Shutting Down an Oracle Database Instance

There are four modes of shutting down an Oracle Instance

1. NORMAL
2. TRANSACTIONAL
3. IMMEDIATE
4. ABORT

1. ABORT:
• Performs the least amount of work before shutting down. Because this mode requires recovery before startup, use it only when necessary.
• It is typically used when no other form of shutdown works, when there are problems when starting the instance, or when you need to shut down immediately because of an impending situation (such as notice of a power outage within seconds).
2. IMMEDIATE: Is the most typically used option. Uncommitted transactions are rolled back.
3. TRANSACTIONAL: Allows existing transactions to finish, but not starting new transactions
4. NORMAL: Waits for sessions to disconnect