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From Jason Smith <...@iriscouch.com>
Subject Re: Unique instance IDs?
Date Tue, 13 Dec 2011 03:10:50 GMT
On Tue, Dec 13, 2011 at 8:40 AM, Paul Davis <paul.joseph.davis@gmail.com> 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

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