Received: from malur.postgresql.org ([2a02:16a8:dc51::56]) by arkaria.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA384:256) (Exim 4.89) (envelope-from ) id 1fnPz8-0001c1-Hp for pgsql-hackers@arkaria.postgresql.org; Wed, 08 Aug 2018 15:02:50 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.89) (envelope-from ) id 1fnPz6-00026e-1E for pgsql-hackers@arkaria.postgresql.org; Wed, 08 Aug 2018 15:02:48 +0000 Received: from magus.postgresql.org ([2a02:c0:301:0:ffff::29]) by malur.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA384:256) (Exim 4.89) (envelope-from ) id 1fnPz5-00026S-Q7 for pgsql-hackers@lists.postgresql.org; Wed, 08 Aug 2018 15:02:47 +0000 Received: from mail-qt0-x244.google.com ([2607:f8b0:400d:c0d::244]) by magus.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1fnPz1-0002Mu-Uz for pgsql-hackers@postgresql.org; Wed, 08 Aug 2018 15:02:47 +0000 Received: by mail-qt0-x244.google.com with SMTP id c15-v6so2808752qtp.0 for ; Wed, 08 Aug 2018 08:02:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=2ndquadrant-com.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:mime-version:content-disposition :content-transfer-encoding:in-reply-to:user-agent; bh=WIhDoHCfMVYHGyf0YELxb8+0OrMfT/piE2B8eJIPquk=; b=UsRiu2CnW7n/5493BapV3UZl1LxPoRH25joliRQNrTmktxfThKFF69DE9f7rdj6HzJ i4IIchOrs91cdu0zlsynnOJROFWbUFyNGBXUjpeJZYFDXSjXNVh8vCwV424XNCjG6v7C fZbXTSNeYiD2g5sJouXt0wXvWBIVeCD5IQCtw3zHADjwStBTw/3vHC4TYUxprU1yHiWm cf9CsMnl9pu4OGwuvSc/R84j3PQLESW7iuMdAoAOzHUIo/Uv2s6rAiENAAdQT/TvSg1/ R2eBuolW+mojXikgyuylrI7J+ybKKRNhE0ZlZ68HVSowYXVLzGz+M+CLDZOqPRG7boke mNIg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:mime-version :content-disposition:content-transfer-encoding:in-reply-to :user-agent; bh=WIhDoHCfMVYHGyf0YELxb8+0OrMfT/piE2B8eJIPquk=; b=mjEZ1VWmlWjhjSraU6fQwhxOfLOC6Idzw5Vie/nVmupQ1hL8x2Wh2EKId9X3Qf4bRv v97O0WaNLm5VeWGYtorl7Z/2UpOqScKulmp+TCAwQcdDvUmAgrFtcBFtebsVji46Yldr Ghw1Y6mkYwETVLI/nvGq5XqBRAo/iWgZGiwjGOXZiVUyz0wSXwAuy2gM62e3oVK+x8Xf XqxldTqVt4Y8a4JbFZA9qUBnT3seAKH7F0e5m2sCOdsXSO9kvJ6IEFPulF1frf9bS1Ic UOZz6KUkGgf/LyF/hjFLHyjgJ62+iUzP3XSZ1hO9W/FEVq2LoF0am21UkKCS3RcnKN54 TFWQ== X-Gm-Message-State: AOUpUlHobiLcAVzqBakpncvNLjuIlLwE5Au8axmGupSTiKlmNoN1+Brn tzs1m794PYx+GRf6+18X0jX/5g== X-Google-Smtp-Source: AA+uWPwtf/4Dv2Bjnhr5SRM93exIr2/fth3kfo8nDLTdV+5NsSseYZnSAEjTISgY3OW1m+fFBtKWFg== X-Received: by 2002:ac8:2ddd:: with SMTP id q29-v6mr2946601qta.3.1533740561833; Wed, 08 Aug 2018 08:02:41 -0700 (PDT) Received: from alvin.alvh.no-ip.org ([190.121.29.3]) by smtp.gmail.com with ESMTPSA id s9-v6sm2333742qke.46.2018.08.08.08.02.41 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 08 Aug 2018 08:02:41 -0700 (PDT) Received: by alvin.alvh.no-ip.org (Postfix, from userid 1000) id 97D1F47C; Wed, 8 Aug 2018 11:02:39 -0400 (-04) Date: Wed, 8 Aug 2018 11:02:39 -0400 From: Alvaro Herrera To: KES Cc: Bruce Momjian , PostgreSQL-development , pgsql@j-davis.com Subject: Re: Typo in doc or wrong EXCLUDE implementation Message-ID: <20180808150239.6gp6vgisxcempyoh@alvherre.pgsql> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <31616681533725753@sas1-d856b3d759c7.qloud-c.yandex.net> User-Agent: NeoMutt/20170306-137-4415bd-dirty (1.8.0) List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Precedence: bulk On 2018-Aug-08, KES wrote: > I do not know many internals and maybe wrong. > > But from my point of view with my current knowledge. > If such exclusion constraint would be marked as UNIQUE we can use it for FK while implementing temporal/bi-temporal tables. > > And this will be simplify relationing while implementing them. I think what you're looking for is "inclusion constraints" from Jeff Davis: https://postgr.es/m/1423354088.12308.117.camel@jeff-desktop -- Álvaro Herrera https://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services