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 1uw1Bl-004y71-FY for pgsql-general@arkaria.postgresql.org; Tue, 09 Sep 2025 16:27:26 +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 1uw1Bk-00DG4h-Jz for pgsql-general@arkaria.postgresql.org; Tue, 09 Sep 2025 16:27:25 +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 1uw1Bk-00DG4X-8y for pgsql-general@lists.postgresql.org; Tue, 09 Sep 2025 16:27:24 +0000 Received: from mail-ed1-x52c.google.com ([2a00:1450:4864:20::52c]) by makus.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.96) (envelope-from ) id 1uw1Bj-001VWU-05 for pgsql-general@postgresql.org; Tue, 09 Sep 2025 16:27:23 +0000 Received: by mail-ed1-x52c.google.com with SMTP id 4fb4d7f45d1cf-6228de280ccso7279030a12.3 for ; Tue, 09 Sep 2025 09:27:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1757435241; x=1758040041; darn=postgresql.org; h=content-transfer-encoding:to:subject:message-id:date:from :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=XdaHL6577eOwDdshoUOpzTiNLKcffze8k/efabWoNfs=; b=ZQl6vto68WzQEB9grsw2N+tZOHjrk4Qk5YF/JpkaW/kIGnq5qSG6BkIxq71eHJLyOr 7LXg9iCTctO6nOUeJaaC+dFlzmWClXaCnWi8qKWQOA5aPcWB/kODlrr3IPrDzV7sMzwS QAO8aOzaAotig6Wgoathhf80xcFThu/0AZVI1DHYLwOOKXvJFvygr8j2iW2Tj/c/IF+z 2YmJOjcILy4ZqoQ5RpLNzj58BvD0t5e4ZYmOsWk5a8VgbABBj+qIV+p9ZPEzReeFH9aF iBdQmGzl4aCJx3+XosJMfNvLYP7Tz3Uxtqt4iHNIMac8KU9h0gYfuwUp2XJ8imKiZb8j 9AMw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1757435241; x=1758040041; h=content-transfer-encoding:to:subject:message-id:date:from :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=XdaHL6577eOwDdshoUOpzTiNLKcffze8k/efabWoNfs=; b=SHwqsq7yCDm53R2bYqOi/IfNdUmxYg1LhUfIBG1dJUEdDmandmFI3K5VwPqouXlYJx pUaEsdizwDTJa7t/6+t6LP2YXpcqJIwNbjtq1rOB+upZ6WJJXU4vGp5uvxwD1CnGzyp+ IB1S7dLzY682ztjg4x9y20Dj0CvIIPNtUOyil4TlfqnPaoR9ViG1YGOQh6qDh0vHOnwc yo1guQgEGCRo7L5e/hhIMLJldiRxIUdEboupNibiS40oP8lj/Il9KMXb45RIyWWleBCu 80KAIamWnDPOztu7/moSBXcEIzCEMI3+5ggjboKBEQlt7R46Qo1aouV73qu+Q+GMiCm5 H2Fg== X-Gm-Message-State: AOJu0YzagwjxkF2QjFK5hJOQFILQAOPWjbGmtOzZWSKT6tFha4TMOQ3k q/EDhFO3oKMrfDxRcGH/SdFBuHDj+Je+L4953xaUWu576diSqKav4vUKVkkUL3XDhwLrv3Oh2z7 FbFXGznfwbcSYe+88p7qKhgNvnkNloXL3ffbj X-Gm-Gg: ASbGncu5NjmNuUA7UCnnx4cffIZCv304DQNRxKYkZnSGWfSyQpVddOcTS2hWMoa+zG0 3jVheHgJ6Bf7D5oaUL2d/qSTQMIaEGBWTOnRx5S73RXPKbGycZzZDAoMVopffqw9H9U1Mfshtl5 qglkN2/MZ2ZM47MimGdQwZAbh+SexD+JWJciKebNGVzZSAMXCiJunMNHHbpxdsXJ5TNEmIzpo+b x6xobY= X-Google-Smtp-Source: AGHT+IEaYV+0iZ4BgvWpHf+TXexosPPKPcEuogtlSNhO3lxTOLl/PsD7Nfzl/BP4F1eONe7ESAZVGwbACQE2zChg4iw= X-Received: by 2002:a17:907:3f26:b0:afe:c6a0:d116 with SMTP id a640c23a62f3a-b04b1446d98mr1256681366b.18.1757435241181; Tue, 09 Sep 2025 09:27:21 -0700 (PDT) MIME-Version: 1.0 From: Ellen Allhatatlan Date: Tue, 9 Sep 2025 17:27:10 +0100 X-Gm-Features: AS18NWCOYEWoYecdahn4peHm74yv3t78PIkm0KVVsX83fwmRkkSAD6YXt_kstZk Message-ID: Subject: MVCC and all that... To: pgsql-general Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Archived-At: Precedence: bulk Reading this article https://firebirdsql.org/migrating-from-firebird-to-postgresql-what-can-go-w= rong- I'm a bit confused (not the first time...) In part 1. Differences in MVCC implementation - he's saying that "It=E2=80= =99s not that the PostgreSQL implementation of MVCC is bad=E2=80=89=E2=80=94=E2= =80=89it=E2=80=99s just fundamentally different" But, I thought Firebird had SWEEP instead of VACUUM (how much closer can the words be?) and that FB's implementation of MVCC was essentially similar. Is this correct? Then why is he pointing out the performance diffs because of MVCC? I'm puzzled! --=20 El!