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innodb数据库 OPTIMIZE TABLE 提示Table does not support optimize, doing recreate + analyze instead

时间:2022-08-26 19:22:08浏览次数:73  
标签:business -- support recreate hr mysqld mysql instead NULL

Table does not support optimize, doing recreate + analyze instead

提要:
1.MySQL官方建议不要经常(每小时或每天)进行碎片整理,一般根据实际情况,只需要每周或者每月整理一次即可。
2.OPTIMIZE TABLE只对MyISAM,BDB和InnoDB表起作用,尤其是MyISAM表的作用最为明显。此外,并不是所有表都需要进行碎片整理,一般只需要对包含上述可变长度的文本数据类型的表进行整理即可。
3.在OPTIMIZE TABLE运行过程中,MySQL会锁定表。
4.默认情况下,直接对InnoDB引擎的数据表使用OPTIMIZE TABLE,可能会显示「 Table does not support optimize, doing recreate + analyze instead」的提示信息。这个时候,我们可以用mysqld --skip-new或者mysqld --safe-mode命令来重启MySQL,以便于让其他引擎支持OPTIMIZE TABLE。

那么怎么使用--skip-new呢?
先看ps看一下mysql的进程吧!
ps aux | grep mysqld

root 2359 0.0 0.0 108300 1308 pts/2 S 13:09 0:00 /bin/sh /usr/bin/mysqld_safe --datadir=/var/lib/mysql --socket=/var/lib/mysql/mysql.sock --pid-file=/var/run/mysqld/mysqld.pid --basedir=/usr --user=mysql
mysql 3028 46.2 56.5 5771800 4554616 pts/2 Sl 13:09 10:13 /usr/libexec/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib64/mysql/plugin --user=mysql --log-error=/var/lib/mysql/122-db.err --open-files-limit=65535 --pid-file=/var/run/mysqld/mysqld.pid --socket=/var/lib/mysql/mysql.sock --port=3306
root 3355 0.0 0.0 103240 872 pts/2 S+ 13:31 0:00 grep mysqld

 

第一个是守护进程,第二个就是mysql的原始进程。我们只要在这个进程最后追加--skip-new即可。

/usr/libexec/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib64/mysql/plugin --user=mysql --log-error=/var/lib/mysql/122-db.err --open-files-limit=65535 --pid-file=/var/run/mysqld/mysqld.pid --socket=/var/lib/mysql/mysql.sock --port=3306 --skip-new

 

先关闭mysqld,然后执行该命令。

不要关闭该命令,重新开启一个ssh窗口。

mysql -uroot -pxxxxx
mysql> use hr_resume_center;
Database changed
mysql> show create table hr_business_from_0\G
*************************** 1. row ***************************
Table: hr_business_from_0
Create Table: CREATE TABLE `hr_business_from_0` (
`id` int(11) unsigned NOT NULL AUTO_INCREMENT,
`resume_id` bigint(20) unsigned NOT NULL COMMENT '简历ID',
`from_id` smallint(4) unsigned DEFAULT NULL COMMENT '来源类型: 与hr_dict_from 来源网站关联',
`link_id` varchar(50) DEFAULT NULL COMMENT '来源网站简历标识',
`add_time` int(11) unsigned NOT NULL DEFAULT '0' COMMENT '添加记录时间',
`sys_time` int(11) unsigned NOT NULL DEFAULT '0' COMMENT '更新记录时间',
`version` smallint(4) unsigned NOT NULL DEFAULT '0' COMMENT '妙招简历版本,默认都为最新的版本',
PRIMARY KEY (`id`),
KEY `resume_id` (`resume_id`),
KEY `sys_time` (`sys_time`)
) ENGINE=InnoDB AUTO_INCREMENT=5853666 DEFAULT CHARSET=utf8 COMMENT='简历来源表'
1 row in set (0.00 sec)
mysql> show index from hr_business_from_0;
+--------------------+------------+-----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment |
+--------------------+------------+-----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| hr_business_from_0 | 0 | PRIMARY | 1 | id | A | 5802629 | NULL | NULL | | BTREE | | |
| hr_business_from_0 | 1 | resume_id | 1 | resume_id | A | 5802629 | NULL | NULL | | BTREE | | |
| hr_business_from_0 | 1 | sys_time | 1 | sys_time | A | 290131 | NULL | NULL | | BTREE | | |
+--------------------+------------+-----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
3 rows in set (0.99 sec)

mysql> optimize table hr_business_from_0 ;
Query OK, 5853665 rows affected (2 min 30.36 sec)
Records: 5853665 Duplicates: 0 Warnings: 0

mysql> show index from hr_business_from_0;
+--------------------+------------+-----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment |
+--------------------+------------+-----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| hr_business_from_0 | 0 | PRIMARY | 1 | id | A | 5898310 | NULL | NULL | | BTREE | | |
| hr_business_from_0 | 1 | resume_id | 1 | resume_id | A | 5898310 | NULL | NULL | | BTREE | | |
| hr_business_from_0 | 1 | sys_time | 1 | sys_time | A | 842615 | NULL | NULL | | BTREE | | |
+--------------------+------------+-----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
3 rows in set (0.00 sec)

 

hr_business_from_0为innodb数据,经过优化Cardinality发生的变化。查询速度提成了10倍以上。

附加:

如果你觉得这样一个表优化速度太慢的话,这里有一键优化脚本:

#!/bin/sh
echo -n "MySQL username: " ; read username
echo -n "MySQL password: " ; stty -echo ; read password ; stty echo ; echo

mysql -u $username -p"$password" -NBe "SHOW DATABASES;" | grep -v 'lost+found' | while read database ; do
mysql -u $username -p"$password" -NBe "SHOW TABLE STATUS;" $database | while read name engine version rowformat rows avgrowlength datalength maxdatalength indexlength datafree autoincrement createtime updatetime checktime collation checksum createoptions comment ; do
if [ "$datafree" -gt 0 ] ; then
fragmentation=$(($datafree * 100 / $datalength))
echo "$database.$name is $fragmentation% fragmented."
mysql -u "$username" -p"$password" -NBe "OPTIMIZE TABLE $name;" "$database"
fi
done
done


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版权声明:本文为CSDN博主「e421083458」的原创文章,遵循CC 4.0 BY-SA版权协议,转载请附上原文出处链接及本声明。
原文链接:https://blog.csdn.net/e421083458/article/details/39522513

标签:business,--,support,recreate,hr,mysqld,mysql,instead,NULL
From: https://www.cnblogs.com/jmbt/p/16628930.html

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