mysql大数据表改表结构方案_MySQL
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有一个表有上千Ｗ数据， 用什么方法给这个表加一个字段最快？
1. alert
2. 建一个表和第一个表一样,只是多了要加的字段,然后用多个INSERT INTO SELECT语句limit写入
3. 就是导出多个文件,然后用loadfile
4. 其它？
试过2.5KW数据， alert要156m。
INSERT INTO SELECT 100W要5m46s
两个工具选择:
http://www.percona.com/software/percona-toolkit
http://www.percona.com/doc/percona-toolkit/2.2/pt-online-schema-change.html
第二个工具是比较好的选择,可以线上改表结构,试试再给报告给大家
正在使用第二个工具,也就是"Facebook 针对 MySQL 开源 Online Schema Change 代码"
参考文档:
http://blog.chinaunix.net/uid-53720-id-3371360.html
http://blog.csdn.net/dbanote/article/details/18261377
正在测试环境测试,测试数据量大约是2500W左右,随后有测试报告,没什么问题就上生产环境了
pt-online-schema-change --alter "ADD category tinyint(4) NOT NULL DEFAULT '0'" D=库名,t=表名 -uroot -p密码 --dry-run
如果你的库有主从结构,执行上面的语句遇到如下问题:
Cannot connect to D=calsync,h=从库的IP,p=...,u=root
No slaves found. See --recursion-method if host localhost.localdomain has slaves.
Not checking slave lag because no slaves were found and --check-slave-lag was not specified.
请在从库上建一个root帐号且密码和上面的密码一样,且主库机可以访问
如果出现如下内容:
Found 1 slaves:
localhost.localdomain
Will check slave lag on:
localhost.localdomain
恭喜主从的没有问题了
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