Re: why hierarchy?
Date: Wed, 26 Jul 2006 15:21:16 GMT
>>> I spoke in a recent thread of my distaste for XML from a theoretical standpoint ... I find this return of focus to hierarchical models since 1995 extremely frustrating.
>> "Codd had a bunch of ...fairly complicated queries," Chamberlin said. "And since I'd been studying CODASYL (the language used to query navigational databases), I could imagine how those queries would have been represented in CODASYL by programs that were five pages long that would navigate through this labyrinth of pointers and stuff. Codd would sort of write them down as one-liners. ... (T)hey weren't complicated at all. I said, 'Wow.' This was kind of a conversion experience for me. I understood what the relational thing was about after that."
> Could someone demonstrate this experience by replicating the Food
> Judging Example at www.dbfordummies.com/example/ex039.asp with RM?
> To verify which method's underlying data model is more general, one can
> observe the impact on existing schema/data/query when meeting future
> unknown data requirements (to be proposed by someone else). Would
> someone be willing to engage in this example?
The question is patently impossible/ridiculous. Only a mystic can predict the 'future unknown'. (Some of us will disagree and say that even mystics are incapable of such predictions. Codd should have added a fourteenth rule - "the first thirteen rules don't apply to mystical db's".)
p Received on Wed Jul 26 2006 - 17:21:16 CEST