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Message-ID: <4B75582A.9090100@gmail.com>
Date: Fri, 12 Feb 2010 14:31:22 +0100
From: Yeb Havinga <yebhavinga@gmail.com>
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To: Luiz Angelo Daros de Luca <luizluca@gmail.com>
CC: pgsql-performance@postgresql.org
Subject: Re: Immutable table functions
References: <8b96e3d21002120454q77b1d72eq38a91b7f486e8f29@mail.gmail.com>
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Luiz Angelo Daros de Luca wrote:
>
> I have a directed graph, or better, a tree in postgresql 8.3. One 
> table are the nodes and another one are the connections. Given any 
> node, I need to get all nodes down to it(to the leafs) that have 
> relation with anotherTable. Also, this connection change on time, so I 
> have a connectionDate and a disconnectionDate for each connection 
> (which might be null to represent open interval). This way, I wrote a 
> pgsql function (I rename the tables and columns to generic names). 
> These are the tables and the function:
>
Hello Luiz,

If you could upgrade to 8.4, you could use WITH RECURSIVE - my 
experience is that it is several orders of magnitude faster than 
recursive functions.

http://developer.postgresql.org/pgdocs/postgres/queries-with.html

regards,
Yeb Havinga