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Re: why hierarchy?

From: paul c <>
Date: Wed, 26 Jul 2006 14:45:44 GMT
Message-ID: <seLxg.242550$Mn5.68416@pd7tw3no>

JOG wrote:
> I spoke in a recent thread of my distaste for XML from a theoretical
> standpoint (nevermind the processing overhead of using an XML parser
> within any even vaguely time critical application).
> ...

Yeah, here's something Chamberlin about an early presentation Codd gave:

"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."

I believe even the CODASYL fans could see that tagging every value in a positional way would result in highly-redundant 'structures' and they were aware that network structure without defined operators is more or less useless. An application that interests me is family trees. We know everybody has a grandfather but sometimes the only other thing we know is that the grandfather must have been born before the father. Having recorded a partial tree, we might discover that two nominal grandfathers were in fact the same person. I'd rather try to deal with   that change using RT. It makes me think that network schemes are nothing more than representations of more fundamental relationships, the latter being what RT deals with.

(I thought the other quotes were pretty sneaky like implying that DNA can be unlocked by XML. The one about "increasingly complex ... structures" was also funny - the complexity seems to have been introduced by XML itself, not the problems it claims to handle - it was news to me that RT can't handle a books database!)

p Received on Wed Jul 26 2006 - 09:45:44 CDT

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