You omitted the context from the rest of the sentence: > most database-like applications do their redundancy themselves, at the application level … If that’s

You omitted the context from the rest of the sentence: > most database-like applications do their redundancy themselves, at the application level … If that’s not the case for your storage (doesn’t sound like it), then the author’s point doesn’t apply to your case anyway. In which case, yes, RAID may be useful.