Auditing Table Changes Using Flashback Transaction Query

Note:

You must be using automatic undo management to use the Flashback Transaction Query feature. It is based on undo information stored in an undo tablespace.

To understand how to configure your database for the Flashback Transaction Query feature, see "Undo Space Data Dictionary Views".

You may discover that somehow data in a table has been inappropriately changed. To research this change, you can use multiple flashback queries to view row data at specific points in time. More efficiently, you can use the Flashback Version Query feature to view all changes to a row over a period of time. That feature lets you append a VERSIONS clause to a SELECT statement that specifies an SCN or timestamp range between which you want to view changes to row values. The query also can return associated metadata, such as the transaction responsible for the change.

Further, once you identify an erroneous transaction, you can then use the Flashback Transaction Query feature to identify other changes that were done by the transaction, and to request the undo SQL to reverse those changes. But using the undo SQL is only one means of recovering your data. You also have the option of using the Flashback Table feature, described in "Recovering Tables Using the Flashback Table Feature", to restore the table to a state before the changes were made.