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From: Jens Alfke <jens@couchbase.com>
To: "user@couchdb.apache.org" <user@couchdb.apache.org>
Date: Mon, 30 Jan 2012 08:50:18 -0800
Subject: Re: Using JavaScript libs in a view's map function
Thread-Topic: Using JavaScript libs in a view's map function
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On Jan 30, 2012, at 6:17 AM, Luscus Readbeard wrote:

What I would like to do is to be able to load some other docs or view
results in the map function in order to make some complex processing.

It=92s part of the definition of map/reduce that map functions are =93pure=
=94 functions without external inputs or side effects. That=92s what allows=
 them to be parallelized, and what allows Couch to determine when their out=
put has been invalidated and needs to be recomputed.

In some map/reduce systems you can do what you=92re asking for by way of mu=
ltiple levels, where the output of one m/r gets fed into another step; but =
CouchDB doesn=92t directly support this.

Maybe if you describe in more detail what you=92re trying to do, people can=
 offer some ideas on how to do it in CouchDB.

=97Jens

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