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 443D611A1D for ; Fri, 27 Jun 2014 00:41:25 +0000 (UTC) Received: (qmail 75589 invoked by uid 500); 27 Jun 2014 00:41:24 -0000 Delivered-To: apmail-hive-dev-archive@hive.apache.org Received: (qmail 75524 invoked by uid 500); 27 Jun 2014 00:41:24 -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 75510 invoked by uid 500); 27 Jun 2014 00:41:24 -0000 Delivered-To: apmail-hadoop-hive-dev@hadoop.apache.org Received: (qmail 75507 invoked by uid 99); 27 Jun 2014 00:41:24 -0000 Received: from arcas.apache.org (HELO arcas.apache.org) (140.211.11.28) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 27 Jun 2014 00:41:24 +0000 Date: Fri, 27 Jun 2014 00:41:24 +0000 (UTC) From: "Navis (JIRA)" To: hive-dev@hadoop.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Commented] (HIVE-7159) For inner joins push a 'is not null predicate' to the join sources for every non nullSafe join condition 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-7159?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14045388#comment-14045388 ] Navis commented on HIVE-7159: ----------------------------- Reviewing this, I found some predicates are removed(replaced?) from plan. For example in auto_join29.q, it was like this {noformat} predicate: ((key > 10) and (key < 10)) (type: boolean) {noformat} But now it became, {noformat} predicate: ((key < 10) and key is not null) (type: boolean) {noformat} Similar things can be found in auto_join12.q,auto_join14.q,auto_join16.q,auto_join27.q,tez/filter_join_breaktask.q, etc. And auto_join_without_localtask.q is changed a lot in plan. I'm not sure it's intended or not. [~rhbutani], Could you check this? > For inner joins push a 'is not null predicate' to the join sources for every non nullSafe join condition > -------------------------------------------------------------------------------------------------------- > > Key: HIVE-7159 > URL: https://issues.apache.org/jira/browse/HIVE-7159 > Project: Hive > Issue Type: Bug > Reporter: Harish Butani > Assignee: Harish Butani > Fix For: 0.14.0 > > Attachments: HIVE-7159.1.patch, HIVE-7159.10.patch, HIVE-7159.11.patch, HIVE-7159.2.patch, HIVE-7159.3.patch, HIVE-7159.4.patch, HIVE-7159.5.patch, HIVE-7159.6.patch, HIVE-7159.7.patch, HIVE-7159.8.patch, HIVE-7159.9.patch, HIVE-7159.addendum.patch > > > A join B on A.x = B.y > can be transformed to > (A where x is not null) join (B where y is not null) on A.x = B.y > Apart from avoiding shuffling null keyed rows it also avoids issues with reduce-side skew when there are a lot of null values in the data. > Thanks to [~gopalv] for the analysis and coming up with the solution. -- This message was sent by Atlassian JIRA (v6.2#6252)