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Re: [castor-dev] Castor & Ozone for XML

On Wed, 19 Apr 2000, Arkin wrote:
> Michael French wrote:
> > 
> > Would anyone like to 'compare and contrast'
> > Castor and Ozone for XML content management ?
> > 
> > I suppose there are the philosophical questions
> > of RDBMS v. ODBMS for XML, but I'm thinking
> 
> There are only philosophical questions, the rest are technical details
> :-)
totally agreed :)

Ok, here goes the ozone/OODBMS philosophy:

> The Castor philosophy is:
> 
> a) RDBMS are best at dealing with large amounts of information, the
> relational model prevails for that
programming languages are OO, app models are OO. The more you need (or want) to
represent your app logic in a persistent environment the more you should
consider a tool that natively supports OO - an OODBMS.

The are many cases where a RDBMS is the best choice. However, I'm in doubt if a
mapping tool like Castor, that does only uses RDBMS as back-end store *without*
trying to map also the set-oriented model behind RDBMSs, is the way to go.

> 
> b) XML documents are best for dealing with the structure of documents
> and conveying information in an impementation-dependent manner
> 
> c) Working with JDBC and SAX/DOM means re-inventing the wheel, it could
> and should be easier to use XML and RDBMS
> 
> Based on that philosophy we do not persist XML documents into a database
> (like XML repositories do), but rather expose the RDBMS as an XML view
> of it. (Doesn't sound like much, but big difference. It also works and
> scales better)
ozone *does* store DOM in the database. One eason: a mapping tool (or an XML
facade of a RDBMS) constructs DOM/SAX in the client (this maybe in an app
server but is still the client of the RDBMS). If the working set of data (your
XML documents) don't fit into cache of the client then the performance is
probably bad for structured query and update operations.

In general: as always, it highly depends on the actual use case.


Falko
-- 
______________________________________________________________________
Falko Braeutigam                         mailto:falko@softwarebuero.de
softwarebuero m&b (SMB)                    http://www.softwarebuero.de