How are we driven to the SODA service ?Re: SODA gripes (1): The Big One

[François Bonnarel]

Hi all,
>> B ) This is now a reminder of the CSP priorities. Remember Data discovery is
>> done via ObsTAP 1.0 (1.1 soon) or SIAV2.0. Both are IVOA recommendations
>> now. DataAccess and cutout is done via acref field in query response (full
>> download) or SODA service. SODA service is referred from the Discovery
> No, as I pointed  out above, the typical way should be to first retrieve
> a datalink document for a discovered dataset, and work on this -- and
> actually, this is what the CADC does in its obscore service throughout
> already, and everything else (i.e., working from a service block) is
> shortcuts for special situations (e.g., mass cutout of the vicinity of a
> spectral line).
>
I don't understand this. From the DataLink and SIAV2 specs there is 
really two different ways you can be driven from discovery response to 
SODA interface.
      One is the one you describe and which CADC is indeed using. the 
acref field in the Obscore table contain the URL of the {link} table. In 
that case the format field is marked as "DataLink". But it's not 
"typical". It is just one of the two ways.
     You can perfectly provide the link for the full dataset download in 
the acref field and use the service descriptor not as a "shortcut" but 
as parallel guide to the associated DataLink service. Or to the SODA 
service. All archives with rather small cubes will probably choose to do 
this at least.

Regards
François