At what stage can you safely delete archive logs?
When recovering from a failure you will need a backup and all archived redo logs created since that backup. So you do not need any archived redo logs before that backup. That being said, some DBAs like to keep the last three backups around, just in case something went wrong with the latest backup. So you will need to keep the archived redo logs since the oldest of those backups.
RMAN can also be used to back up your archived redo logs. This is a great way to get those archived redo logs off of your LOG_ARCHIVE_DEST and free up some space. RMAN can even be instructed to delete the archived redo logs after it has backed them up. You may want to look into this option as well.
This was first published in September 2006