Return-Path: X-Original-To: apmail-hadoop-hdfs-user-archive@minotaur.apache.org Delivered-To: apmail-hadoop-hdfs-user-archive@minotaur.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id 0F7D2CB68 for ; Fri, 7 Jun 2013 16:27:03 +0000 (UTC) Received: (qmail 62129 invoked by uid 500); 7 Jun 2013 16:26:58 -0000 Delivered-To: apmail-hadoop-hdfs-user-archive@hadoop.apache.org Received: (qmail 62032 invoked by uid 500); 7 Jun 2013 16:26:58 -0000 Mailing-List: contact user-help@hadoop.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: user@hadoop.apache.org Delivered-To: mailing list user@hadoop.apache.org Received: (qmail 62025 invoked by uid 99); 7 Jun 2013 16:26:57 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 07 Jun 2013 16:26:57 +0000 X-ASF-Spam-Status: No, hits=-0.0 required=5.0 tests=RCVD_IN_DNSWL_NONE,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (athena.apache.org: domain of harsh@cloudera.com designates 209.85.192.179 as permitted sender) Received: from [209.85.192.179] (HELO mail-pd0-f179.google.com) (209.85.192.179) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 07 Jun 2013 16:26:53 +0000 Received: by mail-pd0-f179.google.com with SMTP id q11so5003098pdj.10 for ; Fri, 07 Jun 2013 09:26:33 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :content-type:x-gm-message-state; bh=zRP8VE9SE0esAn+4JIbpU5+xlJPlQC5NXkKa/o5oIRU=; b=SZNttwwj3Ff+AF/+CrutVHEqqBZ7aYJjh7Z7Pjmm8TFZMamolrySEJBU0rOwp2yo4H myopnKXtQ3mE52sCgmW3VMfsBjrSUia79xvwqgzpol6zvvpwlzryqjBU9XzGNCy6lBMH tFIV8gJYlq+KolYRML3WYccs8zgBRTDO3JV6Z+QeEVixY2TEPoJ8vaeL8oE0JnriMXsR pMWtScdXf13Z7PT/PmdJiG26RJkyg7mRPj9ufzLlKbD3btsouz1B9wpxrtp+XdYsmxUD YEEEZO/7+VFZO5dLHIiogL7F3y1tvZystwduvNXpryXbiwWkqR+lbIxssdgtviuB55PW lNbg== X-Received: by 10.68.228.161 with SMTP id sj1mr45415313pbc.151.1370622393595; Fri, 07 Jun 2013 09:26:33 -0700 (PDT) MIME-Version: 1.0 Received: by 10.70.77.230 with HTTP; Fri, 7 Jun 2013 09:26:13 -0700 (PDT) In-Reply-To: <1370603836.37168.YahooMailNeo@web190704.mail.sg3.yahoo.com> References: <1369191774.59557.YahooMailNeo@web190702.mail.sg3.yahoo.com> <1370603836.37168.YahooMailNeo@web190704.mail.sg3.yahoo.com> From: Harsh J Date: Fri, 7 Jun 2013 21:56:13 +0530 Message-ID: Subject: Re: Why/When partitioner is used. To: "" , Sai Sai Content-Type: text/plain; charset=ISO-8859-1 X-Gm-Message-State: ALoCoQnoGjQeKl1wOiVUd4ddREqgtKm6vwwprXUzD7qnghKRArMviKxtplFXdBRZgg1OgiTKKxcf X-Virus-Checked: Checked by ClamAV on apache.org Why not also ask yourself, what if you do not send all keys to the same reducer? Would you get the results you desire that way? :) On Fri, Jun 7, 2013 at 4:47 PM, Sai Sai wrote: > I always get confused why we should partition and what is the use of it. > Why would one want to send all the keys starting with A to Reducer1 and B to > R2 and so on... > Is it just to parallelize the reduce process. > Please help. > Thanks > Sai -- Harsh J