how to make a publisherDID

[Mark Taylor]

If (at least) '?' is not legal in this context, then my suggestion is
clearly a non-starter - please consider it retracted.

Mark

On Wed, 26 Oct 2011, Douglas Tody wrote:

> But this is a query string and not a fixed identifier of the sort we
> want to use to index archives; the pubDID will often be used as an
> actual key to build DBMS indexes (the proposed syntax might work
> technically as a key but is not in the spirit of what is intended for a
> DID).  Also this contains reserved characters which are not currently
> legal in an IVOA dataset identifier ('?', '&', probably '=').
> Everything which is legal in URI is not necessarily legal in an IVOA
> dataset identifier.
> 
> I don't see any reason to change the simple nature of a DID which is an
> authority ID concatenated with a (unspecified format) resource key.  We
> just need to use this as a simple key as intended to go look up
> additional information stored elsewhere.  The pubDID can be used to find
> the ObsCore record for a data product which contains detailed
> information in a standardized form.  The authority ID can be parsed off
> and used to access a registry record which can be extended if we need to
> store additional information at that level.
> 
> 	- Doug
> 
> On Wed, 26 Oct 2011, Mark Taylor wrote:
> 
> > Pat,
> > 
> > URI permits a query part, so one possible way would be something like:
> > 
> >  ivo://cadc.nrc.ca/archive/cfht?observation=12345&product=raw
> > 
> > As far as I can see this would in principle solve the parsability
> > issues you're looking at, and it's more flexible than putting
> > everything in one hierarchical path.  It's probably a good enough
> > solution for human users.  However, given that it's not
> > currently standardised, the answer to how a machine holding one
> > of these actually works out what it means [still] relies on
> > it's understanding your particular conventions for encoding
> > the information in a URI.  Whether a human and/or machine actually
> > *needs* to understand what it means is another question, I'm not
> > involved enough with this stuff to have an opinion.
> > 
> > Mark
> > 
> > On Tue, 25 Oct 2011, Patrick Dowler wrote:
> > 
> > > I need to decide on a procedure for making publisherDID values for use in
> > > TAP
> > > services, for example in the ivoa.ObsCore table, but also our internal
> > > CAOM
> > > tables which also expose the same identifiers. This is following from the
> > > interesting DAL-DM-DCP discussions on use of URIs.
> > > 
> > > Presumably, I could start with a DataCollection identifier registered in
> > > the
> > > IVOA registry system, eg:
> > > 
> > > ivo://cadc.nrc.ca/archive/cfht
> > > 
> > > (note: more generally, a creatorDID would be linked to a DataCollection
> > > and a
> > > publisherDID might be linked to a provider/service in case they are not
> > > the
> > > same or definitive provider - let's ignore that for now)
> > > 
> > > In the past we would use the fragment, eg
> > > ivo://cadc.nrc.ca/archive/cfht#12345/raw but that implies that one can
> > > somehow
> > > "get" the entire collection and then look for "12345/raw" inside it
> > > (client
> > > side).
> > > 
> > > Instead, I could append some dataset-specific to get an observation
> > > identifier,
> > > eg.
> > > 
> > > ivo://cadc.nrc.ca/archive/cfht/12345
> > > 
> > > and then append something product-specific to get an identifier for the
> > > product,
> > > eg.
> > > 
> > > ivo://cadc.nrc.ca/archive/cfht/12345/raw
> > > 
> > > However, if someone has one of these (the last one), what can they do with
> > > it?
> > > With this approach, there is no prescribed way to extract the identifier
> > > for
> > > the registered DataCollection. Should there be?
> > > 
> > > In VOSpace, the spec invents a new URI scheme (vos) that prescribes
> > > exactly
> > > how to extract/create the service URI from the vos URI, but it comes down
> > > to
> > > being able to separate the URI into two halves: a base that can be looked
> > > up
> > > in a registry and a separate bit (path in vos) that can be used when
> > > talking
> > > to the service. In principle this does not require a new scheme, but it
> > > does
> > > require at least a way to separate.
> > > 
> > > PS-I have the exact same issue with several services where I want to
> > > identify
> > > the service with an ivo URI and I want to make and use URIs for items
> > > found
> > > within/via that service.
> > > 
> > > --
> > > 
> > > Patrick Dowler
> > > Tel/Tél: (250) 363-0044
> > > Canadian Astronomy Data Centre
> > > National Research Council Canada
> > > 5071 West Saanich Road
> > > Victoria, BC V9E 2M7
> > > 
> > > Centre canadien de donnees astronomiques
> > > Conseil national de recherches Canada
> > > 5071, chemin West Saanich
> > > Victoria (C.-B.) V9E 2M7
> > > 
> > 
> > --
> > Mark Taylor   Astronomical Programmer   Physics, Bristol University, UK
> > m.b.taylor at bris.ac.uk +44-117-928-8776 http://www.star.bris.ac.uk/~mbt/

--
Mark Taylor   Astronomical Programmer   Physics, Bristol University, UK
m.b.taylor at bris.ac.uk +44-117-928-8776 http://www.star.bris.ac.uk/~mbt/