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Date: Fri, 10 Dec 2010 14:28:22 +0000
Message-ID: <AANLkTi=jgZ8T9X8rWo2GxQZKYjgOpsoFcbyXn=1a2naQ@mail.gmail.com>
Subject: Re: Suppressing duplicate documents from a view query
From: Robert Newson <robert.newson@gmail.com>
To: user@couchdb.apache.org
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"I seem to remember that there is a request flag that can be passed to
a view query to eliminate document duplicates."

I've never heard of such an option.

To remove duplicate keys from a view, use a reduce function like
"return null" and query with reduce=3Dtrue.

B.

On Fri, Dec 10, 2010 at 2:08 PM, Jean-Pierre Fiset <jp@fiset.ca> wrote:
> This question relates to CouchDb 1.0.1.
>
> I have been reading as much as I can about CouchDb and started implementi=
ng an application. I
> seem to remember that there is a request flag that can be passed to a vie=
w query to eliminate
> document duplicates. However, I do not recall which one it is. A quick re=
view of the wiki did
> not shed any light.
>
> Currently, I am removing duplicates by using a list function. I have docu=
mented the details of
> the list function here:
> http://www.bitsbythepound.com/remove-document-duplicates-from-couchdb-vie=
w-query-using-a-list-function-366.html
>
> In short, this is the list function:
>
> function(head, req) {
> =A0 =A0send('{"total_rows":'+head.total_rows
> =A0 =A0 =A0 =A0+',"offset":'+head.offset+',"rows":[');
> =A0 =A0var ids =3D {}
> =A0 =A0 =A0 =A0,row
> =A0 =A0 =A0 =A0,first =3D true
> =A0 =A0 =A0 =A0;
> =A0 =A0while(row =3D getRow()) {
> =A0 =A0 =A0 =A0if( !ids[row.id] ) {
> =A0 =A0 =A0 =A0 =A0 =A0if( first ) {
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0first =3D false;
> =A0 =A0 =A0 =A0 =A0 =A0} else {
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0send( ',' );
> =A0 =A0 =A0 =A0 =A0 =A0};
> =A0 =A0 =A0 =A0 =A0 =A0send( toJSON(row) );
> =A0 =A0 =A0 =A0 =A0 =A0ids[row.id] =3D 1;
> =A0 =A0 =A0 =A0};
> =A0 =A0};
> =A0 =A0send(']}');
> }
>
> Questions:
> 1. Is there a much simpler way to achieve this?
> 2. If the list function is the way to solve the problem, can someone comm=
ent on the likelihood
> that this function will sustain the scaling up of the database?
>
> Thanks,
>
> JP
>