1 2 Previous Next 15 Replies Latest reply: Apr 18, 2013 4:38 AM by yxes2013 RSS

    Standby Confusions

    yxes2013
      Hi all,

      When you say create standby database is it synonymous to DATAGUARD? or the manual standby? or the poor man's standby?

      http://managingoracle.blogspot.com/2012/04/oracle-manual-standby-no-dataguard.html

      Can this poor man's standby be able to switch over the standby to primary? and back again from primary to standby?


      Manually remove standby databse

      What did Tom from the link above has setup? is it a dataguard or just manual?


      I thank you all,

      zxy
        • 1. Re: Standby Confusions
          asahide
          Can this poor man's standby be able to switch over the standby to primary? and back again from primary to standby?
          What is "poor man's standby" ?
          What did Tom from the link above has setup? is it a dataguard or just manual?
          He use dgmgrl, so he use dataguard.
          dgmgrl is data guard interface.


          Regards,
          • 2. Re: Standby Confusions
            sb92075
            yxes2013 wrote:
            Hi all,

            When you say create standby database
            what is difference between what you label as standby database & RMAN DUPLICATE DATABASE?
            • 3. Re: Standby Confusions
              sulimo
              Have a look at:

              http://www.freelists.org/post/oracle-l/a-really-nontechnical-question-help,6

              HTH
              • 4. Re: Standby Confusions
                Salman Qureshi
                Hi all,
                When you say create standby database is it synonymous to DATAGUARD? or the manual standby? or the poor man's standby?
                http://managingoracle.blogspot.com/2012/04/oracle-manual-standby-no-dataguard.html
                In oracle standby database, redo log is applied to the standby database to keep it in sync with the primary database.
                Dataguard is a setup where one or multiple standby databases are configured which are in sync with primary database all the time and all this is done by Oracle itself.

                What this guy is doing here is creating a copy of primary database and having manual methods to extract redo logs from primary and then shifting them to standby using his own written scripts. Doing this also needs a license from Oracle and hence this is not a "poor man's standby". Because Standard Edition does not have capability of data guard, hence this guy is using his "own" method of standby database. Remember, this still needs a separate standard edition license to have this kind of standby.

                Can this poor man's standby be able to switch over the standby to primary? and back again from primary to standby?
                Manually remove standby databse
                NO. In case of primary database failure, you can't execute any dataguard standard command to failover (switchover will also not work here). You need to manually recover this "manual" standby and then open it using resetlogs and then direct your applications to this database.
                What did Tom from the link above has setup? is it a dataguard or just manual?
                This is data guard configuration.

                Salman

                Edited by: Salman Qureshi on Apr 18, 2013 2:42 PM
                • 5. Re: Standby Confusions
                  yxes2013
                  I thank you all :)
                  What did Tom from the link above has setup? is it a dataguard or just manual?
                  This is not data guard, you may call it a manual standby database (also not supported by Oracle)

                  Can Tom setup be able to switch from standby to primary as well?

                  It is not clear to me :(

                  How many types of standby database does oracle have or how many variations or how many flavors?

                  When I run the command "create standby database" .....is it creating a DATAGUARD, or other types? or does all "standby database" always used this command?

                  Why is that in 11gR2 RAC cluster is already included or free. Does it include free standby license too?

                  Thanks again...

                  Edited by: yxes2013 on 17.4.2013 22:49
                  • 6. Re: Standby Confusions
                    1002948
                    There are 2 types of standby database
                    1 physical standby
                    2 logical standby

                    Data guard is not a standby db it manages the standby database..

                    Varun
                    • 7. Re: Standby Confusions
                      Girish Sharma
                      Data guard is a term and Physical Standby is a type of the standby database within a dataguard configuration i.e. dataguard is just the new marketing label for standby, resulting from an extra interface (Dataguard manager or Dataguard broker) to manage the standby database.

                      Two types of Standby Database (a) : Physical Standby Database (b) Logical Standby Database

                      How they creates and how they works, read relevant version's Oracle docs.

                      Regards
                      Girish Sharma

                      Edited by: Girish Sharma on Apr 18, 2013 11:19 AM
                      Aman And Sybrand @ Difference between physical standby database and Data Guard
                      • 8. Re: Standby Confusions
                        yxes2013
                        I thanks you all, now is getting clearer :)
                        There are 2 types of standby database
                        1 physical standby
                        2 logical standby
                        Which of the above is capable of swithing over from standby>primary>standby? I guess no.2?

                        Does dataguard manages both 1 & 2?
                        • 9. Re: Standby Confusions
                          Hemant K Chitale
                          This is not data guard, you may call it a manual standby database (also not supported by Oracle)
                          No, Tom in that thread does refer to DataGuard Broker Configuration. So it is not a manual standby.


                          Hemant K Chitale
                          • 10. Re: Standby Confusions
                            Hemant K Chitale
                            Which of the above is capable of swithing over from standby>primary>standby?
                            See the documentation on Role Transitions
                            http://docs.oracle.com/cd/E11882_01/server.112/e25608/role_management.htm#i1033702


                            Hemant K Chitale
                            • 11. Re: Standby Confusions
                              Girish Sharma
                              Which of the above is capable of swithing over from standby>primary>standby? I guess no.2?
                              You can switch over to / from both type of Standby Databases.

                              Switchover of Physical standby database in 11g
                              http://shivanandarao-oracle.com/2012/04/23/switchover-of-physical-standby-database/

                              [url http://books.google.co.in/books?id=cpkWoXEWlTsC&pg=PA542&lpg=PA542&dq=switch+from+primary+to+logical+standby&source=bl&ots=WevVPmkVpc&sig=rHowpC9tS50lIG2ULL5mlPajSwY&hl=en&sa=X&ei=XYxvUf3fNISzrAfc4IDwAQ&ved=0CGcQ6AEwCQ#v=onepage&q=switch%20from%20primary%20to%20logical%20standby&f=false]Switchover to Logical Standby database

                              Regards
                              Girish Sharma
                              • 12. Re: Standby Confusions
                                Salman Qureshi
                                Hi,
                                No, Tom in that thread does refer to DataGuard Broker Configuration. So it is not a manual standby.
                                Right, I was actually referring to the first link, not the oracle foums link. Corrected my mistake now by editing my reply.

                                Salman
                                • 13. Re: Standby Confusions
                                  yxes2013
                                  Thanks all :)


                                  So, there is "manual" phycal standby and "manual" logical standby?

                                  And there is "automated" physical standby and "automated" logical standby > which is done thru dataguard?
                                  • 14. Re: Standby Confusions
                                    Hemant K Chitale
                                    You can actually build combinations -- e.g. a "scripted and automated" "standby" not using a standby controlfile, a "manual" standby using a standby controlfile etc.

                                    Oracle allows flexibility in how you setup standbys.
                                    However, in general, using the Enterprise Edition, you build a standby with a standby controlfile and dataguard.
                                    Using Standard Edition, you build a "manual" or "scripted" standby because dataguard is not available in Standard Edition.


                                    Hemant K Chitale
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