Identifiers 2.0 new internal WD

[Pierre Fernique]

Hi Markus and registry members,

Le 12/05/2015 16:33, Markus Demleitner a écrit :
> Dear Pierre, Dear Registry WG,
(...)
>
>> page 16 - Standard Identifiers
>> The # usage for expressing level of compliance (minor, major version number,
>> model version...) seems to me a surprising extension of IVOID usage, and may
>> be a little bit too specific to Markus RegTAP implementation. In fact, this
>> idea merges ID syntax and query language facility. I would prefer to
>> separate these two goals:
>> /standard_id LIKE ???ivo://ivoa.net/std/exampleProto#query-1.%???/
>> =>
>> /standard_id LIKE ???ivo://ivoa.net/std/exampleProto' WHERE query...//
>> /
> Just to remind everyone how this developed -- the initial problem
> came up at
>
> http://mail.ivoa.net/pipermail/registry/2014-February/004909.html
>
> and the solution proposed here then was more or less arrived at
> in Madrid.
(...)
> Now, Aladin clearly is a major (potential) consumer of this kind of
> information ("give me all image services I can talk to"), so
> reservations you guys have are clearly relevant.  Could perhaps try
> again to explain where you see problems with what Identifiers
> proposes and what you think it should do instead?
>
> Thanks,
>
>             Markus


In my mind, the available methods (and associated parameters - 
minor/major version number, relevant model, ...) should be described in 
the registry record as capabilities or something equivalent, and not via 
the IVOID itself. By this way, the client is able to filter the relevant 
records thanks to the available registry query language (OAI, regTap or 
whatever). Also, I do not really see why we would have to dupplicate 
records for each alternate access method. We have to add new 
capabilities, or adjust parameters of capabilities, but not more. But 
may be I missed something of the debate in Madrid, and you have a good 
reason to do that.

Concerning Aladin, until now, it does not access directly to the VO 
registry. By experience, it is too slow, too bad records, not 
homogeneous, not enough stable and reliable for a good direct 
operational usage (sad reality I'm afraid). And OAI has never been 
adapted for a end-user client (my opinion). We bypass this problem by 
populating our own intermediate registry (presently GLU system) from VO 
registry (when it works)  plus other various sources not registered in 
the VO registry (VizieR tables, HiPS surveys, ...). Also, by this way, 
we have the freedom to pre-filter resources, and to add our own 
parameters completing the resource description, and notably we add the 
list of possible target clients (ex: profile = AladinDesktop > 6.1, 
Aladin Lite,  Aladin outreach, ...). It is clearly out of the scope of 
the VO registry, but I have to say that helps a lot for controlling 
which resources are visible by which clients, and also, for an easy and 
clean management of the client version compatibility.

Cheers
Pierre