-------Physical Standby Database:
Real-time apply needs to configure standby redo log;
With real-time apps enabled, the Log app service directly applies the received redo data without waiting for the current standby redo log Archive
The time for failover and switchover is greatly reduced because standby redo log has been applied to the repository at failover or switchover.
ALTER database RECOVER MANAGED STANDBY database
USING current LOGFILE;
-----for logical Standby databases
ALTER DATABASE START LOGICAL STANDBY APPLY IMMEDIATE;
The standby-side RFS (remote file server) process receives redo logs sent over primary LGWR, and writes them to standby redo logfiles;
The Log app service process (log apply services) applies redo data after the standby Redolog is fully written.
Oracle 10g Standby Database Real-time application redo data
