5 Replies Latest reply: Dec 19, 2011 8:44 AM by CKPT RSS

    Different instance_name for standby DB

    resistanceIsFruitful
      DB version : 11g Release 1
      OS : AIX

      I am new to Dataguard.
      I logged into our standby environment(only one DG env here) Here I noticed that Standby DB's instance name is different than its DB name.
      Is this a mandatory requirement for Data guard ? Or is this some kind of mistake ?

      We have our Primary DB called sparkamu running in server manhprod201
      Our Physical standby DB's name is sparkamu as well, but different instance_name
      --- At the primary Side
      
      SQL> select open_mode from v$database;
      
      OPEN_MODE
      ----------
      READ WRITE
      
      SQL> select database_role from v$database;
      
      DATABASE_ROLE
      ----------------
      PRIMARY
      
      SQL> select name from v$database;
      
      NAME
      ---------
      SPARKAMU
      
      SQL> select instance_name from v$instance;
      
      INSTANCE_NAME
      ----------------
      sparkamu
      At the primary Side the VALUE field from show parameter log_archive_dest_2
      SERVICE=sparkmsu VALID_FOR=(ONLINE_LOGFILES, PRIMARY_ROLE) DB_UNIQUE_NAME=sparkmsu
      -----At the Standby DB (manhstdby203)
      export ORACLE_SID=sparkmsu
      
      Logging  in as sys
      
      SQL> select name from v$database;
      
      NAME
      ---------
      SPARKAMU
      
      SQL> select instance_name from v$instance;
      
      INSTANCE_NAME
      ----------------
      sparkmsu    -----------------------> Instance Name is different
      
      SQL> select database_role from v$database;
      
      DATABASE_ROLE
      ----------------
      PHYSICAL STANDBY
      -- The primary DB's tnsnames.ora file looks like
      ############ Primary DB's own tns entry
      sparkamu =
        (DESCRIPTION =
          (ADDRESS_LIST =
            (ADDRESS = (COMMUNITY = tcp.world)
              (PROTOCOL = TCP)(Host =  manhprod201.regcom.net) (Port =  4123))
          )
          (CONNECT_DATA = (SID = sparkamu)
          )
        )
      
      
      
      ############ TNS entry for DG DB sparkmsu ########
      
      sparkmsu =
        (DESCRIPTION =
          (ADDRESS_LIST =
            (ADDRESS = (COMMUNITY = tcp.world)
              (PROTOCOL = TCP)(Host =  manhstdby203.regcom.net) (Port =  3163))
          )
          (CONNECT_DATA = (SID = sparkmsu)
          #(CONNECT_DATA = (SERVICE_NAME = sparkamu)
          )
        )