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Date: Tue, 25 Mar 2008 18:15:08 -0700
From: "Chris Anderson" <jchris@mfdz.com>
Sender: jchris@gmail.com
To: couchdb-user@incubator.apache.org
Subject: Re: incremental map/reduce scope
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On Tue, Mar 25, 2008 at 5:34 PM, Sho Fukamachi <sho.fukamachi@gmail.com> wrote:
>  Will the M/R function be able to reach across databases? For example,
>  if I make one database called couch.local/ blogs and one called
>  couch.local/posts, will I be able to define an index function that
>  reaches into both? Or is it limited to within the scope of one database?

Sho,

I'm not a CouchDB internals expert, but I imagine you could use
replication to merge two databases at any point in the future.

I'm also pretty sure that map functions can't reach into the contents
of more than one document (although reduce will be able to merge all
data with the same key, I think, so you could perhaps "join" together
related documents using a clever map function, although you may be
better off doing joins in your application.)

Chris


-- 
Chris Anderson
http://jchris.mfdz.com