Return-Path: X-Original-To: apmail-cassandra-commits-archive@www.apache.org Delivered-To: apmail-cassandra-commits-archive@www.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id D2F4517498 for ; Thu, 19 Mar 2015 11:06:44 +0000 (UTC) Received: (qmail 18434 invoked by uid 500); 19 Mar 2015 11:06:38 -0000 Delivered-To: apmail-cassandra-commits-archive@cassandra.apache.org Received: (qmail 18390 invoked by uid 500); 19 Mar 2015 11:06:38 -0000 Mailing-List: contact commits-help@cassandra.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: dev@cassandra.apache.org Delivered-To: mailing list commits@cassandra.apache.org Received: (qmail 18373 invoked by uid 99); 19 Mar 2015 11:06:38 -0000 Received: from arcas.apache.org (HELO arcas.apache.org) (140.211.11.28) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 19 Mar 2015 11:06:38 +0000 Date: Thu, 19 Mar 2015 11:06:38 +0000 (UTC) From: "Benedict (JIRA)" To: commits@cassandra.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Commented] (CASSANDRA-8920) Optimise sequential overlap visitation 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/CASSANDRA-8920?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14368868#comment-14368868 ] Benedict commented on CASSANDRA-8920: ------------------------------------- I've rebased this ontop of CASSANDRA-8988, which reduces the boilerplate. > Optimise sequential overlap visitation > -------------------------------------- > > Key: CASSANDRA-8920 > URL: https://issues.apache.org/jira/browse/CASSANDRA-8920 > Project: Cassandra > Issue Type: Improvement > Components: Core > Reporter: Benedict > Assignee: Benedict > Priority: Minor > Fix For: 2.1.4 > > Attachments: 8920.txt > > > The IntervalTree only maps partition keys. Since a majority of users deploy a hashed partitioner the work is mostly wasted, since they will be evenly distributed across the full token range owned by the node - and in some cases it is a significant amount of work. We can perform a corroboration against the file bounds if we get a BF match as a sanity check if we like, but performing an IntervalTree search is significantly more expensive (esp. once murmur hash calculation memoization goes mainstream). > In LCS, the keys are bounded, to it might appear that it would help, but in this scenario we only compact against like bounds, so again it is not helpful. > With a ByteOrderedPartitioner it could potentially be of use, but this is sufficiently rare to not optimise for IMO. -- This message was sent by Atlassian JIRA (v6.3.4#6332)