Oracle Flashback Technology provides a set of features that provide useful alternatives to view past states of data, and winding data back and forth in time, without requiring you to restore large portions of your database from backup or perform point-in-time recovery. The flashback features of Oracle are more efficient and less disruptive than media recovery in most circumstances.
The available Flashback Features:
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A)Oracle Flashback Query: It lets you to view past state data as they would have appeared at that time.
It is based on undo data. Show UNDO_RETENTION parameter.
B)Oracle Flashback Version Query: It lets you view all the versions of all the rows that ever existed in one or more tables in a specified time interval.
It is based on undo data. Show UNDO_RETENTION parameter.
C)Oracle Flashback Transaction Query: It lets you view changes made by a single transaction, or by all the transactions during a period of time.
It is based on undo data. Show UNDO_RETENTION parameter.
D)Oracle Flashback Table: It returns a table to its state at a previous point in time.
It is based on undo data. Show UNDO_RETENTION parameter.
E)Oracle Flashback Drop: To get back a dropped table.
It is based on Recyclebin. Use show recyclebin.
F)Oracle Flashback Database: To get back whole database to a previous point in time. It is based on whether flashback feature is enabled or not. Use select flashback_on from V$database; to see it is on or not. By default it is disabled. However you can enable it by ALTER DATBASE FLASHBACK ON in mount stage.
You can have a look at Flashback Database
Flashback query is discussed on Oracle Flashback query
Flashback version query, flashback transaction query is discussed on Flashback Features
Flashback Table, flashback Drop is discussed on Flashback Table And Flashback Drop
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