Comments Appreciated on Magazine Based on XML/XSL

[Didier PH Martin]

Hi Paul,

Jonathan is right. We have to go beyond the marketing discourse and play
with the product to see that. When I downloaded the product and made some
test. It became obvious that what is stored is objects (their own internal
structure) stored in a PSE pro database (from the dll included).

The hierarchical object data base as a XQL interface and a Java DOM
interface. I tried to find the C++ DOM but I am still searching where is it
documented and how to connect to the C++ DOM. However the Java DOM is well
documented. Thus, these internal objects provide a Java DOM interface. You
also have a XML parser that translate from the serialized format to this
internal hierarchical object database. The whole structure looks like a
directory service because there is several object schemas however, on a
second look, it seems that there is no provisions to add your own schemas
(this is different to a directory service which is extensible). Thus, it
seems that only certain categories of objects could be stored.

About the other data stores, it is still vaporware. My guess is that
independently of any marketing positioning, there will be either a) drivers
that convert external data into DOM objects (do not import/store the
external data into the hierarchical object database) b) import and store the
data into the hierarchical database. The latter is taking more resources but
is faster especially in the case of relational databases located on remote
servers. My guess is that they will probably implement this solution.

So, yes Jonathan is right. ODI marketing people positioned the tool as a
cache. But objectively it is a hierarchical object database with a java DOM
interface (maybe C++ if I can find it), XQL query and storage or folder
objects used to transfer a serialized document into the hierarchical object
database. However, the ODB seems limited compared to directory services
where, in the latter, a new schema could easily be added. But, because it
seems to use PSE pro, this facility could be added to Excelon if they decide
to.

But yes, it is a hierarchical object database with a DOM interface.

Regards
Didier PH Martin
mailto:martind at netfolder.com
http://www.netfolder.com

-----Original Message-----
From: owner-xml-dev at ic.ac.uk [mailto:owner-xml-dev at ic.ac.uk]On Behalf Of
Paul Prescod
Sent: Sunday, April 11, 1999 12:20 AM
To: 'XML Dev'
Subject: Re: Comments Appreciated on Magazine Based on XML/XSL


Jonathan Borden wrote:
>
> Well, for example ODI's eXcelon is basically a DOM interface on an object
> db.

That is not my impression. My impression is that Excelon is a persistent
cache for DOM trees built on an object database. If you have non-XML data
objects it is completely your responsibility to figure out how to build
XML or a DOM for those objects.

The Excelon architectural diagram shows Excelon acting as a front
end to a variety of data stores but my understanding is that the mapping
from arbitrary objects and tables to DOM objects is done by integrators
and programmers not automatically by Excelon.

--
 Paul Prescod  - ISOGEN Consulting Engineer speaking for only himself
 http://itrc.uwaterloo.ca/~papresco

By lumping computers and televisions together, as if they exerted a
single malign influence, pessimists have tried to argue that the
electronic revolution spells the end of the sort of literate culture
that began with Gutenberg’s press. On several counts, that now seems
the reverse of the truth.

http://www.economist.com/editorial/freeforall/19-12-98/index_xm0015.html

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