Dataguard parameter parsing

Db_unique_name

Defines the unique name of the database, because the db_name parameter must be the same for the physical database and must be different for the logical database, so the Db_unique_name parameter is introduced in Oracle 10g to determine each database in the Dataguard configuration, if it is not defined, The db_name parameter value is used by default.

Log_archive_config

Defines a valid db_unique_name parameter list for a dataguard configuration that does not require a name order.

Control_files

Specify the control file for the standby on the repository.

Log_archive_max_processes

The default value for this parameter is 2, and it is not sufficient to configure the Dataguard environment. The archive process on the main library is responsible for archiving the ORL files that are filled and processing the interval between the redo streams of the standby database, the archive process on the repository is responsible for archiving the SRL, and forwarding the archive log to the standby, which is set at least 4, with a maximum value of 30

Db_create_file_dest

If you use ASM storage, you need to set this parameter in the repository

Log_archive_dest_n

This is the main parameter of the Dataguard retransmission, which usually works on the main library, and the following are common features of this parameter

1.SERVICE

Specifies the name of the tnsnames that is created to point to the standby.

2.SYNC

Specifies that you want to use the synchronization method to transport the redo data, which means that the LGWR process waits for a confirmation message from LNS before telling the client that the transaction has been committed. For maximum available and maximum protection mode, you need to have at least one alternate target for this configuration.

3.ASYNC

The default method, if you do not specify a transport type, is to asynchronously redo the transfer, which is the maximum performance mode.

4.net_timeout

Specifies the number of seconds that the LGWR process waits for the LNS process to respond, and the default value is 30 if more than the specified time will be discarded for the failure. The point is not to set less than 10 good, which will encounter a failure of the reset after the recovery.

5.REOPEN

Control Dataguard The default value of 300 seconds before the primary library is allowed to attempt to connect to a failed backup is usually a complaint about the reason why Dataguard is not attached after the standby is aborted. Consider narrowing the feature to 15-30 seconds so that Dataguard will be attached as soon as possible.

6.db_unique_name

To use this attribute in the Log_archive_dest_n parameter, you also need to set the Log_archive_config parameter

7.valid_for

Defines when to use the Log_archive_dest_n target parameter and which type of redo log file to run on. The following are the legal values for log files and roles:

Online_logfile: Valid only when ORL files are archived

Standby_logfile: Valid when only SRL files are archived

All_logfiles: Any redo log file types are valid

Primary_role: Valid only for the primary role's database

Standby_role: Valid only for the database of the standby role

All_roles: Any database role is valid

8.AFFIRM

Default method for sync target. Requires the LNS process to wait for the RFS to perform direct I/O to the Srl file before returning a success message, which is required for "maximum available" and "Maximum protection" sync.

9.NOAFFIRM

If you do not specify the way that will be async, use the "most performance" mode.

10.COMPRESSION

This feature enables compression and does not mean that the redo data remains compressed on the disk, but is compressed during transmission, and the redo data is already uncompressed in the repository written to the Srl file.

11.max_connections

The features introduced by Oracle 10GR2 allow you to specify the number of archive processes that are used to prepare the library at the time of delivery, obsolete in 11g, and the default value of 1.

12.LOCATION

You need to specify an address for the attribute before Oracle 10GR2, where the archive process stores the archived logs. You do not need to force the attribute to be specified after the flash-back zone and the local archive default point.

Log_archive_dest_state_n

This is the parameter that is used with the Log_archive_dest_n, the default value is already enabled, so you do not need to set them.

Db_file_name_convert

On standby This parameter allows you to logically move the data file from the main library location to the repository location, and if the directory structure of the two database systems is different, the operation is required, and only the repository becomes the main library before the conversion is run. Once you switch to a standby or move to a standby after a failure, the values are forced to write to the control file and the data file header.

Log_file_name_convert

The log file conversion parameters are the same as Db_file_name_convert except for ORL and SRL.

Fal_server

FAL, which is the fetch Archive log, is used only for physical repositories, and when a physical repository problem is found, a missing archive log file is obtained from a dataguard configured database to resolve the gap.

Fal_client

For the physical repository only, the TNS name of the requested database is required, and the interval request recipient Fal_server requires the TNS name so that the archive process on the FAL server database can reverse-link the requestor.

Standby_file_management

This parameter is used only for physical libraries, default is manual, and if this parameter is set to auto, whenever the data file is added or deleted on the main library, the corresponding modifications are automatically made on the repository, and the Db_file_name_convert is available as long as the top-level directory exists in the repository.

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