3 Replies Latest reply: Mar 28, 2013 8:21 PM by KR10822864 RSS

    standby control file

    999436
      Hello,

      1) Is multiplexing of standby control file is required on standby database?

      2) How Oracle decides whether the standby database can receive data from primary site?

      3) How can I open the standby in read/write mode in disaster (by activate standby database) if I have no online redo logs?

      Note: DB Version 11.2.0.1 on OEL 5.7
        • 1. Re: standby control file
          Sunny kichloo
          1) Is multiplexing of standby control file is required on standby database?
          Better follow the same architecture of primary database if you have multiplex controlfile on primary environment do it on standby also.

          2) How Oracle decides whether the standby database can receive data from primary site?
          Does data in your case means archive??

          http://docs.oracle.com/cd/B19306_01/server.102/b14239/log_transport.htm

          3) How can I open the standby in read/write mode in disaster (by activate standby database) if I have no online redo logs?
          You can activate standby database.

          Once you have activated a standby database ii losses its standby functionality and become a database in primary role

          So redo logs are required when standby is opened in read/write state.
          • 2. Re: standby control file
            Mahir M. Quluzade
            Hi
            1) Is multiplexing of standby control file is required on standby database?
            It is not required multiplexing standby control file on standby database. But best practice is use multiplex control files.
            2) How Oracle decides whether the standby database can receive data from primary site?
            If you configured data guard and not any problem on network then log transport service must ship redo to standby sides.
            If redo apply service is running then received redo can apply to standby database.

            3) How can I open the standby in read/write mode in disaster (by activate standby database) if I have no online redo logs?
            Note: DB Version 11.2.0.1 on OEL 5.7
            Your database version is 11.2. It means you can open standby database READ ONLY WITH APPLY, it is Active Data Guard.
            You can open standby database read write mode, it means standby database converting to SNAPSHOT standby database.
            or you can ACTIVATE standby database.

            Thanks
            Mahir M. Quluzade
            http://www.mahir-quluzade.com
            • 3. Re: standby control file
              KR10822864
              1) Is multiplexing of standby control file is required on standby database?
              Yes , better to fallow same architecture as primary.
              2) How Oracle decides whether the standby database can receive data from primary site?
              refer:Check status of sync to standby
              3) How can I open the standby in read/write mode in disaster (by activate standby database) if I have no online redo logs?
              Open The Standby Database When The Primary Is Lost
              standby side:

              $sqlplus "/as sysdba"
              sql>shut immediate
              sql>startup mount
              Check Status
              sql> SELECT OPEN_MODE,PROTECTION_MODE,DATABASE_ROLE FROM V$DATABASE;
              Recover if you have logs to apply;
              in this case the primary is lost and I don't have more archived logs to apply:
              sql> RECOVER STANDBY DATABASE;
              once recovery process finish then
              sql> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE FINISH;
              Activate the Standby Database
              sql> ALTER DATABASE ACTIVATE PHYSICAL STANDBY DATABASE;
              Check the new status
              sql> SELECT OPEN_MODE,PROTECTION_MODE,DATABASE_ROLE FROM V$DATABASE;
              Open the Database
              sql> ALTER DATABASE OPEN;
              check status again;
              sql> SELECT OPEN_MODE,PROTECTION_MODE,DATABASE_ROLE FROM V$DATABASE;