8 Replies Latest reply: Apr 6, 2009 2:47 PM by 591186 RSS

    recovery using backup controlfile.

    569820
      Hi,

      Can someone please tell me what is accomplished with the "RECOVER DATABASE USING BACKUP CONTROLFILE UNTIL CANCEL". in this command, I know;

      "recover database" part applies arvhived logs to restored copies of data files, and
      "until cancel" part allows the user to cancel the recovery process if he wants incomplete recovery, but
      WHAT DOES "using backup controlfile" part do??? this is not clear to me.

      If we have restored a control file from a backup of binary control file, then the database will consider it as a normal control file, and will use it to locate data files and redo log files. That is, a restored control file will be a normal control file, then what do we tell by saying "using backup controlfile"?

      Thanks in advance,
      Amir.
        • 1. Re: recovery using backup controlfile.
          153119
          using backup controlfile means the controlfile is from a backup, doesn't contain correct SCN info, so Oracle will ignore all SCN info in the controlfile.


          -----
          Sybrand Bakker
          Senior Oracle DBA
          • 2. Re: recovery using backup controlfile.
            569820
            Can you exaplain in a bit more details. This is still not very clear to me. (Control file backup can be binary or ASCII, can you tell which backup control file type we tell by this using this command?)

            Anybody else??? any ideas??

            Thanks.
            • 3. Re: recovery using backup controlfile.
              153119
              How many details do you require? Should I retype the documentation?
              Do you think you can use an ASCII backup to run the RECOVER DATABASE command?
              Obviously, you can't!!!!!
              If you think you can you should verify this in the documentation. Maybe your boss hits you up for reading the documentation, but that doesn't concern me at all.
              I told you 'using backup controlfile' means you tell to Oracle 'Heck, don't trust whatever is written here, as the controlfile I have restored is not the current one, and does NOT contain the correct information, and you shouldn't trust it. And that is all there is to it. If you need 'the detail steps' visit http://tahiti.oracle.com !!!

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              Sybrand Bakker
              Senior Oracle DBA
              • 4. Re: recovery using backup controlfile.
                569820
                I didn't mean to use the ASCII control file in order to open the database and use in place of a normal control file!, obviously it is not possible (its common sense, and I have it!). By ASCII control file, I meant the text script which is generated by "Alter Database Backup Controlfile To Trace" command, and which is used to create a new control file.

                So, my question in my last message was this:
                "When we use 'recover database using backup controlfile....' command, do we tell oracle that control file is a new file just created with 'create controlfile ...' script, OR, we tell that the control file is an old binary control file restored from a binary backup? "

                Thanks.
                • 5. Re: recovery using backup controlfile.
                  Aman....
                  Well, using backup controlfile means, umm , binary control file picked up from the backup isn't it?

                  HTH
                  Aman....
                  • 6. Re: recovery using backup controlfile.
                    Srini Chavali-Oracle
                    Pl see the documentation - BACKUP CONTROLFILE means exactly what Sybrand and Aman have stated above

                    http://download.oracle.com/docs/cd/B28359_01/server.111/b31189/ch12033.htm#sthref1690

                    HTH
                    Srini
                    • 7. Re: recovery using backup controlfile.
                      569820
                      Ok, agreed. But what does recovery process do when we issue this command?, it considers that control file is not valid, so it does not compare SCNs from control file? so how does it stop applying redo logs? and , does it update control file after we finish recovery process?
                      • 8. Re: recovery using backup controlfile.
                        591186
                        Check Performing Cancel-Based Incomplete Recovery
                        [http://download-uk.oracle.com/docs/cd/B10501_01/server.920/a96572/performingreco.htm#30935]