Important Parameters in Data Guard

• Ashiwini
• 26 Jul, 2024
• 0 Comments
• 2 Mins Read

Important Parameters in Data Guard

1. DB_UNIQUE_NAME

• Specifies a unique name for the database within the Data Guard configuration.
• Primary Example

    ALTER SYSTEM SET DB_UNIQUE_NAME='primary_db' SCOPE=SPFILE;

• Standby Example

  ALTER SYSTEM SET DB_UNIQUE_NAME='standby_db' SCOPE=SPFILE;

2. LOG_ARCHIVE_CONFIG

• Enables or disables the sending of redo logs to remote destinations and specifies the DB_UNIQUE_NAME for all databases in the Data Guard configuration.

  ALTER SYSTEM SET LOG_ARCHIVE_CONFIG='DG_CONFIG=(primary_db,standby_db)' SCOPE=BOTH;
  

3. LOG_ARCHIVE_DEST_n

• Specifies the local and remote destinations for archived redo logs. Multiple LOG_ARCHIVE_DEST_n parameters can be configured.

  ALTER SYSTEM SET LOG_ARCHIVE_DEST_1='LOCATION=/u01/app/oracle/arch VALID_FOR=(ALL_LOGFILES,ALL_ROLES) DB_UNIQUE_NAME=primary_db' SCOPE=BOTH;
  ALTER SYSTEM SET LOG_ARCHIVE_DEST_2='SERVICE=standby_db LGWR ASYNC VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=standby_db' SCOPE=BOTH;

4. LOG_ARCHIVE_DEST_STATE_n

• Specifies the state (ENABLE or DEFER) of the corresponding LOG_ARCHIVE_DEST_n parameter.
• LOG_ARCHIVE_DEST_1 archives redo data generated by the primary database from the local online redo log files to the local archived redo log files in /arch1/chicago/.
• LOG_ARCHIVE_DEST_2 is valid only for the primary role. This destination transmits redo data to the remote physical standby destination boston.

  ALTER SYSTEM SET LOG_ARCHIVE_DEST_STATE_1='ENABLE' SCOPE=BOTH;
  ALTER SYSTEM SET LOG_ARCHIVE_DEST_STATE_2='ENABLE' SCOPE=BOTH;

5. REMOTE_LOGIN_PASSWORDFILE

• Specifies whether Oracle should use a password file to authenticate the database administrator remotely.

  ALTER SYSTEM SET REMOTE_LOGIN_PASSWORDFILE='EXCLUSIVE' SCOPE=SPFILE;
  

6. FAL_SERVER

• Specifies the FAL (Fetch Archive Log) server, which is used by the standby database to fetch missing archived redo logs from the primary database.
• Primary Example:

  ALTER SYSTEM SET FAL_SERVER='standby_db' SCOPE=BOTH;
  

7. FAL_CLIENT

• Specifies the FAL client, which is used by the primary database to fetch missing archived redo logs from the standby database.
• Primary Example:

  ALTER SYSTEM SET FAL_CLIENT='primary_db' SCOPE=BOTH;
  

• Standby Example:

  ALTER SYSTEM SET FAL_CLIENT='standby_db' SCOPE=BOTH;

8. STANDBY_FILE_MANAGEMENT

• Determines whether or not standby file management is enabled. When set to AUTO, Oracle automatically manages the creation and deletion of files on the standby database.

  ALTER SYSTEM SET STANDBY_FILE_MANAGEMENT='AUTO' SCOPE=BOTH;

9. DB_FILE_NAME_CONVERT

• Specifies the conversion parameters for filenames between the primary and standby databases.

  ALTER SYSTEM SET DB_FILE_NAME_CONVERT='/primary/db/location/', '/standby/db/location/' SCOPE=SPFILE;
  

10. LOG_FILE_NAME_CONVERT

• Specifies the conversion parameters for redo log filenames between the primary and standby databases.

  ALTER SYSTEM SET LOG_FILE_NAME_CONVERT='/primary/log/location/', '/standby/log/location/' SCOPE=SPFILE;

11. ARCHIVE_LAG_TARGET

• Specifies the target of how far behind (in seconds) the standby database can be in terms of archived redo log application.

  ALTER SYSTEM SET ARCHIVE_LAG_TARGET=1800 SCOPE=BOTH;