We combine offline/online backups in our Oracle9i backup/recovery solutions. Many of my colleagues feel offlines are a waste of time. I disagree. I do feel our offline intervals can be relaxed. The research I have done up to this point really does not definitively lean one way or the other. Your opinion please?
I know that many DBAs feel more comfortable with offline, or cold backups. The cold backup scripts are easier to write and maintain. And there is a simplicity to cold backups. However, online or hot backups are a must in today's environments where some databases need to be up and running 24x7. Personally, I've become comfortable with both options so I do not have a preference one way or another. I simply let my overall requirements dictate my backup strategy. For instance, if you must be up 24x7, then hot backups are your only alternative. If you cannot afford massive amounts of generated archived redo logs, then cold backups are your only alternative. I prefer to gather all of my backup requirements and whittle away those options which are in opposition to those requirements. If I am still left with many options, then I would use whatever method leaves me the most recovery options. My next thing I look at is the simplicity of my backup/recovery solutions. These days, that means employing RMAN.