Mysql分区表的管理与维护
内容摘要
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 VARCH
创建表
CREATE TABLE trb3 (id INT, name VARCH
文章正文
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
1 2 3 4 5 6 7 | 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
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528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 | 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>调用存储过程插入数据</p><pre class="brush:sql;">call pr_trb3('1985-01-01','2004-12-31','trb3');</pre><p>查看数据分布</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>改变分区方案</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>查看数据</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 class="brush:sql;">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 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>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 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 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="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 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分区管理">Range List分区管理</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="增加分区">增加分区</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="合并分区">合并分区</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="分裂分区">分裂分区</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分区">HASH KEY分区</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="缩建分区从12个到8个">缩建分区从12个到8个</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>没丢数据</p><p>收缩前2004年在P0</p><pre class="brush:sql;">mysql> select mod(2004,12);+--------------+| mod(2004,12) |+--------------+| 0 |+--------------+</pre><p>收缩后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="分区子分区交换">分区(子分区)交换</h3><pre class="brush:sql;"> 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 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 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>创建一个与e结构一样的非分区表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>查看数据在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>将分区p0与e2表进行交换:</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>重做实验，这次在交换前在表e2中插入一些数据</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>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 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为49，这样就属于p0的范围了</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 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>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 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>接下来，开始将p3sp0和es进行交换</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 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 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>改变es2的存储引擎</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 class="brush:sql;">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 class="brush:sql;">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 class="brush:sql;">ALTER TABLE t1 ANALYZE PARTITION p3;</pre><p>Repairing partitions.修补被破坏的分区<br>Example:</p><pre class="brush:sql;">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 class="brush:sql;">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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