What is Real-Time Apply? How to enable for Physical standby and Logical standby?

 By default, redo data is not applied to a standby database until the standby redo log file is archived. when you use the real time apply feature, redo database is applied to the standby database as it is received, Thus reducing the time lag between the databases and potentially shortening the time required to fail over to the database.
 To enable real-time apply in a physical standby database, Execute the following command in the standby database.

 alter database recover managed standby database using current logfile;

 For logical standby database, Execute the following command

 alter database start logical standby apply immediate;