2 Replies Latest reply: Apr 20, 2013 4:46 AM by Aman.... RSS

    clarification on Incomplete recovery

    Arun Natarajan-OC
      Hi Friends,

      Just clarification on 2 Things on incomplete recovery.

      Undo tablespace (datafiles):
      ---------------------------------

      I lost current undo tablespace datafile but i have datafiles from backup,archived logs,current control file,online redo log and still can i perform complete recovery ?

      because complete recovery means= restore datafiles from backup +roll forward (online redo logs which is available) and roll back (current undo datafile , the current file is not available but only the backup undo datafiles is available)

      so in this case how will the roll forward happen? so is this in complete recovery?


      Control Files:
      ------------------

      My control files got lost but i have control trace file , dbf files(inclusing undo),archived logs,online redo logs. in this case i won't lose any data but since i am recreating control file i will perform open reset logs (new incarnation) so is this considered as in complete recovery (though my data is intact - all committed but the DB is incarnated)

      so what is complete recovery?

      DB should not be incarnated? (or) DB should have only commited data (or) both


      Regards,
      DB
        • 1. Re: clarification on Incomplete recovery
          rp0428
          >
          I lost current undo tablespace datafile but i have datafiles from backup,archived logs,current control file,online redo log and still can i perform complete recovery ?
          >
          If the database was shutdown normally the undo tablespace doesn't contain anything of value so you haven't 'lost' anything.

          Why is it you think you need recovery?

          What you need to do is recreate your undo tablespace

          See this AskTom article for how to do that.
          http://asktom.oracle.com/pls/asktom/f?p=100:11:0::::P11_QUESTION_ID:5669213349582

          Why do you think scenario #2 needs complete recovery? Complete recovery involves applying redo changes. You said your datafiles are complete.

          For info about 'complete recovery' see that section in the Database Concepts doc
          http://docs.oracle.com/cd/B28359_01/server.111/b28318/backrec.htm#i1006510
          >
          Complete Recovery

          Complete recovery applies all of the redo changes contained in the archived and online logs to a backup. Typically, you perform complete media recovery after a media failure damages datafiles or the control file.You can perform complete recovery on a database, tablespace, or datafile.
          • 2. Re: clarification on Incomplete recovery
            Aman....
            839396 wrote:
            Hi Friends,

            Just clarification on 2 Things on incomplete recovery.

            Undo tablespace (datafiles):
            ---------------------------------

            I lost current undo tablespace datafile but i have datafiles from backup,archived logs,current control file,online redo log and still can i perform complete recovery ?

            because complete recovery means= restore datafiles from backup +roll forward (online redo logs which is available) and roll back (current undo datafile , the current file is not available but only the backup undo datafiles is available)

            so in this case how will the roll forward happen? so is this in complete recovery?
            If you have all the back up filles, archive logs and you have lost the undo tablespace data file, you would be still doing the complete recovery only. What makes you think that it would be an incomplete recovery?

            >
            Control Files:
            ------------------

            My control files got lost but i have control trace file , dbf files(inclusing undo),archived logs,online redo logs. in this case i won't lose any data but since i am recreating control file i will perform open reset logs (new incarnation) so is this considered as in complete recovery (though my data is intact - all committed but the DB is incarnated)

            so what is complete recovery?
            DB should not be incarnated? (or) DB should have only commited data (or) both
            Read the reply of Rp!

            Aman....