You can use Flashback technology when a logical corruption occurs in the Oracle database and you need to recover data quickly and easily. As with human errors, it is difficult to identify the objects and rows that are affected by an erroneous transaction. With Flashback technology, you can diagnose how errors are introduced into the database, and then repair the damage. You can view the transactions that have contributed to specific row modifications, view the entire set of versions of a given row during a specific time period, or just view data as it appeared at a specific time in the past. The table in the slide shows typical uses of Flashback technology. Flashback Database depends on the flashback logs to perform flashback. Flashback Drop uses the recycle bin. All other techniques use undo data.
Not all flashback features modify the database. Some are simply methods to query other versions of data; these are tools to investigate a problem and aid in recovery. The results of flashback queries help you do one of two things:
Determine the type of database-modifying flashback operation to perform to fix the problem.
Feed the result set of these queries into an INSERT, UPDATE, or DELETE statement that enables you to easily repair the erroneous data.
Flashback Data Archive enables you to use the preceding logical flashback features to access data from far back in the past