看了你的问题，感觉好奇，我也去查了一下资料。设置这个参数，主要是跳过mysql的dns解析这个步骤。具体的我引用了一段：
When a new thread connects to mysqld, mysqld will spawn a new thread to handle the request. This thread will first check if the hostname is in the hostname cache. If not the thread will call gethostbyaddr_r() and gethostbyname_r() to resolve the hostname.

If the operating system doesn't support the above thread-safe calls, the thread will lock a mutex and call gethostbyaddr() and gethostbyname() instead. Note that in this case no other thread can resolve other hostnames that is not in the hostname cache until the first thread is ready.

You can disable DNS host lookup by starting mysqld with --skip-name-resolve. In this case you can however only use IP names in the MySQL privilege tables.
If you have a very slow DNS and many hosts, you can get more performance by either disabling DNS lookop with --skip-name-resolve or by increasing the HOST_CACHE_SIZE define (default: 128) and recompile mysqld.

You can disable the hostname cache with --skip-host-cache. You can clear the hostname cache with FLUSH HOSTS or mysqladmin flush-hosts.

If you don't want to allow connections over TCP/IP, you can do this by starting mysqld with --skip-networking.

name-resolve  

这个问题很多软件都有这个问题, 比如SSH,  老外不知道怎么想的, 为什么不是default false. 遇见很多次了.

hosts 加ip

Sun的AccessManager也有这个问题，上次我就是hosts加ip解决的。

我做的微型系统，第一次用户登陆或是查询数据库，反应都很慢。
不知道什么原因啊。

做个记号，以后找起来方便点。