1 2 Previous Next 17 Replies Latest reply: Aug 14, 2013 4:22 AM by Hemant K Chitale RSS

    Dataguard

    yxes2013

      Hi all,

       

      What is the difference of the following commands? or are they the same?

       

      1. alter database recover managed standby database using disconnect from session;

      2. alter database recover managed standby database using current logfile disconnect;

       

       

      Thanks a lot,

       

      zxy

        • 1. Re: Dataguard
          Abufazal

          1. alter database recover managed standby database using disconnect from session;

                         is used for applying the archive logs to the standby database

           

          2. alter database recover managed standby database using current logfile disconnect;

                     is used for real time apply in standby database using online redo logs

          • 2. Re: Dataguard
            yxes2013

            So ...they are not the same?

            If I run those commands on my physical standby they will have different results?

             

            Thanks

            • 3. Re: Dataguard
              Abufazal

              Both are used to enable media recovery on the standby site.

               

              However, they differ in the type of log apply method.

               

              Please refer Apply Services

              • 4. Re: Dataguard
                yxes2013

                Thanks Abu

                 

                So which one is the preferred command? and has the efficient effects?

                • 5. Re: Dataguard
                  Abufazal

                  real time apply is preferred and default method starting oracle 11g.

                   

                  However, still the configuration is based on your requirement.

                   

                  For example. You have very business critical database configured with real time apply to standby. Somehow, there are few wrong transactions/corruptions made to the primary database. In real time scenario, this wrong transactions/corruptions would be replicated immediately to the standby site and you would be having no chance to revert the transactions/corruptions. However, if you have a non real -time   apply in place with delay options. You can prevent the transactions/corruptions being replicated to the standby database and make the role reversal.

                   

                  Additionally, you can refer

                  MAA - Data Guard Redo Transport and Network Best Practices (Doc ID 387174.1)

                  • 6. Re: Dataguard
                    yxes2013

                    So I think the best way is to have the non-real time? I wonder why this new company I joined choose the real time?

                    I think real time has more rosource overhead?

                    How do you change from realtime to non-real time?

                    • 7. Re: Dataguard
                      JohnWatson

                      yxes2013 wrote:

                       

                      Hi all,

                       

                      What is the difference of the following commands? or are they the same?

                       

                      1. alter database recover managed standby database using disconnect from session;

                      2. alter database recover managed standby database using current logfile disconnect;

                       

                       

                      Thanks a lot,

                       

                      zxy

                      The difference is that the first statement is not valid SQL:

                       

                      orcla> alter database recover managed standby database using disconnect from session;

                      alter database recover managed standby database using disconnect from session

                                                                            *

                      ERROR at line 1:

                      ORA-02000: missing CURRENT keyword

                       

                       

                      orcla>

                      • 8. Re: Dataguard
                        yxes2013

                        oh sorry dear, its  just a typo. that will be : alter database recover managed standby database disconnect from session;

                        • 9. Re: Dataguard
                          Hemant K Chitale

                          >  How do you change from realtime to delayed time?

                           

                          Before you do that  you should have a meeting with the CIO.  Ask him what DataGuard the business wants.  The DBA doesn't decide.  The *business* decides.

                          The DBA can state what are the requirements and limitations.

                           

                           

                          Hemant K Chitale

                          • 10. Re: Dataguard
                            yxes2013

                            I thanks you all

                             

                            We often found overhead resource usage in ASH report which look like this:

                             

                            Top Event P1/P2/P3 Values        DB/Inst: SSSDB/SSSDB  (Jul 30 10:40 to 10:50)
                            control file parallel write      27.27                   "3","3","3"      27.27

                             

                            Is this related to dataguard process?

                             

                            Thanks,

                            • 11. Re: Dataguard
                              Hemant K Chitale

                              I can't say if it is related.  I can't say if it is signficant either.  You are "picking and choosing" what you want to present.

                               

                               

                              Hemant K Chitale

                              • 12. Re: Dataguard
                                yxes2013

                                > You are "picking and choosing" what you want to present.

                                 

                                It is the TOP CPU resource user is ASH . What program  usually associated to or do control file parallel write?

                                 

                                Thanks,

                                • 13. Re: Dataguard
                                  Hemant K Chitale

                                  ALTER TABLESPACE operations.

                                   

                                  NOLOGGING operations.

                                   

                                   

                                  Hemant K Chitale


                                  • 14. Re: Dataguard
                                    yxes2013

                                    Thanks hemant sir, does that operations having to do with dataguard process?

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