Re: native xml processing vs what Postgres and Oracle offer

On Nov 10, 11:40 am, paul c <toledobythe..._at_oohay.ac> wrote:

> Suggest that it is more accurate to say that forums are typically
> implemented with hierarchical techniques.  It would be even more
> accurate to say that forums are inherently ordered, eg., by date & time
> within topic.

I'm not sure what you point was.

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.

Using relations to model hierarchies is possible but tricky (Joe Celko has a good book).
With XML and XPath it is a snap. "Relational Databases" like Oracle and Postgres and now Mysql_5.1 (it turns out) do now (also) support XPath queries over XML (hybrid systems where the XML is stored as big
text blob....while new system functions khow how o forget all about SQL
and do XPath over those blobs). The how-its-done details are a little more straightforward with
'nativel XML' databases. But conceptually (from a client developer's point of view) it's all
much the same. Hierarchical XML is better at hierarchies than relations. Received on Mon Nov 10 2008 - 20:07:38 CET