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 4.96) (envelope-from ) id 1vWaF7-0050C3-1g for pgsql-general@arkaria.postgresql.org; Fri, 19 Dec 2025 13:10:02 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.96) (envelope-from ) id 1vWaF4-007iKV-38 for pgsql-general@arkaria.postgresql.org; Fri, 19 Dec 2025 13:09:59 +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 4.96) (envelope-from ) id 1vWaF4-007iKN-1v for pgsql-general@lists.postgresql.org; Fri, 19 Dec 2025 13:09:59 +0000 Received: from mail-wm1-x332.google.com ([2a00:1450:4864:20::332]) by makus.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.96) (envelope-from ) id 1vWaF3-001VbA-32 for pgsql-general@lists.postgresql.org; Fri, 19 Dec 2025 13:09:58 +0000 Received: by mail-wm1-x332.google.com with SMTP id 5b1f17b1804b1-4777771ed1aso13233815e9.2 for ; Fri, 19 Dec 2025 05:09:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cybertec.at; s=google; t=1766149796; x=1766754596; darn=lists.postgresql.org; h=mime-version:user-agent:content-transfer-encoding:references :in-reply-to:date:cc:to:from:subject:message-id:from:to:cc:subject :date:message-id:reply-to; bh=dMmLfOXc9VPxtLSTxj9nc2sV3JNyk+MF26f9gSFWoA0=; b=LRYANRQdZ584r+2qPT2dF7fo2B0IaUjV14ZZtz8jPo+SHUGagaJbpCOTbDnUg1loAL 8QOTr8QICAQ/+I4jnbTKyoS3jmZS8jnDnp/spGs5oWK28qrN+hlFufZ3HW7QiGGNE3R1 hEcw1ExHigqC30s4h4JvavB+B4Cn1m4buMhT+inNMSrXmQm4pK8QAyVDUbMe7Sevxkkn rSF3uPHCd3f3sK4vy2QGnFBJv+Jb4k0VirT/JGDIxjEjcGLlj2aUbBB/xLgBIwH5CtCC qioG39XRXz8NWQfgNx9RYOSgqDs0IfxZ2xsmNtTvvFovXla1SaLHNJDc9sVa27jMWmRK 5ZAQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1766149796; x=1766754596; h=mime-version:user-agent:content-transfer-encoding:references :in-reply-to:date:cc:to:from:subject:message-id:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=dMmLfOXc9VPxtLSTxj9nc2sV3JNyk+MF26f9gSFWoA0=; b=v1gCRmlTP/9R4LaHkC7jM+OF99QUfZ5VITuJ+f/6t5HdGoYVH/liH8YCpm+IQId1iK icPU+Ids34QaUllWqMSBfH5VKC66jHN/5nXpiqhCh6+fuf6cgspN4GXXN2/oFPXcM3GL 7kbcoJonCpyMpUoB57y7u2zzehf+2P1F8tEH/NMzNtfA2rNCCSWV1/4lCRgaZjNBG3Ki JoRcs6BohqkoVYs9+FirMOZTaLYOqb1o92zKzgDFzqyugPtt/B93UT9VmchCZ+3wEJML kETwNNDr5H96iFW0qktLOdQfL8HTf5IrToutfR+3bYw8PPIgdfAeHybpkeg5JP0jDyXv mOTQ== X-Forwarded-Encrypted: i=1; AJvYcCXU+l2VCKhENML5Np5P9T6UcOLHs/LGNGnoLbvcqOisf3+Icjq+I6wtuXd552sxRhpWcX4sF5v2uKYJ/DkJ@lists.postgresql.org X-Gm-Message-State: AOJu0YzjS7/L7uommwTpei4dUrCBZZepbOqE64SSBXEEOOv1IJZOuqxA tpQ5lNxByTdQWSlN+Ozl/+Qluhx8J/yveeEm+0/mG7247F5YnK1sEKeUmnMj4Shh8ps= X-Gm-Gg: AY/fxX4TB3GQZfbQFmfofYMVEdEFbId3pGUIU/Zi+eMq4j0YJ937vmon1XVF0+hlWvY yIULdNjEwQ7LXLww08qwZE0DnDNPyy5+cVDi3afzka9oOPSnhO6Fj9rr7W7/R6xMrz5XQM/QZ3b nsichYB5VJnF8SCfiCGa3B5VoJjkfwINdfmbqcw4z12X5Rme97b+/m0DG7L0y4xMZIqGZ5ERNbU pScvdHRZKapmmKXGyZ+OqwpaLNDUenZJ0b2Ox312jKysfadW11hPiVQAbqyyeQ2eWkqyC6NIxua Zx5LkTNF8lf+7WtJ9emeoTDzbste6qM/GDn4hxZRpHsr4VrIH16JcyAEYkSQ+XVRlOjn0IJ0wC/ 0yC8iBzpZ5IfR+MlCFOXVNXJzcXevJXPbnkH+pGSB5ukvOBhCwnC98/RtFGI1ZTa7MJJbVMXPDB ifPZ3IQiZMm4i8H6kc8gP2NovghxJ2RdN3osDmqntEyQ== X-Google-Smtp-Source: AGHT+IGy2DVdBvA6vAb5AKXQIHeUHtuPa7ySmg6uNGA1aBNYvAdZs47ReYsZhmVvOBZFvi4qSUs6mA== X-Received: by 2002:a05:600c:8489:b0:471:786:94d3 with SMTP id 5b1f17b1804b1-47d1957d915mr25432495e9.22.1766149796058; Fri, 19 Dec 2025 05:09:56 -0800 (PST) Received: from laurenz.albe-K4N0CV00F97414D ([2001:871:260:85ec:cf67:8776:2d1b:6b5d]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-47be279d6d8sm96380535e9.10.2025.12.19.05.09.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 19 Dec 2025 05:09:55 -0800 (PST) Message-ID: Subject: Re: wal segment size From: Laurenz Albe To: Andrew Cc: Greg Sabino Mullane , Colin 't Hart , PostgreSQL General Date: Fri, 19 Dec 2025 14:09:54 +0100 In-Reply-To: <2890CAF1-6B00-440E-B8FF-3D333DFC5AF3@gmail.com> References: <4e2cfc51d3933a1df28e212ccb0b90f39633422a.camel@cybertec.at> <2890CAF1-6B00-440E-B8FF-3D333DFC5AF3@gmail.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.56.2 (3.56.2-2.fc42) MIME-Version: 1.0 List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Archived-At: Precedence: bulk On Fri, 2025-12-19 at 09:26 +0100, Andrew wrote: > As an oracle dba new to Postgres, I=E2=80=99m used to the concept of cont= ext switches and latch issues > with regards to transaction log switches. Does Postgres have a similar me= chanism with latching > etc when it switches to a new wal segment that is alleviated when increas= ing the size of the > wal segments? Not really. PostgreSQL doesn't reuse WAL segments in a circular fashion li= ke Oracle does. At the end of a checkpoint, it creates new, empty WAL segments for future u= se, so if there is a need to switch to a new segment, there is no need to wait for anything= . Yours, Laurenz Albe