RE: storing xml files into database

[Chris Parkerson <chrisp@exceloncorp.com>]

It would be nice if we could find an independent entity to benchmark us
all... I think there are enough of us in the XML DB and XML-enabled DB
market now to submit to an independent benchmark ;->  We've been
building ours since 1997 ;->.

We've spent a lot of our own resources on standalone and competitive
benchmarking (well, against the products we can get a hold of... so far,
we've only been able to do that with the RDBMS vendors... the rest of
you XML DB vendors do not have fully-functional evals like we at eXcelon
do ;->).

If not ZapThink, maybe there's someone else on this list that can
coordinate such an independent benchmark.

Cheers,
Chris

---------------------------------------
Chris Parkerson
Product Manager
eXcelon Corporation
Burlington, MA
(781) 674-5393
http://www.exceloncorp.com
---------------------------------------


-----Original Message-----
From: Bill Lindsey [mailto:bill@blnz.com] 
Sent: Monday, September 10, 2001 1:08 PM
To: xml-dev@lists.xml.org
Subject: Re: storing xml files into database

Frank Richards wrote:
> XML is a tree of elements. Naively mapping that tree onto a table
causes the
> RDBMS to
> thrash it's guts out doing joins to go down the tree -- 
[ ... ]
> XML in an
> RDBMS can easily hit six or seven joins per query.

A typical, naive definition of a "nodes" table does lead to unacceptable

performance due to the necessity of many self-joins.  It is possible, 
however, to devise a scheme for encoding nodes' context in a compact 
form, optimized for an RDBMS' indexing facility, and build a
generic table structure, capable of storing any well-formed
XML, yet does not exhibit the self-join problem.

With this technique, one can:
* leverage the mature ACID properties of commercial RDBMSs
* support any well formed XML with no additional developer or DBA effort
* provide fine-grained, random access to the content of large
collections
* efficiently query on content and/or structure

Bill Lindsey
B-Bop

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