Return-Path: Delivered-To: apmail-hadoop-pig-dev-archive@www.apache.org Received: (qmail 69244 invoked from network); 12 Nov 2009 01:51:02 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (140.211.11.3) by minotaur.apache.org with SMTP; 12 Nov 2009 01:51:02 -0000 Received: (qmail 95032 invoked by uid 500); 12 Nov 2009 01:51:02 -0000 Delivered-To: apmail-hadoop-pig-dev-archive@hadoop.apache.org Received: (qmail 94998 invoked by uid 500); 12 Nov 2009 01:51:02 -0000 Mailing-List: contact pig-dev-help@hadoop.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: pig-dev@hadoop.apache.org Delivered-To: mailing list pig-dev@hadoop.apache.org Received: (qmail 94988 invoked by uid 99); 12 Nov 2009 01:51:02 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 12 Nov 2009 01:51:02 +0000 X-ASF-Spam-Status: No, hits=-10.5 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_HI X-Spam-Check-By: apache.org Received: from [140.211.11.140] (HELO brutus.apache.org) (140.211.11.140) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 12 Nov 2009 01:50:59 +0000 Received: from brutus (localhost [127.0.0.1]) by brutus.apache.org (Postfix) with ESMTP id 96933234C1EF for ; Wed, 11 Nov 2009 17:50:39 -0800 (PST) Message-ID: <733094851.1257990639601.JavaMail.jira@brutus> Date: Thu, 12 Nov 2009 01:50:39 +0000 (UTC) From: "Alan Gates (JIRA)" To: pig-dev@hadoop.apache.org Subject: [jira] Assigned: (PIG-795) Command that selects a random sample of the rows, similar to LIMIT In-Reply-To: <1259815759.1241133390524.JavaMail.jira@brutus> 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-795?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Alan Gates reassigned PIG-795: ------------------------------ Assignee: Eric Gaudet > Command that selects a random sample of the rows, similar to LIMIT > ------------------------------------------------------------------ > > Key: PIG-795 > URL: https://issues.apache.org/jira/browse/PIG-795 > Project: Pig > Issue Type: New Feature > Components: impl > Reporter: Eric Gaudet > Assignee: Eric Gaudet > Priority: Trivial > Attachments: sample2.diff, sample3.diff > > > When working with very large data sets (imagine that!), running a pig script can take time. It may be useful to run on a small subset of the data in some situations (eg: debugging / testing, or to get fast results even if less accurate.) > The command "LIMIT N" selects the first N rows of the data, but these are not necessarily randomzed. A command "SAMPLE X" would retain the row only with the probability x%. > Note: it is possible to implement this feature with FILTER BY and an UDF, but so is LIMIT, and limit is built-in. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.