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 1vhCnp-00BGSR-25 for pgsql-performance@arkaria.postgresql.org; Sat, 17 Jan 2026 20:21:46 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.96) (envelope-from ) id 1vhCnm-009Qp3-2x for pgsql-performance@arkaria.postgresql.org; Sat, 17 Jan 2026 20:21:43 +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 1vhCnm-009Qos-1t for pgsql-performance@lists.postgresql.org; Sat, 17 Jan 2026 20:21:42 +0000 Received: from mail-wm1-x333.google.com ([2a00:1450:4864:20::333]) by makus.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.96) (envelope-from ) id 1vhCnk-000yIV-1n for pgsql-performance@lists.postgresql.org; Sat, 17 Jan 2026 20:21:42 +0000 Received: by mail-wm1-x333.google.com with SMTP id 5b1f17b1804b1-47ee3a63300so28794895e9.2 for ; Sat, 17 Jan 2026 12:21:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1768681299; x=1769286099; darn=lists.postgresql.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=W5QxZhZsBLM4vULCVutRO+Ix/OSsv/x3oAist0WsozE=; b=mRlSXuiROfTucIXdFESiBdVygER0ezKatGnFXMWoJlkdfw2S8N+ZRn4xM8X0TwQmNY AeTSw2Hrvr0l0TlGaJpOg7Kj7/9EhFx4S/tBbc9XjVdrxO3qoRlNGbwqHVedsWRD9ytl 9knkC9WLlxmS8hPpvnnGWYNXbr3jJxz2LS5sfEYtNmg4gYElJb2zMXqEY3Oq1KRW1ouK uo8DE5OfJ7882ZeE8bzfi0aDvNedmY2vpcqmLelQDgwOK5vqwT61K2imf1WLvFHRnOIb wy0popyX/ADzaZCq0h271JzpnKXeaR4IalUEVvd4AY8Rx6I/4CChvNRTDLy4Idohzf0u uO5w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1768681299; x=1769286099; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-gg:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=W5QxZhZsBLM4vULCVutRO+Ix/OSsv/x3oAist0WsozE=; b=ZjPP450dd8OmnMFUIWfh42oBUKjKXusDrO5dSDr9EepxUjTn+ojPY0t3iIVt2IsVnA Euw5FbuYC9q09fbMJZ86YTHMj+6PrSyaVi/Sv2US5R05uLqUk7ApRVPPiVmyNf6cOzgQ aWb+7BB2DtHMl4EdXZ8r/ITHXJ6hkfZBcXuU6Mwal8RUfp7imDRTWRfoYFcn7pNSWvEC A4EhGiSR3bBJo3Pq2rDLTJks6AhdNB4Zff8fus8XHxInykIXObrb+dx/eCoK2KoSNxr8 gvraV/8dNlVUOaSI0Exing7fpLk5p58/i/0H9s3IDE7P5gK4d7ICaFdrPJS73ZJ2h3Tw tUwA== X-Forwarded-Encrypted: i=1; AJvYcCXbNGoNtilBJKnEUQc5LgUEu0ETzAFYMxEZtM7+BCGbJL9tdaY1pFSG5HVzWlsxEpUpJrgclElvmkq8r9b3Piw3Kg==@lists.postgresql.org X-Gm-Message-State: AOJu0YwKwMNToW1nKo0mwK5b76Ebov00vo+UOrGpevWHiBVJyh42yIiU DUhvEP0vSPm/URDxiYUvgJkge2ONPzIeO7cukYD07t2K3caUKOAcaoBLbOKZlg== X-Gm-Gg: AY/fxX66VquleVbJN6LAWXavAP98DSiGd7Eg9de4/TMsGUGuV/vvGIBgYPxZ0zjWVXz LwoReEYjmtCDLy4af/GZc17FUXsXeyaKVbr6T+EUiNd8Adq7KDTWRDKTZ0Ujs7Bc7x38TPENLxL EdhyaOaQJ9tupQse7ni+aMIQrxAWZVfK16228fVPUljb5afIJwbRfIRJNktQQKxVE5QP1ykFaGO 2yVzVO6l7dCKuiM/dxme8sQhy/49WZfRzyXhnp73hOVhsryJLAMqA8eRvzbWpGNUDhihi1APpto AZW5zsMPB2LN9RLElqhm8sWidswVrTtKS/W/CrlxXuOpjgHUQ+Lvvg9R6QRFCpDB+sKDf9yoSlh 8qeMMjNedkbknkKJ+M2pbd1d6mhKwGWOn7GbxV2wZZGy2Id8UUx4D8ISEOZ7BAI/F5YLatp1M7S rNzhfZb3YiPYvVbbT9IFxDVaHItDV/PrxHfXAp0AgQXLW2shB+twz48Dandwc54w== X-Received: by 2002:a05:600c:3b84:b0:477:7c7d:d9b2 with SMTP id 5b1f17b1804b1-4801e34cf73mr88087925e9.32.1768681298752; Sat, 17 Jan 2026 12:21:38 -0800 (PST) Received: from [192.168.0.86] (84.123.225.106.dyn.user.ono.com. [84.123.225.106]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4801e8c0475sm134266095e9.10.2026.01.17.12.21.37 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 17 Jan 2026 12:21:38 -0800 (PST) Message-ID: <1d79d974-acfe-483c-81da-61989ed2f91b@gmail.com> Date: Sat, 17 Jan 2026 21:21:36 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: Slow queries on simple index To: Lillian Berry , pgsql-performance@lists.postgresql.org Cc: infra@pluralkit.me References: Content-Language: en-US From: Andrei Lepikhov In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Archived-At: Precedence: bulk On 17/1/26 14:58, Lillian Berry wrote: > Logs on our PostgreSQL cluster show frequent slow reads on a simple query by unique index. > > This issue has been present for some years, and survived multiple server moves as well as PostgreSQL version upgrades. > Vacuuming or reindexing the table does not seem to help. Hmm, where is the evidence that your query uses theindex? Maybe the generic plan accidentally forces SeqScan? -- regards, Andrei Lepikhov, pgEdge