6 Replies Latest reply: Mar 25, 2013 9:46 AM by Uwehesse-Oracle RSS

    Real-Time Apply

    997952
      Hello,

      From Oracle doc:

      "If the real-time apply feature is enabled, log apply services can apply redo data as it is received, without waiting for the current standby redo log file to be archived. This results in faster switchover and failover times because the standby redo log files have been applied already to the standby database by the time the failover or switchover begins."

      1)Are there any advantages other than the above to enable the real time apply feature for a physical standby?

      2)What is the recommended way (enable or disable real time apply) and Why is that so?

      Thanks
        • 1. Re: Real-Time Apply
          damorgan
          I generally recommend not enabling this feature ... in fact I am far more inclined to build in an intentional apply delay ... here's why.

          Suppose something really bad happens in the primary ... it will be immediately replicated to the standby ... now both have the problem. I like an apply delay sufficient to catch issues and, perhaps, prevent the apply.
          • 2. Re: Real-Time Apply
            Hemant K Chitale
            in fact I am far more inclined to build in an intentional apply delay
            That would be the case when building more than one standby OR if the standby isn't intended as a real DR site.

            If there is a single standby and it is the real DR site, management would want real-time or the minimal lag achieveable. Advicing a second standby with an apply delay would be a good thing.


            Hemant K Chitale
            • 3. Re: Real-Time Apply
              damorgan
              I understand your point but if they are not expecting transparent failover ... I always try to argue for a delay. I may not get it ... but I try.
              • 4. Re: Real-Time Apply
                Veeresh.S
                994949 wrote:
                1)Are there any advantages other than the above to enable the real time apply feature for a physical standby?
                Corrupted blocks on primary database are automatically repaired.
                Incremental backup's on physical standby is possible.
                2)What is the recommended way (enable or disable real time apply) and Why is that so?
                For active dataguard you need to get license.
                Some times it is not recommended for the clients if they need a minimum xyz minute gap difference btw primary and standby(though it is possible in ADG also).
                yet the recommended one : it depends upon the requirement.

                Its best to explain & leave the decision for the customer/clients/developer.
                • 5. Re: Real-Time Apply
                  Lonion
                  Corrupted blocks on primary database are automatically repaired.
                  Hi, Veeresh.S. i listen this first time . Can u provide some documents' link for me ?
                  • 6. Re: Real-Time Apply
                    Uwehesse-Oracle
                    You are confusing Real-Time Apply (10g New Feature) with Real-Time Query (11g New Feature, requiring the additional Active Data Guard option).

                    Kind regards
                    Uwe Hesse

                    "Don't believe it, test it!"
                    http://uhesse.com