A standby redo log is required for the maximum protection and maximum availability modes and the LGWR ASYNC transport MODE is recommended for all databases. Data Guard can recover and apply more redo data from a standby redo log than from ARCHIVED redo log files ALONE.

If the real-time apply feature is enabled, log apply services can apply redo data as it is received, WITHOUT waiting for the current standby redo log file to be archived.

This results in faster switchover and failover times because the standby redo log files have been applied already to the standby database by the time the failover or switchover begins.

A standby redo log is required for the maximum protection and maximum availability modes and the LGWR ASYNC transport mode is recommended for all databases. Data Guard can recover and apply more redo data from a standby redo log than from archived redo log files alone.

If the real-time apply feature is enabled, log apply services can apply redo data as it is received, without waiting for the current standby redo log file to be archived.

This results in faster switchover and failover times because the standby redo log files have been applied already to the standby database by the time the failover or switchover begins.