Shut down database

How to shut down a database?

There are several types in which we can shut down the database as mentioned below. 

Types of shutting down database	effect/consistency of  database	Preferred or not
SHUTDOWN NORMAL	Db will shut down only after all users got logged off. Database will be consistent after shut down	Preferred but will take much time to get down
SHUTDOWN IMMEDIATE	Db will shut down once PMON commits or roll backs the transactions. DB will be consistent here too	preferred and good way to follow
SHUTDOWN TRANSACTIONAL	DB will wait only after all transactions are completed. . DB will be consistent here too	preferred but will take little more  time compared to SHUTDOWN IMMEDIATE
SHUTDOWN ABORT	Db will shut down with emergence and transactions are neither committed nor rolled back. Db becomes inconsistent after shut down.	Generally not preferred as it is used in case of emergency only