Re: native xml processing vs what Postgres and Oracle offer
Date: Mon, 24 Nov 2008 10:37:39 -0800 (PST)
On Nov 21, 2:56 pm, "Walter Mitty" <wami..._at_verizon.net> wrote:
> "David BL" <davi..._at_iinet.net.au> wrote in message
> > On Nov 11, 5:20 am, paul c <toledobythe..._at_oohay.ac> wrote:
> >> whileone wrote:
> >> > Yes, forum "topic headings" are ordered by date and
> >> > time. But each topic also has 0 or more child responses, and child
> >> > responses might
> >> > be responses to responses, rather than responses to topic headings.
> >> > That's a tree
> >> > (a root node with nested children). And a tree is a hierarchy. You
> >> > do need all those
> >> > parent/child relationships.
> >> Believe that if you want but there is no guarantee in any forum I've
> >> ever seen that response n, quoting response n-1, has any relationship to
> >> say, response n-2, or vice-versa. It might be seen as some kind of
> >> graph but not necessarily a tree.
> > If every post apart from the first post for a topic is made in
> > response to a previously existing post then inevitably it is possible
> > to define a tree structure.
> > Are you suggesting:
> > 1) that isn't actually the case;
> > 2) a post shouldn't actually be regarded as a response to some
> > previous post; or
> > 3) the tree structure can be defined but isn't necessarily
> > pertinent?
> I agree with you, David. The fact that a message is either a topic starter
> or a response to some specific prior message is inherent in the way forums
> work. It isn't just a matter of whether the analyst chooses to see it that
> way. I haven't read the specs on usenet messages, and I don't know whether
> messages are identified by ID or my title. But either way, the distinction
> is clear to the user who clicks on either "Reply to Group" or "Write new
I remember an interesting read a while ago by a threaded newsreader author and the bottom line is the author first worked with the "in reference to" part of the headers (References:) and then the subject line and posting time, just due to the fact that there were so many newsreaders that just one method wasn't going to cut it. While in theory, using the references header you could rebuild the tree (as the references would accumulate using the replied to articles list of references), in practice usenet is subjected to any number of news clients some being better than others. Received on Mon Nov 24 2008 - 19:37:39 CET