What is Oracle Data Guard?

Oracle Data Guard enables and automates the management of a disaster recovery solution for Oracle databases.

In an Oracle Data Guard configuration, two database servers run at the same time. The active one is called the primary database. The second one is called the standby database. As transactions occur in the primary database, redo data is generated and is written to the local redo logs. Data Guard automatically transfers this redo data to the standby sites and applies it to the standby databases, synchronizing them with the primary database. If a problem occurs with the primary database, the standby database can take over as the active database, so the problem on the primary database can be resolved without the site losing access to data.

Oracle Data Guard can be used only with Oracle Enterprise Edition, and not with Oracle Standard Edition. Data Guard can be configured such that backups do not take place, yet the system does not issue an error message. Agfa provides tools to make the configuration and maintenance easier:

1. A set of scripts to automate the configuration of the Data Guard portion of the Oracle database.

2. Implementation of Oracle RMAN (Recovery Manager) to perform a daily backup of the existing database once the configuration has been completed. (Note that RMAN can also be used for backup and recovery exclusive of Oracle Data Guard.)

   We recommend three times the database size for backup allocation.

3. A set of tools to monitor the configuration.