This preface describes the new features added to Oracle Data Guard broker in 10g Release 2 (10.2) and provides links to additional information.
This release provides the following new features:
Fast-start failover
Fast-start failover provides the ability to automatically, quickly, and reliably fail over to a designated, synchronized standby database in the event of loss of the primary database, without requiring that you perform any manual steps to invoke the failover.
This new capability allows you to maintain uptime transparently and increase the degree of high availability, as well the robustness of disaster recovery. Plus, there is less need for manual intervention, thereby reducing management costs.
Reinstatement of the primary database to a standby database after a failover
After a fast-start failover occurs, the old primary database will automatically reconfigure itself as a new standby database upon reconnection to the configuration. Automatic reinstatement restores disaster protection in the configuration easily, without complex manual steps, improving the robustness of the disaster-recovery features of Data Guard, as well as improving Data Guard manageability.
Data Guard enhancements in Oracle Enterprise Manager
Enhancements in Oracle Enterprise Manager include the following items:
Note:
Data Guard features are not available in Enterprise Manager Database Control. You must install Enterprise Manager Grid Control to access Data Guard functionality.See Also:
The Enterprise Manager online help, which is available from any Enterprise Manager page. Click Help on an Enterprise Manager page to display a context-sensitive help topic that contains information about the features available on that page.Compression of backups during standby creation
During the process of creating a standby database, Enterprise Manager has the option to perform an online backup of the primary database. This feature provides the ability to create the backup in a compressed manner, it saves disk storage, and it is especially useful for large-sized databases.
Support for flash recovery area for physical standby databases
Flash Recovery Areas can be automatically configured for physical standby databases during their creation through Enterprise Manager. Archived log files will be automatically managed by Oracle in the flash recovery area of the physical standby database, leading to fewer manual operations and reduced management costs when maintaining a Data Guard configuration.
Support of standby databases in an Oracle Managed Files (OMF) or Automatic Storage Management (ASM) configuration
Standby databases may now be created through Enterprise Manager in an ASM/OMF configuration. This feature provides all the benefits of ASM/OMF to both the primary and standby databases. For example, the storage management issues related to the standby database are automatically handled by Oracle, leading to fewer manual operations and reduced management costs.
New and improved apply statistics
Performance statistics showing redo transfer rates and log apply rates have been improved and enhanced.
Status alerts for non-broker configurations
Ability to scan archiving information and other sources on the primary database to flag problems and error situations in the Data Guard configuration, even though the broker is not enabled. This feature increases the flexibility of Enterprise Manager usage as an effective monitoring interface for all Data Guard configurations.
Test redo generator
Enterprise Manager now ships with a redo generation test application that is easily accessible through the browser-based interface, with which redo data can be generated in the primary database and automatically transmitted to standby databases by Data Guard. This feature helps you test and verify the Data Guard configuration. For example, you can use the application to test the configuration before deploying it in production. Similarly, troubleshooting may also be done in the production configuration using this application.
Broker configuration files can reside on an ASM disk group
The broker's configuration files can reside on an ASM disk group. Because these configuration files must be explicitly named by the user, the configuration files are not Oracle Managed Files (OMF). Now, any storage management issues related to the configuration files will be automatically handled by Oracle, leading to fewer manual operations and reduced management costs.
DelayMins property
Setting the DelayMins property is now the preferred method for indicating whether or not you want to delay the application of redo data to the standby database.
See Also:
Section A.1.2, "Changed Properties" for complete informationNew Data Guard command-line interface (DGMGRL) commands include:
ENABLE FAST_START FAILOVER
DISABLE FAST_START FAILOVER
START OBSERVER
STOP OBSERVER
REINSTATE DATABASE
New database properties include:
FastStartFailoverTarget
FastStartFailoverThreshold
MaxConnections
See Also:
Chapter 9, "Database Properties"New configuration properties include:
FastStartFailoverThreshold
See Also:
Chapter 9, "Database Properties"LogArchiveMaxProcesses property range of valid values is now from 1 to 30 (was from 1 to 10)
See Also:
Section 9.2.15, "LogArchiveMaxProcesses"LsbyTxnConsistency property now imports the value of PRESERVE_COMMIT_ORDER from SYSTEM.LOGSTDBY$PARAMETERS instead of TRANSACTION_CONSISTENCY.
See Also:
Section 9.2.33, "LsbyTxnConsistency"