Re: Canonical DB

On Fri, 23 Jun 2006 11:55:36 +0200, mAsterdam wrote:

> Googling for 'graphs RM' gives
> http://www.rm.com/primary/Products/Product.asp?cref=PD1112
> ;-), substituting 'relational' for 'RM' made me stumble on
> http://www.cs.york.ac.uk/cvpr/relational.php

I'm not sure that the latter is really "relational" in the sense of RM. The algebra of the relations between matched instances of pattern atoms is not necessary RA. [That's all I can derive from the text, I might be wrong.] The approach itself is common for text pattern matching, as well.

> If you don't mind getting your hands dirty:
> http://technology.amis.nl/blog/?p=1160 mentions
> some Oracle specifics, in
> http://www.dbazine.com/oracle/or-articles/tropashko4
> Vadim Tropashko discusses two ways "to model a tree
> in the database". His new book might be on the way
> to the stores by now, but I did not find a reference.
> Joe Celko wrote
> http://www.amazon.com/gp/product/1558609202/102-4421784-8373769?v=glance&n=283155

Reading such things one should always ask himself: what was lost? Any tree built in any way is a tree. Once you have it, it will not fully obey RA or whatever framework you used. That precisely means: an otherwise legal operation applied to a tree may kill it. It is so with all complex structures. Integers can be constructed as sets. But if you tried to arbitrarily apply set-theoretic operations to the sets representing individual integer numbers, you might get rubbish.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de