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Re: Nested Sets WAS: column size too large, is this a bug?

From: Robert Treat <xzilla(at)users(dot)sourceforge(dot)net>
To: Josh Berkus <josh(at)agliodbs(dot)com>,Andrew Rawnsley <ronz(at)ravensfield(dot)com>
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: Nested Sets WAS: column size too large, is this a bug?
Date: 2004-03-30 20:06:08
Message-ID: 200403301506.08882.xzilla@users.sourceforge.net (view raw or flat)
Thread:
Lists: pgsql-performance
On Tuesday 30 March 2004 11:38, Josh Berkus wrote:
> Robert,
>
> > If you search the pgsql-sql archives you'll find some helpful threads on
> > using nested sets in PostgreSQL, one in particular I  was involved with
> > was a generic "move_tree" function that enabled moving a node from one
> > branch to another.
>
> I have to admit to failing to follow -SQL over the last few months.    This
> list and Hackers are pretty much the only ones I read all of.
>
> Maybe I should get back on -SQL and we can compare move_tree functions :-)
>
> Did yours use a temp table, or some other means?

Nope, Greg Mullane and I worked out the math and came up with an algorithm of 
sorts that we could apply to the tree when moving elements.  

<digs a little>
http://archives.postgresql.org/pgsql-sql/2002-11/msg00355.php

Seemed to work though someone else had posted yet another version after 
ours... and in fact the one posted is not exactly what I use now either :-)

Robert Treat
-- 
Build A Brighter Lamp :: Linux Apache {middleware} PostgreSQL

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