mysql大数据量的在线修改表结构和索引工具，比如一个线上的表数据已经有千万级了。现在为了加快速度，我们需要修改表结构，加索引，不停机，怎么搞？
[root@VM_0_4_centos huangxiaoshan]# wget https://www.percona.com/redir/downloads/percona-release/redhat/percona-release-0.1-3.noarch.rpm
--2019-01-03 16:27:09-- https://www.percona.com/redir/downloads/percona-release/redhat/percona-release-0.1-3.noarch.rpm
Resolving www.percona.com (www.percona.com)... 74.121.199.234
Connecting to www.percona.com (www.percona.com)|74.121.199.234|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 6566 (6.4K) [application/x-redhat-package-manager]
Saving to: ‘percona-release-0.1-3.noarch.rpm’
100%[=============================================================================================>] 6,566 --.-K/s in 0s
2019-01-03 16:27:12 (458 MB/s) - ‘percona-release-0.1-3.noarch.rpm’ saved [6566/6566]
具体用法可以参考文章：http://www.huangxiaoshan.xyz/article.php?id=113
