Re: Table Design for Hierarchical Data

Στις Thursday 08 April 2010 17:59:01 ο/η Rob Sargent έγραψε:
> The "parent" node in a genealogy is the mother-father tuple, so given
> that as a singularity it still fits a tree.
No, because the child and parent node would be of different schema.
>
> 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
> >>
> >>
> >
> >
> >
>



--
Achilleas Mantzios