resource identifiers

[Roy Williams]

Everyone seems to be packing all this other stuff into something that is
just an ID. To me, an ID is just a simple, short string.

The ID for the book is 0521-56098-5

The metadata for the book is all these <title> and <author> and <number of
Pages> fields.

The ID is not a place to shove all this metadata.
Can't we just Keep It Simple?

My $0.02.
Rot


--------
Caltech Center for Advanced Computing Research
roy at cacr.caltech.edu
626 395 3670
----- Original Message -----
From: "Tom McGlynn" <Thomas.A.McGlynn at nasa.gov>
To: <ael at star.le.ac.uk>
Cc: <registry at ivoa.net>
Sent: Thursday, May 29, 2003 7:39 AM
Subject: Re: resource identifiers


> Hi all,
>
> I've been trying to follow this conversation.  My apologies
> if I'm rehashing old ground...
>
> Personally I don't have any problem with the idea that
> a ResourceID includes information that's not used by a registry.
Registries
> are just one of the many services available for the VO.  It seems
perfectly
> reasonable for our generic indexing mechanism to be designed for a broader
> scope than registries.  However there is an essential difference between
> the service identifier and the record identifier (as discussed): the
> record identifier is not persistent.  Given the transience
> of the proposed record identifiers, it's not clear how they can be used
> in any context other than the document in which they are created.
>
> Perhaps what we want is a ResourceID which provides persistent linkages
> across the VO and a RecordID which provides transient linkages within
> a document.  The example that I've been considering where a record
> ID would be useful in the SIA is "How do I associate a GIF image and
> a FITS file that derive from the same image?"  If we allow RecordID tags
> within documents these could be used to provide an index (or possible
> multiple indices) within the document.
>
>
> Here's an example of the kind of functionality I'd hope
> that a general Record ID might provide.
>
>   <SiaDocument>
>     <SiaHeader>
>       <ResourceID>
>         <AuthorityID>heasarc.gsfc.nasa.gov</AuthorityID>
>         <ResourceKey>ROSAT/HRI/observations</ResourceKey>
>       </ResourceID>
>       ...
>     </SiaHeader>
>     <SiaRecord>
>       <RecordID context=OriginatingImage>RH900317N00</RecordID>
>       <RecordID context=RecNum> 1 </RecordID>
>       <FORMAT>GIF</FORMAT>
>       ...  All the other SIA fields for an image ...
>     </SiaRecord>
>     <SiaRecord>
>       <RecordID context=OriginatingImage>RH900317N00</RecordID>
>       <RecordID context=RecNum> 2 </RecordID>
>       <FORMAT>FITS</FORMAT>
>       ... Other SIA fields ...
>     <SiaRecord>
>   </SiaDocument>
>
> Since the first two entries have the same RecordID in the OriginatingImage
> context the user knows they are linked.
> If we were to address this document with a URL including the fragement
>    '#OriginatingImage=RH900317N000'
> then this could be interpreted as asking for these records.
>
> Note the use of context to enable multiple indices of records
> to be included in a single document.
>
> I'm not advocating adopting this particular structure, but I think
> this illustrates how  a generic concept of recordID's could
> be used in very powerful ways.  So while I agree with Tony that it's
> not clear that a record ID (at least a non-persistent one)
> belongs in the the Resource identifier, I do believe that some general
> concept of records and their identifiers is also essential for
> successful VO services.   Obviously if we have both resource and
> record ids, then one can compose them to get a record within
> a resource, but it doesn't seem necessary to make one part of the other.
>
>
> Tom
>
> Tony Linde wrote:
> > Hi again, Ray,
> >
> > I think that at heart I am really uncomfortable with having the
ResourceID
> > including a component that never gets used in the registry.
> >
> > The ResourceID should be used solely to describe a resource registered
> > within the VO and this requires only the AuthorityID and the
ResourceKey. If
> > we want to identify *parts* of a resource which are used only by one or
more
> > services, it ought to be up to that service to define those schema. So
SIA
> > could have:
> >
> > <SiaImageID>
> >   <ResourceID>
> >     <AuthorityID>www.ncsa.uiuc.edu</AuthorityID>
> >     <ResourceKey>ADIL/SIA/targeted</ResourceKey>
> >   </ResourceID>
> >   <ImageKey>95.DR.01.01.fits</ImageKey>
> > </SiaImageID>
> >
> > Other services which require more detailed structure would include that
> > detail in their own schema using multiple tags. The ResourceID should be
> > used solely to uniquely identify the resource.
> >
> > Cheers,
> > Tony.
> >
> >
> >>-----Original Message-----
> >>From: Ray Plante [mailto:rplante at poplar.ncsa.uiuc.edu]
> >>Sent: 28 May 2003 06:10
> >>To: Tony Linde
> >>Cc: registry at ivoa.net
> >>Subject: RE: resource identifiers
> >>
> >>...
> >
> >
> >
>
>