[agarren]

If I understand you right, this seems like a very course-grained way to track changes. You can record that a change was made, but not the specific change. It seems like it'd help facilitate something like, say, an etag, but I don't think could get any auditable data using this alone, could you? Keeping track of added/deleted hashes would probably be best handled by a trigger, unless you really want that in your app code, so this seems a lot like an audit trigger, with very little audit data. Have I misunderstood?