改变一个表的分区方案只需使用alter table 加 partition_options 子句就可以了。和创建分区表时的create table语句很像。
创建表
CREATE TABLE trb3 (id INT, name VARCHAR(50), purchased DATE) PARTITION BY RANGE( YEAR(purchased) ) ( PARTITION p0 VALUES LESS THAN (1990), PARTITION p1 VALUES LESS THAN (1995), PARTITION p2 VALUES LESS THAN (2000), PARTITION p3 VALUES LESS THAN (2005) );
创建插入数据存储过程
delimiter $$ drop procedure if exists pr_trb3$$ create procedure pr_trb3(in begindate date,in enddate date,in tabname varchar(40)) begin while begindate<enddate 1="" begindate="date_add(begindate,interval" delimiter="" do="" drop="" end="" execute="" from="" insert="" pre="" prepare="" s="concat_ws('" set="" stmt=""><p>调用存储过程插入数据</p><pre>call pr_trb3('1985-01-01','2004-12-31','trb3');</pre> <p>查看数据分布</p> <pre>select partition_name part, partition_expression expr, partition_description descr, table_rows from information_schema.partitions where table_schema = schema() and table_name='trb3'; +------+------------------+-------+------------+ | part | expr | descr | table_rows | +------+------------------+-------+------------+ | p0 | YEAR(purchased) | 1990 | 1826 | | p1 | YEAR(purchased) | 1995 | 1826 | | p2 | YEAR(purchased) | 2000 | 1826 | | p3 | YEAR(purchased) | 2005 | 1826 | +------+------------------+-------+------------+ 4 rows in set (0.00 sec)</pre> <p>改变分区方案</p> <pre>mysql> ALTER TABLE trb3 PARTITION BY KEY(id) PARTITIONS 4; Query OK, 7304 rows affected (0.07 sec) Records: 7304 Duplicates: 0 Warnings: 0</pre> <p>查看数据</p> <pre>select partition_name part, partition_expression expr, partition_description descr, table_rows from information_schema.partitions where table_schema = schema() and table_name='trb3'; +------+------+-------+------------+ | part | expr | descr | table_rows | +------+------+-------+------------+ | p0 | `id` | NULL | 7472 | | p1 | `id` | NULL | 0 | | p2 | `id` | NULL | 0 | | p3 | `id` | NULL | 0 | +------+------+-------+------------+ 4 rows in set (0.00 sec) mysql> select 1826*4; +--------+ | 1826*4 | +--------+ | 7304 | +--------+ 1 row in set (0.00 sec)</pre> <p>count(*)行数一致，说明数据没出问题，但是information_schema.partitions查出来的不对<del>，这就不知道为什么了</del></p> <blockquote> <p>For partitioned InnoDB tables, the row count given in the TABLE_ROWS column of the INFORMATION_SCHEMA.PARTITIONS table is only an estimated value used in SQL optimization, and is not always exact.</p> </blockquote> <pre>mysql> select count(*) from trb3; +----------+ | count(*) | +----------+ | 7304 | +----------+ 但是count(*)还是7304，什么鬼</pre> <p>再次改变分区方案</p> <pre>ALTER TABLE trb3 PARTITION BY RANGE( YEAR(purchased) ) ( PARTITION p0 VALUES LESS THAN (1990), PARTITION p1 VALUES LESS THAN (1995), PARTITION p2 VALUES LESS THAN (2000), PARTITION p3 VALUES LESS THAN (2005) ); mysql> select -> partition_name part, -> partition_expression expr, -> partition_description descr, -> table_rows -> from information_schema.partitions where -> table_schema = schema() -> and table_name='trb3'; +------+------------------+-------+------------+ | part | expr | descr | table_rows | +------+------------------+-------+------------+ | p0 | YEAR(purchased) | 1990 | 1826 | | p1 | YEAR(purchased) | 1995 | 1826 | | p2 | YEAR(purchased) | 2000 | 0 | | p3 | YEAR(purchased) | 2005 | 0 | +------+------------------+-------+------------+ 4 rows in set (0.00 sec)</pre> <p><del>丢数据了。。</del><br> 更正，实际没丢，这个information_shcema.partitions表有延迟，过一会再查就好了</p> <pre>mysql> select -> partition_name part, -> partition_expression expr, -> partition_description descr, -> table_rows -> from information_schema.partitions where -> table_schema = schema() -> and table_name='trb3'; +------+------------------+-------+------------+ | part | expr | descr | table_rows | +------+------------------+-------+------------+ | p0 | YEAR(purchased) | 1990 | 1826 | | p1 | YEAR(purchased) | 1995 | 1826 | | p2 | YEAR(purchased) | 2000 | 1826 | | p3 | YEAR(purchased) | 2005 | 1826 | +------+------------------+-------+------------+ 4 rows in set (0.00 sec)</pre> <p>官方文档说：<br> This has the same effect on the structure of the table as dropping the table and re-creating it using CREATE TABLE trb3 PARTITION BY KEY(id) PARTITIONS 2;<br> 就是说ALTER TABLE trb3 PARTITION BY与 drop table然后重新create table trb3 partition by key(id) partitions 2一样呢。</p> <h3 id="改存储引擎和普通表没啥区别">改存储引擎，和普通表没啥区别</h3> <pre>mysql> drop table trb3; Query OK, 0 rows affected (0.01 sec) mysql> CREATE TABLE trb3 (id INT, name VARCHAR(50), purchased DATE) -> PARTITION BY RANGE( YEAR(purchased) ) ( -> PARTITION p0 VALUES LESS THAN (1990), -> PARTITION p1 VALUES LESS THAN (1995), -> PARTITION p2 VALUES LESS THAN (2000), -> PARTITION p3 VALUES LESS THAN (2005) -> ); Query OK, 0 rows affected (0.03 sec) mysql> call pr_trb3('1985-01-01','2004-12-31','trb3'); Query OK, 0 rows affected (1.69 sec) mysql> select -> partition_name part, -> partition_expression expr, -> partition_description descr, -> table_rows -> from information_schema.partitions where -> table_schema = schema() -> and table_name='trb3'; +------+------------------+-------+------------+ | part | expr | descr | table_rows | +------+------------------+-------+------------+ | p0 | YEAR(purchased) | 1990 | 1826 | | p1 | YEAR(purchased) | 1995 | 1826 | | p2 | YEAR(purchased) | 2000 | 1826 | | p3 | YEAR(purchased) | 2005 | 1826 | +------+------------------+-------+------------+ 4 rows in set (0.01 sec) mysql> alter table trb3 engine=myisam; Query OK, 7304 rows affected (0.02 sec) Records: 7304 Duplicates: 0 Warnings: 0 mysql> select -> partition_name part, -> partition_expression expr, -> partition_description descr, -> table_rows -> from information_schema.partitions where -> table_schema = schema() -> and table_name='trb3'; +------+------------------+-------+------------+ | part | expr | descr | table_rows | +------+------------------+-------+------------+ | p0 | YEAR(purchased) | 1990 | 1826 | | p1 | YEAR(purchased) | 1995 | 1826 | | p2 | YEAR(purchased) | 2000 | 1826 | | p3 | YEAR(purchased) | 2005 | 1826 | +------+------------------+-------+------------+ 4 rows in set (0.01 sec) mysql> show create table trb3G *************************** 1. row *************************** Table: trb3 Create Table: CREATE TABLE `trb3` ( `id` int(11) DEFAULT NULL, `name` varchar(50) DEFAULT NULL, `purchased` date DEFAULT NULL ) ENGINE=MyISAM DEFAULT CHARSET=utf8 /*!50100 PARTITION BY RANGE ( YEAR(purchased)) (PARTITION p0 VALUES LESS THAN (1990) ENGINE = MyISAM, PARTITION p1 VALUES LESS THAN (1995) ENGINE = MyISAM, PARTITION p2 VALUES LESS THAN (2000) ENGINE = MyISAM, PARTITION p3 VALUES LESS THAN (2005) ENGINE = MyISAM) */ 1 row in set (0.00 sec)</pre> <h3 id="将表由分区表改为非分区表">将表由分区表改为非分区表</h3> <pre>mysql> alter table trb3 remove partitioning; Query OK, 7304 rows affected (0.01 sec) Records: 7304 Duplicates: 0 Warnings: 0 mysql> select -> partition_name part, -> partition_expression expr, -> partition_description descr, -> table_rows -> from information_schema.partitions where -> table_schema = schema() -> and table_name='trb3'; +------+------+-------+------------+ | part | expr | descr | table_rows | +------+------+-------+------------+ | NULL | NULL | NULL | 7304 | +------+------+-------+------------+ 1 row in set (0.00 sec) mysql> show create table trb3G *************************** 1. row *************************** Table: trb3 Create Table: CREATE TABLE `trb3` ( `id` int(11) DEFAULT NULL, `name` varchar(50) DEFAULT NULL, `purchased` date DEFAULT NULL ) ENGINE=MyISAM DEFAULT CHARSET=utf8 1 row in set (0.00 sec)</pre> <h3 id="range-list分区管理">Range List分区管理</h3> <pre>mysql> drop table trb3; Query OK, 0 rows affected (0.01 sec) mysql> CREATE TABLE trb3 (id INT, name VARCHAR(50), purchased DATE) -> PARTITION BY RANGE( YEAR(purchased) ) ( -> PARTITION p0 VALUES LESS THAN (1990), -> PARTITION p1 VALUES LESS THAN (1995), -> PARTITION p2 VALUES LESS THAN (2000), -> PARTITION p3 VALUES LESS THAN (2005) -> ); Query OK, 0 rows affected (0.03 sec) mysql> call pr_trb3('1985-01-01','2004-12-31','trb3'); Query OK, 0 rows affected (1.75 sec) mysql> select -> partition_name part, -> partition_expression expr, -> partition_description descr, -> table_rows -> from information_schema.partitions where -> table_schema = schema() -> and table_name='trb3'; +------+------------------+-------+------------+ | part | expr | descr | table_rows | +------+------------------+-------+------------+ | p0 | YEAR(purchased) | 1990 | 1826 | | p1 | YEAR(purchased) | 1995 | 1826 | | p2 | YEAR(purchased) | 2000 | 1826 | | p3 | YEAR(purchased) | 2005 | 1826 | +------+------------------+-------+------------+ 4 rows in set (0.00 sec)</pre> <h4 id="增加分区">增加分区</h4> <pre>mysql> alter table trb3 add partition (partition p5 values less than(2010)); Query OK, 0 rows affected (0.00 sec) Records: 0 Duplicates: 0 Warnings: 0</pre> <h4 id="合并分区">合并分区</h4> <pre>mysql> alter table trb3 reorganize partition p3,p5 into(partition p5 values less than(2010)); Query OK, 1826 rows affected (0.03 sec) Records: 1826 Duplicates: 0 Warnings: 0 mysql> select -> partition_name part, -> partition_expression expr, -> partition_description descr, -> table_rows -> from information_schema.partitions where -> table_schema = schema() -> and table_name='trb3'; +------+------------------+-------+------------+ | part | expr | descr | table_rows | +------+------------------+-------+------------+ | p0 | YEAR(purchased) | 1990 | 1826 | | p1 | YEAR(purchased) | 1995 | 1826 | | p2 | YEAR(purchased) | 2000 | 1826 | | p5 | YEAR(purchased) | 2010 | 1826 | +------+------------------+-------+------------+ 4 rows in set (0.00 sec)</pre> <h4 id="分裂分区">分裂分区</h4> <pre>mysql> ALTER TABLE trb3 REORGANIZE PARTITION p5 INTO ( -> PARTITION p3 VALUES LESS THAN (2005), -> PARTITION p4 VALUES LESS THAN (2010) -> ); Query OK, 1826 rows affected (0.04 sec) Records: 1826 Duplicates: 0 Warnings: 0 select partition_name part, partition_expression expr, partition_description descr, table_rows from information_schema.partitions where table_schema = schema() and table_name='trb3'; +------+------------------+-------+------------+ | part | expr | descr | table_rows | +------+------------------+-------+------------+ | p0 | YEAR(purchased) | 1990 | 1826 | | p1 | YEAR(purchased) | 1995 | 1826 | | p2 | YEAR(purchased) | 2000 | 1826 | | p3 | YEAR(purchased) | 2005 | 1826 | | p4 | YEAR(purchased) | 2010 | 0 | +------+------------------+-------+------------+ 5 rows in set (0.00 sec)</pre> <h3 id="hash-key分区">HASH KEY分区</h3> <pre>CREATE TABLE trb3 (id INT, name VARCHAR(50), purchased DATE) PARTITION BY hash( YEAR(purchased) ) partitions 12; mysql>call pr_trb3('1985-01-01','2004-12-31','trb3'); select partition_name part, partition_expression expr, partition_description descr, table_rows from information_schema.partitions where table_schema = schema() and table_name='trb3'; +------+------------------+-------+------------+ | part | expr | descr | table_rows | +------+------------------+-------+------------+ | p0 | YEAR(purchased) | NULL | 731 | | p1 | YEAR(purchased) | NULL | 365 | | p2 | YEAR(purchased) | NULL | 365 | | p3 | YEAR(purchased) | NULL | 365 | | p4 | YEAR(purchased) | NULL | 366 | | p5 | YEAR(purchased) | NULL | 730 | | p6 | YEAR(purchased) | NULL | 730 | | p7 | YEAR(purchased) | NULL | 730 | | p8 | YEAR(purchased) | NULL | 732 | | p9 | YEAR(purchased) | NULL | 730 | | p10 | YEAR(purchased) | NULL | 730 | | p11 | YEAR(purchased) | NULL | 730 | +------+------------------+-------+------------+ 12 rows in set (0.00 sec)</pre> <h4 id="缩建分区从12个到8个">缩建分区从12个到8个</h4> <pre>mysql> ALTER TABLE trb3 COALESCE PARTITION 4; Query OK, 7304 rows affected (0.13 sec) Records: 7304 Duplicates: 0 Warnings: 0 select partition_name part, partition_expression expr, partition_description descr, table_rows from information_schema.partitions where table_schema = schema() and table_name='trb3'; +------+------------------+-------+------------+ | part | expr | descr | table_rows | +------+------------------+-------+------------+ | p0 | YEAR(purchased) | NULL | 732 | | p1 | YEAR(purchased) | NULL | 1095 | | p2 | YEAR(purchased) | NULL | 1095 | | p3 | YEAR(purchased) | NULL | 1095 | | p4 | YEAR(purchased) | NULL | 1097 | | p5 | YEAR(purchased) | NULL | 730 | | p6 | YEAR(purchased) | NULL | 730 | | p7 | YEAR(purchased) | NULL | 730 | +------+------------------+-------+------------+ 8 rows in set (0.00 sec) mysql> select count(*) from trb3; +----------+ | count(*) | +----------+ | 7304 | +----------+ 1 row in set (0.00 sec)</pre> <p>没丢数据</p> <p>收缩前2004年在P0</p> <pre>mysql> select mod(2004,12); +--------------+ | mod(2004,12) | +--------------+ | 0 | +--------------+</pre> <p>收缩后2004年在P4</p> <pre>mysql> select mod(2004,8); +-------------+ | mod(2004,8) | +-------------+ | 4 | +-------------+</pre> <h3 id="exchanging-partitions-and-subpartitions-with-tables">Exchanging Partitions and Subpartitions with Tables</h3> <h3 id="分区子分区交换">分区(子分区)交换</h3> <pre> ALTER TABLE pt EXCHANGE PARTITION p WITH TABLE nt</pre> <p>pt是一个分区表，p是pt的分区或子分区，而nt是一个非分区表</p> <h4 id="限制条件">限制条件:</h4> <p>1.表nt不是分区表<br> 2.表nt不是临时表<br> 3.表pt和nt结构在其他方面是相同的<br> 4.表n没有外键约束，也没有其他表引用它的列为外键<br> 5.表nt的所有行都包含在表p的分区范围内(比如p range分区最大values less than 10，那么表nt不能有大于等于10的值)</p> <h4 id="权限">权限:</h4> <p>除了 ALTER, INSERT, and CREATE 权限外，你还要有DROP权限才能执行ALTER TABLE … EXCHANGE PARTITION.</p> <h4 id="其他注意事项">其他注意事项:</h4> <p>1.执行ALTER TABLE … EXCHANGE PARTITION 不会调用任何在nt表和p表上的触发器<br> 2.在交换表中的任何AUTO_INCREMENT列会被reset<br> 3.IGNORE关键字在执行ALTER TABLE … EXCHANGE PARTITION时会失效</p> <h4 id="完整实例语句如下">完整实例语句如下:</h4> <pre>ALTER TABLE pt EXCHANGE PARTITION p WITH TABLE nt;</pre> <p>在一次ALTER TABLE EXCHANGE PARTITION 中，只能有一个分区和一个非分区表被交换<br> 想交换多个，就执行多次ALTER TABLE EXCHANGE PARTITION<br> 任何MySQL支持的分区类型都可以进行交换</p> <h4 id="交换实例">交换实例</h4> <pre>CREATE TABLE e ( id INT NOT NULL, fname VARCHAR(30), lname VARCHAR(30) ) PARTITION BY RANGE (id) ( PARTITION p0 VALUES LESS THAN (50), PARTITION p1 VALUES LESS THAN (100), PARTITION p2 VALUES LESS THAN (150), PARTITION p3 VALUES LESS THAN (MAXVALUE) ); INSERT INTO e VALUES (1669, "Jim", "Smith"), (337, "Mary", "Jones"), (16, "Frank", "White"), (2005, "Linda", "Black");</pre> <p>创建一个与e结构一样的非分区表e2</p> <pre>mysql> create table e2 like e; Query OK, 0 rows affected (0.01 sec) mysql> show create table e2G *************************** 1. row *************************** Table: e2 Create Table: CREATE TABLE `e2` ( `id` int(11) NOT NULL, `fname` varchar(30) DEFAULT NULL, `lname` varchar(30) DEFAULT NULL ) ENGINE=InnoDB DEFAULT CHARSET=utf8 /*!50100 PARTITION BY RANGE (id) (PARTITION p0 VALUES LESS THAN (50) ENGINE = InnoDB, PARTITION p1 VALUES LESS THAN (100) ENGINE = InnoDB, PARTITION p2 VALUES LESS THAN (150) ENGINE = InnoDB, PARTITION p3 VALUES LESS THAN MAXVALUE ENGINE = InnoDB) */ 1 row in set (0.00 sec) mysql> alter table e2 remove partitioning; Query OK, 0 rows affected (0.02 sec) Records: 0 Duplicates: 0 Warnings: 0 mysql> show create table e2G *************************** 1. row *************************** Table: e2 Create Table: CREATE TABLE `e2` ( `id` int(11) NOT NULL, `fname` varchar(30) DEFAULT NULL, `lname` varchar(30) DEFAULT NULL ) ENGINE=InnoDB DEFAULT CHARSET=utf8 1 row in set (0.00 sec)</pre> <p>查看数据在e表中的分布:</p> <pre>select partition_name part, partition_expression expr, partition_description descr, table_rows from information_schema.partitions where table_schema = schema() and table_name='e' +------+------+----------+------------+ | part | expr | descr | table_rows | +------+------+----------+------------+ | p0 | id | 50 | 1 | | p1 | id | 100 | 0 | | p2 | id | 150 | 0 | | p3 | id | MAXVALUE | 3 | +------+------+----------+------------+ 4 rows in set (0.00 sec)</pre> <p>将分区p0与e2表进行交换:</p> <pre>mysql> ALTER TABLE e EXCHANGE PARTITION p0 WITH TABLE e2; Query OK, 0 rows affected (0.01 sec) select partition_name part, partition_expression expr, partition_description descr, table_rows from information_schema.partitions where table_schema = schema() and table_name='e'; +------+------+----------+------------+ | part | expr | descr | table_rows | +------+------+----------+------------+ | p0 | id | 50 | 0 | | p1 | id | 100 | 0 | | p2 | id | 150 | 0 | | p3 | id | MAXVALUE | 3 | +------+------+----------+------------+ 4 rows in set (0.01 sec) mysql> select * from e2; +----+-------+-------+ | id | fname | lname | +----+-------+-------+ | 16 | Frank | White | +----+-------+-------+ 1 row in set (0.00 sec) </pre> <p>重做实验，这次在交换前在表e2中插入一些数据</p> <pre>mysql> insert into e2 values(16,'FAN','BOSHI'); Query OK, 1 row affected (0.00 sec) mysql> insert into e2 values(51,'DU','YALAN'); Query OK, 1 row affected (0.00 sec) mysql> select * from e2; +----+-------+-------+ | id | fname | lname | +----+-------+-------+ | 16 | FAN | BOSHI | | 51 | DU | YALAN | +----+-------+-------+ 2 rows in set (0.00 sec) mysql> ALTER TABLE e EXCHANGE PARTITION p0 WITH TABLE e2; ERROR 1737 (HY000): Found a row that does not match the partition</pre> <p>报错了，因为51超出了p0的范围。<br> 如之前所说，此时使用IGNORE也无济于事</p> <pre>mysql> ALTER IGNORE TABLE e EXCHANGE PARTITION p0 WITH TABLE e2; ERROR 1737 (HY000): Found a row that does not match the partition</pre> <p>修改id为49，这样就属于p0的范围了</p> <pre>mysql> update e2 set id=49 where id=51; Query OK, 1 row affected (0.00 sec) Rows matched: 1 Changed: 1 Warnings: 0 mysql> ALTER TABLE e EXCHANGE PARTITION p0 WITH TABLE e2; Query OK, 0 rows affected (0.01 sec) mysql> select -> partition_name part, -> partition_expression expr, -> partition_description descr, -> table_rows -> from information_schema.partitions where -> table_schema = schema() -> and table_name='e'; +------+------+----------+------------+ | part | expr | descr | table_rows | +------+------+----------+------------+ | p0 | id | 50 | 2 | | p1 | id | 100 | 0 | | p2 | id | 150 | 0 | | p3 | id | MAXVALUE | 3 | +------+------+----------+------------+ 4 rows in set (0.00 sec) e2的数据被交换到了p0中 mysql> select * from e partition(p0); +----+-------+-------+ | id | fname | lname | +----+-------+-------+ | 16 | FAN | BOSHI | | 49 | DU | YALAN | +----+-------+-------+ 2 rows in set (0.00 sec) e的p0分区中的数据被交换到了e2中 mysql> select * from e2; +----+-------+-------+ | id | fname | lname | +----+-------+-------+ | 16 | Frank | White | +----+-------+-------+ 1 row in set (0.01 sec)</pre> <h4 id="交换subpartition">交换subpartition</h4> <pre>CREATE TABLE es ( id INT NOT NULL, fname VARCHAR(30), lname VARCHAR(30) ) PARTITION BY RANGE (id) SUBPARTITION BY KEY (lname) SUBPARTITIONS 2 ( PARTITION p0 VALUES LESS THAN (50), PARTITION p1 VALUES LESS THAN (100), PARTITION p2 VALUES LESS THAN (150), PARTITION p3 VALUES LESS THAN (MAXVALUE) ); INSERT INTO es VALUES (1669, "Jim", "Smith"), (337, "Mary", "Jones"), (16, "Frank", "White"), (2005, "Linda", "Black"); CREATE TABLE es2 LIKE es; ALTER TABLE es2 REMOVE PARTITIONING;</pre> <p>尽管我们没有显示的指定每个子分区的名字，我们仍可以通过information_schema.partitions表获取到子分区的名字</p> <pre>select partition_name part, subpartition_name, partition_expression expr, partition_description descr, table_rows from information_schema.partitions where table_schema = schema() and table_name='es'; +------+-------------------+------+----------+------------+ | part | subpartition_name | expr | descr | table_rows | +------+-------------------+------+----------+------------+ | p0 | p0sp0 | id | 50 | 1 | | p0 | p0sp1 | id | 50 | 0 | | p1 | p1sp0 | id | 100 | 0 | | p1 | p1sp1 | id | 100 | 0 | | p2 | p2sp0 | id | 150 | 0 | | p2 | p2sp1 | id | 150 | 0 | | p3 | p3sp0 | id | MAXVALUE | 3 | | p3 | p3sp1 | id | MAXVALUE | 0 | +------+-------------------+------+----------+------------+</pre> <p>接下来，开始将p3sp0和es进行交换</p> <pre>mysql> select * from es partition(p3sp0); +------+-------+-------+ | id | fname | lname | +------+-------+-------+ | 1669 | Jim | Smith | | 337 | Mary | Jones | | 2005 | Linda | Black | +------+-------+-------+ 3 rows in set (0.00 sec) mysql> ALTER TABLE es EXCHANGE PARTITION p3sp0 WITH TABLE es2; Query OK, 0 rows affected (0.00 sec) mysql> select * from es partition(p3sp0); Empty set (0.00 sec) mysql> select * from es2; +------+-------+-------+ | id | fname | lname | +------+-------+-------+ | 1669 | Jim | Smith | | 337 | Mary | Jones | | 2005 | Linda | Black | +------+-------+-------+ 3 rows in set (0.00 sec)</pre> <p>如果一个分区表有子分区，那么你只能以子分区为粒度进行交换，而不能直接交换子分区的父分区</p> <pre>mysql> ALTER TABLE es EXCHANGE PARTITION p3 WITH TABLE es2; ERROR 1704 (HY000): Subpartitioned table, use subpartition instead of partition</pre> <p>EXCHANGE PARTITION有着严格的要求<br> 两个将要交换的表的 列名，列的创建顺序，列的数量，以及索引都要严格一致。当然存储引擎也要一致</p> <pre>mysql> desc es2; +-------+-------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-------+-------------+------+-----+---------+-------+ | id | int(11) | NO | | NULL | | | fname | varchar(30) | YES | | NULL | | | lname | varchar(30) | YES | | NULL | | +-------+-------------+------+-----+---------+-------+ 3 rows in set (0.00 sec) mysql> create index id_name on es2(id,fname); Query OK, 0 rows affected (0.01 sec) Records: 0 Duplicates: 0 Warnings: 0 mysql> ALTER TABLE es EXCHANGE PARTITION p3sp0 WITH TABLE es2; ERROR 1736 (HY000): Tables have different definitions</pre> <p>改变es2的存储引擎</p> <pre>mysql> drop index id_name on es2; Query OK, 0 rows affected (0.00 sec) Records: 0 Duplicates: 0 Warnings: 0 mysql> alter table es2 engine=myisam; Query OK, 0 rows affected (0.01 sec) Records: 0 Duplicates: 0 Warnings: 0 mysql> ALTER TABLE es EXCHANGE PARTITION p3sp0 WITH TABLE es2; ERROR 1497 (HY000): The mix of handlers in the partitions is not allowed in this version of MySQL</pre> <h3 id="分区表的维护">分区表的维护</h3> <p>CHECK TABLE, OPTIMIZE TABLE, ANALYZE TABLE, and REPAIR TABLE可以被用于维护分区表</p> <p>Rebuilding partitions.相当于将分区中的数据drop掉再插入回来,对于避免磁盘碎片很有效<br> Example:</p> <pre>ALTER TABLE t1 REBUILD PARTITION p0, p1;</pre> <p>Optimizing partitions.如果你的表增加删除了大量数据，或者进行了大量的边长列的更新操作( VARCHAR, BLOB, or TEXT columns)。那么optimize partition将回收未使用的空间，并整理分区数据文件。<br> Example:</p> <pre>ALTER TABLE t1 OPTIMIZE PARTITION p0, p1;</pre> <p>运行OPTIMIZE PARTITION 相当于做了 CHECK PARTITION, ANALYZE PARTITION, and REPAIR PARTITION</p> <blockquote> <p>Some MySQL storage engines, including InnoDB, do not support per-partition optimization; in these cases, ALTER TABLE … OPTIMIZE PARTITION rebuilds the entire table. In MySQL 5.6.9 and later, running this statement on such a table causes the entire table to rebuilt and analyzed, and an appropriate warning to be issued. (Bug #11751825, Bug #42822) Use ALTER TABLE … REBUILD PARTITION and ALTER TABLE … ANALYZE PARTITION instead, to avoid this issue.</p> </blockquote> <p>Analyzing partitions.读取并保存分区的键分布<br> Example:</p> <pre>ALTER TABLE t1 ANALYZE PARTITION p3;</pre> <p>Repairing partitions.修补被破坏的分区<br> Example:</p> <pre>ALTER TABLE t1 REPAIR PARTITION p0,p1;</pre> <p>Checking partitions.可以使用几乎与对非分区表使用CHECK TABLE 相同的方式检查分区。<br> Example:</p> <pre>ALTER TABLE trb3 CHECK PARTITION p1;</pre> <p>这个命令可以告诉你表trb3的分区p1中的数据或索引是否已经被破坏。如果发生了这种情况，使用“ALTER TABLE … REPAIR PARTITION”来修补该分区。</p> <h4 id="以上每个命令都支持将分区换成all">以上每个命令都支持将分区换成ALL</h4> <blockquote> <p>The use of mysqlcheck and myisamchk is not supported with partitioned tables.</p> </blockquote> <p>mysqlcheck和myisamchk不支持分区表</p> <p>你可以使用 ALTER TABLE … TRUNCATE PARTITION. 来删除一个或多个分区中的数据<br> 如:ALTER TABLE … TRUNCATE PARTITION ALL删除所有数据</p> <p>ANALYZE, CHECK, OPTIMIZE, REBUILD, REPAIR, and TRUNCATE 操作不支持 subpartitions.</p> </enddate>
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