[xquery-talk] Re: The State of Native XML databases

Jeff Dexter jeff.dexter at rainingdata.com
Mon Aug 20 09:28:11 PDT 2007


John,

	I've previously had the argument with Ilya on the collection vs.
document notion, and while I do disagree this is a relational concept, it's
important to understand that his use case does not work well with the
concept of collections. He's dealing with very large, single documents
representing the collaboration point and he requires a high degree of
concurrent access to them. We tried melding the collection concept to this,
but in his case he's constrained by a standard schema and so shredding into
sets of smaller documents would not work. Hence the document is the
database, in this use case. 

	In regard to XML Schema, leaving all discussion on the failing and
complexities of the language aside, once you do have the darn things written
they can be quite helpful in authoring XQueries, typing your collections and
other activities so they are germane to the original discussion of the state
of native XML databases. In my anecdotal experience for every person that
squirms when I mention XML Schema in their application there's another who
already has a few dozen cooked up and is raring to use them.

	Finally, "enterprise" and "native" are indeed bandied about
altogether too much, but again Ilya brings up a good point in the discussion
of the state of native XML databases, which is how individual databases and
more general XML platforms handle things like locking/concurrency,
transactions, etc. which are feature very relevant to large scale
applications, and again, an interesting aspect to use in contrasting the
various implementations.

Jeff.

-----Original Message-----
From: talk-bounces at x-query.com [mailto:talk-bounces at x-query.com] On Behalf
Of John Snelson
Sent: Monday, August 20, 2007 2:22 AM
To: Ilya Sterin
Cc: talk at xquery.com; Dr Orlovsky MA
Subject: Re: [xquery-talk] Re: The State of Native XML databases

Ilya,

Even if I ignore your use of the amorphous and irrelevant term "native XML
database", there are still some pretty tall claims in this email.

For a start, not everyone likes or wants XML Schema - it does have a habit
of turning an extensible format into a highly restricted one, which I would
argue was not very forward thinking. Only once in the 3 years I've worked on
Berkeley DB XML has anyone ever commented that we didn't use XML Schema (or
any schema language) to restrict the data stored.

You use the term "enterprise persistence" without any kind of definition.
Can you let us know what "enterprise" use cases are handled by TigerLogic
that other XML databases cannot handle?

Also, I agree with Michael Kay that collections are in no way a relational
concept - so this is another red herring.

I'm not pretending to be partisan in this debate, but I do try to stay away
from marketing spin and sweeping statements.

John

Ilya Sterin wrote:
> I wish I could find more info on it.  The site states acid 
> transactions, but for people people unfamiliar with transaction 
> architectures, that doesn't equate being able to use it in an 
> enterprise application environment.  If consistency is enforced at the 
> collection entry level, that beats the purpose of having a native xml 
> database where ddl=xml schema.  In a perfect world, I wish the vendors 
> would get rid of the collection as a storage metaphor and instead 
> focus on defining schemas with one of the schema languages, which is 
> all that's needed.  Why mix relational concepts, which is what a 
> collection really is, with native xml hierarchal storage.
> 
> We recently engage in numerous native xml storage projects and worked 
> very closely with RainingData on a TigerLogic 3.0 release.  As of 
> right now, that is probably the only truly native xml database that 
> defines all facilities needed for enterprise persistence in XML.
> 
> Ilya
> 
> On 8/19/07, Dr Orlovsky MA <dr.orlovsky at gmail.com> wrote:
>> On Mon, 13 Aug 2007 22:01:19 -0400, Elliotte Harold wrote:
>>
>>> On another list I was recently asked to sum up the state of native 
>>> XML databases, especially open source ones. The result is here:
>>>
>>> http://cafe.elharo.com/xml/the-state-of-native-xml-databases/
>>>
>>> Comments appreciated.
>>>
>>>
>> There is excellent native XML dsatabase completelly implementing XQuery.
>> See for Sexdna XML database in google as well as look at the site 
>> http://modis.ispras.ru/sedna/
>>
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>>
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