Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1qOijv-008k3z-7E for pgsql-bugs@arkaria.postgresql.org; Wed, 26 Jul 2023 17:55:59 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.94.2) (envelope-from ) id 1qOijt-005eJ3-F2 for pgsql-bugs@arkaria.postgresql.org; Wed, 26 Jul 2023 17:55:57 +0000 Received: from makus.postgresql.org ([2001:4800:3e1:1::229]) by malur.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1qOijt-005eIv-6m for pgsql-bugs@lists.postgresql.org; Wed, 26 Jul 2023 17:55:57 +0000 Received: from mail-pf1-x42e.google.com ([2607:f8b0:4864:20::42e]) by makus.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.94.2) (envelope-from ) id 1qOijq-001iVN-9K for pgsql-bugs@lists.postgresql.org; Wed, 26 Jul 2023 17:55:56 +0000 Received: by mail-pf1-x42e.google.com with SMTP id d2e1a72fcca58-686ed1d2594so106852b3a.2 for ; Wed, 26 Jul 2023 10:55:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1690394153; x=1690998953; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=tDqBvn01zrEndK1Yz18jdhBwd2LyidPyqOcL9s+Oq8U=; b=hg5s8+Ew1mHgaGXUAmS7ac7nIsLTRra+MNFsyblLhVWS5gNGHtR+HLhGlmHUTGN4O7 vVSEOm/FxfvRcsIql337EaSCTtTC6j499AKbunhcK3s7790oK1zvzBj5qQ7kedyzpwmN ljB5kCi2/jwnsKoVKE3eHgrvD6ElN9B+4fHdIJvJlj8SWOdst0lvi1r0f1C0p7bKV97j Bp6iG2afO3Z7QP5J7YCpls7EHAoDGUQMH6kwJlRaXGb0Lg/gn8Y/dLuhOtw9y7QdfgDc K6QovirfLNME+kR5BVE8AHD7FDYKfUEn0p7Ha+ex0zCbpEwQ0YP64StbYrpc/VJuwtl2 iL6w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1690394153; x=1690998953; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=tDqBvn01zrEndK1Yz18jdhBwd2LyidPyqOcL9s+Oq8U=; b=YM9TdLvaX2nw/CWCeV0wRVV+2bXpwUhg3WzbMm3jvh8vFhkUv+zX3uIReovcEedOSC 2zDl/Io3HPObqmdjby3GqtPM7ypzqXt2q/ktHK1q1O6PP3WIV62+NdqcR7i4OWQNlGQz NFSUowCYKT3UEIrdDMWvG6IiqEx564/wBosW8sXn+3P8wGkZREG5vB8nWwpjybNuqEbF hkqvvzsCRaYc5jjirdg/iR09AL61fAWLao/j/r0wgQ559Z2iQj0R8655vzBua2kxWS+p NGb9WTKPYXZMsSm7teHTCZ4mKcrXCPIfIedFJ4p+7h9dhVQHlpfV4mQ0U0bOeU4eRm6d Zqmg== X-Gm-Message-State: ABy/qLZGf/K813B2nxrMDXL8w7zaVyeTSv477Jsbm1w/NxrQPcjsCxs7 Z9O9if8wiilyqVA+rvaX/KpWmhtS9cM= X-Google-Smtp-Source: APBJJlFncdF9OGOzz136Wkf08Pv2AEjBmmTfvlKlVxr3BylXoTlnbkXMk1kuY9OO1aiuKyUaNxI6hQ== X-Received: by 2002:a05:6a20:3ca7:b0:134:8d7f:f4d9 with SMTP id b39-20020a056a203ca700b001348d7ff4d9mr3381970pzj.52.1690394152833; Wed, 26 Jul 2023 10:55:52 -0700 (PDT) Received: from nathanxps13 ([50.47.162.83]) by smtp.gmail.com with ESMTPSA id u21-20020a62ed15000000b0067f2f7eccdcsm11616986pfh.193.2023.07.26.10.55.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 26 Jul 2023 10:55:52 -0700 (PDT) Date: Wed, 26 Jul 2023 10:55:50 -0700 From: Nathan Bossart To: Christophe Pettus Cc: pgsql-bugs@lists.postgresql.org Subject: Re: Documentation bug at: current/sql-vacuum.html, Notes Message-ID: <20230726175550.GA3310393@nathanxps13> References: <292046F0-7FA9-4AAE-A632-79EAD3D1280F@thebuild.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <292046F0-7FA9-4AAE-A632-79EAD3D1280F@thebuild.com> List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Archived-At: Precedence: bulk On Wed, Jul 26, 2023 at 10:39:41AM -0700, Christophe Pettus wrote: > Isn't this backwards? > >> If index cleanup is not performed regularly, performance may suffer, because as the table is modified indexes will accumulate dead tuples and the table itself will accumulate dead line pointers that cannot be removed until index cleanup is completed. > > Indexes have line pointers, tables have tuples, so it should read: > >> If index cleanup is not performed regularly, performance may suffer, because as the table is modified indexes will accumulate dead line pointers and the table itself will accumulate dead tuples that cannot be removed until index cleanup is completed. I believe the current phrasing is correct. VACUUM will be able to reclaim the tuple space in the heap, but the line pointers must remain until their corresponding index tuples are removed. -- Nathan Bossart Amazon Web Services: https://aws.amazon.com