MySQL 5.7 Release Notes
Given a path name, returns the modified path name after replacing subpaths that match the values of the following system variables, in order:
datadir
tmpdir
slave_load_tmpdir
innodb_data_home_dir
innodb_log_group_home_dir
innodb_undo_directory
basedir
A value that matches the value of system variable
sysvar
is replaced with the string
@@GLOBAL.
.
sysvar
Prior to MySQL 5.7.14, backslashes in Windows path names are converted to forward slashes in the result.
mysql> SELECT sys.format_path('/usr/local/mysql/data/world/City.ibd');
+---------------------------------------------------------+
| sys.format_path('/usr/local/mysql/data/world/City.ibd') |
+---------------------------------------------------------+
| @@datadir/world/City.ibd |
+---------------------------------------------------------+