Return-Path: Delivered-To: apmail-hadoop-core-user-archive@www.apache.org Received: (qmail 22820 invoked from network); 2 Apr 2009 15:39:17 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (140.211.11.3) by minotaur.apache.org with SMTP; 2 Apr 2009 15:39:17 -0000 Received: (qmail 93795 invoked by uid 500); 2 Apr 2009 15:39:14 -0000 Delivered-To: apmail-hadoop-core-user-archive@hadoop.apache.org Received: (qmail 93722 invoked by uid 500); 2 Apr 2009 15:39:14 -0000 Mailing-List: contact core-user-help@hadoop.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: core-user@hadoop.apache.org Delivered-To: mailing list core-user@hadoop.apache.org Received: (qmail 93712 invoked by uid 99); 2 Apr 2009 15:39:14 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 02 Apr 2009 15:39:14 +0000 X-ASF-Spam-Status: No, hits=2.0 required=10.0 tests=NO_RDNS_DOTCOM_HELO,SPF_NEUTRAL X-Spam-Check-By: apache.org Received-SPF: neutral (athena.apache.org: local policy) Received: from [76.96.30.56] (HELO QMTA06.emeryville.ca.mail.comcast.net) (76.96.30.56) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 02 Apr 2009 15:39:05 +0000 Received: from OMTA07.emeryville.ca.mail.comcast.net ([76.96.30.59]) by QMTA06.emeryville.ca.mail.comcast.net with comcast id aegl1b0031GXsucA6femAn; Thu, 02 Apr 2009 15:38:46 +0000 Received: from battlerock-lm.corp.yahoo.com ([209.131.62.113]) by OMTA07.emeryville.ca.mail.comcast.net with comcast id afee1b00J2SbwD58Tfeg3R; Thu, 02 Apr 2009 15:38:44 +0000 Message-Id: <02B6E54A-704E-4859-A1DF-8678C0F35482@apache.org> From: Owen O'Malley To: core-user@hadoop.apache.org In-Reply-To: <22844277.post@talk.nabble.com> Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (Apple Message framework v930.3) Subject: Re: HELP: I wanna store the output value into a list not write to the disk Date: Thu, 2 Apr 2009 08:38:37 -0700 References: <22844277.post@talk.nabble.com> X-Mailer: Apple Mail (2.930.3) X-Virus-Checked: Checked by ClamAV on apache.org On Apr 2, 2009, at 2:41 AM, andy2005cst wrote: > > I need to use the output of the reduce, but I don't know how to do. > use the wordcount program as an example if i want to collect the > wordcount > into a hashtable for further use, how can i do? You can use an output format and then an input format that uses a database, but in practice, the cost of writing to hdfs and reading it back is not a problem, especially if you set the replication of the output files to 1. (You'll need to re-run the job if you lose a node, but it will be fast.) -- Owen