Re: [xml-dev] XML aggregation question?

[peter murray-rust <pm286@xxxxxxxxx>]

At 15:50 27/08/2006, Andrew S. Townley wrote:
>Thanks for the discussion so far.  Mostly just listening and trying to
>absorb the collective experiences.  One specific point below, however...

<snip/>
>Well, herein lies the crux of Mike's comments about if you don't start
>with a DB that's likely what you'll end up building to some degree.  If
>I was managing "real" documents or providing more of a content
>management system, this would more than likely work.  However, I want to
>be able to "slice and dice" my XML instances to provide different views
>or ways of accessing the instances based on values of specific
>attributes or elements.
>
>As I said originally, if I didn't care about wanting to keep the data in
>XML as the "native" format of the system for easy editing by hand (in
>particular for me, using vi on Linux) as well as providing more GUI
>based view/edit capabilities via a Web-based interface (most probably
>using XForms), I'd just forget about the XML aspect and it would be a
>"traditional" RDBMS application.
>
>Based on all the comments thus far as well as reading some of the
>articles/documentation on eXist, it would seem that an XML database is
>really the only viable choice if I want to keep my data as XML and still
>provide aggregated views across the instances based on values of
>attributes (or other expressions using XPath and/or XQuery).
>
>If I went with the "traditional" RDBMS approach, I'd be spending most of
>my application's CPU cycles going to and from XML, so the benefits of
>being able to use SQL to pull the list of instances really doesn't seem
>worth it.  At the moment, I'm leaning towards trying eXist to see how
>well it'll work for what I want to do.

I have found Ron Bourret's pages:
http://www.rpbourret.com/xml/XMLAndDatabases.htm

gives a complete introduction to the issues. It's very clear that you 
need to understand what you want to do and then find which approaches 
are best. Personally I am using semi-structured nearly-readonly 
documents with highly variable structure and wide vocabulary and 
eXist addresses this well.

http://www.rpbourret.com/xml/XMLDatabaseProds.htm

gives a very comprehensive list of products (well over 100).

>Again, thanks for all the discussion so far.  There's likely to be some
>additional comments during the week, so my decision's far from set in
>stone yet.

I hope so - this is what XML-DEV is for... and I'm not clear there is 
an alternative place to ask these questions.

P.




Peter Murray-Rust
Unilever Centre for Molecular Sciences Informatics
University of Cambridge,
Lensfield Road,  Cambridge CB2 1EW, UK
+44-1223-763069