3 Replies Latest reply: Feb 15, 2014 11:26 AM by UweHesse RSS

    Difference between real time apply and active dataguard

    DBA_PAUL


      Good Day,

      Please help me understand what is the difference between Oracle real time apply and Active Data Guard.If there is a link to set active data guard please send me as well.

      Regards,

      DBA_Paul

        • 1. Re: Difference between real time apply and active dataguard
          944515

          Hi,

           

          Real time apply means that the standby database is applying the redo -information as soon as it hits the standby redo logs. If you're not using real-time apply the redo will be applied after a logswitch has occured on the standby database.

           

          A 'normal' (non Active Dataguard) standby database is in mount mode, and is not open for 'user-queries'. In the normal case, the standby database can be opened read-only, but then managed recovery have to be turned off (meaning it is not applying redo anymore). In an active dataguard configuration the standby database is open read only but at the same time applying redo as it is sent from the primary database. So in that case the standby database can be used for offloading reporting (as an example) using up-to-date information.

          Active dataguard is a separately licensed option.

           

          hth

          regards

          /M

          • 2. Re: Difference between real time apply and active dataguard
            DBA_PAUL

            Hi ,

            Thank you very much for the answer .It cleared the confusion that I was having.

            Regards,

            DBA_Paul


            • 3. Re: Difference between real time apply and active dataguard
              UweHesse

              In addition to the valid answer: Active Data Guard is an option that includes several features.

              The most famous is Real-Time Query, which was referred to by /M.

              But there is also the feature Block Change Tracking on the Physical Standby.

               

              In 12c, Active Data Guard got even more enhanced and includes there also Far Sync Instances and Real-Time Cascading Standby.

               

              Kind regards

              Uwe Hesse