1 2 Previous Next 25 Replies Latest reply on May 19, 2014 5:58 PM by jgarry

    Online recovery?

      Hi,

       

      11.2.0.3

       

      We have PROD1 with dataguard.  The user accidentally deleted some transactions, 2 hrs ago. Now the app is having error related to the deleted transactions.

      The user is asking if the deleted data can be restored. Can our dataguard physical standby recover it?

       

      Thanks,

      pK

        • 1. Re: Online recovery?
          FreddieEssex

          The whole concept of dataguard is to apply changes to your standby.

           

          Depending on the way your dataguard is setup you will most likely have the changes applied to your standby.

           

          If you have some sort of apply lag setup then you may be able to "recoverr the data from your standby.

          1 person found this helpful
          • 2. Re: Online recovery?

            I think it is just a default setup physical standby I did not read about that lag thing.

            Are there other options?

             

            Thanks

            • 3. Re: Online recovery?
              John Stegeman

              Two options off the top of my head:

               

              Flashback (if it has been configured)

              Restore your backup and apply archive logs until just prior to the transaction delete and get the data from there.

               

              Unless you configured a lag on your physical standby, it's not going to help you.

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              • 4. Re: Online recovery?
                Thierry H.

                What is your undo retention?

                Do you know on which table(s) the transactions have to be recovered?

                Did you setup any additional Flashback technology?

                 

                Maybe some hints:

                http://docs.oracle.com/cd/E11882_01/appdev.112/e41502/adfns_flashback.htm#i1008579

                 

                HTH,

                Thierry

                1 person found this helpful
                • 5. Re: Online recovery?

                  I did not set any advance settings just plain standby db. no more no less.

                   

                  My friend Barry said to use flashback query?

                  • 6. Re: Online recovery?
                    Thierry H.
                    My friend Barry said to use flashback query?


                    This is the link given above / previously


                    HTH,

                    Thierry

                    1 person found this helpful
                    • 7. Re: Online recovery?

                      Thanks, but too bad the user said she used the app to delete transactions which also deleted dependencies child-parent tables. So no way to track which exact tables where affected.

                       

                      I can not understand why dataguard can not protect simple errors like this

                       

                      Can I not rollback point in time my physical standby or even my Primary DB? I believe the changes are  still on the online logs.

                      • 8. Re: Online recovery?
                        John Stegeman

                        Dataguard CAN protect against simple errors like this, provided that you READ THE ******* documentation first and set it up to do so.

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                        • 9. Re: Online recovery?

                          Ok I agree with you joHn, But do you have any idea how to rollback  the online logs?

                          • 10. Re: Online recovery?
                            Thierry H.
                            So no way to track which exact tables where affected.

                            Maybe the supplier of the application can answer this question and confirm the feasibility of restoring data via flashback?

                             

                            Rolling back your standby database will result as an equivalent approach than the Flashback approach: you will still have to re-insert the lost transaction into the table(s) and their dependencies if the logic is on the application side. If such logic is on the database side (for example triggers), then the dependencies could be restored as well.

                             

                            And rolling back your primary database ?!?!? … is it a production environment?

                             

                            Otherwise, duplicate the database to a separate system and recover to a desired point in time … would be better that rolling back your primary or standby database.

                             

                            The lost transactions… were they existing for a ‘long’ time?... maybe you took a database export at some point where such records might be available.

                            1 person found this helpful
                            • 11. Re: Online recovery?

                              How can I do point in time when I do not have rman backup

                              I am depending only on our physical standby.

                              • 12. Re: Online recovery?
                                John Stegeman

                                petra-K wrote:

                                 

                                How can I do point in time when I do not have rman backup

                                I am depending only on our physical standby.

                                Learn from your mistakes and realise that a physical standby is not a substitute for a backup.

                                1 person found this helpful
                                • 13. Re: Online recovery?
                                  Thierry H.

                                  no RMAN backup?? how did you plan to do a point in time recovering???

                                  Any chance you run some regular database exports? (but then you still need to understand the application logic to re-insert the data)

                                  Any chance you setup Flashback Database?

                                   

                                  And i can't agree more with John!

                                   

                                  Looks like you have a serious challenge...

                                  1 person found this helpful
                                  • 14. Re: Online recovery?

                                    Thanks,

                                     

                                    Supposing I have RMAN backup, so do I need to distroy my primary just to overwrite  with the backup so I can recover point in time? anyways the  I can not identify which tables are affected and I can not insert them back anyway?

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