VO and ADEC identifiers

[Ray Plante]

On Thu, 18 Sep 2003, Tony Linde wrote:
> Re:
> <<So for instance, from this identifier: 
>         HC.BIMA/BDA#t421/c110.ori 
> I can quickly figure out that in order to resolve it I need to do a 
> registry lookup of "HC.BIMA/BDA", find a dataset resolver associated 
> with it, and then go to the resolver with the string "t421/c110.ori" >>
> 
> Can I confirm that the resource identifier of "HC.BIMA/BDA" will relate to a
> SkyService (or whatever we end up calling it) which provides access to some
> data. 

Yes.

> If you want to then send that service the dataset pointer of
> "t421/c110.ori", will you need an extra standard method built into the
> SkyServices which can resolve that pointer? At the moment, we're likely to
> have some sort of doQuery method (in addition to getMetadata, getStatus
> etc). Do we need to add a getDataset(string DatasetID) method?

ADEC is setting about defining such a service for a fairly specific 
purpose, except that they want to enable getURL(DatasetID), where the URL 
could be a form or a web-based query result or whatever the provider 
wants to provide.  

Note that this particular service need not be the only such widely 
implemented service for resolving datasets.  A more general purpose one 
that provides getDataset(DatasetID) could be defined as well.  

> not registered in the VO as resources, a search of a registry will not find
> them. I'm not sure you could query a dataset either without yet another
> special method (eg queryDataset(string DatasetID, document AdqlQuery) in the
> data access services. It is getting a bit silly if we have to add new
> methods to all the services in order to handle an entity that the VO does
> not recognise. How do you see this being handled?

I see descriptions of data collections providing references to the 
services that give access to the datasets in the collection.  I also see 
service descriptions refering to data collections that they provide data 
for.  

> I guess the simple solution is that if you want to do anything with a
> dataset within the VO then it first needs to be registered as a resource.
> No?

Simple from what standpoint?  I don't see it practical to register 
individual datasets at the replicated registry level, and there are lots 
of reasons for this.  However, if you can find the services that serve 
them, then that should be good enough.

cheers,
Ray