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 1oMa3G-0002U6-VR for pgsql-docs@arkaria.postgresql.org; Fri, 12 Aug 2022 19:10:34 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.92) (envelope-from ) id 1oMa3F-0005QJ-T9 for pgsql-docs@arkaria.postgresql.org; Fri, 12 Aug 2022 19:10:33 +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 1oMa0H-00072Z-16 for pgsql-docs@lists.postgresql.org; Fri, 12 Aug 2022 19:07:29 +0000 Received: from momjian.us ([72.94.173.45]) by magus.postgresql.org with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1oMa0E-0005sf-Ki; Fri, 12 Aug 2022 19:07:28 +0000 Received: from bruce by momjian.us with local (Exim 4.94.2) (envelope-from ) id 1oMa0A-000AbQ-EZ; Fri, 12 Aug 2022 15:07:22 -0400 Date: Fri, 12 Aug 2022 15:07:22 -0400 From: Bruce Momjian To: "David G. Johnston" Cc: Peter Geoghegan , "Jonathan S. Katz" , Pg Docs Subject: Re: documentation on HOT Message-ID: References: MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="rf3+o8x/+wZU1FXP" Content-Disposition: inline In-Reply-To: List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Archived-At: Precedence: bulk --rf3+o8x/+wZU1FXP Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Tue, Jul 26, 2022 at 07:29:10PM -0400, Bruce Momjian wrote: > > Summary paragraph: > > "can only happen if" => "can only be created if" > > Yes, good point. > > Updated patch attached. I applied this patch back to PG 11. (PG 10 had too many conflicts.) I also added a mention about how indexes can prevent HOT to the index introduction section; applied patch of that addition attached. -- Bruce Momjian https://momjian.us EDB https://enterprisedb.com Indecision is a decision. Inaction is an action. Mark Batterson --rf3+o8x/+wZU1FXP Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="hot.diff" diff --git a/doc/src/sgml/indices.sgml b/doc/src/sgml/indices.sgml index 023157d888..2a70e02f7c 100644 --- a/doc/src/sgml/indices.sgml +++ b/doc/src/sgml/indices.sgml @@ -103,7 +103,9 @@ CREATE INDEX test1_id_index ON test1 (id); After an index is created, the system has to keep it synchronized with the - table. This adds overhead to data manipulation operations. + table. This adds overhead to data manipulation operations. Indexes can + also prevent the creation of heap-only + tuples. Therefore indexes that are seldom or never used in queries should be removed. --rf3+o8x/+wZU1FXP--