Re: [WEB400] XML/XSL

["Nathan M. Andelin" <nandelin@xxxxxxxxxxxxxxxxxxx>]

> From: <MEovino@xxxxxxxxxxxxxxxxx>
> Overhead in using it does seem to be high enough that
> it looks like companies are building appliances to handle
> XSLT processing (http://www.datapower.com/)

Reading about this network appliance has changed my perspective.  It
evidently compiles XSL files into machine code, and offers a dedicated CPU
for XML transformation, which addresses my performance concerns.  It also
seems like a good idea to offload SSL encryption to a network appliance.

I think it would altogether eliminate the need for evoking XSL
transformations like the code sample that Aaron shared, which would simplify
server code.  Just output a reference to an XSL file in the XML stream.

It also made me realize that the program code in the XSL file is entirely
dedicated to "transformation", and does not include data validation,
database I/O, business rules, or other control logic that one normally finds
in Net.Data and comparable runtime environments.  XSL files would be easier
to maintain since transformation code is separate from DB I/O and other
control logic.

This appliance evidently runs in "proxy" mode, passing requests to the HTTP
server, and only evokes transformation when a reference to an XSL file is
returned.  Static files like images simply pass through to the browser.

Does it cache compiled XSL code?  Does it automatically recompile changed
XSL files?  Will it retain potentially thousands of compiled XSL files in
memory?  Is it scalable?  How much does the appliance cost?

Although I still have questions, it basically sounds like a good idea.

Nathan M. Andelin
www.relational-data.com