From: yumejin <yumejin@...>
Date: 2004-10-09T03:30:45+09:00
Subject: Re: [ANN] ndb Object-Relational Mapper

This guy works (or used to work for Oracle) and came up with a scheme
for storing trees in a relational structure using real numbers (well
that is where he starts).  Anyway, interesting solution.  the only
thing is that it is only good for hierarchical data.

http://www.dbazine.com/tropashko4.shtml

Kelly Nawrocke


On Sat, 9 Oct 2004 02:59:44 +0900, Its Me <itsme213@hotmail.com> wrote:
> 
> "Brian Candler" <B.Candler@pobox.com> wrote in message
> > This is a very cute data structure which I hadn't come across before.
> 
> Google for "ait-kaci lattice encoding" or "efficient tree encoding" and you
> will see lots of work in this space, covering trees, DAGs, etc. and mapping
> them to bit vectors, integers, integer ranges, etc.
> 
> > However, if I add a new subordinate to 'Bert' (say 'Bob'), don't I end up
> > having to renumber almost the entire tree?
> >
> >             Albert
> >              1,14
> >          /          \
> >      Bert            Chuck
> >      2,5              6,13
> >       |            /   |   \
> >      Bob     Donna   Eddie  Fred
> >      3,4      7,8     9,10  11,12
> >
> 
> Add a couple of zero's (1,14 --> 100, 1400) and you suddenly have a whole
> bunch of breathing room before you have to renumber the whole tree :-)
> 
>