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This article mainly introduces what are the methods of opening and closing Oracle, which can be used for reference by interested friends. I hope you will gain a lot after reading this article.

> 1 start the database

In the cmd command window, enter "sqlplus" directly to enter the oracle management interface. After entering the user name and password, you can start the database. There are three steps to start the database: start the instance, load the database, and open the database.

Command format:

Startup [nomount | mount | open | force] [restrict] [pfile=filename]

Nomount: indicates that the startup instance does not load the database

Mount: means to start the instance, load the database, and keep the database closed

Open: means to start the instance, load and open the database, which is the default option

Force: terminates the instance and restarts the database

Restrict: used to specify that the database is started in a restricted session mode

Pfile: used to specify the text parameter file to be used when starting the instance. Filename is the file name.

1.1 nomount mode

Only the instance (the various memory structures and service processes of the oracle instance) is created, the database is not loaded, and no data files are opened

Startup nomount

Note: users need to log in as sysdba before they have the permission to close and start data instances.

1.2 mount mode

This mode starts the instance, loads the database, and keeps the database closed.

Startup mount

1.3 open mode

This mode starts the instance, loads and opens the database, which is the regular startup mode. If users want to do multiple operations on the database, they must start the database instance using open mode.

Startup

The startup command is followed by no arguments, which means that the database instance is started in open mode

1.4 force mode

This mode, which terminates the instance and restarts the database, is mandatory. For example, you can try to use this startup mode when other startup modes fail

2 close the database

Like starting a database instance, there are three steps to shutting down a database instance: shutting down the database, uninstalling the database, and shutting down the instance

Syntax format:

Shutdown [normal | transactional | immediate | abort]

Normal: means to shut down the database in a normal way

Transactional: shuts down the database after all current active transactions have been committed

Immediate: means to shut down the database immediately in the shortest possible time

Abort: means to shut down the database by terminating

2.1 normal mode

This method is called a normal shutdown method, and it is usually used to shut down the database if there is no time limit for shutting down the database:

Shutdown normal

After executing the above code, oracle will do the following:

Prevent any user from establishing a new connection

Wait for all currently connected users to actively disconnect

When all users are disconnected, the database will be shut down immediately

2.2 transactional mode

This approach is called transaction shutdown, and its first task is to ensure that all currently active things can be committed and shut down the database in the shortest possible time:

Shutdown transactional

After executing the above code, oracle will do the following:

Prevent users from establishing new connections and starting new things

Wait for all active items to be submitted before disconnecting the user

When all active transactions are submitted and all users are disconnected, the database will be closed

2.3 immediate mode

This kind of thing shuts down immediately, which shuts down the database in the shortest possible time:

Shutdown immediate Wuxi Gynecology Hospital http://www.wxbhnkyy39.com/

In this shutdown mode, oracle not only immediately breaks the link of the current user, but also forcibly terminates the user's current activity, rolls back the unfinished things, and shuts down the database immediately, oracle will do the following:

Prevent users from establishing new connections and starting new transactions

Roll back uncommitted active transactions

Shut down the database

2.4 abort mode

This method is called termination closure, which is mandatory and destructive to a certain extent. Using this method will forcefully interrupt any database operation, which may lose some data information and affect the integrity of the database:

Shutdown abort

After executing the above code, oracle will do the following:

Prevent users from establishing new connections and starting new things

Cancel unsubmitted activities, not fallback

Immediately terminate any SQL statements that are being executed

Close the database immediately

Thank you for reading this article carefully. I hope the article "what are the ways to turn Oracle on and off" shared by the editor will be helpful to you. At the same time, I also hope you will support us and pay attention to the industry information channel. More related knowledge is waiting for you to learn!

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