Oracle has several modes for shutting down the database
Normal Mode:
In normal mode the database is shut down by default. It can be used when no other clause is provided. the database waits for all currently linked users to detach from the database before shutting it down and no new connections are permitted once the statement is released. The command line is
SHUTDOWN NORMAL
Transactional Mode:
Transactional mode helps to shut down the database while allowing to complete the active transactions. In this process, no new connections are allowed and this mode waits for all transactions to finish before shutting down the database. Use this command line to shut down the database
SHUTDOWN TRANSACTIONAL
Immediate Mode:
When you know a power outage is coming up fast, then you can use immediate mode. All sessions will be disconnected, all running transactions will be rolled back, the database does not wait for existing database users to disconnect until proceeding and the database will be shut down. No instance recovery is needed during this next startup.
Issue the command SHUTDOWN with an IMMEDIATE clause to shut down a database immediately.
SHUTDOWN IMMEDIATE
Abort Mode:
When you want to shut down the database immediately within seconds without any active transactions then you can use this abort method. Hereafter the statement has been released, no new connections or transactions are permitted to be initiated. The Oracle database automatically terminates all current client SQL statements and does not wait for existing database users to disconnect. Transactions that have not been committed will not roll back. All linked users are automatically disconnected by the database.
Use the command SHUTDOWN with ABORT clause:
