You work as a database administrator for Certkiller .com. In the Certkiller PRODUCTION database you have granted RESUMABLE system privilege to the CONNECT role.Resumablespace operation has been enabled for all user session. You want users NOT to be aware of any kind of space-related problems while performing transactions. Instead， you want the problem to be resolved by a database trigger automatically. Which combination of triggering time and event would you use to achieve this objective？（）