The IVOA in 2006: Assessment and Future Roadmap - Registries

[Brian Thomas]

On Thursday 08 June 2006 11:01, Roy Williams wrote:
> I know there is formal mathematics about relational databases (Codd and Date). 
> Is there substantial formal theory on translating XML to and from RDBMS? 

	Isn't this somewhat mixing of apples and oranges?

	Relational schema require a 'table' outlook and necessarily flatten the
	information into 2D structures, whilst the XML allows a richer expression
	of 'full' objects. I would expect the solution here is to map an object layer
	onto the relational tables. There is substantial theory on how to do that.

	Because the VO has object models which are expressed within XML, then
	the particular solution to look for is an object layer, expressed within XML,
	which may be mapped to relational schema. (*sigh*) - This is the solution which
	we have been working on for a while, and the (slightly out of date) code 
	may be found at the NVO CVS archive ("VO-ORML", 
	http://viewcvs.cacr.caltech.edu/us-vo/viewcvs.cgi/contrib/voorml/)

	Regards,

	=brian