Return-Path: X-Original-To: apmail-flink-issues-archive@minotaur.apache.org Delivered-To: apmail-flink-issues-archive@minotaur.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id 76B5911DFE for ; Thu, 10 Jul 2014 09:46:28 +0000 (UTC) Received: (qmail 98649 invoked by uid 500); 10 Jul 2014 09:46:28 -0000 Delivered-To: apmail-flink-issues-archive@flink.apache.org Received: (qmail 98622 invoked by uid 500); 10 Jul 2014 09:46:28 -0000 Mailing-List: contact issues-help@flink.incubator.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: dev@flink.incubator.apache.org Delivered-To: mailing list issues@flink.incubator.apache.org Received: (qmail 98578 invoked by uid 99); 10 Jul 2014 09:46:28 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 10 Jul 2014 09:46:28 +0000 X-ASF-Spam-Status: No, hits=-2000.7 required=5.0 tests=ALL_TRUSTED,RP_MATCHES_RCVD X-Spam-Check-By: apache.org Received: from [140.211.11.3] (HELO mail.apache.org) (140.211.11.3) by apache.org (qpsmtpd/0.29) with SMTP; Thu, 10 Jul 2014 09:46:27 +0000 Received: (qmail 97392 invoked by uid 99); 10 Jul 2014 09:46:07 -0000 Received: from arcas.apache.org (HELO arcas.apache.org) (140.211.11.28) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 10 Jul 2014 09:46:07 +0000 Date: Thu, 10 Jul 2014 09:46:07 +0000 (UTC) From: "Ufuk Celebi (JIRA)" To: issues@flink.incubator.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Updated] (FLINK-848) Move combine() from GroupReduceFunction to Interface MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-JIRA-FingerPrint: 30527f35849b9dde25b450d4833f0394 X-Virus-Checked: Checked by ClamAV on apache.org [ https://issues.apache.org/jira/browse/FLINK-848?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Ufuk Celebi updated FLINK-848: ------------------------------ Component/s: Java API > Move combine() from GroupReduceFunction to Interface > ---------------------------------------------------- > > Key: FLINK-848 > URL: https://issues.apache.org/jira/browse/FLINK-848 > Project: Flink > Issue Type: Improvement > Components: Java API > Reporter: GitHub Import > Labels: breaking-api, github-import > Fix For: pre-apache > > > Currently, the combine method of the GroupReduceFunction allows to return multiple values using a collector. However, most combiners do not need this because they return only a single value. Furthermore, a single value returning combiner can be executed using more efficient hash-based strategies. > Hence, we propose to introduce a combine method for GroupReduce which returns only a single value. In order to keep support for the rare cases where more than one value needs to be returned, we want to keep the collector-combiner as well. > To do so, we could remove the combine method from the abstract GroupReduceFunction class and add two Combinable interfaces, one for a single-value and one for a multi-value combiner. > This would also make the Combinable annotation obsolete as the optimizer can check whether a GroupReduceFunction implements one of the Combinable interfaces or not. > ---------------- Imported from GitHub ---------------- > Url: https://github.com/stratosphere/stratosphere/issues/848 > Created by: [fhueske|https://github.com/fhueske] > Labels: core, enhancement, > Milestone: Release 0.6 (unplanned) > Created at: Thu May 22 10:23:04 CEST 2014 > State: open -- This message was sent by Atlassian JIRA (v6.2#6252)