Return-Path: 
 <pig-dev-return-16701-apmail-hadoop-pig-dev-archive=hadoop.apache.org@hadoop.apache.org>
Delivered-To: apmail-hadoop-pig-dev-archive@www.apache.org
Received: (qmail 9011 invoked from network); 1 Aug 2010 15:28:38 -0000
Received: from unknown (HELO mail.apache.org) (140.211.11.3)
  by 140.211.11.9 with SMTP; 1 Aug 2010 15:28:38 -0000
Received: (qmail 13436 invoked by uid 500); 1 Aug 2010 15:28:37 -0000
Delivered-To: apmail-hadoop-pig-dev-archive@hadoop.apache.org
Received: (qmail 13348 invoked by uid 500); 1 Aug 2010 15:28:37 -0000
Mailing-List: contact pig-dev-help@hadoop.apache.org; run by ezmlm
Precedence: bulk
List-Help: <mailto:pig-dev-help@hadoop.apache.org>
List-Unsubscribe: <mailto:pig-dev-unsubscribe@hadoop.apache.org>
List-Post: <mailto:pig-dev@hadoop.apache.org>
List-Id: <pig-dev.hadoop.apache.org>
Reply-To: pig-dev@hadoop.apache.org
Delivered-To: mailing list pig-dev@hadoop.apache.org
Received: (qmail 13340 invoked by uid 99); 1 Aug 2010 15:28:36 -0000
Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136)
    by apache.org (qpsmtpd/0.29) with ESMTP; Sun, 01 Aug 2010 15:28:36 +0000
X-ASF-Spam-Status: No, hits=-2000.0 required=10.0
	tests=ALL_TRUSTED
X-Spam-Check-By: apache.org
Received: from [140.211.11.22] (HELO thor.apache.org) (140.211.11.22)
    by apache.org (qpsmtpd/0.29) with ESMTP; Sun, 01 Aug 2010 15:28:36 +0000
Received: from thor (localhost [127.0.0.1])
	by thor.apache.org (8.13.8+Sun/8.13.8) with ESMTP id o71FSFft022414
	for <pig-dev@hadoop.apache.org>; Sun, 1 Aug 2010 15:28:16 GMT
Message-ID: <30131289.108041280676495950.JavaMail.jira@thor>
Date: Sun, 1 Aug 2010 11:28:15 -0400 (EDT)
From: "Mridul Muralidharan (JIRA)" <jira@apache.org>
To: pig-dev@hadoop.apache.org
Subject: [jira] Commented: (PIG-1530)  PIG Logical Optimization: Push
 LOFilter above LOCogroup
In-Reply-To: <32371794.103981280611276229.JavaMail.jira@thor>
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/PIG-1530?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12894388#action_12894388 ] 

Mridul Muralidharan commented on PIG-1530:
------------------------------------------

Cant edit comments .. to add to previous comment : 
To clarify my prev comment, a general pattern would not stop just at co-group, but at most (if not all) operators which dont modify the relevant fields.

>  PIG Logical Optimization: Push LOFilter above LOCogroup
> --------------------------------------------------------
>
>                 Key: PIG-1530
>                 URL: https://issues.apache.org/jira/browse/PIG-1530
>             Project: Pig
>          Issue Type: New Feature
>          Components: impl
>            Reporter: Swati Jain
>            Assignee: Swati Jain
>            Priority: Minor
>             Fix For: 0.8.0
>
>
> Consider the following:
> {noformat}
> A = load '<any file>' USING PigStorage(',') as (a1:int,a2:int,a3:int);
> B = load '<any file>' USING PigStorage(',') as (b1:int,b2:int,b3:int);
> G = COGROUP A by (a1,a2) , B by (b1,b2);
> D = Filter G by group.$0 + 5 > group.$1;
> explain D;
> {noformat}
> In the above example, LOFilter can be pushed above LOCogroup. Note there are some tricky NULL issues to think about when the Cogroup is not of type INNER (Similar to issues that need to be thought through when pushing LOFilter on the right side of a LeftOuterJoin).
> Also note that typically the LOFilter in user programs will be below a ForEach-Cogroup pair. To make this really useful, we need to also implement LOFilter pushed across ForEach. 

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.