Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1n9Vnq-0003oQ-Lz for pgsql-admin@arkaria.postgresql.org; Mon, 17 Jan 2022 17:28:22 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.92) (envelope-from ) id 1n9Vnp-00036N-GI for pgsql-admin@arkaria.postgresql.org; Mon, 17 Jan 2022 17:28:21 +0000 Received: from magus.postgresql.org ([2a02:c0:301:0:ffff::29]) by malur.postgresql.org with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1n9Vnp-00036D-3s for pgsql-admin@lists.postgresql.org; Mon, 17 Jan 2022 17:28:21 +0000 Received: from mail-oi1-x22d.google.com ([2607:f8b0:4864:20::22d]) by magus.postgresql.org with esmtps (TLS1.3:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1n9Vnm-00059Y-Mv for pgsql-admin@lists.postgresql.org; Mon, 17 Jan 2022 17:28:20 +0000 Received: by mail-oi1-x22d.google.com with SMTP id bx18so6073675oib.7 for ; Mon, 17 Jan 2022 09:28:18 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=subject:to:references:from:message-id:date:user-agent:mime-version :in-reply-to:content-language; bh=QPavXqtbKZmfOKJrgsGymYtVQOWrtoUa/t7haEsAsaE=; b=M2KItRmswiGaVKsV2mVXNSnH+3OxoprgT7a47noNprhCQYq44pSb8jr6sZTSECeMw4 wCC0PJ9/9kcuY72jG6tSazX1wSp2STdcXW/s3AXlPxJIzJf7K/eJ85x6e7cbEPoaYXpP KCwyxWffwv2SOnMJEneQXCXzOlfWU9JhfL1nt7ziiqIuPSxGAM2vLp3pfdeHE0sFKM2U S0au5P3GixLZaRgwDz+1RILR8Jn4loPp2gj+kJ9QLriDxBHwZlg6B7Fqx6rN/zttHdOQ qNHdla1PoOj1BXWfZilwWgQxOfi5UCiyVvJYHzMm7M/1RNXwkSVMgwKTkMpp7Imc89Iv 7ikQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:subject:to:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language; bh=QPavXqtbKZmfOKJrgsGymYtVQOWrtoUa/t7haEsAsaE=; b=uR4eLR5bVQr75SBwlglk+sOYpzoH7K6bc/MfoQOjPiVbsntmvn/tgiRdfLkQodZhbJ K/EyiuSD2/Q5ACl7GRRboKC4gKNTBSf/XV+RLpQvjuJ7sKTH0mFt1TBh5+elNQ9JJVcF Hp1ldgnXEucP2kdIuNTEPti83NfwgARRQwgklGDPg87JhQGtSmq8Z1FUlkv6qeAIqz4I yrEGscbQfY+lbU+4yRJL43Q1jjIATGaSZH/B7J8uMKPeHN677KNkXaM7SV/kTdrzKpHx H9WELkdQpVdOkqY1QZpt8OheIKbs3UWyEYjzNI70xe7zknNrOMmwSIylADAI46/iRFrA Kb1Q== X-Gm-Message-State: AOAM530+q3Oa34lS94syQ8Pybqr1KT/IfnHQmjC6FUG61/8Cc3y3RcBj Ug7sf74F03Ve4l9w0jMuQ5fieBNiheE= X-Google-Smtp-Source: ABdhPJyKe0KKJmfjiaWBDAgo7ydO2T8HBHmv2MrKLPLOlgbYfgTYN//yHEycqBPTpdj4tTq57X09qQ== X-Received: by 2002:aca:dac3:: with SMTP id r186mr23942748oig.163.1642440496420; Mon, 17 Jan 2022 09:28:16 -0800 (PST) Received: from [192.168.88.10] (ip68-11-68-85.no.no.cox.net. [68.11.68.85]) by smtp.googlemail.com with ESMTPSA id n19sm5757468otq.11.2022.01.17.09.28.15 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 17 Jan 2022 09:28:15 -0800 (PST) Subject: Re: Large number of partitions of a table To: Pgsql-admin References: <3919502.1642393668@sss.pgh.pa.us> <671340a5-1960-e5dc-1d09-4b7f36cda2c8@gmail.com> <3992395.1642431512@sss.pgh.pa.us> From: Ron Message-ID: <6c8f3a3d-e3c3-10c6-8311-b01606b937e7@gmail.com> Date: Mon, 17 Jan 2022 11:28:15 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.14.0 MIME-Version: 1.0 In-Reply-To: Content-Type: multipart/alternative; boundary="------------4608E3F07B63C23CCF77DBBE" Content-Language: en-US List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Archived-At: Precedence: bulk This is a multi-part message in MIME format. --------------4608E3F07B63C23CCF77DBBE Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit On 1/17/22 9:14 AM, David G. Johnston wrote: > On Mon, Jan 17, 2022 at 7:58 AM Tom Lane > wrote: > > Ron > writes: > > On 1/16/22 11:38 PM, Victor Sudakov wrote: > >> so no query should ever have to use more than 1 partition. > > > I find it hard to believe that you'll *never* run a report against more > > customers than are in a single partition. > > Yeah, I'm a little suspicious of that. > > > Is "never" really the correct threshold here? That's what OP wrote, and that's what we're dubious about.  Users who know a bit too much to be dangerous write a scary about of unexpected queries. -- Angular momentum makes the world go 'round. --------------4608E3F07B63C23CCF77DBBE Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: 8bit On 1/17/22 9:14 AM, David G. Johnston wrote:
On Mon, Jan 17, 2022 at 7:58 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
Ron <ronljohnsonjr@gmail.com> writes:
> On 1/16/22 11:38 PM, Victor Sudakov wrote:
>> so no query should ever have to use more than 1 partition.

> I find it hard to believe that you'll *never* run a report against more
> customers than are in a single partition.

Yeah, I'm a little suspicious of that.

Is "never" really the correct threshold here? 

That's what OP wrote, and that's what we're dubious about.  Users who know a bit too much to be dangerous write a scary about of unexpected queries.
--
Angular momentum makes the world go 'round.
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