Objectives
After completing this lesson,you should be able to:
- Describe Flashback technology
- Configure Flashback Database
- Perform Flashback Database operations
- Monitor Flashback Database
Flashback Technolog:Benefits
- Te Flashback technology is a revolutionary advantage in recovery.
- Traditional recovery techniques are slow.
- The entire database or a file(not just the incorrect data) has to be restored.
- Every change in the database log must be examined.
- Flashback is fast
- Changes are indexed by row and by transaction
- Only the changed data is restred.
- Flashback commands are easy.
- No complex mulitple-step procedures are involved.
Flashsback Technology
| Object Level | Scenario Examples | Flashback Technology | Depends On | Affects Data |
| Database |
Truncate table; Undesired multiple changes made |
Database | Flashback logs | TRUE |
| Table | Drop table | Drop | Recycle bin | TRUE |
| Update with the wrong WHERE clause | Table | Undo data | TRUE | |
| Compare current data with data from past | Query | Undo data | FALSE | |
| Compare version of a row | Versoin | Undo data | FALSE | |
| Keep histrical transaction data | Data Archive | Undo data | TRUE | |
| Transaction | Investigate and back out suspect transactions | Transaction | Undo/redo from Archive logs | TRUE |