I am a little bit confused about real-time apply services. I've read a documentation about the services and I still have a question. Does archived redo logs required for logical standby or not? I've configure logical standby and there are 3 destination for db_recovery_file dest. 1st is local storage, 2nd transmits logs on standby and the 3d is for switchover. But still I do not purely understand how it works. Please, clarify or give some useful links.
Does archived redo logs required for logical standby or not? Yes, it does.
https://docs.oracle.com/cd/B19306_01/server.102/b14239/create_ls.htm#g105412
The archived redo logs (archivelogs, commonly) contain SQL statements to apply the changes being made to the database, as well as SQL statements to undo the work if a rollback occurs later on the primary's activity.
-
So, the achieved redo logs transmits to the standby and RFS processes writing redo data to the standby redo logs to apply changes to the dataguard. Am I correct? – kozlone Jan 11 '17 at 21:50
-
The redo logs (their own specific thing) become archived logs on the primary. The archived logs get shipped to your 3 locations. The archived log is then opened and read by the logical standby to apply the database changes. – Josh Bonello Jan 11 '17 at 22:19
-