The application requirement is to have 15mins of DELAY on standby, so that when disaster occur, the application will suggest that out of 15mins, how many minutes of archives to be applied manually, ie point in time recovery.
For database version 188.8.131.52 on linux, in a dataguard setup what is the behaviour of MRP on standby database if 'DELAY parameter is set and Primary database crashes'.
Will the delayed archives be applied by MRP once DELAY is over, or they will remain untouched ( so that these can be recovered manually to some point in time)
They will be applied.
Delay does not delay shipment of redo. It merely instructs the apply processes of the target database.
Source Chapter 2 of the Data Guard Handbook - page 84.
So if you don't want them to apply you would need to stop MRP. Oracle 10
http://docs.oracle.com/cd/B19306_01/server.102/b14239/log_arch_dest_param.htm#i77472 Oracle 11.1
http://docs.oracle.com/cd/B28359_01/server.111/b28294/log_arch_dest_param.htm#i77472 Oracle 11.2
http://docs.oracle.com/cd/E14072_01/server.112/e10700/log_arch_dest_param.htm#i77472 Oracle 9
If you define a delay for a destination that has real-time apply enabled, the delay is ignored.