Re: XML versus Relational Database

["K. Ari Krupnikov" <ari@iln.net>]

"Bullard, Claude L (Len)" wrote:

> > > most relational systems are now hybridized 
> > > to the point that the XML vs Relational DB is a non-issue. 
> > 
> > Are you referring to XML support in DB products or Object-Relational
> > features?
> 
> Both.  The relational systems I see now in
> commercial work all have object components.
> The two or three that I consider the industry
> leaders now have XML support.

The problem with OR, as well as OO, databases is portability. SQL makes
it reasonable to attempt to migrate applications, and more importantly,
people from one platform to another. OR not only locks you into a
specific product, it also locks you into one (sometimes, two) client
languages, usually, C++ or Java.

XML support in the three leaders (current, not promised releases) looks
more like an afterthought. Sure, there are methods that would give you a
DOM or a SAX stream as a reply to an SQL query, but all they do is
replace the delimiters with angle brackets in text that comes out of the
DB (usually, '|' delimited) and then apply the usual parsers. Not very
efficient. Not very flexible - you are stuck with a DTD that is defined
(either explicitly by you or implicitly by the RDBMS) that is based on
your DB schema.

So to summarize, I don't think that RDBMSs have "hybridized to the point
that the XML vs Relational DB is a non-issue".

> This topic pops up from
> time to time and most of the answers
> can be summarized as, no size fits all.

So can be most other threads :=) 

-- 
K. Ari Krupnikov

DBDOM - bridging XML and relational databases
http://www.iter.co.il