Re: Nested Sets And Pedigrees

On Wed, 10 Apr 2002 10:13:04 +0200, "Jan Hidders" <hidders_at_uia.ua.ac.be> wrote:

>"--CELKO--" <71062.1056_at_compuserve.com> wrote in message
>news:c0d87ec0.0204091405.2295590a_at_posting.google.com...
>>
>> Arkansas marriages? But it is the fact that each child has two, not
>> one, parents is the real sourc eof the problem.
>
>Was my proposal really that unclear? There is no problem if you realize that
>there are actually two hierarchies involved. One hierarchy is defined by the
>father-of relationship and the other hierarchy is defined by the mother-of
>relationship. Both relationships define true hierarchies and can be
>represented with the nested-sets approach.

Well, you can store the information in that way, but there is no real benefit gained from it. The nice thing about the nested set model (and the equivalent materialized path model) is tha you can easily find all ancestors/descendants of a given node. This is not possible in your model.

-- 
Nis Jorgensen
Amsterdam

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