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Oracle Data Guard is a disaster recovery solution where a primary database copies its archived redo logs over a network connection to a standby database.
AppSync supports these types of standby databases:
These types of standby configurations can be opened in one of the following two modes:
AppSync supports Oracle Data Guard configurations for the primary or source database and the Physical Standby or target database which is open in Active or Passive/Non-Active Standby mode. A Physical Standby database open in Active Standby mode means that the standby database can be opened in read-only mode while logs are being applied to it. This allows the database to be queried for information while the logs are being applied. Snapshot Standby configurations also allow the database to be open in read-write mode. A Passive/Non-Active Standby mode setting means that the database is started in mounted mode, and logs are applied in the background.
In a Physical Standby environment, the archive logs are applied as they come in. A Physical Standby has a 1:1 mapping in terms of the file and storage layout from primary to standby. A typical primary-to-standby (source-to-target) Data Guard configuration can be seen in Figure 4. A Physical Standby database can be open in both read-only or mounted mode which means it can be either an Active Standby or Passive/Non-Active Standby configuration.