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 698C0172FD for ; Tue, 3 Feb 2015 23:13:41 +0000 (UTC) Received: (qmail 36215 invoked by uid 500); 3 Feb 2015 23:13:35 -0000 Delivered-To: apmail-hive-dev-archive@hive.apache.org Received: (qmail 36134 invoked by uid 500); 3 Feb 2015 23:13:35 -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 36122 invoked by uid 500); 3 Feb 2015 23:13:35 -0000 Delivered-To: apmail-hadoop-hive-dev@hadoop.apache.org Received: (qmail 36119 invoked by uid 99); 3 Feb 2015 23:13:35 -0000 Received: from arcas.apache.org (HELO arcas.apache.org) (140.211.11.28) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 03 Feb 2015 23:13:35 +0000 Date: Tue, 3 Feb 2015 23:13:35 +0000 (UTC) From: "Prasanth Jayachandran (JIRA)" To: hive-dev@hadoop.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Commented] (HIVE-9188) BloomFilter support in ORC 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-9188?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14304282#comment-14304282 ] Prasanth Jayachandran commented on HIVE-9188: --------------------------------------------- Updated Indexes section in ORC spec with bloom filter information. https://cwiki.apache.org/confluence/display/Hive/LanguageManual+ORC#LanguageManualORC-Indexes [~owen.omalley] can you take a look at the spec? Also the new patch. > BloomFilter support in ORC > -------------------------- > > Key: HIVE-9188 > URL: https://issues.apache.org/jira/browse/HIVE-9188 > Project: Hive > Issue Type: New Feature > Components: File Formats > Affects Versions: 0.15.0 > Reporter: Prasanth Jayachandran > Assignee: Prasanth Jayachandran > Labels: orcfile > Attachments: HIVE-9188.1.patch, HIVE-9188.2.patch, HIVE-9188.3.patch, HIVE-9188.4.patch, HIVE-9188.5.patch, HIVE-9188.6.patch, HIVE-9188.7.patch > > > BloomFilters are well known probabilistic data structure for set membership checking. We can use bloom filters in ORC index for better row group pruning. Currently, ORC row group index uses min/max statistics to eliminate row groups (stripes as well) that do not satisfy predicate condition specified in the query. But in some cases, the efficiency of min/max based elimination is not optimal (unsorted columns with wide range of entries). Bloom filters can be an effective and efficient alternative for row group/split elimination for point queries or queries with IN clause. -- This message was sent by Atlassian JIRA (v6.3.4#6332)