Understanding Flashback Technology - OCP: Oracle Database 12c Administrator Certified Professional - page 390

Flashback Database recovery can also be performed in SQL*Plus with the
FLASHBACK DATABASE command as well as with RMAN.

Real-World Scenario: limitations with the Flashback Database

Flashback Database recovery cannot recover from some common occurrences such as
resizing a data file to a smaller size or deleting a data file In these cases, the data file
would need to be restored with traditional methods to a point in time prior to the deletion
or resizing of the data file Then you could use Flashback Database recovery to recover
the rest of the database.

Flashback Database is a nice substitute for incomplete recovery for logical corruption and
user errors. However, there are some limitations to Flashback Database that you should be
aware of:

You cannot resolve media failure with Flashback Database. You will still need to
restore data files and recover archived redo logs to recover from media failure.

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You cannot undo the resizing of data files to a smaller size, also called shrinking data
files, with Flashback Database.

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You cannot use Flashback Database if the control file has been restored or recreated.

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You cannot drop a tablespace and recover it through reset logs.

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You cannot flash back the database to an SCN prior to the earliest available SCN in
the flashback logs.

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Summary

In this chapter, you learned about Flashback technologies and their dependence on Oracle's
undo functionality. You learned about Automatic Undo Management (AUM) and how it
aids the DBA in managing undo information.
We discussed the Recycle Bin in detail, and you learned how dropped objects are moved
to the Recycle Bin. We showed you how to query the contents of the Recycle Bin and how to
recover objects using the Flashback Drop feature.
Next, you learned about Flashback Query and its ability to show you data as it appeared
at a specific time in the past.
The next section discussed the Flashback Version Query, which retrieves all versions of
the rows that existed between two specific points in time.