Topic : FlashBack Technologies

Is there a separate background process for writing flashback logs?


Answer :

Yes.
RVWR (Recovery Writer; a.k.a Flashback Writer) was introduced in Oracle 10g to write flashback data from the Flashback Buffer in the SGA to the flashback database logs on disk.

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Do I need to shutdown and mount the database to turn flashback on?


Answer :

ALTER DATABASE FLASHBACK ON is an online operation in 11g Release and 12c
2. In 10g Release 2 the database must be mounted; but not open.

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Is it possible to specify the size of the Flashback Buffer in the SGA?


Answer :

YES; but indirectly. The size of the Flashback Buffer is set to 2 * LOG_BUFFER. For performance reasons; it?s recommended to set LOG_BUFFER to at least 8MB for databases running in Flashback Mode.
UPDATED: For large 11.1.0.7+ databases with more than a 4GB SGA; you may consider setting LOG_BUFFER to values in the range of 32-64 MB.

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Can RMAN be used to backup flashback logs?


Answer :

No. Flashback Logs are not backed up. Even if the command BACKUP RECOVERY AREA is used to backup the contents of the FRA to tape only the following file types are backed up: full and incremental backup sets; control file autobackups; datafile copies; and archived redo logs.
Flashback Logs are considered to be transient files and cannot be backed up by RMAN. They are not needed for media recovery.

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