Re: Table Design for Hierarchical Data

The "parent" node in a genealogy is the mother-father tuple, so given
that as a singularity it still fits a tree.

On 04/08/2010 12:56 AM, Achilleas Mantzios wrote:
> Στις Wednesday 07 April 2010 23:33:07 ο/η Yeb Havinga έγραψε:
>> 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.
> 
> 
> Are you suggesting that we should change our definition of trees ADT, just because it does not
> fit the mere detail that humans have two parents?
> Or are you just suggesting that the "genealogical" term is inaccurate?
> 
> Take a look here: www.tetilab.com/roberto/pgsql/postgres-trees.pdf
> 
>>
>> regards,
>> Yeb Havinga
>>
>>
> 
> 
>