Heterogeneous Warm Standby for Oracle

A warm standby application is a pair of databases, one of which is a backup copy of the other. Client applications update the active database; Replication Server maintains the standby database as a copy of the active database.

If the active database fails, or if you need to perform maintenance on the active database or on the data server, a switch to the standby database allows client applications to resume work with little interruption.

To keep the standby database consistent with the active database, Replication Server reproduces transaction information retrieved from the active database’s transaction log. Subscriptions are not needed to replicate data into the standby database.

• How a Warm Standby for Oracle Works
  The active database and the standby database appear in the replication system as a connection from the Replication Server to a single logical database in a warm standby application.
• Warm Standby Requirements and Restrictions
  Be familiar with the requirements and restrictions of Replication Server warm standby applications.
• Function Strings for Maintaining Standby Database
  Replication Server uses the system-provided function-string class rs_oracle_function_class for the standby DSI, which is the connection to the standby database.
• Replicated Information for an Oracle Warm Standby Application
  Replication Agent supports different methods for enabling replication to the Oracle standby database.
• Setting Up Warm Standby Databases
  Set up databases for a warm standby application.
• Switching the Active and Standby Databases
  Switch to the standby database when the active database fails, or you want to perform maintenance on the active database.
• Warm Standby Application Monitoring
  You can monitor warm standby applications using Replication Server log file or using admin commands.
• Replication Definitions and Subscriptions
  The Replication Agent automatically creates the replication definition during initialization (execution of pdb_xlog init command) and by setting the configuration parameter pdb_auto_create_repdefs to true for Oracle warm standby.
• Upgrade Considerations
  Oracle warm standby feature does not require any special instructions that you may need to perform after an upgrade.
• Downgrade Considerations
  After downgrading, the Oracle standby connection will be broken as it is not able to do function string mapping or data translation. If you did not drop standby connection before downgrading the RSSD, you can drop it after the downgrade.