> > http://www.evolt.org/article/Four_ways_to_work_with_hierarchical_
> >data/17/4047/index.html
>
> I have to say I've seen better writeups on this topic - so be
> warned :)
that looks very much like '1st 5 things i found about recursive data'.

> Choosing a strategy for storing hierarchical data in a database
> depends largely on how you will be retrieving  the data (what kind
> of queries do you need to make).
exactly. and one more thing, the way u store data may not be the way u 
retrieve it - i.e. u have one original copy that presents everything 
as is, and one pre-calculated/calculable-on-the-fly view/copy which u 
use for queries. and for differnt queries u may have different 
extracts/views.
For example, storing a graph as links and nodes is fine to keep the 
original data, but is quite difficult for most (graph algorithmical) 
queries - procedural recursion is not SQL's piece of cake. Thus 
storing additional transient-closure of the graph (all possible 
end-to-end paths) is a way to go for some targets which need paths. 
Probably there are other solutions for other targets.

have fun
svil

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