RE: [xml-dev] XML DB - anything new and interesting?

["Michael Kay" <mike@saxonica.com>]

> All of which led me towards Cocoon and then Orbeon...
> 
> >> * You use XHTML+XForms as your templating language.
> >> * You use REST and XQuery to interface with services and 
> XML databases.
> 
> I'm only a couple of days into it, but it appears you could 
> happily create your XHTML + XForms using XSLT 2.0 and that 
> could be really powerful.  Hopefully I'll understand a bit 
> more on that today...

One of my clients has been using this architecture successfully for several
years. User input comes in as an XForms instance, XSLT (Saxon) takes this
instance as input and either generates or parameterizes a query on the
(Tamino) database; the output of the query comes back as XML, and goes
through another stylesheet which generates XHTML+XForms, and the cycle
starts again; all controlled by an Orbeon pipeline. Works very well, except
that it can be tempting to make the pipelines too long, at which stage you
start to lose response time, especially if they include metastylesheets,
which is quite often.

The experience with Tamino - and it's mirrored by another client who uses
DB2 XQuery - is that it's best to keep the queries simple if you want to
have a good chance of them being executed efficiently. Concentrate on
getting the data you need, and don't give the database engine the extra
burden of doing any complex analysis of the data, or formatting it for
display: that's better done outside the database engine in XSLT code.

Michael Kay
http://www.saxonica.com/