Return-Path: X-Original-To: apmail-hive-dev-archive@www.apache.org Delivered-To: apmail-hive-dev-archive@www.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id 11FAC116D4 for ; Tue, 13 May 2014 07:50:17 +0000 (UTC) Received: (qmail 35127 invoked by uid 500); 13 May 2014 07:50:16 -0000 Delivered-To: apmail-hive-dev-archive@hive.apache.org Received: (qmail 35050 invoked by uid 500); 13 May 2014 07:50:16 -0000 Mailing-List: contact dev-help@hive.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: dev@hive.apache.org Delivered-To: mailing list dev@hive.apache.org Received: (qmail 35042 invoked by uid 500); 13 May 2014 07:50:16 -0000 Delivered-To: apmail-hadoop-hive-dev@hadoop.apache.org Received: (qmail 35038 invoked by uid 99); 13 May 2014 07:50:16 -0000 Received: from Unknown (HELO arcas.apache.org) (140.211.11.28) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 13 May 2014 07:50:16 +0000 Date: Tue, 13 May 2014 07:50:16 +0000 (UTC) From: "Lefty Leverenz (JIRA)" To: hive-dev@hadoop.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Commented] (HIVE-6430) MapJoin hash table has large memory overhead MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-JIRA-FingerPrint: 30527f35849b9dde25b450d4833f0394 [ https://issues.apache.org/jira/browse/HIVE-6430?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13996171#comment-13996171 ] Lefty Leverenz commented on HIVE-6430: -------------------------------------- +1 for parameter documentation. > MapJoin hash table has large memory overhead > -------------------------------------------- > > Key: HIVE-6430 > URL: https://issues.apache.org/jira/browse/HIVE-6430 > Project: Hive > Issue Type: Improvement > Reporter: Sergey Shelukhin > Assignee: Sergey Shelukhin > Attachments: HIVE-6430.01.patch, HIVE-6430.02.patch, HIVE-6430.03.patch, HIVE-6430.04.patch, HIVE-6430.05.patch, HIVE-6430.06.patch, HIVE-6430.07.patch, HIVE-6430.08.patch, HIVE-6430.09.patch, HIVE-6430.10.patch, HIVE-6430.11.patch, HIVE-6430.12.patch, HIVE-6430.12.patch, HIVE-6430.13.patch, HIVE-6430.patch > > > Right now, in some queries, I see that storing e.g. 4 ints (2 for key and 2 for row) can take several hundred bytes, which is ridiculous. I am reducing the size of MJKey and MJRowContainer in other jiras, but in general we don't need to have java hash table there. We can either use primitive-friendly hashtable like the one from HPPC (Apache-licenced), or some variation, to map primitive keys to single row storage structure without an object per row (similar to vectorization). -- This message was sent by Atlassian JIRA (v6.2#6252)