Re: Sourcing Metadata for Database Independence

Hi Dawn,

I really think that is whole point to XML, vendor, platform and database independence and data interchange. I will take a bumbling shot at explaining this because I know you are a nice person :-).

For instance, the dublin core defines meta data tags for XHTML. I think that XML DTDs (data type definitions) are meta data of the sort you are looking for, particullarly if you also include XML Schema. Each industry starts it's own initiatives to define the industry specific data they have, and there are many, because attributes generally have a context and data interchange always does.

This results in name spaces or domains if you prefer, which are a context. You end up with DTDs and schema that define their data and ultimately allow that information to be exchanged, there is a URI (basically a URL) that points to that context defined meta data (the current DTD.) This is really a server which in turn automatically redirects you to the correct location and most current definition of that meta data.

Best of all it is all "open", you can store it locally if you like, and you can define your own too. As excessively verbose as XML is, and though the concept of tagged information seems archaic and inneffecient, it is what you are looking for. Go to W3C but also check out groups like OASIS, OWL and ISO. A non-meta data example of the results of these standards and inniatives is SOAP which resolves contentious proprietary or OS battles like ActiveX/DCOM vs. CORBA. Standards are good :-)

If XML and related technology is not the future, it certainly is the future for many years to come. The general idea is that if it is poor database theory as such, then you use it in combination with http, SOAP, and objects you have written in your platform independent languages such as Java or C# to activate an interface to your DMBS created using sound theory. Of course other will have to access your database using XML with the transformation being handled by XSLT and the presentation being handles by XSL. Not bad in theory anyway.

Regards, Dave Horsman Received on Wed Aug 11 2004 - 16:03:51 CEST