What Is Oracle Data Guard?
Oracle DG is a central component of an Oracle Database High Availability (HA) solution set that helps organizations ensure business continuity by minimizing the various kinds of planned and unplanned down time that can affect their businesses.
Oracle Data Guard is a management, monitoring, and automation software infrastructure that works with database and one or more standby databases to protect your data against failures, errors, and corruptions that might otherwise destroy your database. In a Data Guard configuration, a production database is referred to as a primary database.A standby database is a synchronized copy of the primary database. Using a backup copy of the primary database, you can create from one to nine standby databases. The standby databases, together with the primary database, make up a Data Guard configuration.