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বৃহস্পতিবার, ১৬ এপ্রিল, ২০২০

How to Shutdown the Oracle Database

Oracle SHUTDOWN

Summary: in this tutorial, you will learn how to use the Oracle SHUTDOWN statement to shut down the Oracle Database.

TL;DR

Use the SHUTDOWN IMMEDIATE command to shut down the Oracle Database gracefully:
SHUTDOWN IMMEDIATE

Introduction to the Oracle SHUTDOWN statement

To shut down a currently running Oracle Database instance, you use the SHUTDOWN command as follows:
SHUTDOWN [ABORT | IMMEDIATE | NORMAL | TRANSACTIONAL [LOCAL]]
Let’s examine each option of the SHUTDOWN command.

SHUTDOWN NORMAL

The SHUTDOWN NORMAL option waits for the current users to disconnect from the database before shutting down the database. The database instance will not accept any further database connection.  The SHUTDOWN NORMAL does not require an instance recovery on the next database startup.
The NORMAL is the default option if you don’t explicitly specify any option. Therefore SHUTDOWN and SHUTDOWN NORMAL commands have the same effect.
The SHUTDOWN or SHUTDOWN NORMAL is not really practical because you practically cannot wait for all users to come back to their desks and disconnect from the database.

SHUTDOWN TRANSACTIONAL

The SHUTDOWN TRANSACTIONAL waits for all uncommitted transactions to complete before shutting down the database instance. This saves the work for all users without requesting them to log off.
The database instance also does not accept any new transaction after a SHUTDOWN TRANSACTIONAL . When completing all transactions, the database instance disconnects all the currently connected users from the database and shuts down.
The SHUTDOWN TRANSACTIONAL does not require any instance recovery procedure on the next database startup.
The optional LOCAL mode waits for only local transactions to complete, not all the transactions. Then it shuts down local instance. This option is useful in some cases e.g., a scheduled outage maintenance.

SHUTDOWN ABORT

The SHUTDOWN ABORT is not recommended and only used on some occasions. The SHUTDOWN ABORT has a similar effect as you unplug the power of the server. The database will be in an inconsistent state. Therefore, you should never use the SHUTDOWN ABORT command before backing up the database. If you try to do so, you may not be able to recover the backup.
It is recommended to use the SHUTDOWN ABORT only when you want to shut down the database instantaneously. For example, if you know a power shutdown is going to happen in a minute or you experience some problems when starting up a database instance.
The SHUTDOWN ABORT proceeds with the fastest possible shutdown of the database. However, it requires instance recovery on the next database startup.

SHUTDOWN IMMEDIATE

The SHUTDOWN IMMEDIATE is the most common and practical way to shut down the Oracle database.
The SHUTDOWN IMMEDIATE does not wait for the current users to disconnect from the database or current transactions to complete.
During the SHUTDOWN IMMEDIATE, all the connected sessions are disconnected immediately, all uncommitted transactions are rolled back, and the database completely shuts down.
After issuing the SHUTDOWN IMMEDIATE statement, the database will not accept any new connection. The statement will also close and dismount the database.
Unlike the SHUTDOWN ABORT option, the SHUTDOWN IMMEDIATE option does not require an instance recovery on the next database startup.
The following table illustrates the differences between the shutdown modes:
Shutdown ModesAITN
Allow new connectionNoNoNoNo
Wait until all current sessions endNoNoNoYes
Wait until all current transactions endNoNoYesYes
Force a checkpoint and close filesNoYesYesYes
Shutdown Modes:
  • A = ABORT
  • I = IMMEDIATE
  • T = TRANSACTIONAL
  • N = NORMAL

Notes

To issue the SHUTDOWN statement, you must connect to the database as SYSDBA, SYSOPER, SYSBACKUP, or SYSDG. If the current database is a pluggable database, the SHUTDOWN statement will close the pluggable database only. The consolidated instance will continue to run. On the other hand, if the current database is a CDB, the SHUTDOWN statement will close the CDB instance.

Oracle SHUTDOWN statement example

First, launch SQL*Plus:
> sqlplus
Second, log in to the Oracle database using the SYS user:
 
Enter user-name: sys as sysdba
Enter password: <sys_password>
Third, check the current status of the Oracle instance:
SQL> select instance_name, status from v$instance;
Here is the output:
INSTANCE_NAME STATUS ---------------- ------------ orcl OPEN
Fourth, issue the SHUTDOWN IMMEDIATE command:
SQL> shutdown immediate Database closed. Database dismounted. ORACLE instance shut down.
In this tutorial, you have learned how to use the Oracle SHUTDOWN statement to shut down the Oracle Database.

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