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 1vrvH7-00D6B2-2E for pgsql-performance@arkaria.postgresql.org; Mon, 16 Feb 2026 09:52:17 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.96) (envelope-from ) id 1vrvH5-000cht-2n for pgsql-performance@arkaria.postgresql.org; Mon, 16 Feb 2026 09:52:16 +0000 Received: from magus.postgresql.org ([2a02:c0:301:0:ffff::29]) by malur.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1vrvDY-000CHZ-0W for pgsql-performance@lists.postgresql.org; Mon, 16 Feb 2026 09:48:36 +0000 Received: from mail-wr1-x42f.google.com ([2a00:1450:4864:20::42f]) by magus.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.98.2) (envelope-from ) id 1vruY3-00000000zH6-11FV for pgsql-performance@postgresql.org; Mon, 16 Feb 2026 09:05:44 +0000 Received: by mail-wr1-x42f.google.com with SMTP id ffacd0b85a97d-436234ef0f0so1954845f8f.1 for ; Mon, 16 Feb 2026 01:05:42 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1771232737; x=1771837537; darn=postgresql.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:to:subject:user-agent:mime-version:date:message-id:from :to:cc:subject:date:message-id:reply-to; bh=U+Nvjsy9uH29i9VSjc1WUgedwutLDulM/WScqbtKlug=; b=D5kEvrlA8PvqyLzqw9Lkjdhb9YnwdtX5ktMzTe1JdcQYlULrA0YZDwaUnyoaJBWj2c UFJs6dPbdqu5d7yrzXqyzSUF2B5U955Tozj62Is3YOE2ihMfYqAhJEd3jQ7Z4ejvVwdA /sTLsOKLrh7UPOZtl05OmDY3/I2HIh90LSAjW1mqEkSH4eDMuhucQe5eh06MaEXq6cEh ZIP52ukswnX+LDGxrQYP7MEiYOEJaFfp3fjJmEUW5CF3d+2pi/McuSxIgSJqKeDkjPOG MY0Hd7yAPToxewvKds8qdfCkfYBiUiXdzShU71+I0i92zlp37X0NCZ81LQmQB+yoDop/ TAIg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1771232737; x=1771837537; h=content-transfer-encoding:in-reply-to:from:content-language :references: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=U+Nvjsy9uH29i9VSjc1WUgedwutLDulM/WScqbtKlug=; b=ksTjgXqrjbqK84jYx1V7NxumdnBNlWMpf4tdKgsUlgIic1dBqACpko7ar3cjrGVm6B 5RBo/3WN7EBc6+S2q48MCfH0ZFBrKP84nMekQBnU0B5urxHy4JDdpTdXs1ZzwXe9wwSy yo8tempHvONhgdrsW8t5Lmdrq5UQQM4Y4+qaOAXB+0UrHqnu5DNdqxBoKrlHFrgAAKEF TCg6ZBcCJWp30y93v9425D2f8+FibcPI+v2FXOloHo1794P7LFVFrjBE4t9/yuNaxnY9 zxS6oGgJULQ5rcwaVa8wHhWup7U/urBSvBOSYYl0eVWGzOoFAnioGntoK8Rc7Op7Qx0y jbgg== X-Forwarded-Encrypted: i=1; AJvYcCUgBVz8+H6N6k/22qz9UtLvJSt9Qjf1r9wGWb2VHOdXP+3PHmQiXSgS/0ORSRYO3OJqCQZpwA2Z4ngKNn6j5BmfgQ==@postgresql.org X-Gm-Message-State: AOJu0YwH38qufcDQdiA1IZI8rxxUIZIbJu9nxXncbqveT77GlNVj1lx4 0XGcKq6BbfOS+FoMO/6v5wVwpUXxhXi/7gDt5a7qLsOjmGmLVOKcj2VQipU8gw== X-Gm-Gg: AZuq6aI0bky8zw8Lgy26FVZWJaibDZV8rflezE4HF8jxj8IngHgevaFkcXkhAq51ezx Y4+dpK2K/tHAUlDN48oe0H480RSGi8mUFztBGsv6N47GvT7gcpaAz9MB8qnfhHGdKr06swk94im ULZywbCBb9yB0aNXvVvcAPOhRrHASKt4sz9WqhEtiKalp3yMWRQJU3ldCkTypoT03uxLPrlEoQC nZP1c5f/3UXf+lvfanaInPPdxpRnJfjykME1aSliPRU63ZB1M7Bz6HYDkJSqRBjjvvsuAGUfhQs OcySuCPKZ/zZSA096rRhzCsxXyayCgN6cTfVrz2YisgUjjEYrMmhZptiYnc1/XPWNF6jhx5ZGAE W7+nGle1UpdfpJ//7+kQj62ptjt1TicavWrrdQ4Tlznu/bJVJjHjOxEVXvWLPfRKVLol9/ou1hT adP+RpvkCCVAPJQvP0ddOdGcNw6IhzS2C/ISN7Eg== X-Received: by 2002:a05:6000:2002:b0:431:266:d13a with SMTP id ffacd0b85a97d-43797919facmr18314012f8f.48.1771232736634; Mon, 16 Feb 2026 01:05:36 -0800 (PST) Received: from [192.168.15.199] ([80.251.191.198]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-43796ac9d77sm23820681f8f.33.2026.02.16.01.05.35 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 16 Feb 2026 01:05:36 -0800 (PST) Message-ID: Date: Mon, 16 Feb 2026 10:05:35 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: A serious change in performance between PG 15 and PG 16, 17, 18. To: Clive Boughton , pgsql-performance@postgresql.org References: <5A68A5FD-3CD2-4863-B274-51804235BE3C@softimp.com.au> Content-Language: en-US From: Andrei Lepikhov In-Reply-To: <5A68A5FD-3CD2-4863-B274-51804235BE3C@softimp.com.au> 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 16/2/26 04:49, Clive Boughton wrote: > For reasons of security I can't provide all the SQL code, but I can (if > it is necessary) provide an outline of what the code does. In principle, you can provide EXPLAIN and schema in a private email so we can invent a synthetic example for public discussion based on your problem (I wonder if it is related to one of the typical Postgres issues like index picking or Subplan transformation). I already had such an experience with a company from Sydney, and it worked well. -- regards, Andrei Lepikhov, pgEdge