Return-Path: Delivered-To: apmail-couchdb-user-archive@www.apache.org Received: (qmail 35133 invoked from network); 4 Mar 2009 02:29:01 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (140.211.11.2) by minotaur.apache.org with SMTP; 4 Mar 2009 02:29:01 -0000 Received: (qmail 84831 invoked by uid 500); 4 Mar 2009 02:28:59 -0000 Delivered-To: apmail-couchdb-user-archive@couchdb.apache.org Received: (qmail 84803 invoked by uid 500); 4 Mar 2009 02:28:59 -0000 Mailing-List: contact user-help@couchdb.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: user@couchdb.apache.org Delivered-To: mailing list user@couchdb.apache.org Received: (qmail 84792 invoked by uid 99); 4 Mar 2009 02:28:59 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 03 Mar 2009 18:28:59 -0800 X-ASF-Spam-Status: No, hits=-0.0 required=10.0 tests=SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (athena.apache.org: domain of jchris@gmail.com designates 209.85.200.174 as permitted sender) Received: from [209.85.200.174] (HELO wf-out-1314.google.com) (209.85.200.174) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 04 Mar 2009 02:28:51 +0000 Received: by wf-out-1314.google.com with SMTP id 28so3345599wff.29 for ; Tue, 03 Mar 2009 18:28:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:sender:received:in-reply-to :references:date:x-google-sender-auth:message-id:subject:from:to :content-type:content-transfer-encoding; bh=coJFWXRY3MJRrUoCXXmUYoXxSRee6GXjwlcO6t/kKk0=; b=u1grfAhGBP9YuAm/GInjVWMXycjGrHWHxq1xgcaf4NAdFZsiQVLP1vXH2e4qcLu0ZS nSA3IRJEIxXx6xLTGQiH9NPs+ckN5GZ2wK35voKXmjxNFmV0lMzNy94Fh0FjJESB47la AN4ut2dn/yG0NxgCkHP9+EMLq7Ypy1ISOxANc= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:content-type :content-transfer-encoding; b=XSJ9Y42GH0ZfHYIUF0JrHqZVEblv0QjG4kNDOVBsXXJnB8yxd4+WOOc+LMlwNY5Ynz AMeXbaWQJ+4vkqtHUs01LSuMkkuv8BtnYltf4hJdQ0xLc3aWbox/3sLjfoxY5hNEFZbS kQtolSG0lSJgfZtyQvI8BQNTSiVCHVmbQyGmA= MIME-Version: 1.0 Sender: jchris@gmail.com Received: by 10.143.14.6 with SMTP id r6mr3922944wfi.135.1236133710801; Tue, 03 Mar 2009 18:28:30 -0800 (PST) In-Reply-To: <148EE677-9FB0-413C-B0D1-7B84C3BAF811@cisco.com> References: <55fad2460903030527r1295a39bl675478e8a9c5266d@mail.gmail.com> <3EA1C6DC-6331-4068-A89C-DBC462D0B890@cisco.com> <55fad2460903030558r34a2d6b9j5eda578f6002cca4@mail.gmail.com> <64BABFD7-8543-4762-B349-688E76ED6DB2@cisco.com> <92E0BD49-BD57-4CBD-B0BD-2A8391C00E81@apache.org> <148EE677-9FB0-413C-B0D1-7B84C3BAF811@cisco.com> Date: Tue, 3 Mar 2009 18:28:30 -0800 X-Google-Sender-Auth: 7df4c7582c13473e Message-ID: Subject: Re: [user] Obtaining unique values from a view From: Chris Anderson To: user@couchdb.apache.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Virus-Checked: Checked by ClamAV on apache.org On Tue, Mar 3, 2009 at 1:32 PM, Wout Mertens wrote: > Would the problem be alleviated if you could specify for views that couch > should not reduce past the group level? In other words, only calculate > what's needed for views with group=true? > Sort of. Essentially this would require an entirely different map/reduce implementation. It would probably only provide reductions at the group level (like Hadoop reduce). CouchDB is open to / interested in alternate view engines, and something like this could probably be created in a not-to-overwhelming amount of Erlang, on top of CouchDB's btree storage engine. Patches welcome! (Also, there are some patches floating around - once 0.9.0 is off our plate we'll probably have more spare cycles available for evaluating/consolidating them.) Chris -- Chris Anderson http://jchris.mfdz.com