4 Replies Latest reply: Apr 26, 2012 12:18 PM by Santhosh B RSS

    Data Guard

    933241
      I have few basic questions regarding Standby Database:

      1)How many standby databases can be configured?

      2)How to know if a standby DB is associated with primary DB?

      3)What is the purpose of init.ora?

      Thanks in advance

      Regards
        • 1. Re: Data Guard
          mseberg
          Hello;

          1)How many standby databases can be configured?

          Per Primary, that would be 9. ( will double check )

          Clearly states 9 in the Oracle 9 doc's, but only says multiple in the 10 and 11 docs.


          Its 9 because : ( Source Oracle document E10700-01 )
          The LOG_ARCHIVE_DEST_n initialization parameter defines up to 31 
          
          
          LOG_ARCHIVE_DEST_11 through LOG_ARCHIVE_DEST_31 cannot be specified as an ALTERNATE redo transport location.
          Take away the 1 for the local and you have 9. Since 11 -31 are NOT available.



          http://www.oracle.com/technetwork/database/features/availability/maa10gr2multiplestandbybp-1-131937.pdf


          2)How to know if a standby DB is associated with primary DB?


          The INIT or SPFILE file check parameter DB_NAME and DB_UNIQUE_NAME on both the Primary and the Standby.


          3)What is the purpose of init.ora?

          It holds the parameters need for Data Guard. DG will require an SPFILE version of the INIT to work.

          Common DG parameters

          DB_UNIQUE_NAME=PRIMARY
          DB_FILE_NAME_CONVERT='STANDBY','PRIMARY'
          LOG_FILE_NAME_CONVERT='STANDBY','PRIMARY'
          log_archive_dest_1='LOCATION=USE_DB_RECOVERY_FILE_DEST VALID_FOR=(ALL_LOGFILES,ALL_ROLES) DB_UNIQUE_NAME=PRIMARY'
          log_archive_dest_2='SERVICE=STANDBY LGWR ASYNC VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=STANDBY'
          LOG_ARCHIVE_DEST_STATE_1=ENABLE
          LOG_ARCHIVE_DEST_STATE_2=ENABLE
          LOG_ARCHIVE_MAX_PROCESSES=30


          For additional information see :

          Data Guard Concepts and Administration 11g Release 2 (11.2)
          E10700-02

          http://www.oracle-base.com/articles/11g/data-guard-setup-11gr2.php


          Best Regards

          mseberg

          Edited by: mseberg on Apr 26, 2012 10:35 AM

          Edited by: mseberg on Apr 26, 2012 11:32 AM
          • 2. Re: Data Guard
            CKPT
            1)How many standby databases can be configured?
            Depends on versions, basically how many log_archvie_dest other than local.
            2)How to know if a standby DB is associated with primary DB?
            You can check service name in Remote destinations Ex:LOG_ARCHIVE_DEST_2
            3)What is the purpose of init.ora?
            Well, its the root. With only parameters of Init.ora file you can bring database in nomount status. it states what is database name, sga, & so on..
            • 3. Re: Data Guard
              Santhosh B
              Answers to few basic questions regarding Standby Database:

              1) Dataguard can manage one production database and multiple standby databases.(10g - TEN & 11g - Thirty)

              2) By reading the parameter file we can get the details of primary database and the standby database.

              3)init.ora is parameter file. When the database is started this parameter file is to be read. This file consists the parameters related to file locations, memory and more.
              In this parameter file the parameters related to the Dataguard are to be added.
              • 4. Re: Data Guard
                Santhosh B
                Answers to few basic questions regarding Standby Database:

                1) Dataguard can manage one production database and multiple standby databases.(10g - TEN & 11g - Thirty)

                2) By reading the parameter file we can get the details of primary database and the standby database.

                3)init.ora is parameter file. When the database is started this parameter file is to be read. This file consists the parameters related to file locations, memory and more.
                In this parameter file the parameters related to the Dataguard are to be added