept-2012', '4950'),
(40, '4788b', 'US', '09-Oct-2012', '15000'),
(20, '4519a', 'INDIA', '18-Oct-2012', '650000'),
(20, '4519b', 'INDIA', '2-Dec-2012', '5090');
acctg=# SELECT tableoid::regclass, * FROM sales;
tableoid | dept_no | part_no | country | date | amount
---------------+---------+---------+----------+--------------------+--------
sales_q1_2012 | 10 | 4519b | FRANCE | 17-JAN-12 00:00:00 | 45000
sales_q1_2012 | 20 | 3788a | INDIA | 01-MAR-12 00:00:00 | 75000
sales_q1_2012 | 30 | 9519b | CANADA | 01-FEB-12 00:00:00 | 75000
sales_q2_2012 | 40 | 9519b | US | 12-APR-12 00:00:00 | 145000
sales_q2_2012 | 20 | 3788a | PAKISTAN | 04-JUN-12 00:00:00 | 37500
sales_q2_2012 | 30 | 4519b | CANADA | 08-APR-12 00:00:00 | 120000
sales_q2_2012 | 40 | 3788a | US | 12-MAY-12 00:00:00 | 4950
sales_q3_2012 | 10 | 9519b | ITALY | 07-JUL-12 00:00:00 | 15000
sales_q3_2012 | 10 | 9519a | FRANCE | 18-AUG-12 00:00:00 | 650000
sales_q3_2012 | 10 | 9519b | FRANCE | 18-AUG-12 00:00:00 | 650000
sales_q3_2012 | 20 | 3788b | INDIA | 21-SEP-12 00:00:00 | 5090
sales_q3_2012 | 40 | 4788a | US | 23-SEP-12 00:00:00 | 4950
sales_q4_2012 | 40 | 4577b | US | 11-NOV-12 00:00:00 | 25000
sales_q4_2012 | 30 | 7588b | CANADA | 14-DEC-12 00:00:00 | 50000
sales_q4_2012 | 40 | 4788b | US | 09-OCT-12 00:00:00 | 15000
sales_q4_2012 | 20 | 4519a | INDIA | 18-OCT-12 00:00:00 | 650000
sales_q4_2012 | 20 | 4519b | INDIA | 02-DEC-12 00:00:00 | 5090
(17 rows)
ALTER TABLE sales SPLIT PARTITION q4_2012
AT ('15-Nov-2012')
INTO
(
PARTITION q4_2012_p1,
PARTITION q4_2012_p2
);
acctg=# SELECT tableoid::regclass, * FROM sales;
tableoid | dept_no | part_no | country | date |amount
------------------+---------+---------+----------+--------------------+------
sales_q1_2012 | 10 | 4519b | FRANCE | 17-JAN-12 00:00:00 | 45000
sales_q1_2012 | 20 | 3788a | INDIA | 01-MAR-12 00:00:00 | 75000
sales_q1_2012 | 30 | 9519b | CANADA | 01-FEB-12 00:00:00 | 75000
sales_q2_2012 | 40 | 9519b | US | 12-APR-12 00:00:00 |145000
sales_q2_2012 | 20 | 3788a | PAKISTAN | 04-JUN-12 00:00:00 | 37500
sales_q2_2012 | 30 | 4519b | CANADA | 08-APR-12 00:00:00 |120000
sales_q2_2012 | 40 | 3788a | US | 12-MAY-12 00:00:00 | 4950
sales_q3_2012 | 10 | 9519b | ITALY | 07-JUL-12 00:00:00 | 15000
sales_q3_2012 | 10 | 9519a | FRANCE | 18-AUG-12 00:00:00 |650000
sales_q3_2012 | 10 | 9519b | FRANCE | 18-AUG-12 00:00:00 |650000
sales_q3_2012 | 20 | 3788b | INDIA | 21-SEP-12 00:00:00 | 5090
sales_q3_2012 | 40 | 4788a | US | 23-SEP-12 00:00:00 | 4950
sales_q4_2012_p1 | 40 | 4577b | US | 11-NOV-12 00:00:00 | 25000
sales_q4_2012_p1 | 40 | 4788b | US | 09-OCT-12 00:00:00 | 15000
sales_q4_2012_p1 | 20 | 4519a | INDIA | 18-OCT-12 00:00:00 |650000
sales_q4_2012_p2 | 30 | 7588b | CANADA | 14-DEC-12 00:00:00 | 50000
sales_q4_2012_p2 | 20 | 4519b | INDIA | 02-DEC-12 00:00:00 | 5090
(17 rows)