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=JJSx9MUJcipugxtHN3ISan7rge24aXVwpWBmR/vfHrhEF0aMiOA+IPLA8pPkYBq+Ft
	LpWcC5FK8oGxBvD2g1SyIRU5NKDAZfyYOVGPT5u4Bv3CtNL3rtX4swlJVH92gUOUaib1
	ohAG+F+moYcj83WB5zEYE7PBLCaqfqnJd73eE=
Message-ID: <4BBCEC03.3050100@gmail.com>
Date: Wed, 07 Apr 2010 22:33:07 +0200
From: Yeb Havinga <yebhavinga@gmail.com>
User-Agent: Thunderbird 2.0.0.24 (Windows/20100228)
MIME-Version: 1.0
To: Achilleas Mantzios <achill@matrix.gatewaynet.com>
CC: pgsql-sql@postgresql.org
Subject: Re: Table Design for Hierarchical Data
References: <n2i5ab13581004061033j4ed25734xd0504cb95a1fc092@mail.gmail.com>
	<201004071000.15529.achill@matrix.gatewaynet.com>
	<4BBC3D14.8080401@gmail.com>
	<201004071139.42140.achill@matrix.gatewaynet.com>
In-Reply-To: <201004071139.42140.achill@matrix.gatewaynet.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit

Achilleas Mantzios wrote:
> Στις Wednesday 07 April 2010 11:06:44 ο/η Yeb Havinga έγραψε:
>   
>> Achilleas Mantzios wrote:
>>     
>>> You could also consider the genealogical approach, e.g.
>>>
>>>
>>> The parents of any node to the root, i.e. the path of any node to the root are depicted as
>>> parents[0] : immediate parent
>>> parents[1] : immediate parent of the above parent
>>>   
>>>       
>> What I have more than one parent?
>>     
>
> Then it is no longer neither a tree, nor a hierarchical structure, but rather a graph.
> This a totally different problem.
>   
My question was actually an attempt to point at the inability of what 
you call the 'genealogical approach' database design to store 
information of more than one parent.

regards,
Yeb Havinga