Re: Trees in SQL

Hey Please post the translation back here !!
;-)

lot many others like would require it
despo.

regds
mallah.

On Monday 27 May 2002 05:30 pm, Achilleus Mantzios wrote:
> On Fri, 24 May 2002, Gregory Brauer wrote:
>
> I have exactly the same situation.
>
> Some work (argued to have better performance than Celko's implementation)
> has been done by Miguel Sofer. (see http://www.utdt.edu/~mig/trees.tar.gz)
>
> One fast solution would be using pgsql arrays and the contrib/array
> package.
>
> However Oleg's and Theodor's contrib/tree solution looks the most
> attractive.
>
> I will ask my wife today to do a translation of the doc,
> (hoping russian and yugoslavian are alike :)
>
> > I hope this isn't an overly broad topic that ends up diverging into graph
> > theory, but I have a tree structure of identical items (analogous to a
> > filesystem directory tree) that I need to store in Postgres. The
> > "obvious" design is to give the table that will represent these objects
> > a field identifying its "parent" that is a relation to the same table.
> > However, this seems to make many common SQL queries rather difficult.
> >
> > What sort of strategies are best for storing tree structures in a
> > relational database, and how would one structure SQL queries to find,
> > say, "all of the children anywhere under this node", or to represent
> > the condition "if this node is a child at any depth under this other
> > node"? Are there good strategies for preventing cycles?
> >
> > I'd appreciate any insights anyone can give.
> >
> > Thanks.
> >
> > Greg Brauer
> > greg(at)wildbrain(dot)com
> >
> >
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