Re: How to store directory like structures?

On Sun, 3 Apr 2005, Axel Straschil wrote:

> Hello!
>
> I want to store some structure like:
>
> CREATE TABLE node
> (
> nodeid SERIAL PRIMARY KEY,
> parent INT REFERENCES node(nodeid)
> ON UPDATE CASCADE ON DELETE CASCADE,
> label TEXT,
> UNIQUE (parent, label),
> ...
> data
> ...
> );
>
> The label is used to map a node to a directory like strukture, so i can
> have a function directory_for(nodeid) which gives me
> /root_label/parent_label/parent_label/my_label (root labels have NULL as parent)
>
> The problem is the ammount of queries when i've got deep nodes, and I
> often have to query if a node is "in path" of another node.
>
> Is there a good solution to build directory-tree like datastruktures?
> I found, http://www.sai.msu.su/~megera/postgres/gist/ltree/ which seems
> to do what i want, but I've no idea (and probalbly no chance) to get
> that running on my system ;-(

what's a problem with ltree ?

>
> Thanks,
> AXEL.
>
>
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Regards,
Oleg
_____________________________________________________________
Oleg Bartunov, sci.researcher, hostmaster of AstroNet,
Sternberg Astronomical Institute, Moscow University (Russia)
Internet: oleg(at)sai(dot)msu(dot)su, http://www.sai.msu.su/~megera/
phone: +007(095)939-16-83, +007(095)939-23-83