Received: from maia.hub.org (unknown [200.46.204.183]) by mail.postgresql.org (Postfix) with ESMTP id 4B4436337CE for ; Mon, 12 Apr 2010 12:38:11 -0300 (ADT) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024) with ESMTP id 34324-05 for ; Mon, 12 Apr 2010 15:38:00 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mail-ew0-f220.google.com (mail-ew0-f220.google.com [209.85.219.220]) by mail.postgresql.org (Postfix) with ESMTP id A1BE76337C5 for ; Mon, 12 Apr 2010 12:38:00 -0300 (ADT) Received: by ewy20 with SMTP id 20so2317893ewy.21 for ; Mon, 12 Apr 2010 08:37:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from :user-agent:mime-version:to:cc:subject:references:in-reply-to :content-type:content-transfer-encoding; bh=5JCXFurct2Bk8Nf+fXK+/Ad63pR75yiCFoE4KvJcNRs=; b=jVFcIROIzoSbIyyYTcQanCBkYGNh+h7yCnZLq21Kx7XPNMlXLy/LmWhnlUN2izmYJm uHsSWpc+3xVjVCDhOJsUbCgOYF+Qw/fToODFK3FXM0Rb3g83w+US/ifwdqBzpAIJ9aTp iqf3vxvD/X7uch8sqL5VAq73OaS4yreqVqdnA= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; b=fdQixjvAgfTllR/VX363peKfY7zfOyGzQxy1ojdy3DLRNTDE16x9DVWA9N78qhCVCf unGqemEaqTgggUJ4sKvh3pKzas87WtmkSTfm6I7E8SOB68m1lWgbFJ/TpLjE1GF37zkl Ql/qpsiqpylcaAyAZXtX30TQ7VYziYn4EBkcc= Received: by 10.213.46.208 with SMTP id k16mr2188515ebf.8.1271086679367; Mon, 12 Apr 2010 08:37:59 -0700 (PDT) Received: from [0.0.0.0] (5357DA75.cable.casema.nl [83.87.218.117]) by mx.google.com with ESMTPS id 15sm2981200ewy.4.2010.04.12.08.37.58 (version=TLSv1/SSLv3 cipher=RC4-MD5); Mon, 12 Apr 2010 08:37:58 -0700 (PDT) Message-ID: <4BC33E56.3000704@gmail.com> Date: Mon, 12 Apr 2010 17:37:58 +0200 From: Yeb Havinga User-Agent: Thunderbird 2.0.0.24 (Windows/20100228) MIME-Version: 1.0 To: Leif Biberg Kristensen CC: pgsql-sql@postgresql.org Subject: Re: Table Design for Hierarchical Data References: <201004121114.10189.achill@matrix.gatewaynet.com> <4BC334E2.6020600@gmail.com> <201004121730.18837.leif@solumslekt.org> In-Reply-To: <201004121730.18837.leif@solumslekt.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-1.899 tagged_above=-10 required=5 tests=BAYES_00=-1.9, FREEMAIL_FROM=0.001 X-Spam-Level: X-Archive-Number: 201004/45 X-Sequence-Number: 33972 Leif Biberg Kristensen wrote: > On Monday 12. April 2010 16.57.38 Rob Sargent wrote: > >> Believe me: "ego-ma-pa" will correctly define genealogical relationships >> (at least among humans). >> > > Yes, but a family tree is not a hierarchical tree as defined in database > theory. Believe me: I'm a genealogist. > The last sentence is almost like the 'proof by authority' from 36 methods of mathematical proof, see e.g. http://jwilson.coe.uga.edu/EMT668/EMAT6680.F99/Challen/proof/proof.html.