report writer for XML

We are thinking about storing a collection of XML instance documents,
that will all conform to a particular DTD.  But we do not understand
how to run traditional control break reports on these documents.

Currently the report writers we use, e.g. Crystal, SQR, Brio, etc.
expect their data to come from a relational database.
There is clearly a vast difference between writing XSLT or XQuery, 
versus the relatively simple GUI provided by a report writer
to permit a business user to define a report. 

I see a variety of possible approaches, but none of them look
wonderful.  I give a brief description and some Pros and Cons of each.

1.  Wait until the current report writer programs work as well against
an XML source as they do now against SQL.  Con: probably a few years
away.  Possible Pro: the structure of an XML document is a great fit
with that of a traditional control break report.

2. Transform the XML into a set of relational tables.  Con: requires
designing that set of tables, including their columns, datatypes, keys
etc.  Then at runtime we must "shred" the XML into those tables, using
some transformation process.  Note that a naive approach, e.g. store
the DOM into an elements tables, plus an attributes table, plus a few
other tables, is not viable.  This would produce a faithful
(information preserving) copy of the XML, but it would be essentially
impossible to report on it.  I am familiar with the work at
http://www.rpbourret.com/ and we would need to do something like that.
Another Con: there are now two copies of the data (we might find this
acceptable.)  Possible Pro: We are using an industry standard, namely
ACORD (for insurance).  There might be a vendor who has already solved
this problem.

3.  Find a new report writer program that is designed to go against
XML instance documents.  Con: I have not heard of such a thing.  
Pro: If this exists it just may solve the problem.


Other approaches, and other feedback about these, would be appreciated. 
In addition to the query language mailing list www-ql@w3.org
and comp.text.xml are there other or better places to post this? 

Thanks,
Steve
-- 
Steven Tolkin          steve.tolkin@fmr.com      617-563-0516 
Fidelity Investments   82 Devonshire St. V1D     Boston MA 02109
There is nothing so practical as a good theory.  Comments are by me, 
not Fidelity Investments, its subsidiaries or affiliates.

Received on Thursday, 24 January 2002 09:09:54 UTC