ALTER TABLE…SPLIT PARTITION命令將一個(gè)分區(qū)劃分為兩個(gè)分區(qū),并重新分配新分區(qū)的內(nèi)容。
語法介紹
ALTER TABLE…SPLIT PARTITION命令的語法有兩種形式:
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命令用于將分區(qū)添加到現(xiàn)有的分區(qū)表中。在分區(qū)表中對(duì)于分區(qū)數(shù)量沒有上限要求。
當(dāng)您執(zhí)行ALTER TABLE…SPLIT PARTITION命令時(shí),PolarDB就會(huì)創(chuàng)建兩個(gè)新分區(qū),并在這兩個(gè)新分區(qū)之間(如分區(qū)規(guī)則約束的一樣)重新分配舊分區(qū)中的內(nèi)容。
包括TABLESPACE子句指定新分區(qū)要所屬的表空間。如果您沒有指定表空間, 那么分區(qū)將所屬于缺省表空間。
如果對(duì)表進(jìn)行了索引設(shè)置, 那么索引將創(chuàng)建在新分區(qū)上。
要使用ALTER TABLE…SPLIT PARTITION命令,您必須是表的擁有者或有超級(jí)用戶(或管理員)的權(quán)限。
參數(shù)
參數(shù) | 參數(shù)說明 |
---|---|
table name | 分區(qū)表的名稱(可以采用模式限定的方式引用)。 |
partition name | 要?jiǎng)澐值姆謪^(qū)名稱。 |
new_part1 |
要?jiǎng)?chuàng)建的第一個(gè)新分區(qū)的名稱。在所有分區(qū)和子分區(qū)當(dāng)中,分區(qū)名稱必須是唯一的,且必須遵循給對(duì)象標(biāo)識(shí)符命名的慣例。
|
new_part2 |
要?jiǎng)?chuàng)建的第二個(gè)新分區(qū)的名稱。在所有分區(qū)和子分區(qū)當(dāng)中,分區(qū)名稱必須是唯一的,且必須遵循給對(duì)象標(biāo)識(shí)符命名的慣例。
|
range part value | 使用range_part_value 指定邊界規(guī)則來創(chuàng)建新分區(qū)。分區(qū)規(guī)則必須至少包含一列有兩個(gè)運(yùn)算符的數(shù)據(jù)類型(例如,一個(gè)大于等于運(yùn)算符和一個(gè)小于運(yùn)算符)。范圍邊界的評(píng)估是依據(jù)less than 子句進(jìn)行的,且范圍邊界是非包容性的。2010年1月1日這個(gè)日期邊界只會(huì)包括那些在2009年12月31日當(dāng)天或之前的日期值。
|
(value[, value]...) |
使用 更多關(guān)于創(chuàng)建 |
tablespace name | 分區(qū)或子分區(qū)所屬的表空間名稱。 |
劃分LIST分區(qū)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)
劃分RANGE分區(qū)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)