Return-Path: Delivered-To: apmail-lucene-hadoop-dev-archive@locus.apache.org Received: (qmail 79289 invoked from network); 16 Aug 2006 10:46:22 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (209.237.227.199) by minotaur.apache.org with SMTP; 16 Aug 2006 10:46:22 -0000 Received: (qmail 81450 invoked by uid 500); 16 Aug 2006 10:46:21 -0000 Delivered-To: apmail-lucene-hadoop-dev-archive@lucene.apache.org Received: (qmail 81418 invoked by uid 500); 16 Aug 2006 10:46:21 -0000 Mailing-List: contact hadoop-dev-help@lucene.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: hadoop-dev@lucene.apache.org Delivered-To: mailing list hadoop-dev@lucene.apache.org Received: (qmail 81409 invoked by uid 99); 16 Aug 2006 10:46:21 -0000 Received: from asf.osuosl.org (HELO asf.osuosl.org) (140.211.166.49) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 16 Aug 2006 03:46:21 -0700 X-ASF-Spam-Status: No, hits=0.0 required=10.0 tests= X-Spam-Check-By: apache.org Received: from [209.237.227.198] (HELO brutus.apache.org) (209.237.227.198) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 16 Aug 2006 03:46:21 -0700 Received: from brutus (localhost [127.0.0.1]) by brutus.apache.org (Postfix) with ESMTP id 1A0FE7142A7 for ; Wed, 16 Aug 2006 10:43:16 +0000 (GMT) Message-ID: <13224331.1155724996104.JavaMail.jira@brutus> Date: Wed, 16 Aug 2006 03:43:16 -0700 (PDT) From: "Arun C Murthy (JIRA)" To: hadoop-dev@lucene.apache.org Subject: [jira] Commented: (HADOOP-54) SequenceFile should compress blocks, not individual entries In-Reply-To: <442955632.1140640880483.JavaMail.jira@ajax.apache.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Virus-Checked: Checked by ClamAV on apache.org X-Spam-Rating: minotaur.apache.org 1.6.2 0/1000/N [ http://issues.apache.org/jira/browse/HADOOP-54?page=comments#action_12428366 ] Arun C Murthy commented on HADOOP-54: ------------------------------------- Oops... > 1. The Writer class should have the unneeded compression stuff taken out. I've kept this around for this version (deprecated) to ensure existing applications don't break; I plan to get rid of this one hadoop release later. > SequenceFile should compress blocks, not individual entries > ----------------------------------------------------------- > > Key: HADOOP-54 > URL: http://issues.apache.org/jira/browse/HADOOP-54 > Project: Hadoop > Issue Type: Improvement > Components: io > Affects Versions: 0.2.0 > Reporter: Doug Cutting > Assigned To: Arun C Murthy > Fix For: 0.6.0 > > Attachments: SequenceFiles.patch, SequenceFilesII.patch, VIntCompressionResults.txt > > > SequenceFile will optionally compress individual values. But both compression and performance would be much better if sequences of keys and values are compressed together. Sync marks should only be placed between blocks. This will require some changes to MapFile too, so that all file positions stored there are the positions of blocks, not entries within blocks. Probably this can be accomplished by adding a getBlockStartPosition() method to SequenceFile.Writer. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://issues.apache.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira