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From "Paul Davis" <>
Subject Re: newbie question #1
Date Sun, 28 Dec 2008 15:07:21 GMT
On Sun, Dec 28, 2008 at 9:54 AM, Geir Magnusson Jr. <> wrote:
> On Dec 28, 2008, at 9:36 AM, Paul Davis wrote:
>> [snip]
>>> I read the view docs (and have other questions there, like if the M/R is
>>> distributed across a cluster - I've used M/R w/ Hadoop, so I come w/ a
>>> set
>>> of assumptions...)  and I saw that it doesn't *appear* that the key or id
>>> is
>>> injected in the view doc, which of course brings up an obvious question
>>> :)
>> The CouchDB implementation of Map/Reduce (specifically reduce) is a
>> bit different the the canonical implementation. Mostly this is a
>> result of being stored in a btree and Damien's cleverness.
> Does the work get distributed across nodes, or does each node do the same
> thing?

Oh sorry, I totally meant to answer that question in my earlier reply.

No. Not yet. IIRC, the current rough sketch of a design is that
CouchDB will be able to do automatic sharding of a single database,
and each node would be responsible for building a view of its
particular shard. Then at  query time you just have a big merge sort
type of operation.

> geir

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