To: "Axel Straschil" <axel@straschil.com>, pgsql-sql@postgresql.org
Subject: Re: How to store directory like structures?
References: <slrnd4vghu.tp.axel@m2.sine>
Message-ID: <op.son4qhnvth1vuj@localhost>
From: PFC <lists@boutiquenumerique.com>
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Date: Sun, 03 Apr 2005 20:09:43 +0200
In-Reply-To: <slrnd4vghu.tp.axel@m2.sine>
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	Use the ltree datatype !
	It's made specifically for this purpose.
	http://www.sai.msu.su/~megera/postgres/gist/

On Sun, 03 Apr 2005 12:13:48 +0200, Axel Straschil <axel@straschil.com>  
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 ;-(
>
> Thanks,
> AXEL.
>
>
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