Re: [xsl] [xslt performance for big xml files]

[Liam Quin <liam@xxxxxx>]

On Sun, Apr 26, 2009 at 06:47:58AM -0400, Robert Koberg wrote:
> Well, the XML DB vendors pitch the XML DB as a web application  
> platform. There is also the XRX push from some who push this as well.  
> As soon as you get your first request parameter (or import your  
> vendor's request namespace) you are into vendor defined extensions.  
> This happens almost right away. It seems to me that the XQuery  
> standard is a hook for the user that is tossed aside as soon as they  
> are on the line.

XQuery wasn't written ony (or even primarily, really) for Web Apps.
I agree with you that we (W3C) should probably standardise access
to CGI parameters.

Most XQuery implementations do not in fact use databases at all.

Some XQuery implementations are included as a small part of a
larger database server -- e.g. MS SQL SERVER, IBM DB2, Oracle
all include XQuery support, but not directly in a Web framework.
So HTTP request parameters may or may ot belong in the core language.

> Of course, but we are talking about a W3 standard. I can run HTML on  
> any browser, parse XML with any XML parser, run XSL on any XSL  
> processor (and there is a mechanism to check for vendor extensions and  
> choose the correct one based on the processor)

Actually if you write a Web app in XSLT, and e.g. call functions to
determine the height and width of jpeg images, or to access query
parameters, you've gone beyond the standard.  Yes, there's things
like function-available and (in XSLT 2.0) use-when that may help,
I agree.  In XQuery you're more likely to have some separate
modules you implement differently, so that the main query is
unchanged between implementations.

> I am not a DBA, but I use Hibernate to keep the (generated) SQL vendor  
> agnostic. But again, XQuery is a W3 standard. I just can't help  
> feeling there is a con going on. That is probably too strong, but I  
> hear, "Look at my standards compliant XML DB - you can use standards  
> based XQuery. However, to use it as we suggest, you will need to use  
> our extensions."

Please tell me privately who is saying this sort of thing (praise
in public, criticise in private, no names no pack-drill, etc etc).
We (W3C) can't mandate that vendors be honest any more than we
can mandate that users be wise and cautious :)

And yes, we'll be watching what happens with exquery.org.

Liam


-- 
Liam Quin, W3C XML Activity Lead, http://www.w3.org/People/Quin/
http://www.holoweb.net/~liam/ * http://www.fromoldbooks.org/