IVOA Identifiers Working Draft

[Tony Linde]

See below...

> -----Original Message-----
> From: owner-registry at eso.org [mailto:owner-registry at eso.org] 
> On Behalf Of Ray Plante
> Sent: 12 September 2003 20:16
> To: registry at ivoa.net
> Subject: RE: IVOA Identifiers Working Draft
> 
> 
> On Fri, 12 Sep 2003, Tony Linde wrote:
> > > There is also the separate but related question I posed:  Can an 
> > > IVOA
> > > identifier exist for a resource that is not registered 
> > > anywhere?  If so, 
> > > what are the constraints (i.e. "as > long as ...")?
> > 
> > Not really since there is no way the registry can know not 
> to create a 
> > ResourceId that conflicts with it.
> 
> ResourceKeys are created by the owner of the AuthorityID.  If 
> the owner is 
> an organization, and not strictly the registry, then in the 
> registration 
> process, the registry must receive the ResourceKey from the 
> registering organization.  That is, the registry should 
> *not*, in general, 
> choose the ResourceKey for the registrant.  The registry can 
> check its 
> uniqueness against the ResourceIDs it knows about; however, it is 
> ultimately the responsibility of the organization to ensure 
> that it does 
> not conflict with IDs that have not be registered.  
> 
> Is that good enough?

As long as the non-registered ResourceIDs are not used in VO systems (which
would try to resolve them) then I don't suppose it matters. Seems a
dangerous wasy to go though.

> 
> > > Associating Sa.CXO with a data collection's ShortName is not
> > > a good idea, 
> > > because there is no guarantee that it is unique and will 
> consistantly 
> > > refer to the same data collection.  This is exactly the 
> role of an 
> > > identifier: to be a unique reference.  
> > 
> > It isn't unique but could be used to get a list of data collections 
> > which, if it is >1 in length would need human intervention.
> > 
> > Not ideal but where is the list of associations between 
> Sa.CXO and the 
> > unique identifier held?
> 
> I think the point is that Sa.CXO/2000 is a unique identifier.  At the 
> moment, the ADEC group is planning to host a service that 
> resolves such an 
> identifier into a URL (or URLs).  

Would be better if they resolved it into the VO ResourceID and then used
that to get the URL. Or is that what you meant?

> 
> cheers,
> Ray
> 
>