Posts Tagged ‘shutdown immediate’

Oracle Shutdown Concepts

Shut down the database to make operating system offline backups of all physical structures and to have modified static initialization parameters take effect when restarted.

SHUTDOWN [NORMAL | TRANSACTIONAL | IMMEDIATE | 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.

SQL> shutdown

Database closed.

Database dismounted.

ORACLE instance shut down.

SQL>



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 occurs immediately.
• The next startup does not require an instance recovery.

SQL> shutdown transactional

Database closed.

Database dismounted.

ORACLE instance shut down.

SQL>

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 the users, who are 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.

SQL> shutdown immediate

Database closed.

Database dismounted.

ORACLE instance shut down.

SQL>

SHUTDOWN ABORT

If no shutdown option works then database instance can be shutdown using abort option. 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.

SQL> shutdown abort

ORACLE instance shut down.

SQL>

All shutdown options except ABORT are clean shutdown where no instance recovery is required. Shutdown abort is a dirty shutdown as it requires instance recovery before getting back up.