本站中文解释
have_symlink参数变量指的是是否支持符号链接。默认值为DISABLED，即禁止符号链接。若要开启符号链接功能，可以在MySQL的启动参数中添加–symbolic-links参数，然后在mysql服务启动后，执行以下SQL语句可以将have_symlink变量值设置为YES：
SET GLOBAL have_symlink=YES;
官方英文解释
have_symlink
YES if symbolic link support is enabled,
NO if not. This is required on Unix for
support of the DATA DIRECTORY and
INDEX DIRECTORY table options. If the
server is started with the
--skip-symbolic-links
option, the value is DISABLED.
This variable has no meaning on Windows.
