Re: native xml processing vs what Postgres and Oracle offer

From: paul c <>
Date: Mon, 01 Dec 2008 14:22:03 GMT
Message-ID: <fqSYk.1429$yK5.577_at_edtnps82>

Brian Selzer wrote:
> "paul c" <> wrote in message
> news:nUeXk.560$si6.520_at_edtnps83...

>> rpost wrote:
>>> paul c wrote:
>>>> wrote:
>>> [...]
>>>>> Actually, usenet is often displayed as being hierarchical, for
>>>>> instance with so called "threaded" newsreaders, because within a list
>>>>> of discussions, replies to replies are often more comprehensible when
>>>>> you can follow the subthreads.
>>>>> ...
>>>> Nobody said there's anything wrong with hierarchical displays (or
>>>> hierarchical physical storage for that matter).
>>> [...]
>>>> As the general level of literacy continues to decline more and more of
>>>> those who fail to recognize the possibility of a logical model will have
>>>> to put up with that dwindling breed.
>>> You're evading the question.
>>> ...
>> What question would that be?  (The original question was to do with the 
>> best product to use to display hierarchical data.  The OP planned to 
>> invent his own forum, presumably not Usenet-based.  I pointed out that he 
>> was wrong to assume a forum is hierarchical.)

> Pardon me for sticking my nose in, Paul, but you are ignoring facts as plain
> as day: The content of a forum is a directed graph without any
> circuits--that is, a collection of trees--each message being a node and each
> response being a directed edge. How can you possibly argue that it is not
> heirarchical?

I'm amazed that in this day and age there can be any dispute about something so simple. As I said before, one may choose to display messages in a hierarchical way, but that is not at all the same thing as basing a server or reader on a hierarchical model.

The essence of a hierarchy is position and record order. Position ignores the Information Principle and the order is logically extraneous.

Hierarchical implementations depend on pointers or adjacency or both. Without those, some, maybe most, hierarchies are limited to a single presentation. A relational implementation doesn't have that problem.

If you believe that the horizon is flat and airplane window glass makes it appear as a curve then it might be accurate to conclude that the earth is flat, but it wouldn't be pertinent. Same goes for starting with the belief that hierarchy is inherent in the typical forum's actual messages. If that were so, it would just as reasonable to say that every Accounts Receivable data model must be a hierarchy. Received on Mon Dec 01 2008 - 15:22:03 CET

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