Resources = services!

[Ray Plante]

On Fri, 6 Jun 2003, Tony Linde wrote:
 > This is certainly attractive from a comprehensiveness
 > point of view but would be cumbersome if every data service which only
 > served up one set of data had to list the data as a separate resource.

It is not required that the data collections accessed by a service be
registered separately.  All services that access the collection could be
registered independently, and that's okay.  Since (currently) the Service
metadata includes all the Resource metadata that describes data
collections, there is no loss of information.  The advantage of
registering the collection too is that it provides way in the service
descriptions to say that they all access the same collection.

Thus, if the data collection is simple and has only one interface, say a
Web Form, one could just register the Web Form interface.  It's up to the
registrant.  Later, if she wants to register the data collection
separately, she can.  She can update the previously registered service
description to point to the collection info, or not.

The only question in my mind about how to handle collection access is for
the very trivial case where a dataset is available via, say, FTP.  Should
we describe this as a Service (in the XML sense) or should this access be
a specific attribute of a DataCollection class.

 > Maybe we need a combination. Where the data is likely to have multiple
 > services accessing it, the collection can be input as a resource and
 > each service just uses the ResourceID of that collection as a pointer to
 > the data description. But a resource which is a one-collection service
 > can contract to supply the dataset MF itself.

I believe this is effectively done with the current VOResource schema.

cheers,
Ray