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Date: Fri, 28 Aug 2009 21:01:47 +0200
Message-ID: <2fd53c3a0908281201la5d22f6u8e46ae0056e79435@mail.gmail.com>
Subject: Re: 0.9 to 0.10 breaking changes
From: Fabio Forno <fabio.forno@gmail.com>
To: user@couchdb.apache.org
Content-Type: text/plain; charset=ISO-8859-1

On Fri, Aug 28, 2009 at 5:47 PM, Paul Davis<paul.joseph.davis@gmail.com> wrote:
>>
>> Why less then half? Suppose I must merge two docs A,B where I'm
>> counting the occurrences of a set of items ans size(A) >> size(B),
>> size(out) would be less than size(input), but more than half of it
>>
>
> I don't follow. Can you paste some pseudo code?
>

Perhaps I'm thinking of a case where reduce is not supposed to work in
that way.

I've a map producing these intermediate documents

key -> set of features

then the reduce takes the set of features and does the merge.

So let's have after the map:
k1 -> {F1, F2, F3, F4, F5}
k1 -> {F1, F3}

the reduce is called with [{F1, F2}, {F1, F2, F3, F4, F5}], for which I return
{F1', F2, F3', F4, F5} (the features are not simple keys, but are
complex objects which are transformed during reduce)

in this case I'm reducing the result, but the output is greater the
half the size of the input. For what I've understood this would fail,
wouldn't it?

-- 
Fabio Forno, Ph.D.
Bluendo srl http://www.bluendo.com
jabber id: ff@jabber.bluendo.com