On Tue, Dec 13, 2011 at 8:40 AM, Paul Davis <[email protected]> wrote: >> If there were a hypothetical single query which let the receiver >> assess its exact relationship to an arbitrary sender's data, I don't >> think "starts over" would sound as awful. >> > > I agree whole heartedly. And the easiest way I see to making that > happen is to decouple the host and db identities in such a way that > this is a reality. Its possible there's something elegant we could > pull from things like merkle trees. I've spent time considering it and > haven't thought of anything but I'd be tickled pink if there were a > reasonable solution there.
Yeah. That is why I keep thinking of a checksum that works well with incremental map/reduce. I always recall that CRC32 is a commutative, associative checksum algorithm. It could hypothetically give you a checksum of the entire tree, and all subtrees down to the leaves, as a Couch reduce function. So the idea is to reduce the by_seq index. You get checksums of the database or subsets free or cheap. At this point I am out of my expertise though so I defer. -- Iris Couch
