数据切分——Mysql分区表的建立及性能分析

Mysql的安装方法可以参考：

http://blog.csdn.net/jhq0113/article/details/43812895

Mysql分区表的介绍可以参考：

http://blog.csdn.net/jhq0113/article/details/44592865

1.检查你的Mysql是否支持分区

mysql> SHOW VARIABLES LIKE '%partition%';

若结果如下，表示你的Mysql支持表分区:

+-----------------------+-------+

       | Variable_name         | Value |

       +-----------------------+-------+

       | have_partition_engine | YES   |

       +-----------------------+-------+

       1 row in set (0.00 sec)

RANGE分区表创建方式：

DROP TABLE IF EXISTS `my_orders`;
CREATE TABLE `my_orders` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT COMMENT '表主键',
  `pid` int(10) unsigned NOT NULL COMMENT '产品ID',
  `price` decimal(15,2) NOT NULL COMMENT '单价',
  `num` int(11) NOT NULL COMMENT '购买数量',
  `uid` int(10) unsigned NOT NULL COMMENT '客户ID',
  `atime` datetime NOT NULL COMMENT '下单时间',
  `utime` int(10) unsigned NOT NULL DEFAULT 0 COMMENT '修改时间',
  `isdel` tinyint(4) NOT NULL DEFAULT '0' COMMENT '软删除标识',
  PRIMARY KEY (`id`,`atime`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8

/*********分区信息**************/
PARTITION BY RANGE (YEAR(atime))
(
   PARTITION p0 VALUES LESS THAN (2016),
   PARTITION p1 VALUES LESS THAN (2017),
   PARTITION p2 VALUES LESS THAN MAXVALUE
);

以上是一个简单的订单表，分区字段是atime,根据RANGE分区，这样当你向该表中插入数据的时候，Mysql会根据YEAR(atime)的值进行分区存储。

检查分区是否创建成功，执行查询语句：

EXPLAIN PARTITIONS SELECT * FROM `my_orders`

若成功，结果如下：

性能分析：

1）.创建同样表结构，但没有进行分区的表

DROP TABLE IF EXISTS `my_order`;
CREATE TABLE `my_order` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT COMMENT '表主键',
  `pid` int(10) unsigned NOT NULL COMMENT '产品ID',
  `price` decimal(15,2) NOT NULL COMMENT '单价',
  `num` int(11) NOT NULL COMMENT '购买数量',
  `uid` int(10) unsigned NOT NULL COMMENT '客户ID',
  `atime` datetime NOT NULL COMMENT '下单时间',
  `utime` int(10) unsigned NOT NULL DEFAULT 0 COMMENT '修改时间',
  `isdel` tinyint(4) NOT NULL DEFAULT '0' COMMENT '软删除标识',
  PRIMARY KEY (`id`,`atime`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

2）.向两张表中插入相同的数据

/**************************向分区表插入数据****************************/
INSERT INTO my_orders(`pid`,`price`,`num`,`uid`,`atime`) VALUES(1,12.23,1,89757,CURRENT_TIMESTAMP());
INSERT INTO my_orders(`pid`,`price`,`num`,`uid`,`atime`) VALUES(1,12.23,1,89757,'2016-05-01 00:00:00');
INSERT INTO my_orders(`pid`,`price`,`num`,`uid`,`atime`) VALUES(1,12.23,1,89757,'2017-05-01 00:00:00');
INSERT INTO my_orders(`pid`,`price`,`num`,`uid`,`atime`) VALUES(1,12.23,1,89757,'2018-05-01 00:00:00');
INSERT INTO my_orders(`pid`,`price`,`num`,`uid`,`atime`) VALUES(1,12.23,1,89756,'2015-05-01 00:00:00');
INSERT INTO my_orders(`pid`,`price`,`num`,`uid`,`atime`) VALUES(1,12.23,1,89756,'2016-05-01 00:00:00');
INSERT INTO my_orders(`pid`,`price`,`num`,`uid`,`atime`) VALUES(1,12.23,1,89756,'2017-05-01 00:00:00');
INSERT INTO my_orders(`pid`,`price`,`num`,`uid`,`atime`) VALUES(1,12.23,1,89756,'2018-05-01 00:00:00');

/**************************向未分区表插入数据****************************/
INSERT INTO my_order(`pid`,`price`,`num`,`uid`,`atime`) VALUES(1,12.23,1,89757,CURRENT_TIMESTAMP());
INSERT INTO my_order(`pid`,`price`,`num`,`uid`,`atime`) VALUES(1,12.23,1,89757,'2016-05-01 00:00:00');
INSERT INTO my_order(`pid`,`price`,`num`,`uid`,`atime`) VALUES(1,12.23,1,89757,'2017-05-01 00:00:00');
INSERT INTO my_order(`pid`,`price`,`num`,`uid`,`atime`) VALUES(1,12.23,1,89757,'2018-05-01 00:00:00');
INSERT INTO my_order(`pid`,`price`,`num`,`uid`,`atime`) VALUES(1,12.23,1,89756,'2015-05-01 00:00:00');
INSERT INTO my_order(`pid`,`price`,`num`,`uid`,`atime`) VALUES(1,12.23,1,89756,'2016-05-01 00:00:00');
INSERT INTO my_order(`pid`,`price`,`num`,`uid`,`atime`) VALUES(1,12.23,1,89756,'2017-05-01 00:00:00');
INSERT INTO my_order(`pid`,`price`,`num`,`uid`,`atime`) VALUES(1,12.23,1,89756,'2018-05-01 00:00:00');

3）.主从复制，大约20万条左右（主从复制的数据和真实环境有差距，但是能体现出表分区查询的性能优劣）

/**********************************主从复制大量数据******************************/
INSERT INTO `my_orders`(`pid`,`price`,`num`,`uid`,`atime`) SELECT `pid`,`price`,`num`,`uid`,`atime` FROM `my_orders`;
INSERT INTO `my_order`(`pid`,`price`,`num`,`uid`,`atime`) SELECT `pid`,`price`,`num`,`uid`,`atime` FROM `my_order`;

4）.查询测试

/***************************查询性能分析**************************************/
SELECT * FROM `my_orders` WHERE `uid`=89757 AND `atime`< CURRENT_TIMESTAMP();
/****用时0.084s****/

SELECT * FROM `my_order` WHERE `uid`=89757 AND `atime`< CURRENT_TIMESTAMP();
/****用时0.284s****/

通过以上查询可以明显看出进行表分区的查询性能更好，查询所花费的时间更短。

分析查询过程：

EXPLAIN PARTITIONS SELECT * FROM `my_orders` WHERE `uid`=89757 AND `atime`< CURRENT_TIMESTAMP();

EXPLAIN PARTITIONS SELECT * FROM `my_order` WHERE `uid`=89757 AND `atime`< CURRENT_TIMESTAMP();

通过以上结果可以看出，my_orders表查询直接经过p0分区，只扫描了49386行，而my_order表没有进行分区，扫描了196983行，这也是性能得到提升的关键所在。

当然，表的分区并不是分的越多越好，当表的分区太多时找分区又是一个性能的瓶颈了，建议在200个分区以内。

LIST分区表创建方式：

/*****************创建分区表*********************/
CREATE TABLE `products` (
`id`  bigint UNSIGNED NOT NULL AUTO_INCREMENT COMMENT '表主键' ,
`name`  varchar(64) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL COMMENT '产品名称' ,
`metrial`  tinyint UNSIGNED NOT NULL COMMENT '材质' ,
`weight`  double UNSIGNED NOT NULL DEFAULT 0 COMMENT '重量' ,
`vol`  double UNSIGNED NOT NULL DEFAULT 0 COMMENT '容积' ,
`c_id`  tinyint UNSIGNED NOT NULL COMMENT '供货公司ID' ,
PRIMARY KEY (`id`,`c_id`)
)ENGINE=InnoDB DEFAULT CHARSET=utf8

/*********分区信息**************/
PARTITION BY LIST(c_id)
(
    PARTITION pA VALUES IN (1,3,11,13),
    PARTITION pB VALUES IN (2,4,12,14),
    PARTITION pC VALUES IN (5,7,15,17),
    PARTITION pD VALUES IN (6,8,16,18),
    PARTITION pE VALUES IN (9,10,19,20)
);

可以看出，LIST分区和RANGE分区很类似，这里就不做性能分析了，和RANGE很类似。

HASH分区表的创建方式：

/*****************分区表*****************/
CREATE TABLE `msgs` (
  `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT COMMENT '表主键',
  `sender` int(10) unsigned NOT NULL COMMENT '发送者ID',
  `reciver` int(10) unsigned NOT NULL COMMENT '接收者ID',
  `msg_type` tinyint(3) unsigned NOT NULL COMMENT '消息类型',
  `msg` varchar(225) NOT NULL COMMENT '消息内容',
  `atime` int(10) unsigned NOT NULL COMMENT '发送时间',
  `sub_id` tinyint(3) unsigned NOT NULL COMMENT '部门ID',
  PRIMARY KEY (`id`,`sub_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8
/*********分区信息**************/
PARTITION BY HASH(sub_id)
PARTITIONS 10;

以上语句代表，msgs表按照sub_id进行HASH分区，一共分了十个区。

Key分区和HASH分区很类似，不再介绍，若想了解可以参考Mysql官方文档进行详细了解。

子分区的创建方式:

CREATE TABLE `msgss` (
  `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT COMMENT '表主键',
  `sender` int(10) unsigned NOT NULL COMMENT '发送者ID',
  `reciver` int(10) unsigned NOT NULL COMMENT '接收者ID',
  `msg_type` tinyint(3) unsigned NOT NULL COMMENT '消息类型',
  `msg` varchar(225) NOT NULL COMMENT '消息内容',
  `atime` int(10) unsigned NOT NULL COMMENT '发送时间',
  `sub_id` tinyint(3) unsigned NOT NULL COMMENT '部门ID',
  PRIMARY KEY (`id`,`atime`,`sub_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8
/*********分区信息**************/
PARTITION BY RANGE (atime) SUBPARTITION BY HASH (sub_id)
(
		PARTITION t0 VALUES LESS THAN(1451577600)
		(
			SUBPARTITION s0,
			SUBPARTITION s1,
			SUBPARTITION s2,
			SUBPARTITION s3,
			SUBPARTITION s4,
			SUBPARTITION s5
		),
		PARTITION t1 VALUES LESS THAN(1483200000)
		(
			SUBPARTITION s6,
			SUBPARTITION s7,
			SUBPARTITION s8,
			SUBPARTITION s9,
			SUBPARTITION s10,
			SUBPARTITION s11
		),
		PARTITION t2 VALUES LESS THAN MAXVALUE
		(
			SUBPARTITION s12,
			SUBPARTITION s13,
			SUBPARTITION s14,
			SUBPARTITION s15,
			SUBPARTITION s16,
			SUBPARTITION s17
		)
);

检查子分区是否创建成功：

EXPLAIN PARTITIONS SELECT * FROM msgss;

结果如下图：