Re: Jim Gray article on Next Generation Databases
> > In response, databases are evolving from SQL engines to data > > integrators and mediators that offer transactional and nonprocedural > > access to data in many different forms. This means database systems > > are effectively becoming database operating systems, into which > > various subsystems and applications can be readily plugged. > > Seems like an interesting starting point for thinking about the > relationship between XQuery and SOA, and their relationship to other > systems. Thoughts along the same line -- Jim Gray and Michael Rys of Microsoft, Andrew Mendelson of Oracle, Rob High and Nelson Mattos of IBM. 1. Center of the Universe: The Microsoft View" (Jim Gray and Michael Rys) http://www.intelligententerprise.com/030531/609feat1_6.jhtml?_requestid=680915 Gray: "There are two parts to your question: the SQL/OO [object-oriented] impedance mismatch and the SQL/XML data model mismatch. Let's take them in turn...." Rys: "The first scenario is addressed by extending the SQL value space with an XML datatype (both the ANSI standard SQL:2003 and Yukon provide this). This allows SQL databases to operate on native XML data without the need for shredding or marshalling. It bypasses the impedance mismatch by explicit mappings of the more complex XML model to the relational model." Rys: "There's not an impedance mismatch for query formulation if you take a declarative query language such as XQuery. Many existing tricks can be applied. For example, XQuery's FLWR iterator is well suited for parallelization." 2. "Center of the Universe: The Oracle View" (Andrew Mendelson) http://www.intelligententerprise.com/030531/609feat1_5.jhtml Mendelson: "Oracle's approach to this impedance mismatch has been to converge the SQL and XML technologies. Starting in 1997 with the release of Oracle 8.0, we added object constructs to SQL in what was called object-relational technology. ...This gave us the ability to rapidly add native support for XML into the Oracle9i Database. XML Schema and XMLType are native to Oracle9i Database, as are XSLT transformations and XPath traversal" Mendelson: "Integrating messaging software and queues into the database provides many development and operational benefits. Most business messages originate from databases, and eventually update databases. Integrating the database and message queuing software means the developers only need to learn a single product. They only need to manage a single security and transaction model. The data types used for the database are the same as those supported by the message queues, again simplifying development." 3. "Center of the Universe: The IBM View" (Rob High, Nelson Mattos) http://www.intelligententerprise.com/030531/609feat1_4.jhtml Mattos: "While Web services give us a nice framework for connecting distributed components, we need metadata to discover existing components or services, decide how best to integrate them, and understand, once they're integrated, how they're being used. [That understanding] allows us to tune the composed system. In other words, the coupling of Web services and XML with the emerging metadata frameworks gives us the hope of easier application creation and deployment and more dynamic creation and tuning of services." High: "There are some interesting corollaries between reliable messaging based on persistent message queues and distributed databases. However, that's probably not a critical rationale for tightly integrating messaging and databases. What may be more compelling is the potential relationship of distributed notification systems for signaling state transitions in loosely coupled, stateful services. The messaging system can be used to register interest in state transitions." ======== Ken North =========== www.WebServicesSummit.com www.SQLSummit.com www.GridSummit.com
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