改變一個(gè)表的分區(qū)方案只需使用alter table 加 partition_options 子句就可以了。和創(chuàng)建分區(qū)表時(shí)的create table語(yǔ)句很像。
創(chuàng)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)); |
創(chuàng)建插入數(shù)據(jù)存儲(chǔ)過(guò)程
| delimiter $$drop procedure if exists pr_trb3$$create procedure pr_trb3(in begindate date,in enddate date,in tabname varchar(40))beginwhile begindate<enddate 1="" begindate="date_add(begindate,interval" delimiter="" do="" drop="" end="" execute="" from="" insert="" pre="" prepare="" s="concat_ws('" set="" stmt=""><p>調(diào)用存儲(chǔ)過(guò)程插入數(shù)據(jù)</p><pre class="brush:sql;">call pr_trb3('1985-01-01','2004-12-31','trb3');</pre><p>查看數(shù)據(jù)分布</p><pre class="brush:sql;">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>改變分區(qū)方案</p><pre class="brush:sql;">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>查看數(shù)據(jù)</p><pre class="brush:sql;">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(*)行數(shù)一致，說(shuō)明數(shù)據(jù)沒(méi)出問(wèn)題，但是information_schema.partitions查出來(lái)的不對(duì)<del>，這就不知道為什么了</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 class="brush:sql;">mysql> select count(*) from trb3;+----------+| count(*) |+----------+| 7304 |+----------+但是count(*)還是7304，什么鬼</pre><p>再次改變分區(qū)方案</p><pre class="brush:sql;">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>丟數(shù)據(jù)了。。</del><br>更正，實(shí)際沒(méi)丟，這個(gè)information_shcema.partitions表有延遲，過(guò)一會(huì)再查就好了</p><pre class="brush:sql;">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>官方文檔說(shuō)：<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>就是說(shuō)ALTER TABLE trb3 PARTITION BY與 drop table然后重新create table trb3 partition by key(id) partitions 2一樣呢。</p><h3 id="改存儲(chǔ)引擎和普通表沒(méi)啥區(qū)別">改存儲(chǔ)引擎，和普通表沒(méi)啥區(qū)別</h3><pre class="brush:sql;">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: 0mysql> 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 trb3/G*************************** 1. row ***************************Table: trb3Create 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="將表由分區(qū)表改為非分區(qū)表">將表由分區(qū)表改為非分區(qū)表</h3><pre class="brush:sql;">mysql> alter table trb3 remove partitioning;Query OK, 7304 rows affected (0.01 sec)Records: 7304 Duplicates: 0 Warnings: 0mysql> 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 trb3/G*************************** 1. row ***************************Table: trb3Create Table: CREATE TABLE `trb3` (`id` int(11) DEFAULT NULL,`name` varchar(50) DEFAULT NULL,`purchased` date DEFAULT NULL) ENGINE=MyISAM DEFAULT CHARSET=utf81 row in set (0.00 sec)</pre><h3 id="range-list分區(qū)管理">Range List分區(qū)管理</h3><pre class="brush:sql;">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="增加分區(qū)">增加分區(qū)</h4><pre class="brush:sql;">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="合并分區(qū)">合并分區(qū)</h4><pre class="brush:sql;">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: 0mysql> 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="分裂分區(qū)">分裂分區(qū)</h4><pre class="brush:sql;">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: 0select 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分區(qū)">HASH KEY分區(qū)</h3><pre class="brush:sql;">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="縮建分區(qū)從12個(gè)到8個(gè)">縮建分區(qū)從12個(gè)到8個(gè)</h4><pre class="brush:sql;">mysql> ALTER TABLE trb3 COALESCE PARTITION 4;Query OK, 7304 rows affected (0.13 sec)Records: 7304 Duplicates: 0 Warnings: 0select 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>沒(méi)丟數(shù)據(jù)</p><p>收縮前2004年在P0</p><pre class="brush:sql;">mysql> select mod(2004,12);+--------------+| mod(2004,12) |+--------------+| 0 |+--------------+</pre><p>收縮后2004年在P4</p><pre class="brush:sql;">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="分區(qū)子分區(qū)交換">分區(qū)(子分區(qū))交換</h3><pre class="brush:sql;"> ALTER TABLE pt EXCHANGE PARTITION p WITH TABLE nt</pre><p>pt是一個(gè)分區(qū)表，p是pt的分區(qū)或子分區(qū)，而nt是一個(gè)非分區(qū)表</p><h4 id="限制條件">限制條件:</h4><p>1.表nt不是分區(qū)表<br>2.表nt不是臨時(shí)表<br>3.表pt和nt結(jié)構(gòu)在其他方面是相同的<br>4.表n沒(méi)有外鍵約束，也沒(méi)有其他表引用它的列為外鍵<br>5.表nt的所有行都包含在表p的分區(qū)范圍內(nèi)(比如p range分區(qū)最大values less than 10，那么表nt不能有大于等于10的值)</p><h4 id="權(quán)限">權(quán)限:</h4><p>除了 ALTER, INSERT, and CREATE 權(quán)限外，你還要有DROP權(quán)限才能執(zhí)行ALTER TABLE … EXCHANGE PARTITION.</p><h4 id="其他注意事項(xiàng)">其他注意事項(xiàng):</h4><p>1.執(zhí)行ALTER TABLE … EXCHANGE PARTITION 不會(huì)調(diào)用任何在nt表和p表上的觸發(fā)器<br>2.在交換表中的任何AUTO_INCREMENT列會(huì)被reset<br>3.IGNORE關(guān)鍵字在執(zhí)行ALTER TABLE … EXCHANGE PARTITION時(shí)會(huì)失效</p><h4 id="完整實(shí)例語(yǔ)句如下">完整實(shí)例語(yǔ)句如下:</h4><pre class="brush:sql;">ALTER TABLE pt EXCHANGE PARTITION p WITH TABLE nt;</pre><p>在一次ALTER TABLE EXCHANGE PARTITION 中，只能有一個(gè)分區(qū)和一個(gè)非分區(qū)表被交換<br>想交換多個(gè)，就執(zhí)行多次ALTER TABLE EXCHANGE PARTITION<br>任何MySQL支持的分區(qū)類(lèi)型都可以進(jìn)行交換</p><h4 id="交換實(shí)例">交換實(shí)例</h4><pre class="brush:sql;">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>創(chuàng)建一個(gè)與e結(jié)構(gòu)一樣的非分區(qū)表e2</p><pre class="brush:sql;">mysql> create table e2 like e;Query OK, 0 rows affected (0.01 sec)mysql> show create table e2/G*************************** 1. row ***************************Table: e2Create 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: 0mysql> show create table e2/G*************************** 1. row ***************************Table: e2Create Table: CREATE TABLE `e2` (`id` int(11) NOT NULL,`fname` varchar(30) DEFAULT NULL,`lname` varchar(30) DEFAULT NULL) ENGINE=InnoDB DEFAULT CHARSET=utf81 row in set (0.00 sec)</pre><p>查看數(shù)據(jù)在e表中的分布:</p><pre class="brush:sql;">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>將分區(qū)p0與e2表進(jìn)行交換:</p><pre class="brush:sql;">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>重做實(shí)驗(yàn)，這次在交換前在表e2中插入一些數(shù)據(jù)</p><pre class="brush:sql;">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>報(bào)錯(cuò)了，因?yàn)?1超出了p0的范圍。<br>如之前所說(shuō)，此時(shí)使用IGNORE也無(wú)濟(jì)于事</p><pre class="brush:sql;">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為49，這樣就屬于p0的范圍了</p><pre class="brush:sql;">mysql> update e2 set id=49 where id=51;Query OK, 1 row affected (0.00 sec)Rows matched: 1 Changed: 1 Warnings: 0mysql> 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的數(shù)據(jù)被交換到了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分區(qū)中的數(shù)據(jù)被交換到了e2中mysql> select * from e2;+----+-------+-------+| id | fname | lname |+----+-------+-------+| 16 | Frank | White |+----+-------+-------+1 row in set (0.01 sec)</pre><h4 id="交換subpartition">交換subpartition</h4><pre class="brush:sql;">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>盡管我們沒(méi)有顯示的指定每個(gè)子分區(qū)的名字，我們?nèi)钥梢酝ㄟ^(guò)information_schema.partitions表獲取到子分區(qū)的名字</p><pre class="brush:sql;">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>接下來(lái)，開(kāi)始將p3sp0和es進(jìn)行交換</p><pre class="brush:sql;">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>如果一個(gè)分區(qū)表有子分區(qū)，那么你只能以子分區(qū)為粒度進(jìn)行交換，而不能直接交換子分區(qū)的父分區(qū)</p><pre class="brush:sql;">mysql> ALTER TABLE es EXCHANGE PARTITION p3 WITH TABLE es2;ERROR 1704 (HY000): Subpartitioned table, use subpartition instead of partition</pre><p>EXCHANGE PARTITION有著嚴(yán)格的要求<br>兩個(gè)將要交換的表的 列名，列的創(chuàng)建順序，列的數(shù)量，以及索引都要嚴(yán)格一致。當(dāng)然存儲(chǔ)引擎也要一致</p><pre class="brush:sql;">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: 0mysql> ALTER TABLE es EXCHANGE PARTITION p3sp0 WITH TABLE es2;ERROR 1736 (HY000): Tables have different definitions</pre><p>改變es2的存儲(chǔ)引擎</p><pre class="brush:sql;">mysql> drop index id_name on es2;Query OK, 0 rows affected (0.00 sec)Records: 0 Duplicates: 0 Warnings: 0mysql> alter table es2 engine=myisam;Query OK, 0 rows affected (0.01 sec)Records: 0 Duplicates: 0 Warnings: 0mysql> 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="分區(qū)表的維護(hù)">分區(qū)表的維護(hù)</h3><p>CHECK TABLE, OPTIMIZE TABLE, ANALYZE TABLE, and REPAIR TABLE可以被用于維護(hù)分區(qū)表</p><p>Rebuilding partitions.相當(dāng)于將分區(qū)中的數(shù)據(jù)drop掉再插入回來(lái),對(duì)于避免磁盤(pán)碎片很有效<br>Example:</p><pre class="brush:sql;">ALTER TABLE t1 REBUILD PARTITION p0, p1;</pre><p>Optimizing partitions.如果你的表增加刪除了大量數(shù)據(jù)，或者進(jìn)行了大量的邊長(zhǎng)列的更新操作( VARCHAR, BLOB, or TEXT columns)。那么optimize partition將回收未使用的空間，并整理分區(qū)數(shù)據(jù)文件。<br>Example:</p><pre class="brush:sql;">ALTER TABLE t1 OPTIMIZE PARTITION p0, p1;</pre><p>運(yùn)行OPTIMIZE PARTITION 相當(dāng)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.讀取并保存分區(qū)的鍵分布<br>Example:</p><pre class="brush:sql;">ALTER TABLE t1 ANALYZE PARTITION p3;</pre><p>Repairing partitions.修補(bǔ)被破壞的分區(qū)<br>Example:</p><pre class="brush:sql;">ALTER TABLE t1 REPAIR PARTITION p0,p1;</pre><p>Checking partitions.可以使用幾乎與對(duì)非分區(qū)表使用CHECK TABLE 相同的方式檢查分區(qū)。<br>Example:</p><pre class="brush:sql;">ALTER TABLE trb3 CHECK PARTITION p1;</pre><p>這個(gè)命令可以告訴你表trb3的分區(qū)p1中的數(shù)據(jù)或索引是否已經(jīng)被破壞。如果發(fā)生了這種情況，使用“ALTER TABLE … REPAIR PARTITION”來(lái)修補(bǔ)該分區(qū)。</p><h4 id="以上每個(gè)命令都支持將分區(qū)換成all">以上每個(gè)命令都支持將分區(qū)換成ALL</h4><blockquote><p>The use of mysqlcheck and myisamchk is not supported with partitioned tables.</p></blockquote><p>mysqlcheck和myisamchk不支持分區(qū)表</p><p>你可以使用 ALTER TABLE … TRUNCATE PARTITION. 來(lái)刪除一個(gè)或多個(gè)分區(qū)中的數(shù)據(jù)<br>如:ALTER TABLE … TRUNCATE PARTITION ALL刪除所有數(shù)據(jù)</p><p>ANALYZE, CHECK, OPTIMIZE, REBUILD, REPAIR, and TRUNCATE 操作不支持 subpartitions.</p></enddate> |
