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 C67F8EF73 for ; Thu, 24 Jan 2013 06:29:15 +0000 (UTC) Received: (qmail 77244 invoked by uid 500); 24 Jan 2013 06:29:15 -0000 Delivered-To: apmail-hive-dev-archive@hive.apache.org Received: (qmail 77057 invoked by uid 500); 24 Jan 2013 06:29:15 -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 77041 invoked by uid 500); 24 Jan 2013 06:29:14 -0000 Delivered-To: apmail-hadoop-hive-dev@hadoop.apache.org Received: (qmail 77035 invoked by uid 99); 24 Jan 2013 06:29:14 -0000 Received: from arcas.apache.org (HELO arcas.apache.org) (140.211.11.28) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 24 Jan 2013 06:29:14 +0000 Date: Thu, 24 Jan 2013 06:29:14 +0000 (UTC) From: "Namit Jain (JIRA)" To: hive-dev@hadoop.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Updated] (HIVE-3784) de-emphasize mapjoin hint 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-3784?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Namit Jain updated HIVE-3784: ----------------------------- Attachment: hive.3784.8.patch > de-emphasize mapjoin hint > ------------------------- > > Key: HIVE-3784 > URL: https://issues.apache.org/jira/browse/HIVE-3784 > Project: Hive > Issue Type: Improvement > Components: Query Processor > Reporter: Namit Jain > Assignee: Namit Jain > Attachments: hive.3784.1.patch, hive.3784.2.patch, hive.3784.3.patch, hive.3784.4.patch, hive.3784.5.patch, hive.3784.6.patch, hive.3784.7.patch, hive.3784.8.patch > > > hive.auto.convert.join has been around for a long time, and is pretty stable. > When mapjoin hint was created, the above parameter did not exist. > The only reason for the user to specify a mapjoin currently is if they want > it to be converted to a bucketed-mapjoin or a sort-merge bucketed mapjoin. > Eventually, that should also go away, but that may take some time to stabilize. > There are many rules in SemanticAnalyzer to handle the following trees: > ReduceSink -> MapJoin > Union -> MapJoin > MapJoin -> MapJoin > This should not be supported anymore. In any of the above scenarios, the > user can get the mapjoin behavior by setting hive.auto.convert.join to true > and not specifying the hint. This will simplify the code a lot. > What does everyone think ? -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira