Query on Standby redo logs - Oracle I have a oracle 11g (11.3) database running with two standby databases (at different locations) in Maximum performance mode. The platform is Linux. 

Log transport parameters are:

log_archive_dest_5 string SERVICE= * * * * **ASYNC NOAFFIRM** valid_for= ... **

Correct me if i'm wrong, so ASYNC noaffirm means the log transfer method is ARCH right? Meaning the archives generated in primary gets copied to standby and then applied there. Right?

The database is primary has been generating too much archives beccause of which my DR lags behind when archives are more. Oracle MOS asks me to create standby redo to resolve the same. My question is that how will standby redo help in reducing the lag since the SRL is used so as not to lose data in case of disaster right?

Also, SRL should be used only when the parameter is LGWR right? Since i have mentioned it as ASYNC NOAFFIRM and there is no standby, the archives are only sent to DR and not redo.

IF I do not have Standby redo, then how does redo gets shipped? Does it gets shipped as archive logs from primary to standby's archive directly and gets applied?

Help me clear out my doubts.
Thanks!
NOAFFIRM means the redo transport will be acknowledged before writing the received redo to disk (standby redo logs).


  ASYNC noaffirm means the log transfer method is ARCH right?


No, it does not. Without specifying LGWR or ARCH, LGWR is the default. You can check it on the primary database by:

select archiver from v$archive_dest where dest_id = 5;


There you should see LGWR. However, specifying ARCH or LGWR became deprecated in 11g:

http://docs.oracle.com/cd/E11882_01/server.112/e40402/initparams125.htm#CHDJDFCJ

Deprecated does not mean it will not work, so it is still possible to specify ARCH in log_archive_dest_n and revert to the way it worked in 10.2 (and what you described). But that is not how you configure MAXIMUM PERFORMANCE anymore, because of the changes, even MAXIMUM PERFORMANCE uses LGWR and standby redo logs. See below:

http://docs.oracle.com/cd/E11882_01/server.112/e41134/log_transport.htm#BABCBEGJ


  The synchronous and asynchronous redo transport modes require that a
  redo transport destination have a standby redo log.