Discovering Data Collections Within Services: Endorsed Note - Request for TCG Comments and Approvals

Document Link: http://ivoa.net/documents/Notes/discovercollections/20161111/

Source Repository: https://volute.g-vo.org/svn/trunk/projects/registry/discovercollections

RFC period: 2017-03-01 through 2017-04-12

Implementations

Several publishing registries (at least GAVO's, HEASARC's, and CADC's) already produce records as defined in this specification. Also, the future Registry Interfaces 1.1 (also in RFC) intends to employ the method proposed here.

On the client side, WIRR implements discovery of data collections in this way -- sample query.

Also, TOPCAT has experimented with this scheme since several releases. At ftp://andromeda.star.bris.ac.uk/pub/star/topcat/pre/topcat-full.jar, you'll find it in the TAP window (TAP -> Service Discovery -> Reg Prototype). If your TAP service isn't shown with the right number of tables there, please consider fixing your service's registry interface.

Comments from the interested public

Comments from TCG members

WG chairs or vice chairs must read the Note, provide comments if any and formally indicate if they approve or do not approve of the Note. IG chairs or vice chairs are also encouraged to do the same, although their inputs are not compulsory.

TCG Chair & Vice Chair ( _Matthew Graham, Pat Dowler )

Applications Working Group ( _Pierre Fernique, Tom Donaldson )

I have to thanks the authors of this note to bring a solution to a serious problem in the orginal design of VO registry. I have to say that elements presented in this note would have help a lot in the implementation of Aladin v10 which had to do, in some cases fragile assumption (based on prefix url...), and in some other cases, has no solution at all. If this note is followed by the providers, my client developper life will be definitively easier. Also, I appreciate a lot that the solution proposed has concretely a very light impact on the existing content of the registry. I will clearly encourage all providers to follow this note as fast as possible in order to improve the quality and the usability of the VO registry content.

I approve this note

Some minor suggestions:

* Page 6: The detal of the rational for standardID suffix syntax is probably not really required in this note. or ?

* Page 9 : the specific citation of VizieR current state for illustrating the impact of the addition of aux. will be obsoleted when VizieR will applied the note recommendation. I would suggest to remove VizieR citation, and just evocate "a service"...

* page 11: The reference http://gavo... for WIRR is a little bit obscured for me.

* Page 15: typo: Removed secion on => section

Data Access Layer Working Group ( François Bonnarel, Marco Molinaro )

Data Model Working Group ( _Mark Cresitello-Dittmar, Laurent Michel )

a bit out of my area of expertise, but the content seems consistent and logical. This does seem like content where we should be giving a 'preferred' method and guidance to implement.

I had one question in reading the text, which does not effect the assessment, merely a curiosity. Section 2.1.2 specifically states that an ID of form "ivo://ivoa.net/std/sia#query-aux-2.0" generates queries for all minor versions as well (tag-n.%). My question is what happens for ID with a specified minor version "ivo://ivoa.net/std/sia#query-aux-2.2"? If this returns exact match only, how does one get exact match for '2.0'? It seems that the minor version is irrelevant in this thread, given the backward compatibility requirements.

• No, the query-aux-2.0 is not the query pattern ignoring the minor version, it is the full identifier that lets people match for minor versions if they have to for some reason. The actual query patterns are discussed in sect. 2.2. Any hints on how to make that clearer are appreciated -- MarkusDemleitner - 2017-09-13

typos in section 2.1.4: 2 instances of 'notherntel' rather than 'northerntel', and 1 instance of 'sourtherntel' rather than 'southerntel'

• Fixed, thanks -- MarkusDemleitner - 2017-09-13

I have no objection to the content and approve the Note. -- MarkCresitelloDittmar - 2017-09-11

Grid & Web Services Working Group ( Brian Major, Giuliano Taffoni )

Registry Working Group ( _Markus Demleitner, Theresa Dower )

Semantics Working Group ( _Mireille Louys, Alberto Accomazzi )

Education Interest Group ( _Massimo Ramella, Sudhanshu Barway )

Time Domain Interest Group ( _John Swinbank, Mike Fitzpatrick )

Data Curation & Preservation Interest Group ( Françoise Genova )

Operations Interest Group ( _Tom McGlynn, Mark Taylor )

Knowledge Discovery in Databases Interest Group ( Kai Polsterer )

Theory Interest Group ( _Franck Le Petit, Carlos Rodrigo )

Standards and Processes Committee ( Françoise Genova)