The Red Bird Sessions class uses the MySQL database to take over the PHP session originally supported by the file system, which solves the problems of session compatibility and the inability of the virtual host to customize the session. It has a built-in gc function that can trigger the deletion of expired sessions based on probability. While the original PHP session usage remains unchanged, the performance of the original session is improved. Document structure: demo.php: sample file; hn_session.class.cfg.php: Redbird Sessions class configuration file; hn_session.class.php: Redbird Sessions class core file; hn_sessions.sql: database sql file;