[development] improving the speed of Simpletest during development

Hello, Performance; improving the speed of Simpletest during development http://drupal.org/node/466972 I tried to follow the above tutorial to speed simpletest, but to no avail. A file is attached to the above page: http://drupal.org/files/mysql-tmpfs.txt The handbook does not say how it should be used. I am using Ubuntu, a Debian derivative. Did anyone here managed to move MySQL database to tmpfs ? tia!