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 1wBu0E-001Tpm-1Q for pgsql-hackers@arkaria.postgresql.org; Sun, 12 Apr 2026 12:33:26 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.96) (envelope-from ) id 1wBu0A-002B61-2O for pgsql-hackers@arkaria.postgresql.org; Sun, 12 Apr 2026 12:33:23 +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 1wBu0A-002B5t-1F for pgsql-hackers@lists.postgresql.org; Sun, 12 Apr 2026 12:33:23 +0000 Received: from mail-wm1-x32a.google.com ([2a00:1450:4864:20::32a]) by magus.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.98.2) (envelope-from ) id 1wBu08-00000000fIv-391P for pgsql-hackers@lists.postgresql.org; Sun, 12 Apr 2026 12:33:22 +0000 Received: by mail-wm1-x32a.google.com with SMTP id 5b1f17b1804b1-488b8efed61so32516595e9.1 for ; Sun, 12 Apr 2026 05:33:20 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1775997198; cv=none; d=google.com; s=arc-20240605; b=FyPGteTOHd8jIeflux7Jv+NwNZu9xIbR5WOblma9sv9xsDTKIbSD38Ue4gS+iU91K4 XQrTpRs0XrSoDJ8JqzErFLhrpnl2NMM06IpgOBqZULnE1MiAPkIuYfy9QguhfXhcWutr rISGqHVvhqZC2o3p8WXESIxi/gMKABQDlkmpk3ySofOMxP92ty6zOo7abs+PGjmr658r pUOZFOljYygKytqe9KDr9nuL4/9XP3TKtIcZ6/hmvbQvK8RckdXb4cRKOGz4NHeu8gjx TTuU7yWxO3asIB9+KxK7DhEdzahzeTUvVtYSIWE7SNLkbr5SY5naPtfxtAo9lcXLnBwg Rykg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20240605; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:dkim-signature; bh=jWLjrPUegBAp8jxw/wEBrZEVit7A4b4Bu8HKbHOMDec=; fh=NNZnGxbaQhS/xbUY1WQpQtdwg0kibnIhcXEzpOXQl/k=; b=ST+vkXDrAmMFVnzTCj6EcOzWsfAh0dWZA8SgCSVjk65G/MGFq/C1x6mzSBfBvQaDF2 AvJgHSEboY8jHwVUCfCg2AC0Hiq/oywM19BM2KKeGdD3yq7RgiCBL8AfwFDankA4LFWd 55eLZCV6VQJPpLI69oyNn/WmYUcizB8EJnJ7P4Pe3YNcVONlCFlsDeGuW8oUIAA+yWIj W6sX7s/6IrPcgrqGoKHkzy+WrkAvRa9oHNDBgRAmkaipzyhK+FqUdH2M8I/QQjY5/VdR HYHra/8NrPmkNVjmWDdgQeouqj53CkMWgT9M3wTU/7CZX+Y5XGyuy1oHeQjjnz27d4/W zEMw==; darn=lists.postgresql.org ARC-Authentication-Results: i=1; mx.google.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1775997198; x=1776601998; darn=lists.postgresql.org; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=jWLjrPUegBAp8jxw/wEBrZEVit7A4b4Bu8HKbHOMDec=; b=XUd5t7bcFvcVUScsJEq+AEchK2AHmGRAqhR6QDUGqwNxs7uEcIsRV0WU46QwQhj9q8 kUdo/Gz8PDiaXhL7iMV7CrS/N/KBzcVv5uqCxzih75zhPmOhkY/MmEZ5w5XNbYumFopc aVS9oKZe0Fwj7+UOgM4TPw3zERiuCJPBKP4PF4ZSEnfjhZJ9qfEQ/g4iQe9/4WP2dn73 AB89JlX+XdMJSXQWksICb9WgBkQ9zplCvd6usX63hZtnHzRqekPw/XgxEfeNKw+/GFNU HXrgT0bz0wUjMUC5H9e0NIx3CgK8WTcIzHN0+MgaXOcR+86zxIRHaYwhlNkDh8a9DUTt WKnw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1775997198; x=1776601998; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=jWLjrPUegBAp8jxw/wEBrZEVit7A4b4Bu8HKbHOMDec=; b=I8XOvvqCIQCCZqfCCWERhdQBUVn09p7WSKSZiRS4LP52txsn/ElSSt877j2buB6dg7 DPJbTKfo60uUo9ANLovoPPDs3zLLsHARFuO1iZFesVFUPeOFd/kiUYkFmpAyfgMXr8o/ WSF1cGmZTrtDiBzXg0z0V4v9xDf6kHjUKwyEL3V2B44KsPL988Vyy+KL+5CbdMXmQ+bn ueLdWOabvDx7sBg2aC0g/3vGRMYfG0KnQLRzHQhz/+t35sWabdJIQlqj+mw1Z98GAaRi OuXXjGRhwdhnPdwJLsb6pp9iLMEbMywl7oXizD0exRhXH6mazyDOIIvucUmcmb4pcNnX JxEQ== X-Forwarded-Encrypted: i=1; AJvYcCX2sgEhRxVw7DNMhBhjkdzKGoWtFQFqshJAMFgjbZxQB4aW+Hy/uN6WEYRf4j0L81w6NF82qVa0NbTdQNOv@lists.postgresql.org X-Gm-Message-State: AOJu0YyY+0RdQ2xoCp76PeIkt75zSoRn/AHXdPqVpiebriWyJhwP4Fyq j2E3cOi2S4Tzcl66p4sWR8Sw0O89eq6m/JfqGkFz4mxVBbnSj1Oa2hdf3mZAC0lujptAhQ+JkFt jOC61TZWUimSSClZrZgJWXfUqtsX6l+4= X-Gm-Gg: AeBDiesc4BUpJw6CBkBbeFEYLzw/l3u+uzhpS8APM+M4FgjxFf1ssREvQo69D4nVh5n MrXfPOH21VCd4n1BnTwsiJKWzB+P0owGfKM1Uw1vy7W3YvrQ0jWwGveV0jmIez6/nAb3HK341Ac BGCSXh0QHN38lRZ8e7dV7TmtaBrRDlKLe2QoEKp4gZkMqIsPhg78ngrU9narOp+ClKwIWCvwGHg MSHoTZBbLZG3zqtENuqJ3YYZm39jrfURsvYycqUe7Q2Q/OLj2zuPiLrVnv+2r/FuSCUU8vXY/tb R8G8Fy33nBxorP/3BjBBU3LZ/EPO6hn1IjnYREp19w0AKnUiQq8tK5M4jw0Z8pJ/HJVWBLq9QA= = X-Received: by 2002:a05:600c:c0dc:b0:486:fe83:861c with SMTP id 5b1f17b1804b1-488d686837bmr81629575e9.7.1775997197512; Sun, 12 Apr 2026 05:33:17 -0700 (PDT) MIME-Version: 1.0 References: <3190647.1775103768@sss.pgh.pa.us> <59B9EFAF-84DF-40A9-847F-9CF457A798BB@gmail.com> <64C19DC3-CE9B-4222-B71E-31B88574FBDC@gmail.com> In-Reply-To: <64C19DC3-CE9B-4222-B71E-31B88574FBDC@gmail.com> From: David Rowley Date: Mon, 13 Apr 2026 00:33:04 +1200 X-Gm-Features: AQROBzDk8FOD3hckQ2qJpw2Vurgz4-MvAddDt6kRFrXMRV4y7IwiRACdG2kcmh8 Message-ID: Subject: Re: Small and unlikely overflow hazard in bms_next_member() To: Chao Li Cc: Tom Lane , PostgreSQL Developers Content-Type: text/plain; charset="UTF-8" List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Archived-At: Precedence: bulk On Mon, 6 Apr 2026 at 14:01, Chao Li wrote: > > On Apr 4, 2026, at 11:30, David Rowley wrote: > > Not quite perfect as a set made first as a single word set that later > > becomes a multi-word set will be double counted. The number of > > operations on the sets is likely more important anyway, not the number > > of sets being created. The point is, multi-word sets are rare for most > > workloads. > > > > What tests did you run after adding the logs to collect the data? This is a method I might borrow in the future for similar investigations. "make check" then grep regression.diffs for the NOTICE message and pipe to "wc -l"