Return-Path: X-Original-To: apmail-accumulo-notifications-archive@minotaur.apache.org Delivered-To: apmail-accumulo-notifications-archive@minotaur.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id 4E8631084B for ; Tue, 22 Oct 2013 16:11:49 +0000 (UTC) Received: (qmail 37184 invoked by uid 500); 22 Oct 2013 16:11:49 -0000 Delivered-To: apmail-accumulo-notifications-archive@accumulo.apache.org Received: (qmail 37018 invoked by uid 500); 22 Oct 2013 16:11:45 -0000 Mailing-List: contact notifications-help@accumulo.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: jira@apache.org Delivered-To: mailing list notifications@accumulo.apache.org Received: (qmail 36899 invoked by uid 99); 22 Oct 2013 16:11:44 -0000 Received: from arcas.apache.org (HELO arcas.apache.org) (140.211.11.28) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 22 Oct 2013 16:11:44 +0000 Date: Tue, 22 Oct 2013 16:11:44 +0000 (UTC) From: "William Slacum (JIRA)" To: notifications@accumulo.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Commented] (ACCUMULO-1801) Create a SelectColumnsIterator 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/ACCUMULO-1801?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13801960#comment-13801960 ] William Slacum commented on ACCUMULO-1801: ------------------------------------------ What's the difference between this iterator and a stack that consists of a column family filter for the projection columns + the predicate input columns, the user predicate, and a column family filter for the projection columns? > Create a SelectColumnsIterator > ------------------------------ > > Key: ACCUMULO-1801 > URL: https://issues.apache.org/jira/browse/ACCUMULO-1801 > Project: Accumulo > Issue Type: Improvement > Components: client > Reporter: Mike Drob > Priority: Minor > Fix For: 1.5.1, 1.6.0 > > > A user can already limit columns on a scanner, however there is not an easy way to limit the columns propagated in the middle of an iterator stack. For example, if a user has data like the following: > {noformat} > user-1 age:25 > user-1 occupation:Student > user-2 age:45 > user-2 occupation:Engineer > {noformat} > and wants to get only the users that are younger than 30, it is easy to write a custom {{RowFilter}} to do that. > However, to get only the occupation of users under 30, there would need to be additional filtering done on the client side. If the rows get large or particularly numerous, then this becomes undesirable. And setting the fetch columns is not an option since that would hide the age column from the {{RowFilter}}. -- This message was sent by Atlassian JIRA (v6.1#6144)