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 33E65115E1 for ; Thu, 21 Aug 2014 05:58:28 +0000 (UTC) Received: (qmail 8410 invoked by uid 500); 21 Aug 2014 05:58:27 -0000 Delivered-To: apmail-hive-dev-archive@hive.apache.org Received: (qmail 8326 invoked by uid 500); 21 Aug 2014 05:58:27 -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 8315 invoked by uid 500); 21 Aug 2014 05:58:27 -0000 Delivered-To: apmail-hadoop-hive-dev@hadoop.apache.org Received: (qmail 8312 invoked by uid 99); 21 Aug 2014 05:58:27 -0000 Received: from arcas.apache.org (HELO arcas.apache.org) (140.211.11.28) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 21 Aug 2014 05:58:27 +0000 Date: Thu, 21 Aug 2014 05:58:27 +0000 (UTC) From: "Gunther Hagleitner (JIRA)" To: hive-dev@hadoop.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Updated] (HIVE-7826) Dynamic partition pruning on Tez 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-7826?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Gunther Hagleitner updated HIVE-7826: ------------------------------------- Labels: tez (was: ) > Dynamic partition pruning on Tez > -------------------------------- > > Key: HIVE-7826 > URL: https://issues.apache.org/jira/browse/HIVE-7826 > Project: Hive > Issue Type: Bug > Reporter: Gunther Hagleitner > Assignee: Gunther Hagleitner > Labels: tez > Attachments: HIVE-7826.1.patch > > > It's natural in a star schema to map one or more dimensions to partition columns. Time or location are likely candidates. > It can also useful to be to compute the partitions one would like to scan via a subquery (where p in select ... from ...). > The resulting joins in hive require a full table scan of the large table though, because partition pruning takes place before the corresponding values are known. > On Tez it's relatively straight forward to send the values needed to prune to the application master - where splits are generated and tasks are submitted. Using these values we can strip out any unneeded partitions dynamically, while the query is running. > The approach is straight forward: > - Insert synthetic conditions for each join representing "x in (keys of other side in join)" > - This conditions will be pushed as far down as possible > - If the condition hits a table scan and the column involved is a partition column: > - Setup Operator to send key events to AM > - else: > - Remove synthetic predicate -- This message was sent by Atlassian JIRA (v6.2#6252)