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This article will explain in detail how to enable the Flashback Database flashback database function, the content of the article is of high quality, so the editor will share it for you as a reference. I hope you will have a certain understanding of the relevant knowledge after reading this article.

If you want to use the flashback database function smoothly, you need to put the database in the flashback database state first. This article records the steps to turn on the flashback database function, noting that the adjustment process requires restarting the database and ensuring that the database is in archive mode.

1. Confirm whether the Flashback Database function is enabled in the database

If it is not open, then continue. If it has already been opened, please float by from now on.

SYS@ora11g > select flashback_on from v$database

FLASHBACK_ON

-

NO

two。 Modify the contents of three parameters: db_recovery_file_dest, db_recovery_file_dest_size and db_flashback_retention_target

1) db_recovery_file_dest and db_recovery_file_dest_size are used to specify the location and maximum size of the flashback log. It can be adjusted according to the specific environment.

SYS@ora11g > show parameter recovery_file

NAME TYPE VALUE

-

Db_recovery_file_dest string / u01/app/oracle/flash_recovery

_ area

Db_recovery_file_dest_size big integer 3852M

2) confirm the content of the db_flashback_retention_target parameter setting.

The db_flashback_retention_target parameter limits the time range within which flashbacks can be recovered. The default is 1440 minutes, one day.

SYS@ora11g > show parameter db_flashback_retention_target

NAME TYPE VALUE

Db_flashback_retention_target integer 1440

3. Restart the database to the mount state

SYS@ora11g > shutdown immediate

Database closed.

Database dismounted.

ORACLE instance shut down.

SYS@ora11g > startup mount

ORACLE instance started.

Total System Global Area 313860096 bytes

Fixed Size 1336232 bytes

Variable Size 239078488 bytes

Database Buffers 67108864 bytes

Redo Buffers 6336512 bytes

Database mounted.

4. Enable Flashback function in mount state

SYS@ora11g > alter database flashback on

Alter database flashback on

*

ERROR at line 1:

ORA-38706: Cannot turn on FLASHBACK DATABASE logging.

ORA-38707: Media recovery is not enabled.

The error is reported here because the database is not running in archive mode, and the prerequisite for enabling the flashback database feature is that the database is running in archive mode. Therefore, you need to adjust the database to archive mode first.

SYS@ora11g > alter database archivelog

Database altered.

SYS@ora11g > alter database flashback on

Database altered.

Flashback database opened successfully.

5. Open the database

SYS@ora11g > alter database open

Database altered.

6. Verify that the Flashback feature has been turned on successfully

SYS@ora11g > select flashback_on from v$database

FLASHBACK_ON

-

YES

7. Summary

The process of enabling the flashback database is relatively simple, so make sure that the database is running in archive mode first. This is a prerequisite for using a flashback database and requires proficiency.

On how to enable Flashback Database flashback database function to share here, I hope 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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