RE: [xml-dev] ANN: Article on using RDF to provide extensibility and modularity

["Dare Obasanjo" <dareo@microsoft.com>]

Some thoughts...

1.) "Kerry also plans to parse each document as it arrives, but because
the documents are RDF, the information can be stored in a triple store,
which may be implemented in a relational database. Kerry doesn't need to
define the tables to store the information items because the RDF model
dictates how the data is to be represented."

So a benefit of the RDF solution is that instead of leveaging existing
investements in relational data stores that are common place in the
enterprise one can use a different, potentially incompatible data store?
Have you missed the occurences within the database world in the past few
years with regards to Object Oriented Databases and Native XML
databases? This should be taken to heart whenever one touts some new
data storage technology as a replacement for relational stores. 

2.) "A lot of Sam's time is spent writing code that stores the context
of the current element in the SAX stream so the various prices can be
disambiguated. Another large chunk of time is spent writing SQL to store
the various information items to the correct tables in the database.
Once this work has been completed, Sam can move onto writing more SQL to
query the database in order to produce a list of products that the
customer wants to buy."

Or he could just define a mapping between the input XML and his
relational tables using a number of XML mapping technologies that target
his database of choice. For instance if he was a user Microsoft's SQL
Server 2000 this could easily be handled by SQLXML
(http://msdn.microsoft.com/sqlxml). Also in we are close to having the
major relational databases providing native XML storage and query which
makes this point moot. 

3.) "The next week, Sam is presented with the XML schema for the
invoices the company plans to send out. Sam reads through the schema and
notes that there are small inconsistencies with the purchase order
schema. For example, this schema uses attributes for the customer number
whereas the previous schema used elements. Sam realises that there isn't
going to be much reuse of the code that was written for parsing the
purchase orders. In fact, Sam ends up writing a completely new SAX
reader for the invoice format, plus another chunk of invoice-specific
SQL and database code. Sam also discovers that products can have
discounts for bulk orders and has to change the database schema to
account for this. Sam ends up re-writing the purchase order query as
well to ensure that the prices are being pulled from the new table. "

XSLT is your friend. Soon we'll have XQuery and this will be even more
of a moot point. 


-- 
PITHY WORDS OF WISDOM 
The other line always moves faster.


This posting is provided "AS IS" with no warranties, and confers no
rights. 

>  
>  
> -----Original Message-----
> From: Ian Davis [mailto:iand@internetalchemy.org] 
> Sent: Thursday, April 24, 2003 7:42 AM
> To: xml-dev@lists.xml.org
> 
> Hello all,
> 
> I've written an article called 'RDF for Modular, Extensible Markup':
> 
>   "XML provides extensibility through a common syntax but leaves the
>   interpretation of the information to the developer. Increasing
>   modularity through the use of XML namespaces further increases
>   developers' workload as they struggle to interpret ever more
>   complex data models. RDF leverages the syntactic extensibility of
>   XML and the modularity of XML namespaces and additionally provides
>   global extensibility through a common data model."
> 
> http://www.semanticplanet.com/2003/04/rdfForModularExtensibleM
arkup.html

Any comments are very welcome.



- Ian <iand@internetalchemy.org>
"Never discourage anyone...who continually makes progress, no matter how
slow."


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