Oracle Database: Flashback Vs. Recovery

Along with the skills you need as a database administrator to backup an Oracle database, are the skills needed to perform a recovery. You're limiting yourself in terms of what Oracle has to offer if you consider "normal" recovery as anything having to do with RMAN (and what it replaced). In the traditional sense, recovery isn't just recovery anymore; it's more like recovery plus various flashback options. Oracle has even gone as far as suggesting that flashback be your first choice in some situations.

Flashback is pretty simple; how it is implemented within the database can be a bit confusing. The confusion originates from where flashback resides in the database and what timeframes are involved. In what I'll call RMAN recovery, we know recovery comes from backups and the application of archived redo logs. The RMAN timeframe for recovery lasts as long as you maintain backups and related archived redo logs (which can be essentially forever). Flashback lives in a couple of places in Oracle. One location is in the UNDO tablespace, and the other is in flashback log files. Both of these areas are limited by space, which is related to time, but less of it. Flashback, depending on what is being flashed back, can also require archived redo logs. Yet another way to look at flashback is to consider what it is used for: error analysis or error recovery.

Read the full article at Database Journal:
Flashback versus Recovery in Oracle to learn the positive and negative options you have when it comes time to flash back some object.

» See All Articles by Columnist Steve Callan