Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1inhI4-000227-QI for pgsql-docs@arkaria.postgresql.org; Sat, 04 Jan 2020 11:08:21 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.89) (envelope-from ) id 1inhI2-0001KQ-7i for pgsql-docs@arkaria.postgresql.org; Sat, 04 Jan 2020 11:08:18 +0000 Received: from makus.postgresql.org ([2001:4800:3e1:1::229]) by malur.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1ingD6-0007De-Kp for pgsql-docs@lists.postgresql.org; Sat, 04 Jan 2020 09:59:09 +0000 Received: from mail-oln040092011052.outbound.protection.outlook.com ([40.92.11.52] helo=NAM04-SN1-obe.outbound.protection.outlook.com) by makus.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1ingCy-0006oC-2Q for pgsql-docs@lists.postgresql.org; Sat, 04 Jan 2020 09:59:07 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=QVRylknAFHGbgYKvQhS+5nGh9cvfrAaPJMVLcNIod2LGChu+PztqUyLLk91ZJpDlufoyC1PJ3W7rNlgFcEg7tMywBt7xbYC+uITq4qBcD9t94H40NXXbdfOSqdnjRqNQN/9BDIg7Ko4At60gbUwijToL065fbdYZN5PRXllU0iAvyoBgJaNv9B7oSzNIU5stEMLMjYGPFKum/jI526aYNw5/aBwkWVvKpGJuUTk9ecUp/+uSmXGnAy8wIy6xJ9GAyQwB+nE9hfOYJy9LwwtgGqCMOVXysIg2iN8zKTpVFuiOUCsq2pdgDB86H2I/EulPqcYUhnMgEpiAZ7Ozv5lOBQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=qR3CeLpgMHsiR0r3xAenQSPJDo8e+X+tfZbW54t15T4=; b=Dp8oifrZB+ctvo9ig3EGOp1kiLX/fBl1icgdzdhyp+cSgTB+sifouFlo3t5evUem+5auT4FYhAUKBITCihgHJxW6GNw4n9oVhrgQBFWL/ceLAHeWArICdx3iWwzb73TnrgonlXYGnuZrnIs/rMlr9kbGU5xAAfNTEjtNzlrfomACxTvymd/4Or+0WVjfJkC3m0yD8OReeUWz5vZYGGfF1orRo/5LkGcHiCdGjMdTynlq7W3DU+4qHSMYpcY+ECjVnYpxYtPXQ12hU538/MFl7bVJGaDplW/Xr77n9e8+l/pPAMNctR3zhT8TQmK/zMTb8dbUfiYzq9uo6XwdtW/FiQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=none; dmarc=none; dkim=none; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=hotmail.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=qR3CeLpgMHsiR0r3xAenQSPJDo8e+X+tfZbW54t15T4=; b=RlfiCCwjCHTD8gqfQZIoMVtL5xRdZSd/ZhVfTb9rX2aCJUeIElaxIDyeZ/z14fOyHc3FDvN4x3BvvM4/7R1eKDX3TNqbCgSjVpiLm9aTeaDbp52n0wHjOO14Px95qzEokTQyPtW7eFiF6y+FsyQmBHkC+a6FMkXGoOChOvOwDUmKpFOyWeS22jBNQ0zMZlkQ3q0PwjSSXX6IdjMNiclMsGaxkmjTmGZgmdIp8ec1P6tTtkMhTLO0Xsre5XT5WNpfvPraRdR8ebbLVK6M5C8MHoXVogJBDRJjyhJTMXRgvV0dbS9u6su+NXE5oa2/Q1/JNNv8+taaEkIphEsfoyFS0w== Received: from SN1NAM04FT028.eop-NAM04.prod.protection.outlook.com (10.152.88.52) by SN1NAM04HT104.eop-NAM04.prod.protection.outlook.com (10.152.89.26) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.2602.11; Sat, 4 Jan 2020 09:58:57 +0000 Received: from MWHPR15MB1839.namprd15.prod.outlook.com (10.152.88.52) by SN1NAM04FT028.mail.protection.outlook.com (10.152.88.113) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.2602.11 via Frontend Transport; Sat, 4 Jan 2020 09:58:57 +0000 Received: from MWHPR15MB1839.namprd15.prod.outlook.com ([fe80::6c84:ae5c:f808:75ad]) by MWHPR15MB1839.namprd15.prod.outlook.com ([fe80::6c84:ae5c:f808:75ad%12]) with mapi id 15.20.2602.012; Sat, 4 Jan 2020 09:58:57 +0000 From: Paul Weiss To: "David G. Johnston" , "pgsql-docs@lists.postgresql.org" Subject: Re: the concept of a database cluster Thread-Topic: the concept of a database cluster Thread-Index: AQHVwg0Kv6cN+bHOD0S+Dl9W5MJcoafYmWGAgAGmH6M= Date: Sat, 4 Jan 2020 09:58:57 +0000 Message-ID: References: <157801363409.1149.3930072152315481638@wrigleys.postgresql.org>, In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-incomingtopheadermarker: OriginalChecksum:764387796253B68BB1B7EFE12604E767DFEDC666A91C38011DF1357D87C793EC;UpperCasedChecksum:6ADAD8773E2480075AD54AE839F45248B57FD4E9D388B9DCCE35D5E4495E1665;SizeAsReceived:7105;Count:45 x-ms-exchange-messagesentrepresentingtype: 1 x-tmn: [smJocTH2twKk0Ahn3gyF61OHv7M/6yX/9zqeJJ6jLLw=] x-ms-publictraffictype: Email x-incomingheadercount: 45 x-eopattributedmessage: 0 x-ms-office365-filtering-correlation-id: cbc14833-6037-4f92-3951-08d790fcb6f5 x-ms-traffictypediagnostic: SN1NAM04HT104: x-microsoft-antispam: BCL:0; x-microsoft-antispam-message-info: shr/mW4tM4QOD9IFsy8/PKGiJGK5Sz79MT8jdjpDXt/iOoniOauc1vc0t/mUnWNVl+E0kZOIEVw5gmhQPRZ5wSxkYZk+kAk5eEkoKPwIGm6nui3LgCZbRY4yXNxuRkdSTq3GL/hFFi5vuc7Idzkcxd4bu1ybk+Ts2H44+PlKt/27uRmrhRk8C5jKzlPzue+27TPqSs/Krl8PNq6Anqoer+ES5Mx9zn/LE61bV26giuc= x-ms-exchange-transport-forked: True Content-Type: multipart/alternative; boundary="_000_MWHPR15MB18397BC83DBD850FB8A2327CDC220MWHPR15MB1839namp_" MIME-Version: 1.0 X-OriginatorOrg: hotmail.com X-MS-Exchange-CrossTenant-RMS-PersistedConsumerOrg: 00000000-0000-0000-0000-000000000000 X-MS-Exchange-CrossTenant-Network-Message-Id: cbc14833-6037-4f92-3951-08d790fcb6f5 X-MS-Exchange-CrossTenant-rms-persistedconsumerorg: 00000000-0000-0000-0000-000000000000 X-MS-Exchange-CrossTenant-originalarrivaltime: 04 Jan 2020 09:58:57.1527 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Internet X-MS-Exchange-CrossTenant-id: 84df9e7f-e9f6-40af-b435-aaaaaaaaaaaa X-MS-Exchange-Transport-CrossTenantHeadersStamped: SN1NAM04HT104 List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Precedence: bulk --_000_MWHPR15MB18397BC83DBD850FB8A2327CDC220MWHPR15MB1839namp_ Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable Oh, I didn't mean to imply that I am confused. It is clear that there are t= wo concepts here, sharing a term. I was trying to communicate that the manu= al does not always make it immediately clear from context which concept is = meant in a particular sentence. A garage is a good analogy. A garage is a container for cars rather than a = collection of cars. You wouldn't say "I sold my garage" to mean "I sold my = car collection". Containers and collections are different things. Here's a simple example In our context: "remove the cluster" could mean "de= lete the folder containing the databases", or "drop the databases". Those a= ctions are not identical. I would think we would want to be clear to our us= ers which we mean. Paul ________________________________ From: David G. Johnston Sent: Friday, January 3, 2020 12:21 AM To: libcub@hotmail.com ; pgsql-docs@lists.postgresql.or= g Subject: Re: the concept of a database cluster On Thursday, January 2, 2020, PG Doc comments form > wrote: The following documentation comment has been logged on the website: Page: https://www.postgresql.org/docs/12/creating-cluster.html Description: In 18.2, a database cluster is said to be "a database storage area on disk"= , and then shortly afterward is is defined as "a collection of databases that is managed by a single instance of a running database server". Those seem very different things. Sometimes in the manual I can't tell which usage is intended. A garage is a =93car storage area for a house=94. A garage can (typically) = store multiple cars just as a database cluster can store multiple databases= . The files are only useful if there is a running instance and all databas= es stored in the cluster are managed by a single shared instance. You will= need to better explain your confusion because the documentation is describ= ing a complex system accurately but in parts that are related - two sides o= f the same coin, if you will. David J. --_000_MWHPR15MB18397BC83DBD850FB8A2327CDC220MWHPR15MB1839namp_ Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable
Oh, I didn't mean to imply that I am confused. It is clear that there are t= wo concepts here, sharing a term. I was trying to communicate that the manu= al does not always make it immediately clear from context which concept is = meant in a particular sentence.

A garage is a good analogy. A garage is a container for cars rather than a = collection of cars. You wouldn't say "I sold my garage" to mean &= quot;I sold my car collection". Containers and collections are differe= nt things.

Here's a simple example In our context: "remove the cluster" coul= d mean "delete the folder containing the databases", or "dro= p the databases". Those actions are not identical. I would think we wo= uld want to be clear to our users which we mean.

Paul

From: Davi= d G. Johnston <david.g.johnston@gmail.com>
Sent: Friday, January 3, 2020 12:21 AM
To: libcub@hotmail.com <libcub@hotmail.com>; pgsql-docs@lists.= postgresql.org <pgsql-docs@lists.postgresql.org>
Subject: Re: the concept of a database cluster
 
On Thursday, January 2, 2020, PG Doc comments form <noreply@postgresql.org> wrote:=
The following documentation comment has been logged on the website:

Page: https://www.postgresql.org/docs/12/creating-cluster.html
Description:

In 18.2, a database cluster is said to be "a database storage area on = disk",
and then shortly afterward is is defined as "a collection of databases= that
is managed by a single instance of a running database server". Those s= eem
very different things. Sometimes in the manual I can't tell which usage is<= br> intended.

A garage is a =93car storage area for a house=94. A garage can (typica= lly) store multiple cars just as a database cluster can store multiple data= bases.  The files are only useful if there is a running instance and a= ll databases stored in the cluster are managed by a single shared instance.  You will need to better explain your co= nfusion because the documentation is describing a complex system accurately= but in parts that are related - two sides of the same coin, if you will.

David J.

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