Does Oracle Flashback use archive logs?

Your database must be running in ARCHIVELOG mode, because archived logs are used in the Flashback Database operation. You must have a fast recovery area enabled, because flashback logs can only be stored in the fast recovery area.

Table of Contents

What is Flashback archive in Oracle?

A flashback data archive consists of multiple tablespaces and stores historic data from all transactions against tracked tables. The data is stored in internal history tables. Flashback data archives retain historical data for the time duration specified using the RETENTION parameter.

Where are the flashback database logs stored?

Flashback logs are stored as Oracle-managed files in the fast recovery area and cannot be created if no fast recovery area is configured. You must have enabled the flashback logging before the target time for flashback using the SQL statement ALTER DATABASE FLASHBACK ON . Query V$DATABASE.

What is the difference between rollback and flashback in Oracle?

The main difference is that flashback rolls back changes including the changes made by others in the whole table or database to any point of time in the past within the range of flashback setting.

Can we delete flashback logs in Oracle?

Yes, oracle will delete the flashback logs by itself whenever it need space. If you want to use flashback you can reduce the size of you FRA so that oracle will think that it is full and it will delete the logs automatically.

How can I tell if my database is in flashback mode?

Use the following command to check if Flashback Database is enabled for your target database: SELECT FLASHBACK_ON FROM V$DATABASE; To enable Flashback Database: Ensure that you configure a fast recovery area and that the database is running in ARCHIVELOG mode.

What is Db_flashback_retention_target?

db_flashback_retention_target specifies the upper limit (in minutes) on how far back in time the database may be flashed back. How far back one can flash back a database depends on how much flashback data Oracle has kept in the recovery area.

What are different types of backup in Oracle database?

There are two types of backups: image copies and backup sets. An image copy is an exact duplicate of a datafile, control file, or archived log.
…
Archived Redo Log Backups

The RMAN BACKUP ARCHIVELOG command.
The RMAN BACKUP PLUS ARCHIVELOG command.
An operating system utility.

What is flashback log?

Flashback logs were introduced in Oracle Database 11g. These optional files allow the database to be rolled backwards in a similar fashion to a redo log allowing a database to be rolled forward.

What to do if FRA is full in Oracle?

8.9. 1 Resolving a Full Flash Recovery Area

Make more disk space available, and increase DB_RECOVERY_FILE_DEST_SIZE to reflect the new space.
Move backups from the flash recovery area to a tertiary device such as tape.
Delete unnecessary files from the flash recovery area using the RMAN DELETE command.

How does Oracle Flashback query work?

Flashback Query allows the contents of a table to be queried with reference to a specific point in time, using the AS OF clause. Essentially it is the same as the DBMS_FLASHBACK functionality or Oracle 9i, but in a more convenient form.

What is the use of flashback query?

You use a Flashback Query to retrieve data as it existed at some time in the past. The query explicitly references a past time using a timestamp or SCN. It returns committed data that was current at that point in time.

How do I delete expired archive logs in RMAN?

Delete expired archivelogs and create new backup

rman target /
crosscheck archivelog all;
delete noprompt expired archivelog all;
backup database plus archivelog;

How do you check flashbacks?

How do I know if flashback is enabled?

What are 4 types of backups?

Each backup program has its own approach in executing the backup, but there are four common backup types implemented and generally used in most of these programs: full backup, differential backup, incremental backup and mirror backup.

What is difference between restore and recovery in Oracle?

Restoring involves copying backup files from a secondary storage (backup media) to disk. This can be done to replace damaged files or to copy/move a database to a new location. Recovery is the process of applying redo logs to the database to roll it forward.

How do I backup my flashback logs?

To make space for flashback logs, back up the other contents of your flash recovery area to tape, using commands such as BACKUP RECOVERY AREA , BACKUP BACKUPSET and so on. Then use the DELETE command to explicitly remove files from the flash recovery area once they have been backed up on tape.

How do you use flashbacks in SQL?

To flash back a table to an earlier SCN or timestamp, you must have either the FLASHBACK object privilege on the table or the FLASHBACK ANY TABLE system privilege. In addition, you must have the SELECT , INSERT , DELETE , and ALTER object privileges on the table.

How do I check archive log space?

The following commands can be used to locate the Oracle archive logs:

Issue the archive log list command: SQL> archive log list.
Issue the show parameter command: SQL> show parameter db_recovery_file_dest.
Query the v$archive_dest view: SQL> select dest_name, status, destination from v$archive_dest;

How do I delete FRA archive logs?

And, as part of the backup procedure, we try to delete the archivelog files: RMAN> delete noprompt archivelog all backed up 1 times to device type disk; released channel: ORA_DISK_1.

What are the features of a flashback?

Flashback is a device that moves an audience from the present moment in a chronological narrative to a scene in the past. Often, flashbacks are abrupt interjections that further explain a story or character with background information and memories.

Can I delete archive logs manually?

You can delete the archivelogs already backed up, or if you are using the FRA for the archivelogs, the FRA will autodelete the backed up archivelogs for you when the FRA fills. 2&3. You need to set the backup policy to redundancy of 2. You can then let the FRA delete the archivelogs and backups that you don’t need.

How do I get rid of expired archive logs?

How do you stop a flashback in Oracle?

Symptoms. the database can be opened: SQL> alter database flashback off; Database altered.

Does Oracle Flashback use archive logs?