Return-Path: X-Original-To: archive-asf-public-internal@cust-asf2.ponee.io Delivered-To: archive-asf-public-internal@cust-asf2.ponee.io Received: from cust-asf.ponee.io (cust-asf.ponee.io [163.172.22.183]) by cust-asf2.ponee.io (Postfix) with ESMTP id C431B200D1D for ; Sat, 9 Sep 2017 07:30:05 +0200 (CEST) Received: by cust-asf.ponee.io (Postfix) id C2FE71609C1; Sat, 9 Sep 2017 05:30:05 +0000 (UTC) Delivered-To: archive-asf-public@cust-asf.ponee.io Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by cust-asf.ponee.io (Postfix) with SMTP id 19D081609A7 for ; Sat, 9 Sep 2017 07:30:04 +0200 (CEST) Received: (qmail 54175 invoked by uid 500); 9 Sep 2017 05:30:03 -0000 Mailing-List: contact dev-help@phoenix.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: dev@phoenix.apache.org Delivered-To: mailing list dev@phoenix.apache.org Received: (qmail 54154 invoked by uid 99); 9 Sep 2017 05:30:03 -0000 Received: from pnap-us-west-generic-nat.apache.org (HELO spamd1-us-west.apache.org) (209.188.14.142) by apache.org (qpsmtpd/0.29) with ESMTP; Sat, 09 Sep 2017 05:30:03 +0000 Received: from localhost (localhost [127.0.0.1]) by spamd1-us-west.apache.org (ASF Mail Server at spamd1-us-west.apache.org) with ESMTP id 8D1E7CFD8E for ; Sat, 9 Sep 2017 05:30:02 +0000 (UTC) X-Virus-Scanned: Debian amavisd-new at spamd1-us-west.apache.org X-Spam-Flag: NO X-Spam-Score: -99.202 X-Spam-Level: X-Spam-Status: No, score=-99.202 tagged_above=-999 required=6.31 tests=[KAM_ASCII_DIVIDERS=0.8, RP_MATCHES_RCVD=-0.001, SPF_PASS=-0.001, USER_IN_WHITELIST=-100] autolearn=disabled Received: from mx1-lw-eu.apache.org ([10.40.0.8]) by localhost (spamd1-us-west.apache.org [10.40.0.7]) (amavisd-new, port 10024) with ESMTP id eRnz2L2Zgm7m for ; Sat, 9 Sep 2017 05:30:02 +0000 (UTC) Received: from mailrelay1-us-west.apache.org (mailrelay1-us-west.apache.org [209.188.14.139]) by mx1-lw-eu.apache.org (ASF Mail Server at mx1-lw-eu.apache.org) with ESMTP id 3AC8E5F3CF for ; Sat, 9 Sep 2017 05:30:01 +0000 (UTC) Received: from jira-lw-us.apache.org (unknown [207.244.88.139]) by mailrelay1-us-west.apache.org (ASF Mail Server at mailrelay1-us-west.apache.org) with ESMTP id 75388E00C9 for ; Sat, 9 Sep 2017 05:30:00 +0000 (UTC) Received: from jira-lw-us.apache.org (localhost [127.0.0.1]) by jira-lw-us.apache.org (ASF Mail Server at jira-lw-us.apache.org) with ESMTP id 3036B23F0D for ; Sat, 9 Sep 2017 05:30:00 +0000 (UTC) Date: Sat, 9 Sep 2017 05:30:00 +0000 (UTC) From: "Lars Hofhansl (JIRA)" To: dev@phoenix.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Resolved] (PHOENIX-4164) APPROX_COUNT_DISTINCT becomes imprecise at 20m unique values. MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-JIRA-FingerPrint: 30527f35849b9dde25b450d4833f0394 archived-at: Sat, 09 Sep 2017 05:30:05 -0000 [ https://issues.apache.org/jira/browse/PHOENIX-4164?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Lars Hofhansl resolved PHOENIX-4164. ------------------------------------ Resolution: Invalid Had to do with how I ran my test... Sorry for the noise. > APPROX_COUNT_DISTINCT becomes imprecise at 20m unique values. > ------------------------------------------------------------- > > Key: PHOENIX-4164 > URL: https://issues.apache.org/jira/browse/PHOENIX-4164 > Project: Phoenix > Issue Type: Bug > Reporter: Lars Hofhansl > Assignee: Ethan Wang > > {code} > 0: jdbc:phoenix:localhost> select count(*) from test; > +-----------+ > | COUNT(1) | > +-----------+ > | 26931816 | > +-----------+ > 1 row selected (14.604 seconds) > 0: jdbc:phoenix:localhost> select approx_count_distinct(v1) from test; > +----------------------------+ > | APPROX_COUNT_DISTINCT(V1) | > +----------------------------+ > | 17221394 | > +----------------------------+ > 1 row selected (21.619 seconds) > {code} > The table is generated from random numbers, and the cardinality of v1 is close to the number of rows. > (I cannot run a COUNT(DISTINCT(v1)), as it uses up all memory on my machine and eventually kills the regionserver - that's another story and another jira) > [~aertoria] -- This message was sent by Atlassian JIRA (v6.4.14#64029)