Sometimes we do not need the auto save function in the editor in WordPress, it will increase your database or slow down you editing experience while you are in slow internet connection.
Here is the solution to disable it, if you need to re-enable it just comment them away.
define( 'AUTOSAVE_INTERVAL', 60*60*60*24*365 ); // Set autosave interval to a year
define( 'EMPTY_TRASH_DAYS', 0 ); // Empty trash now: Zero days
define( 'WP_POST_REVISIONS', false ); // Do not save any revisions