As far as I know, up through at least 10g R2, there is no "Oracle" way to delete archived log files that have been applied to the standby. I built a script to do this that you're welcome to use however. It's called "stby_maint" and has proven reliable for the systems that I've used it on. I've made it available as open source on SourceForge.net - http://orautil.sourceforge.net. Unfortunately it's not real well documented except in the header of the code, but it's just a korn shell script so you should be able to figure it out. Someday I will get around to creating a user manual for it, but it is available if you want to take a look at it.