Re: native xml processing vs what Postgres and Oracle offer

From: Brian Selzer <>
Date: Mon, 1 Dec 2008 17:09:38 -0500
Message-ID: <DgZYk.8982$>

"paul c" <> wrote in message news: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.

I didn't say anything about a heirarchical model. I'm arguing that the content of a forum--messages and responses to messages--is in essence heirarchical. This is not about how messages are displayed, it's about what they are: each message either starts a topic or is a reply to another message.


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

The essence of a heirarchy is precedence. A heirarchy is a collection of individuals (objects) connected in such a way that each individual has at most one direct predecessor and that no individual can be a direct or indirect predecessor of itself. Records and the position of records are at best orthogonal.


> 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 - 23:09:38 CET

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