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Linda Grimaldi <email@example.com> writes:
> The statement was motivated by an earlier thread on this
> list, where one person was obviously thinking in XML document
> terms, and the other in XML database terms. I found that
> thread frustrating because the two people in it were
> obviously talking at cross-purposes- an XML database is not
> simply a collection of documents, which is perhaps a better
> way of stating it.
> Moreover, there were (are?) several XML database offerings
> that used relational engines under the hood, so there is a
> distinction to be made between those implementations and the
> ones that started "from scratch" with the underlying
> assumption that XML would be the data stored. Both called
> themselves "native", although one was a wrappering of
> relational technology. And if you can succeed in wrappering
> it efficiently enough, eliminate schema dependencies, and
> provide a pure XML interface, who's to know the difference?
Hmmm, didn't I just say that earlier today? :-)
> I also wonder- if you have a complex set of related XML
> documents, such that different document types point to one
> another in relationships that are not well-modeled
> hierarchically, do you end up building something that looks
> pretty relational anyway? If you want to avoid lots of data
> duplication, you probably do. Hence the concept of the
> XML-Relational hybrid, I suppose. Don't know if it really
> works, but I can see where it might come in handy.
Yes, if you're doing graph traversal straight XML doesn't really help
vs. relational (it's messy either way). And yes, as I pointed out
earlier, a relational mapping design really works. It's "interesting"
(as in the Chinese curse meaning of interesting) getting the whole thing
to perform efficiently, but we can retrieve thousands of node/attributes
with sub-second response time.
<snip>Other relational vs. XML DB discussion</snip>