SHUTDOWN Database Concepts

Shutdown Options:
a)Shutdown normal
b) Shutdown transactional
c) Shutdown immediate
d) Shutdown abort

Here are the difference between Shutdown Normal, transactional, immediate and abort:

Shutdown Normal
Normal is the default shutdown mode. Normal database shutdown proceeds with the following conditions:
• No new connections can be made.
• The Oracle server waits for all users to disconnect before completing the shutdown.
• Database and redo buffers are written to disk.
• Background processes are terminated, and the SGA is removed from memory.
• Oracle closes and dismounts the database before shutting down the instance.
• The next startup does not require an instance recovery.

Shutdown Transactional
A transactional shutdown prevents clients from losing work. A transactional database shutdown proceeds with the following conditions:
• No client can start a new transaction on this particular instance.
• A client is disconnected when the client ends the transaction that is in progress.
• When all transactions have finished, a shutdown immediately occurs.
• The next startup does not require an instance recovery.

Shutdown Immediate
Immediate database shutdown proceeds with the following conditions:
• Current SQL statements being processed by Oracle are not completed.
• The Oracle server does not wait for users currently connected to the database to disconnect.
• Oracle rolls back active transactions and disconnects all connected users.
• Oracle closes and dismounts the database before shutting down the instance.
• The next startup does not require an instance recovery.

Shutdown Abort
If the normal and immediate shutdown options do not work, you can abort the current
database instance. Aborting an instance proceeds with the following conditions:
• Current SQL statements being processed by the Oracle server are immediately terminated.
• Oracle does not wait for users currently connected to the database to disconnect.
• Database and redo buffers are not written to disk.
• Uncommitted transactions are not rolled back.
• The instance is terminated without closing the files.
• The database is not closed or dismounted.
• The next startup requires instance recovery, which occurs automatically.