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 1u1npC-008M0k-HI for pgsql-general@arkaria.postgresql.org; Mon, 07 Apr 2025 14:51:46 +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 1u1npA-00HORD-Fe for pgsql-general@arkaria.postgresql.org; Mon, 07 Apr 2025 14:51:44 +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 1u1npA-00HOR5-4J for pgsql-general@lists.postgresql.org; Mon, 07 Apr 2025 14:51:44 +0000 Received: from mail-ej1-x62a.google.com ([2a00:1450:4864:20::62a]) by makus.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.96) (envelope-from ) id 1u1np8-003UQg-1L for pgsql-general@postgresql.org; Mon, 07 Apr 2025 14:51:43 +0000 Received: by mail-ej1-x62a.google.com with SMTP id a640c23a62f3a-ac25520a289so781913566b.3 for ; Mon, 07 Apr 2025 07:51:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cybertec.at; s=google; t=1744037501; x=1744642301; darn=postgresql.org; h=mime-version:user-agent:content-transfer-encoding:references :in-reply-to:date:to:from:subject:message-id:from:to:cc:subject:date :message-id:reply-to; bh=iOfQYRVFbARZBbWAFrtojFSz8/Q6b+Mx6IgHnuLjKW8=; b=Saz56eGKtTjIoFnLFM431aPP669Aa1mWYdZPsIf78JO2u1BoLtCBQnxKvEGq1Jgoh5 P0r5qLQdyIUrd/C5boJkRy/hJ+Tth2Bawo3kC1Rz7s8dXjNjZJQO4//r7TbJ+n3Zl/Jd OZSpSqAzvqnSad/6LtUmaizxuE2r5rFcZVu+afJSBr+KRQXRnWv/gj61OQIXo47qmADl fRMCW00jbQfqAbddCKxjUptSjRLqAnKYmW9sqtlcVq3j1NTo7YbZWGVQbaATUuEi57Wi Scr/CGcBZd+M8/1SLCKukDrv3ZHWGhS/nk44SlqFe99WBOaCrcRpUkkBGqhrPeIOClM3 aMkQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1744037501; x=1744642301; h=mime-version:user-agent:content-transfer-encoding:references :in-reply-to:date:to:from:subject:message-id:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=iOfQYRVFbARZBbWAFrtojFSz8/Q6b+Mx6IgHnuLjKW8=; b=j+ffHH7QWUzrwxc1OdG5xBNxT3PxieMBcv2tEnD/jf52REkR1C5oUfP6PfELfN8tF2 CYSrBe+pdXc2WP0ptO9OYvBCa081kK83L+7DnksFijKrqPnjLSIk/DRqd5UwZ90aer8X Q6EsRZRhx8ZwulNIxel4hmR3p9jWHap5D6WUCAECRS6kORnpKwfd/kTevf7rk8Uywblf OD0zXUpuXIEm6vmdaqos1ggYOGpszO07/f9UNEBAnBr6q5tekQWwohyUrVR8v7STp6Xt t4gPSG5diaBthMN9XERzcwpn+bTiworS+HYoXvRzBu/kI+wcKV84M364Q3v4yknjk7dz 6ljA== X-Forwarded-Encrypted: i=1; AJvYcCVI7sDqIOkMz0VTzZJynv4ARLnCfOCkGc3sb7VXyL+TZZfFfI4JCg/ocufG5HlC+luVo/qeSjt/8n95m+3R@postgresql.org X-Gm-Message-State: AOJu0Yy+4JSlk2NeIsMOpBiisVayU3gxTHPemrEaVn6ZshulPwVpl7dv u4tsXsMNs2O7CstiwabB9k/mno+/KCHsp1X7yaMr6ifO7nEbKfC+US/er+2GJKURbYgIrqgZ7b0 OO8o= X-Gm-Gg: ASbGnct9t+JXRQNArMaLMVEPuE4FRmCEZ414D9NeC3YKMv8hi/0mQYrjOKlSRPAQGM/ FwHwxpvV8Ac2/EOZZGDr2mhGikcmsgdUMTqTrBv/3htFSYpyjp5PV2iiw7MN/TAAaQszGFn+1p6 FMZitARcsEcZyZTPuo9lpW4nNTsAFpBF7traoooqkxcQts5rBM4rpjYdb3GrhUlJZxVfLZmSHhK tXi5dTea4OsOiyGhEWfmEPHn9q9kupjr7hRP1mqp7mlu4MsGcRn3wb8VGUVuA2aOogWViUFlAEk 2qRsugyjBmfSpKbi+Q8gLlBatlWqRKc1PMtsu04pO9+5aKy/lPj/hriP59oST0PZ7g== X-Google-Smtp-Source: AGHT+IEoD2Mnow+SpV3za/TkUzna1VyyeUAg532nSbCIIM9/yt0VwXCv55FLigjR+CFKgfy05FHqug== X-Received: by 2002:a17:907:97c1:b0:abf:c20d:501a with SMTP id a640c23a62f3a-ac7d6d00c1fmr983071466b.16.1744037500922; Mon, 07 Apr 2025 07:51:40 -0700 (PDT) Received: from localhost.localdomain ([2001:871:5e:9a63:6e75:d921:166e:9c61]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-ac7bfe99c7dsm762478566b.57.2025.04.07.07.51.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 07 Apr 2025 07:51:40 -0700 (PDT) Message-ID: <092224fb0376bbc6a5f777199dde3cb9cd1ebf99.camel@cybertec.at> Subject: Re: Slow timestamp query after upgrading from Pg13 to Pg16 From: Laurenz Albe To: Simon Windsor , pgsql-general@postgresql.org Date: Mon, 07 Apr 2025 16:51:40 +0200 In-Reply-To: <27b2975b-c078-45cf-815d-eddbedbda153@cornfield.me.uk> References: <27b2975b-c078-45cf-815d-eddbedbda153@cornfield.me.uk> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.54.3 (3.54.3-1.fc41) MIME-Version: 1.0 List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Archived-At: Precedence: bulk On Mon, 2025-04-07 at 15:48 +0100, Simon Windsor wrote: > After upgrading a Db from Pg13 (Centos) to Pg16(Ubuntu) some queries > on a simple, large table (200M rows) are very slow If you used "pg_upgrade", did you ANALYZE the database? If that is not the problem, we can't guess what your problem might be unless you provide EXPLAIN (ANALYZE, BUFFERS, SETTINGS) output for auch a slow query. Ideally, add the same information for the fast v13 case. Yours, Laurenz Albe