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 1taelC-003tJ6-Bp for pgsql-hackers@arkaria.postgresql.org; Wed, 22 Jan 2025 17:43:26 +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 1taelB-002owJ-85 for pgsql-hackers@arkaria.postgresql.org; Wed, 22 Jan 2025 17:43:25 +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 1taelA-002owA-V5 for pgsql-hackers@lists.postgresql.org; Wed, 22 Jan 2025 17:43:24 +0000 Received: from mail-io1-xd2e.google.com ([2607:f8b0:4864:20::d2e]) by makus.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.96) (envelope-from ) id 1tael8-000x58-2a for pgsql-hackers@lists.postgresql.org; Wed, 22 Jan 2025 17:43:23 +0000 Received: by mail-io1-xd2e.google.com with SMTP id ca18e2360f4ac-844d7f81dd1so1207039f.2 for ; Wed, 22 Jan 2025 09:43:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1737567802; x=1738172602; darn=lists.postgresql.org; 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=dzHgGs/9YlVF6cNo1pGRlgyOsYZIDUeYaayi5qkr95c=; b=KQAwP0gV/TtZaWCC70gyygMZZgmCBOqiKoAHzMdbf3rDVp44MBKJ/FJnXYc5OBwKD4 MoYcydw2Tdqxlm02aGrUuuCMmpbL+xWbKGKKnWP3nBVzzSrfPn3jUKPg6zXtx73AQX5S Hj+Oi2At3Z8VLBo/I7L2GmAsy28Qdb6iL4JxKUulxHRQBeSgkbv2/mP2LQFampycJIst wcx82iZmFzQ5MaRaIdSRrakxYEgqjRBqKXbjbJXnFzlL+MJHJve9I/NbHyO/jtQuHT/q hiW/rmxdnaSgq1DVIAzAs5FSK28vYtFZa5IuSYFDQYxvQjJEs3uXBEm92/lWHx8yTCo0 0HgA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1737567802; x=1738172602; 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=dzHgGs/9YlVF6cNo1pGRlgyOsYZIDUeYaayi5qkr95c=; b=Kn65OLVqhiJvwyzWaGDv1ANlFqJHTwo//7KyEOnDK+AxT4clnZbUOmeh4Gb9auIVOi Oo/vF9NQEIKfptkZ+nlYdFTftPZFWRhN/R+7JHeaZM6jGqzHOK62a1BEcpOce2x4SR2h NCd4RO4Ag4U/l2wz//x7BCuTulXjDJ5Dqt1OdWsNselvSQ0ck0L2Tj7rjkoj3tNuvAgV GIKFLs+mB/iI7rQk4ZnuCb5LRJDGWQR/ZrIVs/lHSJzWD0Y9oWcJ2FDcKnR9sZVcvEZW csTtOHuLHIMxfVVulzzrPEZwpP0aFxZo40CXCU4Qr0B/XWHJZwaigpxDurrDEu/u/Phc 792w== X-Forwarded-Encrypted: i=1; AJvYcCVCNNNvYe2jiMbVyWXRWmh2ebHu5OkQjPKam4Nm/CBcJmR9KA5LbBmr+jK0JF1x3tVkk85z0k+Z4Hnd2ElX@lists.postgresql.org X-Gm-Message-State: AOJu0YzlJKhjvNh5ebFhwbVgp8GxT/7hfQ64rAL26WjJc8XZy0KV4MJS ntNC1Hl4R+GhCERBgmr47PE83xpkGxqQ/ClvhHfYs/QoaMJFuy6d X-Gm-Gg: ASbGncvEsI3rCOjAdCNX640egZMq+NHHHLs+roRgWU2LSVDWASRPo6J2H9qLo1UmlJ6 /RTLCJ6v0PXy0qrHAFVTqn21jPOIUH/RNW2MF6ZPmvBHaKz/r68W1vbDXGNqC5f2UooLKUXWxF0 XEXkImassucd3trEwrYJjTrKJ1eSywNsBRa09+B+tn6ESujjw+2NMy/JbSwORBrsVscfsUniVqA JnpVC+HGRezxelYDPH5RoqWLzGyskGiK30gOgohBK2MDzCT/PVgFB4hHbEYE3AKEbXQdChb5/hH oPv37ROMS5Ag8toF9Q/hC9YoN5WkLvRWPYtThZ3hUXUsuEzvLRWWnKrjl+6L X-Google-Smtp-Source: AGHT+IHJzAc0M0V47ac7o5uW9JsbAixo5d5RFdw4DbQ4qlBJDE51YxMCX81+F4uwtN9VcmtEl6rKyQ== X-Received: by 2002:a05:6e02:480e:b0:3cf:afd2:e54a with SMTP id e9e14a558f8ab-3cfafd2e8f0mr46327395ab.10.1737567802285; Wed, 22 Jan 2025 09:43:22 -0800 (PST) Received: from nathan (162-195-168-172.lightspeed.stlsmo.sbcglobal.net. [162.195.168.172]) by smtp.gmail.com with ESMTPSA id 8926c6da1cb9f-4ea753f6edcsm4297138173.19.2025.01.22.09.43.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 22 Jan 2025 09:43:21 -0800 (PST) Date: Wed, 22 Jan 2025 11:43:20 -0600 From: Nathan Bossart To: Andres Freund Cc: Andy Fan , Justin Pryzby , Maxim Orlov , Pavel Borisov , "Bossart, Nathan" , Maxim Orlov , pgsql-hackers@lists.postgresql.org Subject: Re: Pre-allocating WAL files Message-ID: References: <20220301144044.GG25269@telsasoft.com> <20220301150704.GA1030078@nathanxps13> <20220317231212.GB1415284@nathanxps13> <20220408203003.GA1630183@nathanxps13> <87sepc4zcg.fsf@163.com> <87o6zz4pld.fsf@163.com> <745zvagaf6tfn2zbvtmqvxsr6kmybjbzcw6rsm55jnql4233je@tudeipoewruo> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <745zvagaf6tfn2zbvtmqvxsr6kmybjbzcw6rsm55jnql4233je@tudeipoewruo> List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Archived-At: Precedence: bulk On Wed, Jan 22, 2025 at 11:21:03AM -0500, Andres Freund wrote: > fsync(open(oldname1)); > fsync(open(oldname2)); > .. > fsync(open(oldnameN)); > > rename(oldname1, newname1); > rename(oldname2, newname2); > .. > rename(oldnameN, newnameN); > > fsync(open(newname1)); > fsync(open(newname2)); > .. > fsync(open(newnameN)); > > fsync(open("pg_wal")); What is the purpose of syncing the file before the rename? -- nathan