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This article will explain in detail how to start and shut down the database in oracle. The content of the article is of high quality, so the editor shares it for you as a reference. I hope you will have a certain understanding of the relevant knowledge after reading this article.

Start and shut down the database:

Each database contains at least one routine, which is an entity used by oracle to manage data files, which consists of a set of logical memory structures and a series of background server processes in the server. These services and memory are allocated when the database is started. A routine can access only one database, and a database can be accessed by multiple routines. The process of starting a routine includes:

Read the parameter file, or the text parameter file, or the server parameter file.

Allocate the corresponding space in memory according to the values set by the parameters of SGA area and PGA area in the parameter file.

Start the appropriate background process.

Open the tracking file and alarm file.

Start the database using startup nomount, in which case you can create a new database or create a new control file.

When loading the database, the routine opens the control file of the database, finds the control file according to the setting of the initialization parameter control_file, and obtains the database name, database physical file and other information from the species. The database is required to be mounted (but not open) when performing the following tasks

Rename, add, delete data files, and redo log files.

Perform a full recovery of the database.

Change the archiving mode of the database.

Use the startup mount command to start the routine and load the database (but do not open the database)

As you can see in the figure above, the following startup mount has an extra line of database mount than startup nomount, indicating that the database has been loaded but not opened.

Open the database:

Only when the database is opened can the user establish a connection or session with the database and read the information of the database. When opening a database, the routine opens all online data files and redo log files. Use the startup open command to start the routine, load the database, and open the database.

The order in which files are used when opening the database is: parameter file, control file, data file, redo log file.

Startup force forces the database to be opened, no matter what mode the database is in.

Startup restrict starts the database and puts it in open mode, but at this point only users with restricted session privileges can manipulate the database.

If you want to do something in database open mode, you can use the restrict option, and you can perform the following tasks. Perform the import and export operation of the database, carry out the data loading operation, temporarily prevent ordinary users from accessing the database, and transplant or upgrade the database.

Use alter system disable restricted session after the work is finished

Startup has only the pfile option, not the spfile option.

To shut down the database, you need to log in as a dba user.

You can kill all sessions with the alter system kill session command.

The startup mode of the database can be changed through the alter database command, alter database mount, and so on.

On how to start and shut down the database in oracle to share here, I hope that the above content can be of some help to you, can learn more knowledge. If you think the article is good, you can share it for more people to see.

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