Resources = services!

[Tony Linde]

Thanks, Roy. The question still is: why would we need it listed as a
resource? A client will only want to know about the services which
access 2MASS. What this may mean is that one would want the name of the
data collection included as part of the metadata for this type of
service.

I realise that including the data collection as a resource means that
you can list it and then multiple services can list it as one of the
resources it hits. 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.

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.

There you go, Ray - another use for multiple MFs :)

Cheers,
Tony. 

> -----Original Message-----
> From: Roy Williams [mailto:roy at cacr.caltech.edu] 
> Sent: 06 June 2003 17:44
> To: ael at star.le.ac.uk; registry at ivoa.net
> Subject: Re: Resources = services!
> 
> 
> > - What is 'DataCollection' and why would one want to list 
> it if it is 
> > not the service which gives access to the data?
> 
> A major data collection (eg 2MASS) may have many services 
> that suck from it.
> 
> A service may be able to talk to many data collections (eg a 
> mosaicking service).
> 
> It's a many to many relation.
>