Are you sure you will be able to activate your standby??

A couple of weeks I faced a scenario where the standby database crashed

On looking at the alert.log I see the following message in the alert.log of the standby

***********************************************************
Sat Jun 6 06:48:52 2009
Recovery interrupted!
cannot find needed online log for redo thread 1
Some recovered datafiles maybe left media fuzzy
Media recovery may continue but open resetlogs may fail
Sat Jun 6 06:48:53 2009
Errors in file /u01/app/oracle/admin/TEST/bdump/test1_mrp0_24533.trc:
ORA-10576: Give up restoring recovered datafiles to consistent state: some error occurred
ORA-16037: user requested cancel of managed recovery operation
Some recovered datafiles maybe left media fuzzy
Media recovery may continue but open resetlogs may fail
Sat Jun 6 06:48:54 2009
Waiting for MRP0 pid 24533 to terminate
************************************************************

Hmmm... this means that if the standby does not have the redo and cannot get it from the primary you will not be able to online media fuzzy files using supported methods

The same issue is explained in Bug 5956646
as an architectural limitation.

This is a very unlikely scenario but a possibility none the less