Data and services

[Tony Linde]

Hi Doug,

Thanks for that.

> > A sky service is a service which provides access to a data 
> collection.
> 
> I think we should omit this term - it belongs in the 
> application domain. That is, a service implementor might 
> define something they call a sky service (or many other types 
> of services) but these are not registry concepts.  The 
> registry will be used to register such services, but it 
> doesn't "know" about them.

The registry will 'know' as much about a registered sky service as a
registered data collection or any other resource. SkyService *is* a registry
concept in that it is one of the types of resource defined in the new 0.8.1
schema which Ray and I have proposed.

Cheers,
Tony. 

> -----Original Message-----
> From: Doug Tody [mailto:dtody at nrao.edu] 
> Sent: 12 September 2003 19:04
> To: Tony Linde
> Cc: registry at ivoa.net
> Subject: Re: Data and services
> 
> 
> On Fri, 12 Sep 2003, Tony Linde wrote:
> 
> > Can I suggest some naming rules (bit rich since I'm not an 
> astronomer) 
> > to avoid confusion.
> > 
> > Everything referred to by a registry entry is a resource, 
> uniquely and 
> > globally identified by a ResourceId.
> 
> Yes - registries register resources, which should include 
> both services and data (and possibly other things).
>  
> > A service is anything which is invocable, ie is a web service with 
> > callable methods.
> 
> Yes.
>  
> > A data collection is any set of data which can be queried.
> 
> A data collection is a logically-related grouping of datasets.
> 
> > A sky service is a service which provides access to a data 
> collection.
> 
> I think we should omit this term - it belongs in the 
> application domain. That is, a service implementor might 
> define something they call a sky service (or many other types 
> of services) but these are not registry concepts.  The 
> registry will be used to register such services, but it 
> doesn't "know" about them.
>  
> > A dataset is any addressable part of a data collection. 
> Access to the 
> > dataset is via the sky service of the data collection.
> 
> The first statement is ok.  More formally a dataset is a 
> structured data object which we treat as a unit in terms of 
> data management, e.g., a FITS image.
> 
> 	- Doug
> 
>