A common question in Oracle interview questions advanced, don't miss this one. Oracle provides numerous methods for shutting down the database.  Normal Mode: By default, the database is shut down in normal mode. It is appropriate when no other clause is present. Before shutting down the database, it waits for all presently associated users to disconnect, and no new connections are authorized until the statement is published. The command line is as follows:  SHUTDOWN NORMAL  Transactional Mode: Transactional mode aids in the shutdown of the database while enabling ongoing transactions to be completed. No new connections are allowed during this procedure, and the database is shut down when all transactions have completed. To shut down the database, use this command line.  SHUTDOWN TRANSACTIONAL  Immediate Mode: When you know a power loss is imminent, you can activate urgent mode. All sessions will be disconnected, all active transactions will be rolled back, the database does not wait for existing database users to quit before proceeding, and the database will be shut down. There will be no requirement for instance recovery on the next startup.  To instantly shut down a database, use the command SHUTDOWN with the IMMEDIATE argument.   SHUTDOWN IMMEDIATE  Abort Mode: If you want to shut down the database immediately without any active transactions, use this abort method. No new connections or transactions may be established after the statement has been issued. The Oracle database ends all current client SQL queries automatically and does not wait for existing database users to disconnect. Uncommitted transactions will not be rolled back. The database automatically disconnects all related users.  Use the SHUTDOWN command with the ABORT clause:  SHUTDOWN ABORT